Focus Group Abstracts

Sleep and Biological Rhythms 2005; 3: A2–A73 Symposia Abstracts S-1. Recent advances in the understanding of hypothalamic regulation of sleep-wake function Chairperson: Joshi John (USA) ROLE OF HYPOCRETIN/OREXIN IN NORMAL BEHAVIORS AND SLEEP DISORDERS JEROME M SIEGEL Brain Research Institute & UCLA School of Medicine, Neurobiology Research (151 A3), 16111 Plummer Street, North Hills, CA 91343, USA The hypocretins (Hcrts, also known as orexins) are two peptides, both synthesized by a small group of neurons, most of which are in the lateral hypothalamic and perifornical regions of the hypothalamus. The hypothalamic Hcrt system directly and strongly innervates and potently excites noradrenergic, dopaminergic, serotonergic, histaminergic, and cholinergic neurons. Hcrt also has a major role in modulating the release of glutamate and other amino acid transmitters. Behavioral investigations have revealed that Hcrt neurons are maximally active in active waking. In rats, hypocretin neuronal activity is maximal during exploration and minimal during quiet waking and sleep. Degeneration of Hcrt neurons or genetic mutations that prevent the normal synthesis of Hcrt or of its receptors causes human and animal narcolepsy. Administration of Hcrt can reverse symptoms of narcolepsy in animals, may be effective in treating human narcolepsy, and may affect a broad range of motivated behaviors. LATERAL HYPOTHALAMIC AND BASAL FOREBRAIN INTERACTIONS IN SLEEP-WAKE REGULATION ERIC MURILLO-RODRIGUEZ, MAN XU, LING LIN, DMITRY GERASHCHENKO, CARLOS BLANCO-CENTURION, ANJELICA SHIROMANI, SEIJI NISHINO, EMMANUEL MIGNOT AND PRIYATTAM J SHIROMANI West Roxbury VA and Harvard Medical School, West Roxbury, MA 02132 & Stanford University, Palo Alto, CA The lateral hypothalamus (LH) has been implicated in wakefulness. One possibility is that it induces wakefulness by driving the basal forebrain (BF) wake-active neurons (Gerashchenko and Shiromani 2004). The activity of the BF wake-active neurons is hypothesized to release the sleep-inducing factor adenosine (AD), which begins to accumulate as wakefulness progresses. The AD is then hypothesized to inhibit the wake-active neurons (Strecker et al. 2000) and their silence allows the VLPO and median preoptic GABAergic sleep-active neurons to fire and sleep ensues. Here we measure AD levels in the BF and test the LH-BF circuit in Sprague-Dawley rats with lesions of the LH induced by hypocretin-2-saporin. 64 days after lesions the rats were implanted with sleep-recording electrodes and a guide cannula into the basal forebrain. Two weeks later, the rats were kept awake (gentle handling) for six hours (ZT 3–9) and A2 microdialysis samples (5 mL) were collected hourly for 9 h (24 h after probe stabilization). AD levels were assessed using HPLC (see MurilloRodriguez et al. 2004 for details). Hypocretin-saporin ablated 95% of the hypocretin neurons with a resultant decline in CSF levels (–75% vs. control). AD levels increased with 6 h waking in saline control rats (n = 9), consistent with previous studies in cats (Strecker et al. 2000) and rats (Murillo-Rodriguez et al. 2004). However, in rats with LH lesions (n = 5) such an increase with waking did not occur. The homeostatic response to sleep loss was measured by conducting a rodent version of an MSLT where the rats were kept awake for 20 min and then allowed 20 min to sleep. This protocol was started at ZT2 and continued until lights were turned off. The lesioned rats were found to have more sleep during the 20 min sleep periods indicating a higher sleep drive in these rats. Previously, we (Gerashchenko et al. 2001) found that rats with LH lesions had increased sleep during the night, and here we found that they have increased sleep drive as measured by an MSLT. The increased sleep drive in these rats might result from a loss of stimulation of the wake-active BF neurons. Thus even though AD is not increasing with waking, the lesioned rats are sleepier. This finding provides support for one circuit (LH to BF) driving waking. Support: VA Medical Research, and the National Institutes of Health grant NS30140, AG15853, AG09975, and MH55772. References Gerashchenko D, Kohls MD, Greco M, Waleh NS, Salin-Pascual R, Kilduff TS, Lappi DA, Shiromani PJ (2001) Hypocretin-2-saporin lesions of the lateral hypothalamus produce narcoleptic-like sleep behavior in the rat. J. Neurosci. 21: 7273–83. Gerashchenko D, Shiromani PJ (2004) Different phenotypes of neurons in the lateral hypothalamus and their role in sleep. Cellular & Molecular Neurosci 29(1): 41–60. Murillo-Rodriguez E, Blanco-Centurion C, Gerashchenko D, SalinPascual RJ, Shiromani PJ (2004) The diurnal rhythm of adenosine levels in the basal forebrain of young and old rats. Neuroscience 123: 361–70. Strecker RE, Morairty S, Thakkar MM, Porkka-Heiskanen T, Basheer R, Dauphin LJ, Rainnie DG, Portas CM, Greene RW, McCarley RW (2000) Adenosinergic modulation of basal forebrain and preoptic/anterior hypothalamic neuronal activity in the control of behavioral state. Behav. Brain Res. 115: 183–204. REGULATION OF HYPOTHALAMIC NEURONS DURING SLEEP MD NOOR ALAM Research Service, VA GLAHS, Sepulveda, California, and Department of Psychology, University of California, Los Angeles, California, USA The preoptic area (POA) has been identified as a sleep regulating system whereas the perifornical-lateral hypothalamic area (PF-LHA) has been implicated in the regulation of behavioral arousal. Majority of neurons in the POA region exhibit activation during nonREM and REM sleep whereas most of the PF-LHA neurons are active during waking and quiescent during nonNREM sleep. We conducted a series of in vivo experiments to determine the state-dependent neurochemical regulation of © 2005 Japanese Society of Sleep Research Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 PF-LHA neurons as well as the interactions between POA sleep- and PF-LHA wake-promoting systems. We hypothesized that sleep-active neurons within POA promote sleep, in part, by inhibiting PF-LHA arousal system. We found that electrical stimulation of median preoptic nucleus (MnPN) of the POA suppressed the discharge activity of majority of wake/REM and wake-active PF-LHA neurons during waking. We also found that stimulation of MnPN cell bodies by glutamate suppressed the discharge activity of PFLHA neurons. We examined the effects of microinjection of muscimol, a GABAA receptor agonist, into MnPN (MnPN neuronal inactivation) on c-fos expression (Fos-IR) in PF-LHA neurons in anesthetized rats. Microinjection of muscimol into MnPN increased the number of HCRT and other PF-LHA neurons exhibiting Fos-IR. We have shown earlier that majority of warm-sensitive neurons within POA are sleep-active. We found that 52% of the neurons recorded within PF-LHA responded to POA warming and 90% of the responsive neurons exhibited a reduction in discharge in response to POA warming. These findings are consistent with our hypothesis that PF-LHA neurons are inhibited by MnPN neurons during spontaneous sleep. The PF-LHA contains local GABAergic interneurons and also receives GABAergic inputs from POA. We examined the effects of microdialytic delivery of bicuculline, a GABAA receptor antagonist, into the PF-LHA in spontaneously sleeping rats during the lights-on period on (i) sleepwake profile and (ii) Fos-IR in PF-LHA neurons. In presence of bicuculline into the PF-LHA, rats exhibited a dose-dependent decrease in nonREM and REM sleep time and an increase in time awake. The number of HCRT and other PF-LHA neurons exhibiting Fos-IR adjacent to the microdialysis probe also increased dose-dependently. These results support our hypothesis that PF-LHA neurons, including HCRT neurons, are subject to increased endogenous GABAergic inhibition during sleep. Support: NS-050939, MH-47489, HL-60296, and MH-63323. ROLE OF POSTERIOR HYPOTHALAMIC HISTAMINERGIC NEURONS IN AROUSAL JOSHI JOHN, MING-FUNG WU, LISA N BOEHMER AND JEROME M SIEGEL Department of Psychiatry, University of California at Los Angeles, Los Angeles, CA 90095, Neurobiology Research (151A3), VA GLAHS, North Hills, CA 91343, and Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095 Posterior hypothalamic histamine containing neurons have widespread projections. Several studies have indicated that histamine-containing neurons are important for the control of waking. There is a reciprocal anatomical connection between the wake promoting histaminergic system and sleep promoting preoptic area. Histaminergic, noradrenergic and serotonergic neurons are continuously active during waking, reduce discharge during NREM sleep and cease discharge during REM sleep. Cataplexy is one of the major symptoms associated with narcolepsy. Cataplexy is a waking state in which muscle tone is lost, as it is in REM sleep, while environmental awareness continues as in alert waking. We have studied single cell activity in freely moving genetically narcoleptic (Hcrtr2 mutant) Doberman Pinschers across sleep-wake cycle and cataplexy. We reported that during cataplexy, noradrenergic ‘REMoff’ neurons cease discharge and serotonergic ‘REM-off’ neurons greatly reduce activity. We have found that during cataplexy attacks presumed histamine containing ‘REM-off’ cells fire at levels similar to or higher than those seen in quiet waking. Our microdialysis-HPLC measurements showed that GABA release into the tuberomammillary nucleus was significantly reduced in cataplexy relative to sleep and waking Sleep and Biological Rhythms 2005; 3: A2–A73 levels. This reduction in GABA release is likely to disinhibit histamine cells. We found that, in contrast to other monoaminergic ‘REM-off’ cell groups, histamine neurons are active in cataplexy at a rate similar to or greater than that in quiet waking. We hypothesize that the activity of histamine cells is linked to the maintenance of waking, in contrast to activity in noradrenergic and serotonergic neurons, which is more tightly coupled to the normal maintenance of muscle tone in waking and its loss in REM sleep and cataplexy. It is possible that a reduction in the activity of preoptic sleep active neurons during cataplexy allows continued activity of histamine neurons or the firing of histamine neurons suppress the preoptic cells to produce physiological changes required for waking. Financial disclosure: Research supported by NS 14610, MH 64109 and the VA. S-2. New approaches to understanding and treating disturbed sleep Chairperson: Richard R. Bootzin (USA) FAST: A NOVEL BRIEF BEHAVIOURAL THERAPY FOR PRIMARY INSOMNIA LEON LACK AND JODIE HARRIS School of Psychology, Flinders University of South Australia Chronic insomnia is a prevalent disorder, often associated with significant daytime deficits. Clinical research has demonstrated that cognitive behavioural therapies for insomnia produce lasting benefits. However, implementing these therapies usually requires considerable time, effort and commitment that may reduce compliance. In response to these issues we have been investigating the Flinders Accelerated Sleep Therapy (FAST), a brief, concentrated therapy for insomnia. The therapy involves a 28-h period of acute sleep deprivation during which 50 sleep onset opportunities and very brief naps (less than 4 min sleep) are given. The aim was to use the sleep deprivation to produce numerous short sleep onset latencies (most less than 5 min) to reduce the putative psychophysiologic conditioned response of primary insomnia. The present study evaluated the efficacy of FAST. Seventeen volunteer chronic primary insomniacs (12 females and 5 males) participated in the study (Mean age = 39.12, SD = 12.41 years). Treatment response was determined using sleep diaries, actigraphy, and psychological questionnaires. Assessment involved two-week periods of measurement 1. Prior to treatment, 2. Immediately following treatment, and 3. Six weeks after treatment. Improvements in subjective sleep latency over time (70 mins. to 39 mins, and 47 mins.), sleep efficiency (62% to 76% and 74%), and total sleep time (317 mins. to 382 mins. and 360 mins.) were all significant as shown by repeated measures ANOVAs (F15 = 9.46, P < 0.05) (F15 = 22.66, P < 0.001), and (F15 = 16.46, P < 0.001), respectively. Improvements in actigraphy measured sleep latency and efficiency were also significant (F10 = 4.15, P < 0.05 and F10 = 10.5, P < 0.05, respectively). Questionnaires indicated significant improvements in sleep self-efficacy, fatigue, vigour, and cognitive aspects of sleep anticipatory anxiety. This preliminary data indicates the potential for this brief behavioural therapy to rapidly treat chronic insomnia. To maximize treatment response and enhance long-term improvement, however, a follow-on adjunctive therapy may be a worthwhile addition to this accelerated therapy procedure. A3 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 IMPROVING INSOMNIACS’ SLEEP MISPERCEPTION AND SLEEP THROUGH POLYSOMNOGRAPHICALLY DERIVED FEEDBACK JEREMY D MERCER, RICHARD R BOOTZIN AND LEON C LACK Adelaide Institute for Sleep Health, University of Arizona, Flinders University, South Australia Compared to good sleepers, insomniacs are more likely to overestimate time spent awake overnight and underestimate total sleep time. Insomniacs are more than twice as likely as good sleepers to report being already awake when woken from Stage 2 and REM sleep. This is primarily an inability to discriminate between sleeping and waking states rather than a general bias toward reporting wakefulness. Insomniacs’ response to perceiving prior wakefulness may be perpetuating their insomnia. Improving sleep perception may therefore be a beneficial therapeutic approach for treating insomnia. To investigate the origin of insomniacs’ sleep misperception, verbal reports of mental activity were collected in the laboratory from good and poor sleepers, from both wake and sleep conditions. No difference was found in the quality or quantity of reported mental activity between groups. Insomniacs’ perception of prior wakefulness upon awakening therefore appears to be the product of the attribution of normal sleep mentation as wakefulness, rather than the product of increased nocturnal activation. Presenting feedback to insomniacs on their sleep should be an appropriate therapy to address this misattribution. The effects of two forms of feedback on subjective and objective sleep were compared. The first form involved retrospective, whole-night feedback on participants’ sleep following two nights of home polysomnography. Sleep following feedback showed an increase in Total Sleep Time from an initial mean (sd) of 334.8(54.7) mins to 382.6(51.3) mins [t(9) = –3.26, P < 0.01]. Subjective Sleep Efficiency improved from 61.6%(22.3) to 73.1%(11.4) [t(9) = –2.70, P < 0.05], and objective Sleep Efficiency increased from 75.5%(8.58) to 81.5%(7.19) [t(9) = –2.55, P < 0.05]. The second form of feedback involved four weekly laboratory nights where participants were given immediate feedback on their sleep/wake state several times across the night. Prior to each feedback, participants were asked to evaluate whether they had been awake or asleep. The combined probability of reporting being awake prior to sleep probes decreased from 51.7% on night 1–14.0% on night 4. Subsequent home PSGs indicated that Total Sleep Time had further increased to 422.0(56) mins [t(9) = –3.01, P < 0.01]. Subjective Sleep Efficiency improved to 81.6%(15.2) [t(9) = –3.29, P < 0.01], and Objective Sleep Efficiency increased to 85.0%(7.31) [t(9) = –2.26, P < 0.05]. Both retrospective and immediate feedbacks improved the subjective and objective and sleep of insomniacs. Supported by the National Health and Medical Research Council of Australia. IMPROVEMENT IN SLEEP AND DEPRESSION FOLLOWING MINDFULNESS MEDITATION: A PSG STUDY WILLOUGHBY B BRITTON, KEITH W FRIDEL, JESSICA PAYNE AND RICHARD R BOOTZIN University of Arizona, Department of Psychology, Tucson, AZ USA Although mindfulness meditation-based interventions have been repeatedly shown to improve depressive symptoms and help prevent relapse, the physiological mechanisms of mindfulness’ therapeutic effects are unknown. Both sleep disturbance (increased sleep onset latency, increased awakenings and arousals, decreased sleep efficiency) and a disinhibition of REM sleep (as manifested by an earlier onset) are associated with depression and elevate risk for recurrence. In this study A4 we examine sleep and REM disturbances as possible mediators of meditation’s therapeutic effects. Individuals with partially remitted depression (n = 14) underwent overnight PSG sleep studies before and after an 8-week meditationbased depression relapse prevention program called Mindfulness-Based Cognitive Therapy (MBCT). All participants also completed weekly sleep diaries and depression inventories before and after the program. Sleep diaries (n = 14) showed a significant increase in sleep efficiency (P = 0.004), a marginal decrease in wake after sleep onset (P = 0.054), and a trend toward decreased sleep onset latency (P = 0.11) between baseline and week 7 of the meditation treatment. From PSG data of participants with baseline sleep efficiency below 90% (n = 8), the number of microarousals decreased significantly (P < 0.05), stage 1 min decreased marginally (P = 0.07), and there was a trend toward decreased awakenings (P = 0.10) following treatment. Medicated participants (n = 6) showed more improvement in their sleep disturbance after meditation compared to unmedicated participants (n = 8). However, the medicated participants showed more disrupted sleep at baseline, as evidenced by significantly more microarousals (P = 0.001), minutes in stage 1 (P = 0.008), and a trend towards more wake after sleep onset (P = 0.17). REM latency increased in the nonmedicated participants and decreased in the medicated subjects. Multiple regressions with sleep efficiency and arousals as predictors for REM latency were calculated for medicated and unmedicated participants separately. Sleep efficiency significantly predicted REM latency in the medicated participants (R2 = 0.70, P < 0.05), but not in the unmedicated ones. Thus, decreases in REM latency in the medicated group were strongly associated with reductions in sleep disturbance, although increases in REM latency were unrelated to sleep disturbance. BDI scores decreased significantly from pre to post treatment (P < 0.05), with no effect of medication on baseline or change in depressive symptoms. Changes in self-reported sleep efficiency predicted improvement in depression scores (R2 = 0.46, P < 0.05). Improvement in sleep disturbance, including REM abnormalities, appears to be a mechanism by which MBCT improves depressive symptoms. TREATING INSOMNIA AND DAYTIME SLEEPINESS IN ADOLESCENTS WITH A DRUG ABUSE HISTORY RICHARD R BOOTZIN1, SALLY J STEVENS1, SHAUNA L SHAPIRO2, JENNIFER C COUSINS1, KEITH W FRIDEL1, BRANT P HASLER1, ELAINE T BAILEY1, WILLOUGHBY B BRITTON1, SABRINA HITT3, MICHAEL CAMERON1 AND BARBARA ESTRADA1 University of Arizona1, Santa Clara University2, and Tucson VAMC3 We developed a six-session small group treatment for adolescents who had received treatment for substance abuse to improve sleep, decrease sleepiness, and lower the risk for recidivism of substance abuse. The treatment consisted of six 90-minute weekly small group sessions. The intervention components included: sleep education, regularizing sleep schedules, stimulus control instructions, cognitive restructuring and relapse prevention, and mindfulness-based stress reduction (MBSR). Participants included 55 adolescents (age M = 16.09, range 13–19; 34 male) of whom 23 (42%) were completers who attended four or more sessions. Assessments included sleep diaries, actigraphy, dim light melatonin onset (DLMO), and measures of drug use, among other measures. Data from the completers showed marked improvement on sleep as reported in their sleep diaries. Significant improvement was shown in Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 sleep efficiency (P < 0.001, n = 17, 84% to 92%), sleep onset latency (P < 0.01, n = 17, 36–17 min) number of awakenings (P < 0.001, n = 17, 2.29–1.41), total sleep time (P < 0.05, n = 17, 440–501 min), quality of sleep (P < 0.001, n = 17, 2.71–3.47) and soundness of sleep (P < 0.01, n = 17, 1.94–2.41). Actigraphy showed trends confirming these findings for total sleep time and sleep onset latency. DLMO results showed a trend for noncompleters to show increased phase delay from pre to post-treatment while completers maintained the degree of phase delay they had exhibited at pretreatment (P < 0.20). Drug use increased for both completers and noncompleters through the treatment period. At follow-up, an encouraging pattern emerged that indicates that drug use decreases for completers but continues to increase for the noncompleters (interaction P < 0.20, n = 10 completers, n = 11 noncompleters). Sleep disturbance can be successfully treated in adolescents with a substance abuse history. Although sleep improves during treatment, the effect on drug use appears to be delayed until the 12-month follow-up. Support: This research was supported by a contract from the Office of National Drug Control Policy. S-3. Sensory information processing in sleep Chairperson: Anton Coenen (Netherlands) Co-chair: Ricardo Velluti (Uruguay) THE AUDITORY SYSTEM IN SLEEP RICARDO A VELLUTI Neurofisiolog’a, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay The brain activity during the sleep/wakefulness cycle is continuously modulated by the incoming sensory information from the environment and the body. Interactions between sleep and sensory input were reported, and a surgical quasi-total deafferentation revealed significant shifts in the sleep organization. Although profoundly modified, the processing of sensory information is still present during sleep, while it is not yet fully understood how the brain processes such information. A cell assembly/neuronal network coding is a tenable aspect on how the brain may operate in sleep and wakefulness. Why the auditory system? 1. Hearing is the only tele-receptive modality relatively open during sleep. 2. While auditory stimuli can affect sleep, e.g. a noisy night, the total lack of auditory input alters the guinea pig sleep architecture. 3. Because of the presence of auditory images in 65% of recalled dreams. 4. The local blood flow is significantly increased in the auditory system. 5. Human deaf patients after intracochlear implants may recover hearing while changing their sleep architecture. Processing approaches. The premises are that processing changes throughout the sleep-wakefulness cycle may be at least partially evidenced in single neurons activity by: 1. changes in the discharge rate; 2. firing pattern shifts; 3. phase-locking between the auditory unit and the hippocampal theta rhythm. During both slow wave and paradoxical sleep, the auditory units evoked firing increases, decreases or remained similar to that observed during quiet wakefulness. Approximately half of the cortical neurons studied did not change their firing rate when passing into sleep while the other ~half increased or decreased. Neurons not exhibiting firing rate shifts, instead, may display a different firing pattern. It is postulated that the system is continuously aware of the environment. Besides, those auditory neurons that changed their evoked or pattern firing during sleep may be related to cell assemblies/neuronal networks associated with some still unknown sleep Sleep and Biological Rhythms 2005; 3: A2–A73 active process. There was no auditory unit that stopped firing when the guinea pig entered sleep. Considering that neonates and infants spend most of the time asleep, the continuous arrival of sensory information to the brain during both sleep phases may serve to ‘sculpt’ the brain by the activity-dependent mechanisms of neural development. Moreover, these basic approaches may contribute as a first step towards the possibility of auditory learning, as it was reported in sleeping newborns. INFORMATION PROCESSING IN SLEEP AS A FUNCTION OF STIMULUS SALIENCE AND SLEEP INTENSITY URSULA VOSS J.W. Goethe-University Frankfurt am Main, Germany Research on information processing in sleep has shown that acoustic events are processed with regard to stimulus salience, instrumentalised by varying intensity, novelty, probability, and semantic properties of the presented stimuli (Voss & Harsh 1998). However, sleep processing differs from that of wakefulness, as is evident from research on eventrelated potentials (ERPs) and imaging studies. While in wakefulness, salient stimuli are related to a heightened attentiveness, stimulus salience in sleep is met with an inhibitory response, as evidenced by a reduced BOLD signal and a high-amplitude negative deflection in the sleep-ERP. Since highly salient stimuli have also been shown to disrupt sleep, it can be assumed that the inhibitory response reflects an effort at attention-inhibition, which is aimed at sleep maintenance. In addition to stimulus salience, sleep processing varies as a function of sleep intensity. During NREM sleep, high sleep intensity is accompanied by reduced amplitude of attention-related evoked 40-Hz activity and inhibition-related ERP components as well as an increased arousal threshold. These findings suggest that high sleep intensity is associated with further restricted information processing. As for REM sleep, its position in the sleep intensity hierarchy is still not fully determined. The protective field model (Voss 2004) proposes a continuum of increasing sleep intensity across NREM stages I-IV, reaching peak intensity in phasic REM sleep. New data from an arousal threshold experiment as well as frequency analyses of gamma band activity are presented and discussed with regard to this assumption of the protective field model. Concerning the possible function of continued information processing in sleep, it is proposed that the altered modus of information processing, switching from voluntary allocation of attentional resources to an inherent sleep monitoring is aimed at the detection of potential danger cues. Non-salient stimuli are recognized but only salient stimuli evoke a behavioral response. The progression of sleep intensity depends on the feedback of the information processing system signalling a secure or endangered sleep environment. Higher sleep intensity is accompanied by a lesser degree of sleep monitoring. References Voss U, Harsh J. Information processing and coping style during the wake/sleep transition. J. Sleep Res. 1998; 7: 225–32. Voss, U. Functions of sleep architecture and the concept of protective fields. Rev Neuroscienc. 2004; 15: 33–46. A5 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 MODELING OF AUDITORY EVOKED POTENTIALS OF SLEEP-WAKE STATES ANTON ML COENEN NICI, Department of Biological Psychology, Radboud University Nijmegen, The Netherlands Vigilance related changes in the human auditory evoked potential, constructed from 1000 Hz 40 dB tones recorded from 12 subjects, were identified. Records made during the several sleep-wake states are shown in the right panel of the figure. N1 is clear during wakefulness, smaller during stage 1, and further no longer visible. On the contrary, P2 is growing with declining vigilance, with a maximal size in stage 4. As N1, also N2 is decreasing during sleep, while a major N3 component becomes visible during stage 4. In the left parts of the figure the evoked potentials are modelled. This is based on two factors: ‘gating’ and ‘firing mode’. During sleep ‘sensory gating’ occurs. Evoked activity is filtered and the activity ultimately arriving at the cortex declines with decreasing vigilance. This decrement in activity gives rise to a decrease in N1, associated with the primary excitation of cortical cells. Besides a primary excitation, a stimulus elicits a secondary excitation, which is expressed in N2. Hence, this component is also declining during sleep. These excitations are separated by an inhibitory phase, thought to contribute to P2. The evoked responses of cortical cells are superimposed on the spontaneous activity. Cortical neurons fire in the ‘tonic’ or ‘relay’ mode during waking and in the ‘burst-pause’ mode during sleep. This is related to the degree of membrane polarization of cells. The stimulus seems to force the EEG activity in a rhythm of 1–2 Hz (800 ms), assumed to start with a positive component. This oscillation decreases with increasing vigilance. To fit the REM sleep-evoked potential best, it is accepted here that gating during REM sleep is high and that cells are firing in the tonic mode. Thus, two main factors shape the sleep-wake auditory evoked potentials: the ‘gating’ factor, reducing the components underlying stimulus registration (N1 and N2) and the ‘firing mode’ factor, responsible for the growth of N3 in sleep. P2 is a mixture of the inhibitory phase and a part of the oscillation due to the burst-firing mode. The large N3, facilitated by P2, dominating the sleep auditory evoked potential, is the pure reflection of the burst-firing mode. THE EXTENT OF AUDITORY PROCESSING DURING NREM AND REM SLEEP KENNETH CAMPBELL School of Psychology, University of Ottawa, Canada In order to sleep, the processing of all but the most relevant of stimulus input must be inhibited or ‘gated’. The extent of processing can conveniently be monitored by event-related potentials (ERPs). ERPs consist of a series of negative- and positive-going components. In the waking state, an auditory stimulus will elicit a characteristic negative component, ‘N1’, peaking at about 100 ms followed by a positive component, ‘P2’, peaking at about 180 ms. R. Naatanen claims that N1 reflects the activity of a transient feature detection system located in the auditory cortex. N1 is thus thought to mainly affect stimulus parameters, such as its intensity or rate of presentation. Psychological factors such as the extent of attention paid to the stimulus are thought to affect another long-lasting negative component (the Processing Negativity or ‘PN’) that may overlap and summate with N1 and P2 in the waking state. This causes N1 to appear to be larger and P2 to be smaller on the scalp. Active attention is not possible during sleep. During the sleep onset period, PN is thus removed resulting in a decrease in the amplitude of N1 and an increase in the amplitude of P2. N1 is at or near baseline during NREM sleep, probably because of the gating of input prior to the auditory cortex. N1 however, returns to 25–50% of its waking A6 amplitude during REM sleep. In an oddball task, the subject is presented with a frequently occurring ‘standard’ stimulus and an infrequently presented ‘deviant’. In the waking state, in addition to the usual N1-P2, the deviant elicits another negative component, the Mismatch Negativity (MMN). The MMN occurs independently of attention and is claimed to reflect a very basic change detection system, also located in the auditory cortex. The MMN cannot be elicited in NREM sleep. Again, a much-reduced MMN can be elicited in REM but only if the extent of deviance is very large. Although N1 and the MMN cannot be elicited in NREM, highly obtrusive or highly relevant stimuli will elicit different ERPs and these are unique to sleep. They do not occur at all in the waking state, or in REM sleep. A negative wave peaking at 300–350 ms (N350) is a marker of the sleep onset period and probably corresponds to the vertex sharp wave. The same stimulus may also elicit a KComplex, which is a composite of a larger amplitude N350 and the massively large N550. How can the N350 and N550 be elicited in NREM if N1 and the MMN, reflecting activity in the auditory cortex, cannot be elicited? There is good evidence that many neurons in the auditory cortex remain active (see, for example, Velluti, this symposium). It is possible that these neurons trigger the large N350/N550 components while those that are responsible for the N1 and MMN are inhibited. On the other hand, it is also possible that these large amplitude late negativities are elicited by a modality independent system. The K-Complex can be elicited by stimuli in many different modalities. S-4. Mechanisms of regulation of sleep related to sexual dysfunction in humans and effects of sleep deprivation in sexual behavior in rats Chairpersons: Sergio Tufik and Monica L. Andersen (Brazil) SLEEP AND SEXUAL BEHAVIOR: A CROSS TALK KAMALESH K GULIA, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India The normal healthy pattern of sleep and sexual behavior is achieved through a complex interaction of neural circuits at different levels. It is imperative that each of these behavior states has been worked out independently to a great extent, as both of these are essential physiological entities of life in its own prospective. Equally important is the fact that activation of neural circuitry for any of these behaviors exert influences on the other. The sleep is enhanced during postcoital episodes in animals as well as in human subjects. Rapid eye movement (REM) sleep deprivation brings about an increase in sexual behavior in male rats. Although a number of brain areas are involved in regulation of these pursuits, some areas are common to both like the preoptic area, septum, bed nucleus of stria terminalis and amygdala. There is a strong possibility of a multimodal interaction as activation in the neural sites of one of these behavior exhibit tremendous influence on the other for homeostatic processes in the body. The subjects with Kluver–Bucy syndrome show disturbance in sleep-wake pattern. The narcoleptic patients are found to have profound variations in their libido. Another aspect of this interaction is evident during REM sleep in form of penile erections, when skeletal muscles tone is nearly absent in body. This is a clear indication of partial activation of the system involved in erectile response at the onset of REM sleep. The disruption in this organization is reflected in a form of a clinical disorder in which sexual activity is performed during sleep and the subject is unaware of the event when awake. This new entity sexsomnia or sleepsex adds a new Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 dimension to the parasomnias. These evidences strongly suggest of a cross talk between the circuitries for sleep and sexual behavior regulation. SLEEP-RELATED ERECTIONS: HISTORICAL BACKGROUND, ANIMAL MODEL AND CLINICAL SIGNIFICANCE MARKUS H SCHMIDT Adjunct Assistant Professor, Ohio Sleep Medicine and Neuroscience Institute, The Ohio State University, 4975 Bradenton Avenue, Dublin, OH 43017, USA Penile erections during paradoxical sleep (PS), or rapid eye movement (REM) sleep, are a robust physiological phenomenon in all normal healthy males from infancy to the elderly. Sleep-related erection (SRE) testing has been used by clinicians to differentiate psychogenic from organic impotence, given the involuntary nature of erections in sleep. The historical background of SRE testing and its current use will be discussed. We have developed a new animal model for recording penile erections in freely moving rats. This technique involves placing an open tipped pressure catheter into the bulb of the corpus spongiosum of the penis (CSP) using a telemetric transmitter placed subcutaneously. This recording technique has been validated to quantitatively and qualitatively record penile erections in freely moving rats. This animal model for erection recording may have important clinical applications. For example, although several clinical studies have demonstrated that obstructive sleep apnea (OSA) syndrome is associated with an increased risk for developing erectile dysfunction in human males, the cause of ED in OSA remains unclear given the many comorbidities found in OSA patients such as obesity and hypertension which can also independently lead to ED. Using this new animal model for erection recording, we have recently demonstrated that erectile activity significantly decreases in rats exposed to 8 weeks of intermittent hypoxia even though serum testosterone levels remain unchanged. These data suggest that intermittent hypoxia associated with OSA may be an independent risk factor for causing ED in human males. Guidelines regarding SRE testing with polysomnography have not been available, contributing to a decline in the United States in use of formal SRE testing, even though erections in sleep are commonly evaluated by urologists using home screening devices that do not record sleep. We propose a set of clear clinical indications when formal SRE evaluation in a sleep laboratory should be considered. HYPERSEXUALITY INDUCED BY SLEEP DEPRIVATION IN MALE RATS MONICA L ANDERSEN Department of Psychobiology, UNIFESP, R Napoleao de Barros 925, Vila Clementino, Sao Paulo-04024–002, Brazil Sleep deprivation resulting from the agitation and stress of modern life, long working hours and psychological stress may have yet not described adverse effects over a person’s health and well-being. In spite of the constellation of well-documented behavioral and neuropharmacological consequences brought upon by paradoxical sleep deprivation (PSD) sexual behavior remains little investigated. Thus, our purposes have been to investigate the effects of PSD associated to several psychotropic compounds in the induction of genital reflexes (erection and ejaculation) in rats under several aspects. Indeed, drug abuse is on the rise in modern society and is closely related to the intensification of sexual pleasure and performance. Not much is known about these two targets. At first, the animals were paradoxically sleep deprived for 96 h and then Sleep and Biological Rhythms 2005; 3: A2–A73 administered with either saline or cocaine. The results revealed that the PSD group that received cocaine was the one that produced the highest percentage of animals displaying erection and ejaculation (100% and 60%, respectively) and differed statistically from the control groups that received either saline or cocaine. The proportion of PSD animals injected with saline was 50% of erection and 20% of ejaculation. The administration of cocaine in home-cage animals induced erection and ejaculation in only 10% of the animals. Thus, further studies were carried out in an effort to comprehend the mechanisms that are involved in these behaviors. We verified that the maximum frequency response of genital reflexes was at the 96th hour of PSD and that there was no substantial evidence of diurnal variation of the erectile response in PSD rats although ejaculatory events were significantly reduced at 4:00 AM in the PSD + cocaine group. We observed that genital reflexes also occurred in young as well as in aged rats tested at different time points. Since sexual behavior is under hormonal control we investigated the effect of sleep deprivation at hormonal concentrations. The results showed that testosterone and estrone were reduced while progesterone, prolactin, corticosterona, ACTH, dopamine and noradrenaline increased during PSD. In addition to the hormonal aspects we also verified possible mechanisms of neurotransmission involved in the genital reflexes of PSD rats. Besides the effects of acute administration of cocaine, we investigated the effects of other substances such as: dopaminergic agonists (apomorphine, bromocriptine e piribedil), modafinil, sildenafil, caffeine, and the following drugs of abuse: methamphetamine, morphine, ecstasy, ethanol e D9-tetrahydrocannabinol. Pre-treatment with dopaminergic, noradrenergic, serotonergic, cholinergic and GABAergic drugs resulted in significant alterations in the incidence of genital reflexes induced by cocaine in PSD rats indicating that each of these neurotransmission systems do not act separately. The potentiating effects of cocaine and other drugs should be considered as a result of the interaction of different factors. Sexual behavior is a fascinating, complex and vast topic. It ranges from the most mechanical and biological acts of copulation to the great diversity of cultural practices of human societies besides being dependent on countless interactions. The results demonstrated that there is a relevant association between sleep deprivation and different substances in the induction of sexual reflexes. Such phenomena seem to critically depend on temporal, hormonal and neurotransmitter systems. STEROID HORMONES, REM SLEEP DEPRIVATION AND SEXUAL BEHAVIOR JAVIER VELAZQUEZ-MOCTEZUMA Neurosciences. Universidad Autónoma Metropolitana-Iztapalapa. México City. C.P. 09340 The functions of sleep and particularly of REM sleep stage have been an elusive issue for a number of years. Studies using selective deprivation of REM sleep (REMd) have been the main source of information. Concerning the relationship between REMd and sexual behavior, pioneer experiments suggested a generalized increase of activity. On the other hand, the regulation of sexual behavior by steroid hormones is well known. In a serie of experiments we analyzed the interaction of REMd with the effects of steroid hormones in the induction of sexual behavior in rats. In female rats the sequential treatment of estradiol followed by progesterone, that usually induce 100% of receptivity, was unable to reach 50% of receptivity in REMd subjects. On the other hand, the administration of estradiol does not induce receptivity, but in REMd rats the receptivity increase to more than 50%. These data suggest that REMd facilitates the effects of estradiol, while interferes with the effects of progesterone. Regarding masculine sexual behavior, A7 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 male rats were gonadectomized and the lost of sexual activity was recorded. Thereafter, subjects received a daily treatment with testosterone and the experimental group was also submmited to REMd for 7 days. Results indicated that REM deprived males recovered the behavioral patterns of mount, intromission and ejaculation with 8 injections of testosterone, while control groups required 16 injections and did not reach 100% of responding subjects. These results suggeste that REMd facilitates the action of testosterone. In addition, when males were treated with estradiol benzoate, REMd males displayed a significantly higher lordosis quotient, which means that estradiol is also facilitated by REMd in males. S-5. Sleep related penile erections: from neural circuitry to erectile dysfunctions Chairperson: Dr Sunao Uchida (Japan) and Dr Kamalesh K. Gulia (India) ROLE OF SEPTUM IN SLEEP RELATED PENILE ERECTIONS KAMALESH KUMARI GULIA, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India Sleep related penile erections (SREs) are observed in males during the rapid eye movement (REM) sleep. The central neural mechanisms for regulation of these sleep related erections still remains enigma in spite of SREs being routinely used clinically for differentiation of organic impotence from psychogenic ones. Recently, the lateral preoptic area has been shown to contribute in sleep-related erectile mechanisms (Schmidt et al. 2000). The septum is an important structure in the forebrain, which is shown to modulate sleep and male copulatory behaviour (Gulia et al. 2002, Kumar et al. 1996, Mallick et al. 2003). The bilateral lesion of the medial and lateral septi using excitotoxin Nmethyl D-aspartic acid produces distinct effects on the BS muscle activity during REM sleep (Gulia et al. 2004). Lesion at the lateral septum produced a significant decrease in the BS muscle activity during REM sleep as compared to prelesion control. The rat with lesion in the medial septum showed increase in the REM associated BS muscle activity after the lesion. These findings suggest that the septum plays important role in REM sleep related penile erection. References Gulia KK, Kumar VM, Mallick HN. Role of the lateral septal noradrenergic system in the elaboration of male sexual behavior in rats. Pharmacol. Biochem. Beh. 2002; 72: 817–23. Gulia KK, Mallick HN, Kumar VM. The septum modulates REM sleeprelated penile erections in rats. Iranian J. Pharmacol. Res. 2004; Supplement 1: 21. Kumar VM, Khan NA, John J. Male sexual behaviour not abolished after medial preoptic lesion in adult rats. NeuroReport 1996; 7: 1481–4. Mallick HN, Srividya R, Gulia KK, Kumar VM. Inhibitory control of REM sleep by medial septum neurons in rats. Sleep 2003; 26: A6. Schmidt MH, Valatx JL, Sakai K, Fort P, Jouvet M. Role of the lateral preoptic area in sleep-related erectile mechanisms and sleep generation in the rat. J. Neurosci. 2000; 20: 6640–7. Financial disclosure: Department of Science and Technology, Government of India supported this work. A8 ROLE OF THE MESOPONTINE TEGMENTUM IN THE REGULATION OF PENILE ERECTION DURING PARADOXICAL SLEEP Y KOYAMA1, K TAKAHASHI2, C TOLEDO2, Y KAYAMA2, H IWASAKI2, A KAWAUCHI3, T MIKI3 AND MH SCHMIDT4 1 Department of Science and Technology, Fukushima University, Fukushima, Japan, 2Department of Physiology, Fukushima Medical University, Fukushima, Japan, 3Department of Urology, Kyoto Prefectural University, Kyoto, Japan, 4Ohio Sleep Medicine and Neuroscience Institute, Dublin, OH, USA The laterodorsal tegmental nucleus (LDT) plays a crucial role in the regulation of paradoxical sleep (PS) and wakefulness (W). It contains several types of cholinergic neurons, some are most active during PS and others are active during PS and W. In addition to these tonic-firing neurons, the LDT also contains a subset of neurons, which show phasic firing during PS, the function of which remains to be known. One of the characteristic phasic events during PS is penile erection (PS-related penile erection). The crucial site in the preoptic area for the regulation of PS-related erection receives cholinergic afferents from the LDT 1, 2. To elucidate the brainstem mechanisms for the regulation of penile erection during PS, experiment was performed to record and examine the correlation of the activity of the LDT neurons with penile activity. Using unanesthetized, head restrained male rats, we found two types of putative cholinergic LDT neurons and a group of noncholinergic neurons that were associated with PS-related penile erections. The first type cholinergic neurons increased their tonic activity, 20–30 s before the onset of a PS-related erection, then decrease back to baseline during the erection. The second type showed phasic bursts several seconds before each erectile event. The noncholinergic neurons exclusively decreased or stopped their firing during PS-related erection. The firing changes of these types of neurons were specific for PS-related erection, but not for erection during waking. These data suggest that different subsets of LDT neurons play different roles; preparation, execution or inhibition of PS-related erection. References 1. Schmid MH, Valatx JL, Sakai K, Fort P, Jouvet M, Role of the lateral preoptic area in sleep-related erectile mechanisms and sleep generation in the rat. J. Neurosci. 2000; 20: 6640–7. 2. Schmidt MH, Gervasoni D, Luppi PH, Fort P. Carbachol administration into the lateral preoptic area induces erections and wakefulness. Abst, 31st Ann. Meeting Soc. Neurosci. (CD-ROM), 2001. SLEEP-RELATED PAINFUL ERECTION: AN OVERVIEW SZUCS ANNA National Institute of Psychiatry and Neurology, Budapest, Hungary Parasomnias are disorders of partial arousal frequently associated with sleep stage transitions characterised by inadeuqate movements, emotional or vegetative phenomena during sleep. They include arousal disorders, sleep-wake transition disorders, parasomnias usually associated with REM sleep and other parasomnias. Sleep-related painful erection (SRPE) is one of the REM sleep related parasomnias including nightmares, sleep paralysis, impared sleep-related penile erections, REM sleep-related sinus arrest and REM sleep behaviour disorder. SRPE is characterised by penile pain waking the patient during sleeprelated erection, typically during REM sleep. Due to several awakenings, the night sleep of the affected patients becomes fragmented – possibly resulting in insomnia and daytime sleepiness. Owing to recurrent, serious pain and discomfort, severe mood disturbance may develop. Erections during sexual intercourse are generally maintained. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 The disorder affects adults or elderly men. No familial pattern and no provoking factors are known. The relatively frequent occurence of concomittant urosurgical interventions has been described. In SRPE the origin of pain is enigmatic. It might result from erectile hyperactivity during REM sleep, but a case where SRPE was associated with impaired nocturnal penile tumescence has been described. Our reported case with relatively short erection-episodes during sleep, lasting 3–8 min, has also contradicted this hypothesis. The theory of SRPE as a psychosomatic disorder or any other psychogenic condition is supported by the depressive symptoms of some affected patients, peculiar personality characteristics of others, as well as by data on impaired nocturnal penile tumescence found transitorily in depressed men. However, the preservation of sleep-related erections also in vegetative state- patients and the independence from presleep sexual arousal makes it improbable. According to clinical experience, clonazepam, clomipramin, clozapine and some beta-blockers have been found to be sometimes useful, but as the mechanism is unknown, therapy is basically unresolved. The prevalence is unknown. According to the International Classification of Sleep disorders it is rare, occuring in less than 1% of patients presenting with sexual and erectile problems. However, the few known patients’ distress calls for relief. As the torturing pain develops during REM sleep related erections, clearing the pathogenesis of the strange disorder may help to understand the mechanism of the REM sleep related erections as well as some REM sleep phenomena themselves. and nPGi. Although the source of brainstem control of forebrain erectile mechanisms in sleep was previously unknown, our recent work demonstrates the presence of putative cholinergic neurons in the lateral dorsal tegmental (LDT) nucleus that increase their firing rate directly in association with PS-related erectile activity. Our work further suggests that the LDT may modulate or trigger forebrain erectile mechanisms through their ascending projections, potentially by releasing acetylcholine into the LPOA during PS. These new findings have allowed for the first time the development of a neural model regarding PS-related erectile control3. References 1. Schmidt et al. Sleep. 22: 409–18, 1999. 2. Schmidt et al. J. Neuroscience 20: 6640–7, 2000. 3. Schmidt MH. In: Principles and Practice of Sleep Medicine, 4th edition. Elsevier Saunders, Philadelphia, pp. 305–17, 2005. S-6. Insights into the nature of the Restless Legs Syndrome (RLS) Chairpersons: Wayne Hening (USA) and Dr Richard Allen (USA) RLS, ADHD, AND IRON DEFICIENCY – OVERLAPPING DISORDERS SLEEP-RELATED ERECTILE MECHANISMS: ROLE OF THE PREOPTIC AREA MARKUS H SCHMIDT Ohio Sleep Medicine and Neuroscience Institute, Adjunct Assistant Professor, The Ohio State University, USA Penile erections are a characteristic phenomenon of paradoxical sleep (PS) or rapid eye movement (REM) sleep. Although the neural mechanisms of these erections has only recently been explored, new data have led to the development of a new neural model for PS-erectile control. The spinal control of penile erections has been relatively well elucidated and is characterized by a complex interplay among parasympathetic, somatic motor, and sympathetic components. Although the supraspinal control is less well understood, numerous structures have been implicated in erectile mechanisms, including the medial preoptic area, which plays an essential role in copulatory behavior. Advances in erectile neurophysiology suggest that the generation of penile erections involves a descending oxytocinergic excitation of the spinal erection generator from the hypothalamic paraventricular nucleus (PVN) and the removal of a descending serotonergic inhibition from the medullary nucleus paragigantocellularis (nPGi). The executive mechanisms of PS, as well as the subsystems that generate its tonic and phasic phenomena, are located in the pedunculopontine tegmentum and rostral medulla. Although these brainstem structures are sufficient for the generation of PS and its classic phenomena, the brainstem is not sufficient for the generation of PS-related erections as demonstrated by brainstem transection experiments1. An essential role of the forebrain in PS-related erectile control is confirmed by lesion experiments of the preoptic area. Neurotoxic lesions of the lateral preoptic area (LPOA) severely disrupt PS-related erections while leaving at least some types of waking-state erections intact2, suggesting that the higher central mechanisms of erections are contextspecific. Similar lesions of the medial preoptic area have only minimal effects on sleep-related or waking-state erectile activity. Although it does not project to the spinal cord, the LPOA may modulate the spinal erection generator during PS through its relay connections with the PVN Sleep and Biological Rhythms 2005; 3: A2–A73 NAIPHINICH KOTCHABHAKDI, NITTAYA J KOTCHABHAKDI, RICHARD P ALLEN, WAYNE A HENING AND ARTHUR WALTERS Neuro-Behavioural Biology Center, Institute of Science and Technology Family, Development, Mahidol University, Salaya, Nakornpathom 73170 Thailand, John Hopkins Medical School, Baltimore, MD, UMDNJ-RW Johnson Medical School, New Brunswick, NJ, Neuroscience Institute at JFK Medical Center, Edison, NJ. USA The objective of this study is to determine the prevalence of restless legs syndrome (RLS), periodic limb movement in sleep (PLMS), and attention deficit hyperactivity disorder (ADHD) in a population of children suffering from iron deficiency. In recent surveys by Thailand National Institute for Child and Family Development between 1996 and 1999 school-age children under 18 years in suburban areas, we found between 13 and 14% with iron deficiency, 10–15% with PLMS, and 5–10% percentage with ADHD. We further investigated this population using studies of ferritin level to assess iron deficiency, activity meter recording to establish the PLMS, and questionnaire screens for symptoms of ADHD and RLS. 400 children under 18 years old in 6 suburban villages in Thailand who are within the field-study area of Mahidol University center at Salaya were screened for low ferritin (50 microgram/L). 50 children with low ferritin were selected and compared to 50 children with normal ferritin matched for age and sex. Three night recordings of leg movements were performed using a portable meter and associated software to calculate the activity overnight as well as the number of PLM broken down into hourly units. All children were screened for ADHD with the Connors scale. The Hopkins diagnostic interview was administered to the children and/or their parents to determine the presence of the restless legs syndrome. Childhood RLS was determined by (a) the presence of PLMS and either (b) a family history of RLS or (c) a positive RLS diagnosis using the Hopkins interview. First, we found that children with iron deficiency have a higher prevalence of RLS, ADHD, and elevated PLMS at night. Approximately half of the children with iron deficiency have either ADHD or PLMS compared to less than 10% of the control children. Second, we found that children with both iron deficiency and ADHD also have a still higher prevalence of symptoms of RLS and PLMS. The A9 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 majority of these children have PLMS and that some also have symptoms of RLS. The study also indicates that RLS and PLMS are a significant population in Oriental as well as Western populations, and RLS, ADHD, and iron deficiency may be overlapping disorders. THE PATHOPHYSIOLOGY OF RESTLESS LEGS SYNDROME (RLS): AN OVERVIEW ARTHUR S WALTERS New Jersey Neuroscience Institute, At JFK Medical Center, 65 James Street, Edison, New Jersey 08818, USA Restless Legs Syndrome (RLS) is responsive to dopaminergic and opioid medications. Symptoms in treated patients return with dopaminergic and opioid receptor blockade, implicating the endogenous dopaminergic and opioid systems in the pathogenesis of RLS. Unfortunately neither autopsy material nor studies of the cerebrospinal fluid nor brain imaging with either PET or SPECT in RLS patients have shown marked alterations in dopaminergic activity. On the other hand, destruction of the cell bodies for A11 diencephalospinal dopaminergic fibers results in restlessness in the rat that is reversed with dopaminergic treatment. Post-synaptic opioid receptor scan studies in RLS patients suggest that as RLS symptoms increase that more endogenous opioids are released in the brain, perhaps as compensation for the discomfort that RLS patients get in their legs. The fact that idiopathic RLS patients have decreased temperature sensation and a hyperalgesia to pin prick suggests that there is an abnormal processing of bodily sensations in the central nervous system in RLS. RLS is also responsive to iron therapy. There is evidence of iron deficiency in RLS by autopsy material, cerebrospinal fluid examination and MRI scanning with special settings. Iron may indirectly influence the dopaminergic system since it is a cofactor for tyrosine hyroxylase, the rate limiting step in the formation of dopamine. Iron also affects the binding of dopamine to its receptor. Various neurophysiological studies have suggested that the Periodic Limb Movements (PLMs) seen in RLS are due to a disinhibition of a spinal cord generator that produces the PLMs. The most dramatic evidence for this is the presence of PLMs in patients with total spinal cord transection. Functional MRI studies in RLS patients show that during the sensory symptoms the thalamus and cerbellum are activated whereas during the PLMs the brain stem is activated near the red nucleus. Studies in families with RLS have shown evidence of genetic linkage to chromosomes 9, 12, and 14 but so far no genes have been identified. The discovery of these genes will allow us to more clearly understand the pathophysiology of hereditofamial RLS which may represent up to 2/3 of all cases. S-7. Inter-individual differences in sleep and sleepiness Chairperson: Hans P.A. Van Dongen (USA) TRAIT CHARACTERISTICS OF SLEEP TENDENCY AND AROUSAL ELKE DE VALCK1, STIJN QUANTEN2, RAYMOND CLUYDTS1 AND DANIËL BERCKMANS2 1 Department of Cognitive and Biological Psychology, Free University of Brussels, Brussels, Belgium, 2Laboratory for Agricultural Buildings Research, Catholic University of Leuven, Leuven, Belgium Systematic individual differences in sleepiness and related phenomena such as the sensitivity to sleep deprivation are recently being reported A10 (Van Dongen et al. 2004). When establishing these individual discrepancies in relation to the traditional two-process model for sleep regulation, a second step is to offer an explanation for these differences. Recent research suggests that not only the sleep drive, under the control of the neurotransmitter adenosine and the ventro-lateral preoptic area of the hypothalamus, plays an important role in the determination of the tendency to fall asleep. Also the wake drive or arousal, where orexine/hypocretine plays a coordinating role within the different arousal structures in the human brain, has a decisive influence on the tendency to fall asleep (Willie et al. 2001). It seems for instance that the circadian variation in sleepiness reflects not as much a fluctuation in sleep drive, measured as the delta-activity of the EEG, but more a fluctuation in wake drive as measured through beta-activity in the EEG (Cajochen et al. 2002). Moreover, it is shown that an experimentally induced cognitive arousal, evoked by public speech, has a significant and substantial effect on the tendency to fall asleep, objectively measured by the MSLT (De Valck et al. 2004). The value of the indicators of the wake drive, like cortisol level and beta-activity in the EEG, as input variables in the existing predictive models for the tendency to fall asleep is not yet investigated. However, these parameters are promising to partially account for the individual differences in response to sleep deprivation. A field study on shift work in fast and slow rotating shift systems shows that night shifts not only induce sleepiness and performance decrements, but also evoke stress, as indicated by cortisol levels through saliva. The extent to which the individual stress response to night shifts has an impact on the sleepiness related performance decrement of shift workers following a night shift, is investigated. Using the data-based mechanistic (DBM) technique, an individualised and time-varying predictive sleep model is developed. Financial disclosure: The research board of the Free University of Brussels, Belgium has supported this work. INDIVIDUAL DIFFERENCES IN EXCESSIVE DAYTIME SLEEPINESS AMONG SLEEP APNEA PATIENTS TERRI E WEAVER Biobehavioral and Health Sciences Division, School of Nursing and Center for Sleep and Respiratory Neurobiology and Division of Sleep Medicine, School of Medicine, University of Pennsylvania, USA The criteria for the diagnosis of obstructive sleep apnea syndrome (OSA) are the presence of physiological impairment as well as the manifestation of excessive daytime sleepiness (EDS). However, the extent that sleepiness is characteristic of this population and the primary method of measuring daytime sleepiness remains unresolved. It is also unclear how many of those with more severe disease do not manifest sleepiness both objectively and subjectively and therefore would not be candidates for treatment based on the current criteria. In this presentation, the profile of sleepiness in a group of subjects with moderate/ severe sleep apnea will be described and the consistency and proportion of subjects that manifest sleepiness will be examined based on three conceptually distinct measures: a measure of subjective sleepiness (Epworth Sleepiness scale [ESS], objective sleepiness (Multiple Sleep Latency Test (MSLT), and a sustained attention task (Psychomotor Vigilance Task [PVT] (Dinges 1992). Sleepy subjects were differentiated from nonsleepy subjects based on cut-points reflective of an abnormal level of daytime sleepiness: Epworth Sleepiness Scale (ESS) > 11; Multiple Sleep Latency Test (MSLT) < 10; and presence of > 2 performance lapses/10 min on the Psychomotor Vigilance Test (PVT). Patients with OSA manifest sleepiness differentially. For example, a report from the large, NIH-initiated Sleep Heart Health Study indicated Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 consistent percentages of nonsleepy subjects within the same degree of disease severity –72% patients with mild OSA, 72% with moderate and 65% with severe OSA (AHI > 30) did not self-report on the ESS. In a study of patients with more severe disease, approximately half with diagnosed with OSA (AHI > 15) manifested sleepiness both subjectively and objectively using the MSLT to measure objective sleepiness, with approximately a third presenting with subjective and objective sleepiness when objective sleepiness was measured by the PVT. Interestingly, only 29% exhibit sleepiness consistently as measured by all three metrics. The poor relationship among all three measures suggests either the presence of primary error variance, domain variance, or both. Moreover, sizeable proportions of patients do not manifest sleepiness measured either subjectively or objectively. This raises the issue regarding which measure of sleepiness should be the basis for treatment decisions, especially in the presence of discordant responses and whether those who do not manifest sleepiness both subjectively and objectively should be candidates for treatment. AGING AND INDIVIDUAL VARIABILITY IN RESPONSES TO DIFFERENT ROTATION SYSTEMS FOR SHIFT WORK MIKKO HÄRMÄ Brain@Work Research Center, Finnish Institute of Occupational Health, Helsinki, Finland The changing sleep/activity pattern in night and shift work can cause severe sleep disturbances and other health problems. Most ‘field’ studies on the circadian adaptation to shift work show only a small mean phase delay of the internal body clock during the consecutive night shifts. In individual level, the majority of shift workers are still not able to adjust their circadian rhythms to night work. Differences in individual light exposure during the early morning hours explain a large amount of the individual variation in circadian adaptation, in addition to age, circadian phase (morningness-eveningness) and other factors. Most shift workers thus sleep and work at unfavourable times of their internal circadian rhythms since the timing of the biological clock has a major impact on factors like sleep onset and offset, sleepiness, performance at work and accidents. To remove this mismatch between the internal circadian rhythmicity and sleep/work pattern in shift work, slowly rotating schedules and/or the use of bright light during the consecutive night shifts are often recommended. Although the use of bright light with exact timing can be used to phase-delay the circadian rhythms of permanent night workers, bright light treatments are often not feasible for rotating shift workers. Ageing of the working population is one of the greatest structural changes of the working life during the next decades. According to age, problems with day sleep after the night shifts tend to increase. The curtailment of day sleep and observed decreases in cognitive performance during the night shifts may be related with age-dependent increases in morningness and the slower circadian adjustment during consecutive night shifts, as shown by experimental studies. We have recently done two separate, controlled intervention studies at work settings, which have aimed at reducing sleep problems by minimizing the circadian adaptation and the time needed for recovery after the night shifts. These schedules, which included only one or two consecutive night shifts, proved to be an excellent choice for both sleep and wakefulness, as well as for social and family life of the shiftworkers, compared to earlier schedules with three consecutive night shifts. The very rapidly forwardrotating shift schedules were especially designed for elderly shift workers with the greatest difficulties to adjust to consecutive night shifts. Indeed, the most positive changes in sleep, fatigue and objective performance at work due to the changes in shifts were also found among these older groups. Sleep and Biological Rhythms 2005; 3: A2–A73 S-8. Current concepts in sleep disordered breathing Chairperson: Peretz Lavie (Israel) LINKING METABOLIC SYNDROME AND SLEEP APNEA: MECHANISM & MYTHS RON GRUNSTEIN Woolcock Institute of Medical Research, University of Sydney and Royal Prince Alfred Hospital, Austalia Most patients with obstructive sleep apnea (OSA) are characterised by cental obesity. Accumulating epidemiological data over the past 20 years clearly indicates that central obesity is an integral part of a cluster of conditions associated with adverse health risk, entitled metabolic syndrome (MSynd). Patients with OSA and central obesity appear to be at increased risk of this syndrome. However, it is controversial whether sleep apnea, in the absence of change in body weight will have an impact on MSynd. A number of mechanisms linking MSynd and OSA have been conceptualised including promotion of pro-inflammatory cytokines or adipokines, altered central neurotransmitters or endothelial dysfunction. Prospective epidemiological studies in this area as well intervention studies with CPAP will be reviewed. It is likely that in nonobese patients with obstructive sleep apnea the sleep breathing disorder may contribute to insulin resistance and hypertension components of MSynd but in more obese patients the confounding effects of adiposity dominate the relationship between MSynd and OSA. In the end, a common treatment approach using weight loss with or without specific mechanical treatment for OSA is required. OXIDATIVE STRESS: THE CULPRIT OF SLEEP APNEA SYNDROME LENA LAVIE Lloyd Rigler Sleep Apnea Research Laboratory, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel institute of Technology, Haifa, Israel Obstructive sleep apnea is associated with a higher prevalence of cardiovascular morbidity and stroke than the general population. However, the underlying mechanisms are not entirely understood. This presentation will summarize the evidence that substantiates the notion that the repeated apnea-related hypoxic events, which are the hallmark of sleep apnea, similarly to hypoxia/reperfusion injury, initiate oxidative stress via increased production of reactive oxygen species (ROS). A limited number of studies substantiate this hypothesis directly by demonstrating increased free radical production in leukocytes of patients with OSA. A great number of studies, however, support this hypothesis indirectly by demonstrating an increase in plasma-lipid peroxidation and a decrease in total antioxidant capacity and paraoxonase1 activity. Reactive oxygen species are highly chemically reactive molecules that can damage nucleic acids, proteins and lipids. However, ROS can also act as signaling molecules, notably, activating hypoxiaadaptive (for instance VEGF, erythropoietin) and inflammatory pathways that affect many cellular and molecular mechanisms. Activation of the inflammatory response results in increased expression of inflammatory cytokines such as TNF, IL-6 and IL-8 that further promote activation of endothelial cells, circulating leukocytes and platelets. Activated endothelial cells and circulating leukocytes express higher levels of adhesion molecules of the selectin and integrin families. These facilitate recruitment of leukocytes and platelets to the activated endothelium and further promote endothelial/leukocyte/platelet interactions. These cellular interactions injure the endothelium and by that promote endothelial dysfunction, which is considered the initial step in A11 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 the development of atherosclerosis. These underlying processes could be amplified in sleep apnea patients due to the repeated apneic events, and therefore may increase cardio-cerebro-vascular events. PORTABLE MONITORING FOR OBSTRUCTIVE SLEEP APNEA ANUJA SHARMA Metropolitan Sleep Disorders Center, 255 N. Smith Avenue, Suite 203, St. Paul, MN 55122, USA The percentage of population who are ‘at risk’ of having Obstructive Sleep Apnea (OSA) is high. Because it is expected that the treatment would make a significant difference in quality of life and cardiac morbidity for many of these, there is a steadily increasing demand for investigation. American Academy of Sleep Medicine (AASM) classifies sleep study systems into four categories: level 1-in-laboratory attended full polysomnography (PSG); level 2-attended home sleep study with comprehensive portable devices incorporating the same channels as the inlaboratory standard PSG; level 3-unattended devices that measure at least four cardiorespiratory parameters; and level 4-unattended devices recording one or two parameters. AASM published Practice Parameters for the Use of Portable Monitoring Devices in the Investigation of Suspected Obstructive Sleep Apnea in Adults in 2003. The guidelines concluded that Type 3 devices appeared to be capable of being used in an attended setting to increase or decrease the probability that a patient has an Apnea-hypopnea index >15, and that these devices may be acceptable to both rule in and rule out a diagnosis of OSA, with certain limitations in place. Recommendation was made regarding future research to include decision making and outcomes along with cost effectiveness of the approach. Technological advances have opened up new possibilities for the ambulatory detection of OSA. Peripheral Arterial Tonometry (PAT) records episodic changes in the tone of peripheral vasculature in response to bursts of sympathetic nervous system activation. The obstructive events common to OSA produce arousals from sleep resulting in an increase in sympathetic tone and peripheral vasoconstriction. The Watch Pat 100 (WP) (Itamar Medical) utilizes this technology to assess OSA in the ambulatory setting. Pittman studied 30 patients with suspected OSA, with PSG and WP 100 in lab, and WP100 at home, in random order. Using Chicago criteria, in lab correlation coefficient was 0.88 and ROC-AUC was 0.89–0.95 for RDI cut off of 5–30/h. Comparison between lab and home RDI revealed a correlation coefficient of 0.72. Townsend studied the efficacy and cost savings of ambulatory vs. inlaboratory OSA diagnosis and treatment. Individuals diagnosed at home via PAT did not differ significantly from those having split night polysomnography on measures of PAP compliance, daily functioning and overall satisfaction. The cost savings were significant. Clinicians need to develop algorithms incorporating ambulatory monitoring in investigation of OSA. MORTALITY RISK FACTORS IN MEN WITH SLEEP APNEA: A MATCHED CASE CONTROL STUDY PERETZ LAVIE Ruth and Bruce Rappaport faculty of Medicine, Lloyd Rigler Sleep Apnea Research Laboratory, Technion-Israel Institute of Technology, Haifa-Israel There is a large body of evidence linking obstructive sleep apnea (OSA) with increased cardiovascular morbidity, but there is less information if A12 it is associated with mortality. In this presentation a case-control study of mortality in sleep apnea patients based on a sleep laboratory population will be presented. The study population consisted of adult men studied during 1991–2000 by polysomnography because of suspected OSA. Their vital status was determined by searching the Israel National Population Registry. Cases were defined as men who died prior to 1 September 2001. For each case, a living control matched by year of birth, time and place of sleep examination, and reason for conducting the sleep study, was selected from the study population. The association of demographic, sleep laboratory findings and medical history data with mortality risk was investigated through conditional logistic regression. 14 984 patients were studied because of suspected OSA during the study period, 481 of whom died prior to 1 September 2001. 353 of them (74%) could be matched with controls. The best fitting multivariate model showed that increased risk of mortality was associated with chronic obstructive pulmonary disease (OR: 9.03, 95% CI 3.72, 21.93), chronic heart failure (OR: 4.75, 95% CI 1.17, 19.27), cerebrovascular accident (OR: 4.88, 95% CI 1.30, 18.33), diabetes (OR: 2.96, 95% CI 1.43, 6.14), ischemic heart disease (OR: 1.89, 95% CI 1.08, 3.29) and BMI (OR: 1.66, 95% CI 1.23, 2.25). When models with interactions were fitted, significant interactions were found between apnea-hypopnea-index and BMI and lung disease. Our observations suggest that sleep apnea mainly contributes to mortality by interacting with obesity and chronic obstructive pulmonary disease. Possibly, sleep apnea also contributes indirectly to mortality by its association with cardiovascular morbidities and diabetes that then become the proximal causes of death.To prevent cardiovascular morbidity OSA diagnosis should be made at the youngest age possible. S-9. Evolving concepts of REM sleep: GABA-inhibition, disinhibition or both Chairpersons: Robert McCarley (USA) & Mahesh Thakkar (USA) ANATOMY OF GABAERGIC MACHINERY IN REM SLEEP CONTROL PIERRE-HERVÉ LUPPI, ROMAIN GOUTAGNY, LAURE VERRET, DAMIEN GERVASONI, ROMUALD BOISSARD, DAMIEN LAPRAY, DENISE SALVERT, LUCIENNE LÉGER, CHRISTELLE PEYRON AND PATRICE FORT CNRS UMR5167, Institut Fédératif des Neurosciences de Lyon (IFR 19), Université Claude Bernard Lyon I, 7 Rue Guillaume Paradin, 69372 LYON Cedex 08, FRANCE In the middle of the last century, a series of historical observations lead to the discovery of a sleep phase paradoxically characterized by cortical activation and rapid eye movements and a muscle atonia. Michel Jouvet named this state of sleep, paradoxical sleep (PS) and soon after showed that it was still present in ‘pontine cats’ in which all structures rostral to the brainstem have been removed. Later on, a small region in the dorsal pons named peri-LC by Sakai was shown to be responsible for PS onset. It contains neurons presumably cholinergic specifically active during PS while the raphe and locus coeruleus nuclei contain monoaminergic neurons ceasing firing during PS. It was then proposed that the onset and maintenance of PS is due to a reciprocal inhibitory interaction between these two types of neurons. In the last decade, we tested this hypothesis using a new head restrained rat model and c-Fos staining after PS deprivation and recovery. Our results confirmed that a small region in the dorsal pons named the sublaterodorsal nucleus in Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 rats contains the neurons responsible for the onset and maintenance of PS. They further indicate that (1) these neurons are rather noncholinergic possibly glutamatergic neurons (2) they directly project to the glycinergic premotoneurons localized in the ventral and lateral medullary reticular formation (3) the main neurotransmitter responsible for their inhibition during W and SWS is GABA rather than monoamines (4) they are constantly and tonically excited by glutamate and (5) the GABAergic neurons responsible for their tonic inhibition during W and SWS are localized at the border of the ventrolateral periaqueductal gray and the mesencephalic reticular formation. During the same period, we also showed combining bicucculine applications on LC noradrenergic and dorsal raphe serotonergic neurons and unit recordings in head restrained rats that GABA is responsible for the tonic inhibition of monoaminergic neurons during PS. Our study combining injection of CTb as a retrograde tracer with C-Fos labeling after PS rebound further suggests that the GABAergic neurons responsible for such inhibition are localized in the dorsal paragigantocellular reticular nucleus and/or the ventrolateral periaqueductal gray. Altogether our results indicate the existence of two types of GABAergic neurons, respectively, active and inactive during PS with therefore opposite effects on PS onset and maintenance. ROLE OF GABA IN LC AND PPT IN THE REGULATION OF REM SLEEP IN RATS BIRENDRA N MALLICK School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India During REM sleep the neurons in the locus coeruleus (LC) cease firing, the REM-OFF neurons, while those in the pedunculo-pontine area (PPT) increase firing, the REM-ON neurons. A close interaction between these sets of neurons has been proposed1,2. We conducted series of studies to investigate the chemical nature of the neurotransmitters possibly involved in mediating inhibition of those REM-sleep related neurons for the regulation of REM sleep. The objective of our study was to confirm our earlier proposed model3,4 that GABA may be acting on the REM sleep related neurons in LC and PPT for the regulation of REM sleep. The studies were conducted on freely moving normally behaving male wistar rats (250–280 gs) maintained under 12 : 12 L : D cycle and with food and water ad lib. Under surgical anaesthesia rats were prepared for sleep-waking recording. Additionally, guide cannulae were bilaterally implanted so that microinjection could be done locally either in the LC or PPT. After recovery from surgical trauma baseline sleepwaking recordings were taken in freely moving rats. Thereafter, 200–250 nL either agonist or antagonist of GABA, acetylcholine or noradrenaline was bilaterally microinjected alone or in combination and the effects on sleep-waking recorded. Saline was injected at the same site as control and recording continued. GABA-ergic and cholinergic agonist individually into the LC increased, while their antagonist decreased REM sleep. Injection of combination of agonist of one and antagonist of the other showed that the effect of GABA-ergic agonist or antagonist prevailed. In PPT, agonist and antagonist of GABA-ergic increased and decreased, respectively, while noradrenergic antagonist increased REM sleep. A combination of these agonist and antagonist apparently did not affect REM sleep significantly. These results suggest that in the LC the cholinergic input is mediated through the GABA-ergic neuron, while in the PPT the GABAergic inputs act presynaptically on the noradrenergic inputs for REM sleep regulation. Based on these results a model showing interplay of neurotransmitters in the LC and PPT that enhances our understanding about the generation and regulation of REM sleep will be presented. Sleep and Biological Rhythms 2005; 3: A2–A73 References 1. Hobson JA et al. Science 189 (1975) 55–8. 2. Sakai K. Arch. Ital. Biol. 126 (1988) 239–57. 3. Alam N et al. Sleep Res. 22 (1993) 541. 4. Mallick et al. In: Rapid Eye Movement Sleep (Mallick BN and Inoue S, eds) Marcel Dekker, 1999, pp. 153–66. Research supported by funding from CSIR, DBT, DST, ICMR and UGC GABA: INHIBITION AND/OR DISINHIBITION IN REM SLEEP CONTROL? ROBERT W MCCARLEY, RITCHIE BROWN AND MAHESH THAKKAR Department Psychiatry, Harvard Medical School and VA Boston Healthcare System, Brockton, MA 02301 USA In the 60 years since the discovery of REM sleep, our understanding of the REM sleep control system has advanced significantly. Strong evidence indicates that the brainstem contains the REM sleep generator. A current empirically supported theory suggests that the mesopontine cholinergic neurons (LDT/PPT) are the source of the cholinergic innervation to the REM sleep ‘effector zone’ within the pontine reticular formation (PRF). Electrophysiological studies revealed two major subpopulations of LDT/PPT neurons, one that preferentially discharges just before and during REM sleep (REM-on) and the other that is predominantly active during both wakefulness & REM sleep (W/REM-on). With respect to control of mesopontine cholinergic activity, we have suggested that the monoaminergic locus coeruleus (LC) and dorsal raphe (DRN) neurons might suppress REM sleep by inhibiting the REMon neurons, without affecting the wake/REM-on neurons. It should be noted that the both LC and DRN exhibit a pattern of discharge activity that is opposite to that of the LDT/PPT REM-on neurons, i.e. waking > non-REM > REM sleep. In addition to the monoamines and acetylcholine as modulators of REM sleep, there is accumulating evidence that GABAergic influences may also play an important role. Experimental data implicate GABA in inhibiting REM-off monoaminergic neurons. On the other hand, other data suggest that GABA may inhibit the PRF REM sleep ‘effector’ neurons. We suggest that, during REM sleep, GABAergic PRF interneurons may be inhibited by LDT/PPT cholinergic inputs, thereby disinhibiting the PRF ‘effector’ neurons. We have performed microdialysis sampling and measured GABA from the mPRF in freely behaving cats during behavioral states. The lowest level of GABA was observed during REM sleep. Perfusion of carbachol induced a REM-like state and simultaneously reduced GABA release. In vitro studies performed in our lab are in agreement with the in vivo data and support our hypothesis. A subpopulation of neurons recorded in vitro from the subcoerulean reticular formation of rat brain was inhibited by carbachol. These neurons had short action potentials and a prominent low-threshold calcium spike which triggered between one and four fast action potentials on the rebound from hyperpolarizing pulses. Preliminary immunohistochemistry data using GAD67 indicates that these cells are GABAergic. Thus, we suggest, the GABAergic neurons have a dual role in REM sleep control: they inhibit the monoaminergic REM-off neurons and disinhibit the PRF ‘effector’ neurons. Financial support: US National Institute of Health MH39683 and MH01798; Department of Veterans Affairs. A13 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 S-10. Molecular Biology of Sleep Chairperson: Peter Shiromani (USA) CRITERIA FOR CLASSIFYING GENES AS ‘SLEEP’ OR ‘WAKE’ GENES PRIYATTAM J SHIROMANI, CARLOS BLANCO-CENTURION AND DMITRY GERASHCHENKO West Roxbury VA and Harvard Medical School A number of recent studies have identified that specific genes are expressed during sleep-wake states. We propose that in order for these data to be of heuristic value it is necessary to define a set of criteria for labeling a gene as a ‘wake gene’ or a ‘sleep gene’. We suggest that for a particular gene to be classified as a ‘sleep’ or ‘wake’ gene it should satisfy each of these criteria, from the most general (criterion 1) to the most stringent (criterion 6). Using microarray methods, a number of genes have been found to oscillate with sleep (criterion 1) and deletion of some (such as hypocretin) also affects behavioral state (criterion 5). For each of these genes, it is necessary to satisfy the other criteria so that the function of the gene in the sleep process may be fully understood. 1. Gene and protein expression are associated with a specific behavioral state (i.e. wakefulness, SWS or REM) independent of circadian time. It is possible that the expression of the gene occurs in one state, for instance, wakefulness, and the protein product may occur during sleep. 2. Gene and its protein product are expressed in cell type(s) implicated in behavioral state control. Although, gene expression has been noted in the cortex, are these genes expressed in neurons implicated in behavioral state regulation? 3. Feedback loops involving positive and negative elements control transcription/translation of specific genes. 4. These loops are activated by action of putative sleep factors (neurotransmitters, adenosine, prostaglandin D2, etc.) onto specific receptors. 5. Manipulation of gene (mutation/knockout/knockin/inducible) has a distinct and predictable effect on the behavioral state. The evidence is strongest for hypocretin/orexin as a ‘wake’ gene. 6. Evolutionary conservation of gene/protein across species that sleep. SLEEP AND PROTEIN TRANSLATION NIRINJINI NAIDOO Center fro Sleep and Respiratory Neurobiology, University of Pennsylvania Sleep is purported to be a multifunctional phenomenon. One of the commonly accepted functions of sleep is to restore and replenish cellular components. Consistent with this, is the idea that protein translation is one of those processes that is up-regulated during sleep. Several brain transcript studies support the involvement of sleep in protein translation and in complementary aspects of synaptic plasticity. Sleep has been associated with increased mRNA levels of key components of the translational machinery, offering molecular support for the observation that brain protein synthesis as measured by amino acid incorporation in both rats and monkeys is increased during NREM sleep. Additionally, sleep deprivation studies indicate that protein translation is attenuated during extended wakefulness. Data from microarray, protein and proteomic studies provide evidence that there is a general decrease in protein translation during wakefulness. Using a sleep deprivation model in mice we investigated changes in protein translation; the mechanisms of translational control in sleep and wakefulness will be discussed. A14 CELLULAR AND MOLECULAR SUBSTRATE FOR THE SLEEP-DEPENDENT MEMORY PROCESSING SUBIMAL DATTA Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, Bldg. M-902, 715 Albany Street, Boston, Massachusetts 02118, USA The idea that rapid eye movement (REM) sleep is important in processing memory traces acquired during wake has received considerable experimental support. However, the mechanisms underlying this REM sleep-dependent memory consolidation process are relatively unknown. Our recent studies have demonstrated that the REM sleep-dependent memory processing of the two-way active avoidance learning (TWAA) depends on the activation of the pontine wave (P-wave) generator (Datta 2000; Datta et al. 2004; Mavanji et al. 2004). The present study explored possible physiological and molecular mechanisms of REM sleep-dependent memory processing in the rat using a TWAA learning paradigm. The results show that learning training increased REM sleep and activated brainstem cells in the P-wave generator. During this period, there was a time-dependent increase in phosphorylation of cAMP response element binding protein (pCREB) in the dorsal hippocampus and amygdala, increased synthesis of activity regulated cytoskeletal associated protein (Arc) in the dorsal hippocampus, amygdala, frontal cortex, and occipital cortex. Learning training also increased synthesis of brain derived nerve growth factor (BDNF) in the occipital cortex, amygdala, and dorsal hippocampus at different time intervals. During this time, we did not see any changes in the levels of nerve growth factor (NGF) in these brain areas. These results suggest that REM sleep-dependent memory processing of TWAA learning involves excitation of P-wave generating cells in the brainstem, activation of transcription factor pCREB, and increased expression of downstream genes, Arc and BDNF, in a time-dependent manner in the forebrain. These dynamic changes in cellular and molecular features provide considerable insight into the mechanisms of the REM sleep-dependent memory consolidation process. References Datta S. Avoidance task training potentiates phasic pontine-wave density in the rat: a mechanism for sleep-dependent plasticity. J. Neurosci. 2000; 20: 8607–13. Datta S, Mavanji V, Ulloor J, Patterson EH. Activation of phasic pontinewave generator prevents rapid eye movement sleep deprivationinduced learning impairment in the rat: a mechanism for sleep-dependent plasticity. J. Neurosci. 2004; 24: 1416–27. Mavanji V, Ulloor J, Saha S, Datta S. Neurotoxic lesions of phasic pontine-wave generator cells impair retention of 2-way active avoidance memory. Sleep 2004; 27: 1282–92. S-11. Humoral Mechanisms of Sleep Control Chairpersons: Robert W. McCarley and Radhika Basheer (USA) PHYSIOLOGICAL AND MOLECULAR STUDIES OF ADENOSINE IN SLEEP CONTROL ROBERT W MCCARLEY, VIJAY RAMESH AND RADHIKA BASHEER Department Psychiatry, Harvard Medical School and VA Boston Healthcare System, Brockton, MA 02301 Previously we have shown that the levels of extracellular adenosine increase during waking in the wake-active cholinergic basal forebrain Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 (CBF) leading to increased sleepiness, compatible with a role of adenosine as an endogenous sleep factor. A mechanism for the sleep inducing effects of adenosine was found in the adenosine A1 receptor mediated-hyperpolarization of the wake active neurons, an effect that was mediated by an inwardly rectifying K + conductance in cholinergic neurons and by the blockade of the hyperpolarization-activated current (Ih) in presumptively GABAergic neurons. In addition to the immediate inhibitory effects, recent data lead us to hypothesize that adenosine also acts a mediator of the long-term effects of sleep deprivation. Prolonged sleep deprivation results in a selective accumulation of extracellular adenosine in cholinergic basal forebrain. Our molecular studies have shown that a high level of adenosine induced by sleep deprivation, acting via the A1 adenosine receptor, induces an intracellular cascade. This cascade includes IP3 receptor-mediated endoplasmic reticulum mobilization of intracellular calcium in cholinergic neurons; this, in turn, induces nuclear translocation of transcription factor NF-kB in cholinergic neuron (review in Basheer et al. 2004). We hypothesized that a sleep deprivation-induced increase in extracellular adenosine and transcriptional activation of NFkB might play a role in mediating the long-term effects of sleep deprivation, such as increased sleepiness and decreased attention. One such target of NF-kB activation is the A1 receptor itself and we found A1 mRNA to be up-regulated with sleep deprivation. To determine if nuclear translocation of NF-kB was essential for the up-regulation of A1 mRNA, nuclear translocation of NF-kB was blocked by injecting an inhibitor peptide, SN50, into cholinergic basal forebrain of rats prior to sleep deprivation. A1R mRNA levels increase following 3 and 6 h of SD without any change in the receptor density when compared to undisturbed sleeping controls. However, detectable changes in A1R protein may require longer SD periods. We thus examined the changes in: (a) membrane receptor density by using 3H-DPCPX receptor autoradiography of brain sections following 12 and 24 h of SD; (b) total A1R protein (membrane + cytoplasmic stores) using Western blotting of rat CBF & cingulate cortex homogenates following 6 and 12 h SD. The membrane receptor density showed a trend-level increase following 12 h SD & a more profound and statistically significant increase after 24 h SD (P < 0.04, N = 6). Whereas the total A1R protein levels first decreased (–29%, P < 0.05; N = 6) following 6 h SD, they increased to control levels following 12 h SD. All experiments showed no cingulate cortex changes. Together these results suggest that, initially, an increase in extracellular adenosine may result in extensive receptor internalization and subsequent degradation, a process accompanied by an immediate replacement of the membrane receptors from the cytoplasmic reserves. This maintains the membrane receptor density but decreases the total A1R protein following 6 h SD. The increase in mRNA results in increased A1R translation and production of receptor protein by 12 and 24 h SD. This A1R up-regulation would have the functional effect of increasing the sensitivity of the cell to extracellular adenosine, and hence increasing the inhibitory influence and the propensity to sleep for a given extracellular AD level, a resetting of the homeostatic set point. References 1. Basheer R, Strecker RE, Thakkar MM, McCarley RW (2004) Adenosine and sleep-wake regulation. Progress in Neurobiol. 73: 379–96. 2. Porkka-Heiskanen T, Strecker RE, Thakkar M, Bjorkum AA, Green, RW, McCarley RW (1997) Adenosine: A mediator of the sleepinducing effects of prolonged wakefulness. Science 276: 1265–8. Supported by NIMH 39683 (RWM) and a VA Medical Research Service Award (RB). Sleep and Biological Rhythms 2005; 3: A2–A73 NON-REM SLEEP HOMEOSTASIS MEDIATED BY PROSTAGLANDIN D2-ADENOSINE SYSTEM YOSHIHIRO URADE Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565–0874, Japan Here, we introduce our recent progress in the research of sleep regulation by humoral prostaglandin D2 (PGD2) and adenosine. PGD2 is a potent endogenous somnogen that is synthesized by PGD synthase (PGDS) predominantly localized in the leptomeninges and in oligodendrocytes. PGD2 is secreted into the cerebrospinal fluid, circulates within the brain as a sleep hormone, and binds to DP receptors (DPR) localized in the arachnoid membrane on the surface of the basal forebrain. The DPR activation increases adenosine concentration in the subarachnoid space of the basal forebrain, transmitting the sleep-inducing signal to the brain parenchyma. Intracerebroventricular administration of agonists for DPR or adenosine A2A receptors (A2AR), but not A1 receptors, induces non-REM sleep and increases the expression of fos protein in the ventrolateral preoptic (VLPO) area, a sleep center. The activation of VLPO neurons suppresses the activity of the histaminergic tuberomammillary nucleus(TMN), an arousal center, through GABAergic inhibitory projections to induce non-REM sleep. We believe that the interaction between VLPO and TMN plays a key role in the non-REM sleep induction by PGD2 and adenosine. We also assessed the contribution of the PGD2-adenosine system to the homeostatic regulation of non-REM sleep after sleep deprivation (SD) by using geneknockout (KO) mice for PGDS, DPR and A2AR. Wild type mice showed strong rebound of both non-REM and REM sleep after SD in a SD-time dependent manner. The PGDS, DPR and A2AR-KO mice, however, did not show any rebound of non-REM sleep after SD. These results clearly demonstrate that the PGD2-DPR-adenosine- A2AR system is crucial for the homeostatic regulation of non-REM sleep. ROLE OF OREXINS IN SLEEP-WAKEFULNESS REGULATION MAHESH THAKKAR Department of Psychiatry, Harvard Medical School & Boston VA HealthCare system, Brockton, MA, 02301 In the past 7 years convincing evidence has implicated orexin/hypocretin neurons of the perifornical region in the lateral hypothalamus (PFH) in the regulation of sleep-wakefulness. The importance of orexins in sleep-wake regulation became evident following orexin’s link to narcolepsy. Abnormalities in the orexin-type II receptor gene have been identified as the basis of inherited narcolepsy in dogs. Constitutive orexin peptide, and/or orexin receptor knockout mice (–/–) have increased REM sleep and cataplexy-like episodes that are entered directly from states of active movement. Narcoleptic humans have undetectable levels of orexin in CSF whereas the brains of narcoleptic patients have a significant loss of orexin neurons. Increased REM sleep and spontaneous cataplexy-like episodes were also reported in rats with a targeted destruction of orexin-receptor expressing neurons in the PFH and in transgenic mice and rats in which orexin neurons are ablated by orexinergic-specific expression of ataxin-3. Single-unit recording studies from the PFH found a substantial proportion of units that showed the pattern of W > > nonREM > REM discharge. Thus, a reduction or loss of orexinergic tone leads to an increase in REM sleep coupled with cataplexy. In contrast, application of orexins, either intracerebrally or locally increases wakefulness. Although the just cited studies have provided much insight, there are many unanswered questions. What are the anatomical/neurochemical substrates mediating orexin’s action on wakefulness and REM sleep? Is A15 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 orexin necessary for controlling the intracycle events of the wakenonREM-REM sleep cycle or is it a consolidating factor shaping the diurnal (circadian) phase of occurrence of REM sleep? Our laboratory has utilized novel technologies to answer some of these questions. Using reverse microdialysis, we locally perfused antisense oligonucleotides against orexin-type II receptor mRNA into the subcoerulean reticular (SubC) region of the brainstem and found a significant increase in REM sleep and spontaneous cataplexy-like episodes in freely behaving rats. We used reverse microdialysis application of orexin-A in the cholinergic zone of the basal forebrain and found a significant increase in wakefulness. Recently, we have used RNA mediated interference to suppress preproorexin gene expression and our preliminary data suggested that orexin may be involved in diurnal control of REM sleep. S-12. Recent Views and Concepts on Neurobiological Mechanisms of REM Sleep CYTOKINE–HPA INTERACTIONS AND THE REGULATION OF SLEEP It has been known for many years that the cholinergic system of the brainstem is involved in generating REM sleep (Datta 1995). This knowledge was based upon the observation that microinjection of cholinergic agonists into the pontine reticular formation induces a state which is behaviorally and electrophysiologically similar to REM sleep. Anatomical studies have shown that the major sources of cholinergic input to the cholinoceptive REM sleep-inducing sites are the pedunculopontine tegmentum (PPT) and laterodorsal tegmentum (LDT). Single cell recording studies in the cat and rat have shown that the majority of PPT cells are more active during REM sleep than during slow-wave sleep. For the last 10 years, our major goal has been to understand the cellular and molecular mechanisms for how PPT cell activity is regulated to turn-on and turn-off REM sleep. To understand these mechanisms we have used a number of cellular, pharmacological, and molecular approaches. First, we recorded single cell activity patterns of the PPT cells in the behaving cat and rat across the sleep-wake cycle. Second, using a chemical stimulation technique, we activated the cholinergic cell compartment of the PPT at different levels to turn-on and turn-off REM sleep. Third, we used different neurotransmitter receptor-specific agonists and antagonists to identify the receptor types involved in activation and inhibition of the PPT cells. Recently, we began to study PPT intracellular signal transduction pathways involved in the receptor activation-mediated regulation of REM sleep. The results of our single cell recordings and chemical stimulation studies suggest that a 30% level of activity within the cholinergic cell compartment of the PPT triggers REM sleep. To maintain REM sleep, the activity level should remain between 30% and 70% otherwise REM sleep terminates. Our results also demonstrate that activation of kainate receptors within the cholinergic cell compartment of the PPT induces both spontaneous and glutamate-induced REM sleep, activation of GABA-B receptors in the cholinergic cell compartment of the PPT suppress REM sleep by inhibiting REM-on cells, and that both kainate and GABA-B receptors on the PPT cells convey their message via a cAMPdependent second messenger pathway to regulate normal REM sleep. Reference Datta S. Neuronal activity in the peribrachial area: relationship to behavioral state control. Neurosci. Biobehav. Rev. 1995; 19: 67–84. Financial disclosure: This work was supported by National Institutes of Health Research Grants MH59839 and NS34004. MARK R OPP, PH.D. Departments of Anesthesiology and Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109 Sleep is altered in response to stressors of different modalities. Responses to psychosocial stressors, i.e. those stressors that do not include tissue injury, infection, or trauma, are characterized by sleep disruption and increases in the amount of wakefulness. The major, although not only, mediator in brain of acute responses to stressors is corticotropin-releasing hormone (CRH). CRH is a powerful inducer of cortical arousal and electroencephalo-graphically (EEG)-defined wakefulness. As such, any stimulus that alters basal CRH concentrations has the potential to increase wakefulness and disrupt sleep. Recent data suggest that a CRH-related peptide, urocortin 2, also increases EEGdefined waking and may be responsible for increases in REM sleep that follow exposure to some stressors. Immune activation is a different type of stressor that also alters sleep, i.e. sleep is altered during sickness. Cytokines, protein mediators of immune responses, are now known to be expressed within the CNS. Some cytokines, such as interleukin-1 (IL-1) are likely mediators of infection-induced alterations in sleep because when administered into normal animals they increase nonrapid eye movement (NREM) sleep. Early in the course of an immune challenge there are periods during which NREM sleep is enhanced. Often, this period of NREM sleep enhancement is followed by sleep suppression. Because cytokines are known to induce CRH and the HPA axis, we previously hypothesized that interactions between CRH and IL-1 are responsible for the complex changes in arousal state during immune challenge. We will present data in this symposium indicating that interactions between IL-1 and CRH are of functional relevance to arousal state regulation, in the absence of overt stressors. These initial studies have been extended to incorporate interactions between IL-1 and IL-6. We will present data suggesting that IL-6 is capable of altering arousal state, and that mice lacking a functional IL-6 gene respond to immune challenge differently than control animals. Collectively, data we present will support the hypothesis that interactions within the CNS between cytokines and neurotransmitters are important determinants of behavioral outcome. Acknowledgements: The excellent technical assistance of Dr Jonathon Morrow, Ms. Jill Priestley, Ms. Jamee Bomar, and Ms. Melissa Olivadoti is acknowledged. This research supported in part by the National Institutes of Health: MH52275, MH56873, MH54976, MH62644, HL080972. A16 Chairperson: Subimal Datta (USA) MECHANISMS FOR REM SLEEP REGULATION: ROLE OF THE CHOLINERGIC CELL COMPARTMENT OF THE PEDUNCULOPONTINE TEGMENTUM SUBIMAL DATTA Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, Bldg. M-902, 715 Albany Street, Boston, Massachusetts 02118, USA Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 REM SLEEP AND THE SEROTONERGIC SYSTEM: WHAT WE LEARN FROM MUTANT MICE JOËLLE ADRIEN UMR677-INSERM/UPMC, Faculté de Médecine Pitié-Salpêtrière, 91 Bd de l’Hôpital, 75013 Paris – France A growing number of studies have used mice bearing a mutation of genes coding for various proteins with the aim of investigating sleepwakefulness mechanisms. With this approach, we have focused on 5HT neurotransmission and explored sleep regulations under various conditions (pharmacology and acute stress) in knock-out or transgenic mice that do not express either the serotonin transporter (5-HTT), the catabolism enzyme of serotonin, monoamine oxydase A (MAO-A), the receptors of the 5-HT1A, 5-HT1B, 5-HT2A, or both the 5-HT1A and 5-HT1B types. Mice lacking the 5-HTT-/–, the 5-HT1A, 5-HT1B, or both the 5HT1A and 5-HT1B receptors, exhibited enhanced amounts of REM sleep, an effect that could be reproduced by pharmacological blockade of these receptors in wild-types. In 5-HTT knock-out mice, the tonic facilitation of REM sleep is due, at least in part, to desensitization of mainly 5-HT1A receptors triggered by the excessive serotonin levels in the extracellular space consecutive to absence of reuptake. Such adaptation most probably builds up during early postnatal development, since it can be (i) prevented in 5-HTT-/– mutants by neo-natal treatment with a serotonin synthesis inhibitor or an antagonist of 5-HT1A receptors, and (2) induced in wild-type mice by neo-natal treatment with a serotonin reuptake inhibitor. In contrast to the previous mutants, MAO-A transgenic mice exhibited decreased REM sleep, associated with an enhanced response to 5-HTT blockade. Finally, 5-HT2A-/– mutants, expressed more wakefulness and less SWS than wild-types. These effects could not be reproduced by 5-HT2A blockade in wild-types, a paradox that can be explained partly by functional adaptations of 5-HT2B receptors in these mutants. In addition, all mutant mice studied here failed to exhibit the classical REM sleep rebound observed normally after an acute stress challenge. This lack of adaptive response to stress paralleled an enhanced and sustained secretion of corticosterone after the challenge. Thus, serotonergic neurotransmission impairment interacts with the Hypothalamo-Pituitary Axis to modulate REM sleep amounts. To conclude, in constitutive knock-outs, adaptive processes involving other proteins than those coded by the invalidated gene occur, which render the interpretation of the corresponding sleep phenotype difficult. Inducible knock-outs will probably help to overcome this difficulty. On another hand, the fact that early life treatment with compounds aiming at controlling 5-HT neurotransmission has a long-trem/permanent effects on sleep-wakefulness regulations should get attention, notably in the clinical field. ROLE OF NEUROTROPHINS IN THE CONTROL OF RAPID EYE MOVEMENT (REM) SLEEP YAMUY J, BORDE M, XI M, FUNG SJ, SAMPOGNA S, RAMOS O, TORTEROLO P AND CHASE MH Department of Physiology, UCLA School of Medicine, Los Angeles, CA, 90095 and Websciences International, Los Angeles, CA, 90024 Neurotrophins are endogenous polypeptides that have been classically implicated in mechanisms of survival and differentiation of neurons. During the past decade, a wealth of data has been developed demonstrating that, in addition to their trophic actions, neurotrophins are capable of modulating the activity of neurons. We have shown that the microinjection of nerve growth factor (NGF), the prototypical neu- Sleep and Biological Rhythms 2005; 3: A2–A73 rotrophin, into the nucleus pontis oralis (NPO) of the intact cat rapidly induces long-lasting episodes of REM sleep. Based upon this finding, we hypothesized that NGF is an endogenous neuromodulator that acts, in conjunction with cholinergic mechanisms, on NPO neurons that are responsible for the generation and maintenance of REM sleep. A multidisciplinary approach was employed to test the preceding hypothesis. First, immunohistochemical experiments were conducted to determine the existence of neurons that contain neurotrophins and/or neurotrophin receptors in regions that are involved in the generation of REM sleep. We were also interested in determining whether neurotrophin- or neurotrophin receptor-containing neurons are active, as determined by their expression of c-fos, during prolonged REM sleeplike states. Second, behavioral states were monitored prior to, during, and following the application of neurotrophins, a neurotrophinreceptor blocker, and antisense directed against NGF mRNA. Finally, in in vivo and in vitro experiments, neurons in the NPO were recorded intracellularly prior to and following the juxtacellular application of neurotrophins and a neurotrophin blocker. The results of the immunohistochemical studies indicate that neurons in the latero-dorsal and pedunculo-pontine tegmental nuclei (LDT and PPT, respectively) contain neurotrophins. In addition, neurons in the NPO exhibit high- and low-affinity neurotrophin receptors; a large portion of these neurons expressed Fos during neurotrophin-induced REM sleep. The microinjection of K-252a, a high-affinity neurotrophin receptor blocker, into the NPO suppressed the ocurrence of neurotrophin-induced REM sleep; NGF antisense injected into the LDT produced a significant decrease in the time spent in natural REM sleep. Finally, the juxtacellular microapplication of NGF depolarizes and increases the rate of discharge of a subpopulation of NPO neurons; this effect is blocked by K-252a. In toto, these data strongly support the concept that NGF and/or NT3 act, through their high-affinity receptors, as endogenous modulators of the processes that promote the occurrence of REM sleep. This work was supported by NIMH grant MH59284. ENHANCEMENT OF REM SLEEP IN THE RAT THROUGH A VARIETY OF MANIPULATIONS OF THE PONTINE RETICULAR FORMATION GERALD A MARKS Department of Psychiatry, University of Texas South-western Medical Center, Dallas, Texas 75390, USA A region of the pontine reticular formation has been identified as a REM sleep induction zone based mainly on pharmacological studies in the cat. Studies in the rat are uncovering similar, but not identical, mechanisms implicating the nucleus pontis oralis (PnO) of the pontine reticular formation in the long term control over the propensity to express REM sleep and wakefulness. Cholinergic, adenosinergic, GABAergic and other systems have been investigated giving rise to a model of intrareticular mechanisms underlying control of arousal states. Behavioral pharmacology utilizing small-volume intracerebral microinjection into the PnO of freely moving rats implicates a variety of systems capable of inducing long-lasting increases in the expression of REM sleep. As in cat, cholinergic agonists increase REM sleep, but parameters of effective injections and of the alterations in state produced can be greatly different between these species. Several other mechanisms investigated require muscarinic receptors for their action and are thus implicated in presynaptic control of acetylcholine release. The action of adenosine to increase REM sleep through its A1 receptor subtype is resistant to muscarinic receptor blockade and appears to be a mechanism acting in PnO that is independent of the cholinergic system. A17 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 The long-lasting (>8 h) effects on REM sleep following single microinjections indicate that the injected agents are initiating processes that continue on after the agents have diffused away. Involvement of several G-protein coupled receptors implicates mediation by intracellular mechanisms. One of these mechanisms is a reduction in cAMP formation. Injection of a cell permeant inhibitor of adenylyl cyclase in PnO results in a long-lasting increase in REM sleep similar to that produced by injecting cholinergic and adenosinergic agonists. Alterations in intracellular levels of cAMP can have many consequences on cellular function and could result in changes in the network properties of the reticular formation important for state control. Research supported by NIH grant MH57434. S-13. Sleep, Breathing and Hormones Chairperson: Prof. Olli Polo (Finland) FEMALE HORMONES AND SLEEP-DISORDERED BREATHING TARJA SAARESRANTA University of Turku, Sleep Research Unit, Turku, Finland Number of hormones contribute control of breathing (Saaresranta & Polo 2002 and 2003). Obstructive sleep apnea syndrome has a male predominance. This suggests a protective effect of female hormones and/or causative role of androgens in the pathogenesis of sleepdisordered breathing (SDB). SDB is more prevalent also in patients with polycystic ovary syndrome and after menopause. This presentation focuses on the role of estrogen and progesterone in the pathophysiology and treatment of SDB. Sex steroid receptors are located also in the central nervous system in the areas related to control of breathing. Sex steroids act directly or via neuromodulatory systems but also peripherally contributing to upper airway patency. Progesterone is a powerful respiratory stimulant and estrogen up-regulates progesterone receptors. Although snoring is common during pregnancy, high levels of estrogen and progesterone protect pregnant women from SDB. However, pre-existing SDB may deteriorate in obese pregnant women. Partial upper airway obstruction during sleep is common in pre-eclampsia and is associated with increased systemic blood pressure. Epidemiological studies show lower prevalencies of SDB in postmenopausal hormone therapy users than in nonusers (Shahar et al. 2003). SDB with low apnea-hypopnea index (AHI) predominates in women. However, women are symptomatic with lower AHI than men. This is likely due to high prevalence of partial upper airway obstruction in women resulting in low AHI with increased carbon dioxide levels. Nasal CPAP is the treatment of choice for SDB. Estrogen and progestins may have a role as a second line treatment in selected postmenopausal women (Manber et al. 2003, Saaresranta et al. 2001 and 2003) but the risks of hormone therapy need to be carefully considered and further studies are needed. References Manber R, Kuo TF, Cataldo N et al. The effects of hormone replacement therapy on sleep-disordred breathing in postmenopausal women: a pilot study. Sleep 2003; 26: 163–8. Saaresranta T, Polo-Kantola P, Rauhala E et al. Medroxyprogesterone in postmenopausal females with partial upper airway obstruction during sleep. Eur. Respir. J. 2001; 18: 989–95. Saaresranta T, Polo O: Hormones and breathing. Chest 2002; 122: 2165–82. A18 Saaresranta T, Polo O. Sleep-disordered breathing and hormones. Eur. Respir. J. 2003; 22: 161–72. Saaresranta T, Aittokallio T, Polo-Kantola P et al. Effect of medroxyprogesterone on inspiratory flow shapes during sleep in postmenopausal women. Respir. Physiol. Neurobiol. 2003; 134: 131–43. Shahar E, Redline S, Young T et al. Hormone-replacement therapy and sleep-disordered breathing. Am. J. Respir. Crit. Care Medical 2003; 167: 1186–92. Financial Disclosure: Supported by Turku University Central Hospital. IMPACT OF TESTOSTERONE AND GROWTH HORMONE ON SLEEP AND BREATHING RON GRUNSTEIN Woolcock Institute of Medical Research, University of Sydney and Royal Prince Alfred Hospital, Australia Obstructive sleep apnea (OSA) is characterised by sleep fragmentation and intermittent hypoxemia. These pathophysiological changes are known to affect neurobiological function including neuroendocrine parameters. A number of studies have shown that OSA is associated with impaired anabolic hormone (testosterone and growth hormone (GH)) output. In turn, these hormonal changes may predispose individuals with obstructive sleep apnea to worsening central obesity and muscle function. Interestingly, conditions characterised by an excess of endogenous or use of exogenous testosterone and GH have been linked to OSA. In women, the polycystic ovary syndrome is linked to OSA and over 60% of patients with acromegaly, an excess of GH production, have OSA. Use of exogenous testosterone is becoming increasingly frequent, especially in older subjects. Recent data indicating that testosterone may exacerbate sleep apnea suggest caution in use in patients with sleep breathing disorders. S-14. Brainstem networks for respiratory control: relevance for sleep-related breathing disorders Chairperson: David W. Carley (USA) and Miodrag Radulovacki (USA) ANATOMY AND PHYSIOLOGY OF THE VENTRAL RESPIRATORY COLUMN DONALD R MCCRIMMON AND GEORGE F ALHEID North-western University, Feinberg School of Medicine, Chicago, IL USA Pontomedullary circuits controlling respiratory motoneurons are usually summarized as several distinctive neuronal clusters, including the dorsal respiratory group (in the nucleus of the solitary tract), a ventral respiratory column (VRC; in the ventrolateral medulla; extending from the facial nucleus caudally following the motoneurons of nucleus ambiguus), and a pontine respiratory group – associated with portions of the parabrachial nuclear complex. On the other hand, tracer injections in the VRC retrogradely label an essentially continuous, lateral column of neurons stretching from the most rostral levels of the pons to caudal portions of the medulla. This pattern of labeling is consistent with physiological experiments that have identified respiratoryrelated neuronal compartments at practically every level of the rhombencephalon. Distinctive rhombencephalic respiratory-related compartments are segregated rostro-caudally by the functional and phasic-firing Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 characteristics of their component neurons. In the VRC, excitatory expiratory propriobulbar-projecting neurons, are (likely) located adjacent and/or ventral to the facial nucleus (Janczewski et al. 2002). These cells, which appear to drive the expiratory rhythm, are succeeded caudally by mainly inhibitory expiratory neurons in the Bötzinger complex. These are followed by mainly excitatory inspiratory propriobulbar neurons in the preBötzinger complex (pBC), among which are found pacemaker neurons and/or microcircuits responsible for the generation of inspiratory rhythm. Caudally, the pBC segues into an anterior part of the rostral ventral respiratory group (arVRG) in which a substantial number of inhibitory inspiratory propropriobulbar neurons are located (Alheid et al. 2002). These are gradually replaced posteriorly (i.e. posterior part of the rostral VRG; prVRG) by mainly excitatory, inspiratory spinal projecting premotor neurons which are, in turn, replaced by mainly excitatory, expiratory spinal projecting premotor neurons. While anatomical and physiological borders between these various compartments are not sharply drawn, data emanating from the application of increasingly refined neurochemical and neurohistochemical methods generally reinforce the existence of these functionally defined rhombencephalic respiratory compartments and to some extent relate them to their ontogeny in the rhombomeres of the embryonic vertebrate brain. References Alheid GF, Gray PA, Jiang MC, Feldman JL, McCrimmon DR. Parvalbumin in respiratory neurons of the ventrolateral medulla of the adult rat. J. Neurocytol. 2002; 31: 693–717. Janczewski WA, Onimaru H, Homma I, Feldman JL. Opioid-resistant respiratory pathway from the preinspiratory neurones to abdominal muscles: in vivo and in vitro study in the newborn rat. J. Physiol. 2002; 545: 1017–26. Financial disclosure: This work was supported by NIH grants HL72415 and HL 73474. MEDULLARY CONTROL OF THE UPPER AIRWAYS LESZEK KUBIN Department of Animal Biology, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania, Philadelphia, PA 19104–6046, USA Obstructive sleep apnea (OSA) occurs in individuals with compromised upper airway anatomy in whom sleep reduces the activity of pharyngeal dilator muscle tone below that required for effective prevention of airway collapse caused by negative inspiratory pressure. Obstructive episodes are most severe during rapid eye movement (REM) sleep, when upper airway motor tone is profoundly reduced parallel to the characteristic postural atonia. The central neural mechanisms of REM sleep-related upper airway hypotonia have been extensively studied in hypoglossal (XII) motoneurons that innervate tongue muscles, including the genioglossus, which in OSA patients has an important pharyngeal dilatory function. The focus of many of those studies was on neurochemically distinct pontomedullary pathways that project to XII motoneurons and have REM sleep-related changes in activity (reviewed in ref. [1]). Studies in carbachol models of REM sleep [2] show that the activity of medullary inspiratory neurons which project to XII motoneurons is not reduced during REM sleep-like atonia [3], whereas that of medullary serotonin (5-HT)-containing neurons projecting to XII is profoundly reduced [4]. The levels of 5-HT [5] and norepinephrine [6] are reduced, whereas those of the inhibitory acids GABA and glycine are increased [7], and the frequency and amplitude of inhibitory postsynaptic potentials increase in XII motoneurons [8] during REM sleeplike atonia. However, injections into the XII nucleus of either inhibitory receptor antagonists [9–10] or 5-HT [11–12] do not abolish the atonia, Sleep and Biological Rhythms 2005; 3: A2–A73 suggesting that motoneuronal depression is mediated by convergent actions mediated by several distinct pathways. Consistent with this, the depressant effect of the REM sleep-like state on XII motoneurons is completely eliminated by combined microinjections into the XII nucleus of antagonists of á1-adrenergic receptors (prazosin), 5-HT receptors (methysergide), GABAA receptors (bicucuilline) and glycinergic receptors (strychnine) [13]. The atonia is also eliminated with only three antagonists (prazosin, methysergide and bicuculline) [14], or just two antagonists (prazosin and methysergide) [15]. This indicates that, at least in the carbachol models, REM sleep-related depression of XII motoneuronal activity can be fully accounted for by a withdrawal of noradrenergic and serotonergic effects. Of the two, the noradrenergic effect appears to be stronger, but the location of the responsible noradrenergic cells is unknown [16]. References 1. Kubin L, Davies RO. In: Pack AI, ed., Sleep Apnea. Pathogenesis, Diagnosis, and Treatment. Dekker 2002; 99–154. 2. Kubin L. Arch. Ital. Biol. 2001; 139: 147–68. 3. Woch G, Ogawa H, Davies RO, Kubin L. Exp. Brain Res. 2000; 130: 508–20. 4. Woch G, Davies RO, Pack AI, Kubin L. J. Physiol. 1996; 490: 745–58. 5. Kubin L, Reignier C, Tojima H, Taguchi O, Pack AI et al. Brain Res. 1994; 645: 291–302. 6. Lai YY, Kodama T, Siegel J. J. Neurosci. 2001; 21: 7384–91. 7. Kodama T, Lai YY, Siegel JM. J. Neurosci. 2003; 23: 1548–54. 8. Fung SJ, Yamuy J, Xi MC, Engelhardt JK, Morales FR et al. Brain Res. 2000; 885: 262–72. 9. Kubin L, Kimura H, Tojima H, Davies RO, Pack AI. Brain Res. 1993; 611: 300–12. 10. Morrison JL, Sood S, Liu H, Park E, Liu X et al. J. Physiol. 2003; 552: 975–91. 11. Kubin L, Tojima H, Reignier C, Pack AI, Davies RO. Sleep 1996; 19: 187–95. 12. Jelev A, Sood S, Liu H, Nolan P, Horner RL. J. Physiol. 2001; 532: 467–81. 13. Fenik V, Davies RO, Kubin L. Arch. Ital. Biol. 2004; 142: 237–49. 14. Fenik V, Davies RO, Kubin L. J. Sleep Res. 2005, in press. 15. Fenik V, Davies RO, Kubin L. Soc. Neurosci. Abstr. 2003; 29: 769.9. 16. Fenik V, Marchenko V, Janssen P, Davies RO, Kubin L. J. Appl. Physiol. 2002; 93: 1448–56. Support: NIH grants HL-47600 and HL-60287. NOVEL SITES AND PATHWAYS FOR RESPIRATORY MODULATION BY THE PONS MIODRAG RADULOVACKI Department of Pharmacology, University of Illinois at Chicago, Chicago, Il 61612, USA Recently, two areas in the rostral pons have been found to modulate respiration: the pedunculopontine tegmental nucleus (PPT) [1,2] and the intertrigeminal nucleus (ITR)[3–5]. Lydic and Baghdoyan [2] first showed in barbiturate anesthetized cats that PPT continuous electrical stimulation leads to increased acetylcholine release in the medial pontine reticular formation and to respiratory depression. However, the respiratory depression was mild and transient, diminishing even before cessation of the stimulus. In anesthetized and spontaneously breathing Sprague-Dawley rats we demonstrated a longlasting increase in variability of respiratory parameters following glutamate microninjection into PPT [1,6,7]. The induced respiratory perturbations were characterized by intermittent apneas and increased variability of expiratory A19 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 and total breath durations in all animals. Findings of these studies point to a significant impact of the PPT on the brainstem respiratory pattern generator. In addition, our findings in freely moving rats demonstrated that neurochemical stimulation of the PPT significantly increased sleeprelated respiratory variability – including apnea expression. These responses, followed similar time courses during both REM and NREM sleep, and were not associated with significant changes in sleep architecture, respiratory rate, or minute ventilation [8]. In exploring the role of ITR in respiration, our data in anesthetized spontaneously breathing animals showed that one physiological role for the ITR in respiration is to attenuate vagal reflex apneas and to dampen respiratory instability [5]. In accordance, in freely moving rats a small and well localized unilateral lesion of the ITR produced a lasting sleeprelated breathing disturbance by increasing sleep apnea expression over a two week period [9]. These findings are in agreement with the general modulatory role of pontine structures in respiration. Taken together, our findings indicate that two regions in the lateral pons, PPT and ITR, have previously unsuspected role in regulating respiration and respiratory variability. References Saponjic J, Radulovacki M, Carley DW. Resp. Physiol. Neurobiol. 138: 223, 2003. Lydic R, Baghdoyan HA. Ann. J. Physiol. 264:(3 Pt.2), R544, 1993. Chamberlin NL. Resp. Physiol. Neurobiol. 143: 115, 2004. Chamberlin N, Saper CB. J. Neurosci. 18: 6048, 1998. Radulovacki M, Pavlovic S, Saponjic J, Carley DW. Brain Res. 975: 66, 2003. Saponjic J, Radulovacki M, Carley DW. Sleep Breath. 2005. Saponjic J, Cvorovic J, Radulovacki M, Carley DW. Sleep 28: 560, 2005. Radulovacki M, Pavlovic S, Saponjic J, Carley DW. Resp. Physiol. Neurobiol. 143: 293, 2004. Radulovacki M, Pavlovic S, Carley DW. Sleep 27: 383, 2004. S-15. Mechanisms of the sleep promoting and mood improving effects of sleep deprivation Chairperson: Edith Holsboer-Trachsler (Switzerland) GABA-ERGIC INVOLVEMENT IN REM-SLEEP DEPRIVATION BIRENDRA N MALLICK School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India The significance of rapid eye movement (REM) sleep may be appreciated by the fact that its loss affects the living systems globally including brain maturation, excitability, irritability, memory consolidation and so on, however, the mechanism of action for mediation of such action was unknown. Since the noradrenergic REM-OFF neurons in the locus coeruleus (LC) cease firing during REM sleep but continue to remain active during REM sleep deprivation1, it was hypothesized that noncessation of activity of those neurons could be at least one of the primary reasons for the loss of REM sleep and the resulting associated effects. Male wistar rats (250–280 gs), maintained in 12 : 12 L : D cycle with food and water ad lib, were used in this study. Under surgical anaesthesia rats were prepared for sleep-waking recording and either bilateral stimulating electrode or guide cannulae were implanted in the LC. In other sets, rats were deprived of REM sleep by flower-pot method and large platform was used as control. Free moving rats and recovery A20 of REM sleep after deprivation were used as other controls. The effects of REM sleep deprivation were studied on brain Na-K ATPase activity and neuronal cytomorphometry. There was significant decrease in REM sleep after electrical activation of the LC neurons which showed rebound increase during the poststimulatory period. After REM sleep deprivation there was increased Na-K ATPase activity and alterations in neuronal cytomorphometry in the rat brain and all these changes were prevented by ip injection of prazosin, alpha1 adrenoceptor antagonist. Since in other studies we showed that GABA in LC increases REM sleep possibly by inhibiting the LC neurons, picrotoxin, GABA-antagonist was infused into the LC, which reduced REM sleep and simultaneously increased the Na-K ATPase activity. The findings of these studies suggest that noncessation of REM-OFF neurons results in REM sleep loss. Increased norepinephrine, due to noncessation of the REM-OFF neurons, is responsible for at least some of the REM sleep deprivation induced physiological effects. At the synaptic level since GABA maintains the inhibition of the REM-OFF neurons for REM sleep regulation, disturbance in GABA is likely to play a significant role in REM sleep regulation and resulting disorders. Based on our other studies it may be said that the GABA may be reaching LC at least from prepositus hypoglossus. 1 Mallick et al. Brain Res. 515 (1990) 94–98. Research funding from CSIR, DBT, DST, ICMR and UGC is acknowledged. MEDIATORS OF SLEEP-DEPRIVATION-EFFECTS: THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM AND THE GABA/GLUTAMATE EQUILIBRIUM HARALD MURCK*, DOROTHEA AUER, HEIKE KUENZEL, KATJA HELD, IRINA A ANTONIJEVIC AND AXEL STEIGER Max-Planck-Institute of Psychiatry, 80804 Munich/Germany; *Present address: Laxdale Ltd, FK7 9JQ Stirling/UK Total sleep deprivation is a means to induce a rapid improvement to in some patients with depression. The mechanism of action is still unknown. Dysregulation of several endocrine and neurotransmitter systems are involved in the pathophysiology of depression. Changes in the activity of the renin-angiontensin-aldosterone system (RAAS), the hypothalamus-pituitary-adrenocortical (HPA) axis and the GABA/ glutamatergic pathways have been reported. We were interested if and how these pathways react to sleep deprivation. We used polysomnography and analysed the serum concentrations of several hormones in the course of the night to determine hormone concentrations in healthy subjects and patients with depression before and after one night of total sleep deprivation (TSD). Furthermore we performed an analysis by means of NMR spectroscopy of intracerebral GABA, glutamine and glutamate in healthy subjects before and after TSD. For the polysomnographic studies we compared the sleep related activity of RAAS and HPA hormones before and after TSD in seven depressed patients. After an accommodation night a polysomnographic examination was performed between 23.00 hours and 07.00 hours. This was followed by 40 h of TSD and the second polysomnography. During the examination nights blood samples were taken every 20 min for analysis of renin, aldosterone, ACTH and cortisol. During recovery-sleep renin was significantly increased (P < 0.05). Aldosterone showed no change. ACTH and cortisol were decreased by trend in the first half of the night. REM-density and intermittent wakefulness was significantly decreased (P < 0.05), whereas slow wave sleep increased by trend in the first half of the night. TSD in patients with Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 depression leads to changes, which are in accordance with a desensitisation of angiotensin II receptor sensitivity. The NMR spectroscopic analysis was performed with 7 healthy controls in the morning of the first day and again 24 h later. An increase in GABA and glutamine levels in pontine areas was observed. It is known that angiotensin via ATII receptors and glutamate act synergistically to increase the HPA axis activity whereas GABA reduces it. As a reduction of HPA axis activity is accompanied by a clinical improvement in hypercortisolemic patients these findings are in line with the hypothesis that the same group of patients might benefit from therapeutic sleep deprivation. Finacial disclosure: The studies were performed and financed by the Max-Planck-Institute of Psychiatry, Munich, Germany. GABAERGIC MECHANISMS OF SLEEP DEPRIVATION HOLSBOER-TRACHSLER EDITH1, HATZINGER MARTIN1 AND HEMMETER ULRICH1,2 1 Psychiatric University Clinics Basel, Department of Depression Research, Sleep Medicine and Neurophysiology, Basel, Switzerland, 2University of Marburg, Clinic of Psychiatry and Psychotherapy, Marburg, Germany Sleep deprivation (SD) has an antidepressive, but temporary efficacy in 60% of depressed patients. Characteristic sleep EEG alterations of depression are improved after SD in the recovery night due to increased NonREM pressure. Naps and short microsleep (MS) episodes during SD reduce NonREM pressure in the recovery night and can prevent the antidepressant effect (Hemmeter et al. 1998). The GABA-Abenzodiazepine receptor antagonist flumazenil reduces daytime sleep and is able to suppress NonREM pressure in early morning recovery sleep after SD in volunteers, which is the critical time for a detrimental effect of MS and naps on SD response (Seifritz et al. 1995). Therefore, 27 patients with major depression were subjected to a partial SD (PSD). In a double blind randomized design either flumazenil or placebo was orally applied in two hourly intervals from 1.30 to 10.30 a.m. during PSD. EEG was registered continuously for 60 h by a portable device allowing the assessment of wake and sleep EEG at baseline, wake EEG during PSD and sleep EEG of the recovery night. Flumazenil significantly reduced MS during PSD, predominantly during the time interval flumazenil was applied (unt il noon). In the recovery night after PSD and flumazenil treatment sleep continuity improved, stage 1 was reduced and slow wave sleep increased more than under PSD and placebo. These findings show that flumazenil is able to suppress MS during PSD in depressed patients. The suppression of MS by flumazenil seems to be related to an increased NonREM pressure in the recovery night. The different effects between flumazenil and placebo suggest that GABAergic mechanisms are substantially involved in sleep-wake regulation and thus, may contribute to the sleep deprivation response in depression. References Hemmeter U, Bischof R, Hatzinger M, Seifritz E, Holsboer-Trachsler E (1998) Microsleep during Partial Sleep Deprivation in Depression. Biol. Psychiatry 43: 829–39 Seifritz E, Hemmeter U, Trachsler L, Lauer CJ, Hatzinger M, Emrich HM, Holsboer F, Holsboer-Trachsler E (1995) Effects of flumazenil on recovery sleep and hormonal secretion after sleep deprivation in male controls. Psychopharmacology 120: 449–56 Financial disclosure: Swiss National Science Foundation supported this work. Sleep and Biological Rhythms 2005; 3: A2–A73 THE INFLUENCES OF PEPTIDES, GENDER AND AGE ON SLEEP PROMOTION BY SLEEP DEPRIVATION AXEL STEIGER, PETRA SCHÜSSLER, MANFRED UHR AND ALEXANDER YASSOURIDIS Max Planck Instiute of Psychiatry, Munich, Germany Sleep deprivation is the most powerful method to promote sleep. During the recovery night after sleep deprivation slow-wave sleep (SWS) and rapid-eye-movement sleep (REMS) increase and intermittent wakefulness decreases. During sleep a bidirectional interaction exists between sleep EEG and hormone secretion. Neuropeptides were delineated to be common regulators of these components of sleep. In male human subjects and animals growth hormone(GH)-releasing hormone (GHRH) stimulates SWS and GH and blunts the hormones of the hypothalamo-pituitary adrenocortical (HPA) system. Corticotropinreleasing hormone (CRH) exerts opposite effects. These findings suggest a reciprocal interaction of GHRH and CRH in sleep regulation. In females, however, GHRH impairs sleep and enhances HPA hormones. Preclinical studies suggest that GHRH participates in the sleep promotion after sleep deprivation. There is a lack of studies on the effects of GHRH and CRH on human sleep-endocrine activity in the recovery night after sleep deprivation. In order to disentangle the influences of these peptides, gender and age on this issue we performed a sleependocrine study in controls. Since nocturnal oscillations of renin are linked to the NonREMS-REMS-cycle we included analyses of this hormone. 48 normal subjects (19–69 years old) were investigated during 4 consecutive nights. After one night of adaptation sleep EEG was recorded from 2300 to 0700 and, by long catheter specimens for the later analysis of GH, cortisol and renin levels were collected simultaneously. This baseline night was followed by 40 h of sleep deprivation. During the recovery night sleep-endocrine activity was retested. Then, age- and sex-matched groups of 16 subjects received between 2200 and 0100 hourly bolus injections of either placebo (PL), 4 ¥ 50 mg CRH or 4 ¥ 50 mg GHRH. Without distinction between genders we found that after sleep deprivation sleep period time (SPT), sleep efficiency index (SEI), SWS and NonREMS increased and wakefulness decreased significantly compared to baseline. By considering the two genders separately, only males showed the aforementioned pattern of changes. In females only SWS and wakefulness changed. When the role of age was examined, in the subjects who were younger than 40 years SEI, SPT, SWS and REMS increased, whereas in those who are older SWS increased and wakefulness decreased. Analyzing the treatment effect we found, that the decreasing effect of GHRH on wakefulness was significantly stronger than after placebo. In contrast to GHRH and placebo REMS remained unchanged after CRH. The enhancement of SWS after CRH was more pronounced in women than in men. Renin increased after sleep deprivation. As expected GH was elevated after GHRH, and cortisol increased after CRH. Cortisol levels decreased after GHRH indepensently from gender. Our data suggest that GHRH augments the sleep promotion after sleep deprivation. The lack of stimulation of REMS after CRH during the recovery night is in line with the REMS suppression after CRH in young males. In females, however, CRH appears to enhance SWS. In contrast to the sexual dimorphism of the effects of GHRH on sponataneous sleep, cortisol was reduced after GHRH in women and men. Sleep deprivation appears to elevate renin levels. This is in line with the view that SWS and renin are linked. References Obál F, Krueger J (2004) GHRH and sleep. Sleep Medical Rev. 8: 367–77. A21 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Steiger A (2003) Sleep and endocrine regulation. Front Biosci. 8: s358– 76 Supported by a grant from the Deutsche Forschungsgemeinschaft (YA 12/1–2) S-16. The no-man’s land between dream and hallucinations Chairperson: Jean Askenasy (Israel) THE NO-MAN’S LAND MAP OF VISUAL HALLUCINATIONS JEAN ASKENASY Department. of Neurology, Research Authority of the Faculty of Medicine Tel. Aviv University Dream during sleep and visual hallucinations during wakefulness are ‘imagery phenomenon’. Imagery phenomenon during sleep with unusual affective charge, vivid color and dynamic content are considered ‘altered dream’. One third of the parkinsonian with altered dreams display visual hallucinations related to sleep. A comparative analysis between Parkinsonian hallucinators vs. Parkinsonian nonhallucinators showed a highly statistical significant relationship between hallucinators with altered dreams and REM aberrations recorded on PSG. The drug induced hallucinations, due to MAO inhibitors and anticholinergics, are significantly associated with altered dreams. When the patient is convinced that they are false the lesion is mainly of the calcarine cortex, mesencephal or retina. When the patient is convinced of their reality and reacts to them, the lesion is mainly of the associative area and temporal lobes. The imagery phenomenon may be caused by migraine, confessional syndromes, delirium, peduncular lesions (Kandinsky or Lhermitte), narcolepsy/cataplexy syndrome, degenerative disorders, drugs, blindness and neuro-optic apparatus lesions. Imagery phenomenon during wakefulness in Parkinson’s disease were shown to be related to cognitive degradation, long duration of the disease, advanced age and excessive daytime sleepiness. The presence of imagery phenomenon during wakefulness in elderly and the alleviating effect of illumination and clozapine (potent blocker of mesolimbic dopamine) suggest that multiple sites lesions of this phenomenon. A NEUROPHYSIOLOGICAL AND NEUROIMAGING PERSPECTIVE ON HALLUCINATIONS IN DREAMS AND IN SCHIZOPHRENIA ROBERT W MCCARLEY AND KEVIN SPENCER Department Psychiatry, Harvard Medical School and VA Boston Healthcare System While the naive hypothesis that schizophrenia represents a ‘waking dream’ has been refuted, there still remains the important question of brain mechanisms of hallucinations in both disorders. Current views of schizophrenia suggest that it results from abnormalities in neural circuitry, but empirical evidence in the millisecond range of neural activity has been difficult to obtain. In schizophrenia we have investigated the possible brain origins of hallucinations and disordered thinking by examing response-linked gamma oscillations (about 40 Hz), using Wavelet analysis of phase locking of gamma activity to a response indicating the perception of an illusory square. This phase analysis is much A22 more sensitive than FFT and is useful in detecting the low level of gamma activity recordable from scalp electrodes in humans. The novel finding that emerged from our studies was that, in both healthy controls and schizophrenia patients, visual Gestalt stimuli elicited a gammaband oscillation that was phase-locked to the response reaction time, and hence may reflect processes leading to conscious perception of the stimuli. However, the frequency of this oscillation was lower in schizophrenics than in healthy individuals. This finding suggested that, while synchronization must occur for perception of the Gestalt, it occurs at a lower frequency due to a reduced capability of neural networks to support high-frequency synchronization in the brain of schizophrenics. Furthermore, the degree of phase-locking of this abnormal oscillation was correlated with visual hallucinations, thought disorder, and disorganization in the schizophrenia patients. These data provided support for linking dysfunctional neural circuitry and the core symptoms of schizophrenia. With respect to hallucinations, we speculated that hallucinations had as a basis a failure of the subject to recognize the difference between an internally generated image and an externally derived sensory experience. The underlying mechanism was postulated to be a deficit in communication between brain regions due to the gamma oscillation abnormality, since this is the preferred frequency for communication between cell assemblies in animals and, based on our data, in healthy humans (see full data description in our paper: Spencer et al. PNAS USA, 2004). In dreams the same failure to recognize the difference between an internally generated image and an externally derived sensory experience is present (and defines a hallucination) but appears to have a different mechanism. During dream sleep, external sensory input is blocked and there is an internally generated activation, based on an initial instigation by the REM sleep brainstem generator. Neuroimaging data suggest a lessened activation of the prefrontal cortex (PFC) during dreams, a possible source of the inability of the dreamer to distinguish internally from externally generated sensory activation. Since PFC development is a late arrival in evolution and REM sleep is ancient, it may be that the REM sleep activation stemming from the brainstem and present in more primitive brain systems did not evolve fully for the PFC. Of note, other neuroimaging data indicate that visual imagination activates the same higher order visual areas as do percepts, so the critical feature in both schizophrenic and dream hallucinations is the inability to distinguish internal from external origin. In schizophrenia there may be a trait deficit in communication due to neural assembly abnormalities in generating gamma band oscillation while in dreams there is a state abnormality due to a difference in brain activation. Supported by: VA Medical Research Service; NIMH 39683, 40799: MIND Institute. THE ROLE OF HYPOCRETIN NEURONS IN MENTAL ACTIVITY JEROME M SIEGAL Brain Research Institute & UCLA School of Medicine, Neurobiology Research (151 A3), 16111 Plummer Street, North Hills, CA 91343, USA The loss of hypocretin neurons is responsible for human narcolepsy. In general human narcoleptics are cognitively normal, apart from the sleepiness that is a central part of the disorder. However, one of the tetrad of symptoms that define narcolepsy is hypnagogic hallucinations, i.e. hallucinations at the onset and offset of sleep. A second cognitive problem that has been attributed by some to narcolepsy is depression. The anatomy and physiology of the hypocretin system suggest ways in which such symptoms could arise out of the loss of hypocretin cells. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 UNANSWERED QUESTIONS ABOUT THE ROLE OF HYPOCRETIN IN CATAPLEXY AND HYPNAGOGIC HALLUCINATIONS PRIYATTAM J SHIROMANI AND CARLOS BLANCO-CENTURION Harvard Medical School and West Roxbury VA, West Roxbury, MA USA, 02132 The hypocretin/orexin neurons located in the lateral hypothalamus have been implicated in narcolepsy but it is not known which target region is responsible for what symptom of narcolepsy. To answer this question we have developed a chemical lesion method that lesions neurons containing the HCRT neurons (Gerashchenko et al. J Neuroscience, 51: 7273–7283, 2001). The HCRT2-saporin conjugate was administered to specific targets implicated in arousal and here we summarize these findings. 1. A rat that does not have orexin/hypocretin neurons wakes up at the correct time of day indicating that these neurons are not the primary recipients of an awakening signal from the SCN (Gerashchenko et al. Neuroscience, 116: 223–235, 2003). A similar conclusion was reached by the Tom Scammell’s group using the HCRT null mice. 2. The hypocretin projection to the pons is important for keeping the animal awake at night. We reached this conclusion based on our finding that lesion of the pontine orexin/hypocretin receptor bearing neurons increase sleep at night (Blanco-Centurion et al. European J Neurosci 19: 2741, 2004). 3. The hypocretin projection to the LC awakens the animal at a specific time of day but is not important in maintaining wakefulness. We reach this conclusion from our finding that lesions of the LC do not change the overall amount of wakefulness during the day, night or over the 24-h period (Blanco-Centurion et al. European J Neurosci 19: 2741, 2004). Others who monitored sleep in dopaminebeta-hydroxylase null mice reached a similar conclusion (Hunsley & Palmiter, Sleep 26: 521, 2003). 4. The hypocretin projection to the medial septum/diagonal band influences theta activity but does not regulate overall levels of sleep or wakefulness. Lesions of the medial septum/diagonal band neurons decrease theta but do not change overall levels of sleep or wakefulness, or trigger sleep onset REM sleep periods (Gerashchenko et al. Brain Research Interactive 913: 106–115, 2001). 5. The hypocretin projection to the tuberomammillary nucleus keeps the animal awake when faced with an unfamiliar environment, but overall levels of wakefulness over the 24-h period do not change (Gerashchenko et al. Sleep 27: 1275–1281,2004). 6. The orexin/hypocretin neurons can survive when transplanted into adult rat pons (Arias et al. Sleep 27: 1465–1470, 2004). From these studies we have found that specific HCRT projections affect sleep. However, we have yet to determine which innervation is responsible for the SOREMPs, and the cataplexy. Supported by the VA and NIH. S-17. Exercise and Sleep Chairperson: Dr Sunao Uchida (Japan) EXERCISE FOR A GOOD NIGHT TIME SLEEP: EFFECTS OF TIMING OF 1 H EXERCISE UPON THE NIGHT SLEEP TOSHINORI KOBAYASHI, TOHRU ISHIKAWA, SHINICHI TOMITA, HIRONORI YOSHIDA AND KAZUNARI ARAKAWA Ashikaga Sleep Research Center, Ashikaga Institute of Technology, Tochigi-ken Japan The importance of daily physical exercise is recognized to increase the quality of life. The effects of daytime exercise upon the night sleep have been reported by many studies. However, the effect of timing of exercise during daytime upon the night sleep has not been reported. The effects of timing of 1 h exercise with the strength of anaerobic threshold (AT) level (50–60% VO2max) upon the night sleep, particularly on the slow wave sleep (SWS), and on the subjective sleep feeling, was examined. After informed consent was obtained from subjects, seven healthy paid volunteer mail university students (aged 21.0 ± 0.9 years) with no exercise habit underwent the exercise at three different times of the day. Morning exercise (ME-day) consisted of 1 h exercise taking in the morning (07:40–08:40), the evening exercise (EE-day) was performed in the evening (16:30–17:30), and the late evening exercise (LEE-day) was performed in the late evening (20:30–21:30). They performed 1 h exercise at one time zone of the exercise day, and they slept from 23:30 to 07:30 of the after exercise day. The subjective sleep feelings were estimated by Japanese sleep inventory. The subjective sleep feeling of the LEE-day was significantly better than any other exercise day. The sleep latency of the night sleep in the LEE-day was significantly shorter than on any other exercise day. A large amount of SWS (measured by delta EEG power) was found in the first sleep cycle of the night in the LEE-day compared with any other exercise day. These results suggest that 1 h exercise with AT level taken in late evening improves sleep onset process and contributes to a good night sleep. IMPLICATIONS OF YOGA ON SLEEP: AN OVERVIEW BINDU M KUTTY Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS Deemed University), Bangalore 560029 Decreased quality of sleep is one of the most common health complaints of old age. The most consistent alterations associated with aging include increased number and duration of awakenings, decreased amount of slow wave sleep and REM sleep. In men, age related changes in slow wave sleep and REM sleep occur with markedly different chronologies. Meditation practices appear to bring significant physiological changes, which contribute towards a better physical and mental well-being. Meditation techniques are claimed to enhance the quality of sleep. However studies to substantiate the possible beneficial effect of yoga on sleep structure and quality are lacking. We have demonstrated that proficient practice of yoga helps to restore the deep sleep states in the middle aged practitioners.In addition, yog a practice also appear to influence the REM sleep states. These observations were based on the whole night polysomnographic studies Sleep and Biological Rhythms 2005; 3: A2–A73 A23 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 carried out in 65 healthy male subjects practicing different yogic techniques viz; the sudarshana kriya yoga (age groups 20–30 years; 31–55 years) and vipassana meditation (age group between 31 and 55 years) and age matched non practitioners. Our results suggest that yogic/meditative practice perhaps help in regulating a perfect sleepwakefulness behavior. EFFECT OF EXERCISE FOR CIRCADIAN RHYTHM KEN-ICHI HONMA, YUJIRO YAMANAKA, TOSHIHIKO MIYAZAKI, SATOKO HASHIMOTO AND SATO HONMA Department of Physiology, Hokkaido University Graduate School of Medicine, Sapporo 060–8638, Japan The mammalian circadian rhythm is driven by human biological clock located in the hypothalamic suprachisamatic nucleus (SCN) and entrained by light-dark cycles through the retina. In subjects living in the real world, the natural sun light is considered as a dominant stimulus for entraining human circadian rhythm to the local time. When deprived of time cue and light-dark cycles, the circadian rhythm of plasma melatonin and core body temperature in human show near 24-h period that is called free running rhythm. In humans, the period of free running rhythm is slightly longer than 24 h. Therefore, the clock has to phase advance about 1 h to entrain the 24 h day-night alternation. Physical exercise, such as wheel running and forced treadmill running, has been reported to entrain and phase shift the circadian rhythms in rodent. Several studies have assessed a single trial of exercise on the circadian rhythms in human. A significant phase delay shift has been reported by nocturnal exercise (Buxton et al. 1997). However, a phase advance shift has never been observed. In our previous studies, subjects performed two bouts of bicycle ergometer exercise at a heart rate of 140 beat/min during the morning and afternoon. A 1.6 h phase advance shift in the peak of the plasma melatonin rhythm was observed in exercise subjects, whereas subjects in the nonexercise control condition showed a 0.8 h phase delay. The findings indicate that regular physical exercise entrains the human circadian pacemaker and helpful for rapid adaptation to a new sleep-wake cycle (Miyazaki et al. 2001). In addition, the effect of physical exercise on the circadian phase of plasma melatonin was examined in subjects who stayed under dim light conditions for 4 weeks. With exercise subjects performed after 2 h lunch everyday. Plasma melatonin rhythm were measured every second week. The results of this experiment showed phase delay shift without exercise subject, whereas not changed with regular exercise. These results indicate that regular physical exercise would have a phase resetting ability. References Buxton OM, Frank SA, L’Hermite-Baleriaux M, Leproult R, Turek FW, Van Cauter E. Roles of intensity and duration of nocturnal exercise in causing phase delay of human circadian rhythms. Am. J. Physiol Endocrinol. Metab. 1997; 273: E536–42. Miyazaki T, Hashimoto S, Masubuchi S, Honma S, Honma K. Phase advance shifts of human circadian pacemaker are accelerated by daytime physical exercise. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2001; 281: R197–205. A24 EPIDEMIOLOGY OF EXERCISE AND SLEEP YOUNGSTEDT SD Department of Exercise Science, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, SC USA In large random surveys people report that exercise promotes their sleep. Moreover, numerous epidemiologic studies have shown a significant association of self-reported exercise with better self-reported sleep. Nonetheless, there are numerous limitations to these studies. They have often assessed exercise and sleep using instruments of dubious validity. Moreover, the studies have generally not included clinical diagnoses of sleep disorders, and often they have not included questions that address accepted criteria for sleep disorders. Thus, the clinical relevance of these findings is unclear. There are numerous plausible alternative explanations to the epidemiological and survey associations of exercise with better sleep. First, it is known that better sleep is associated with greater willingness to exercise. Second, it is know that people who exercise regularly also tend to engage in other health habits that are conducive to sleep, and regular exercisers generally have superior health, which is conducive to sleep. Third, it seems apparent that the notion that exercise promotes sleep is based partly on an incorrect assumption that sleepiness and physical fatigue are synonymous. Finally, the epidemiological association could be explained by a third factor such as light exposure. SLEEP PROBLEMS IN COLLEGE ATHLETES JUNKO MUKAI AND SUNAO UCHIDA Department of Sleep Medicine, Shiga University of Medical Science, Seta, Ohtsu, Shiga, 520–2192, JAPAN It is generally accepted that sleep becomes more restorative and more effective with appropriate level of physical exercise. Therefore, athletes can enjoy good sleep. However, inappropriate training or physical characteristics of athlete sometimes cause sleep problems. One example is dyssomnia caused by overtraining syndrome. Puffer et al. (1991) showed that the characteristics of the college athletes were somewhat rigid, strongly goal oriented, and strives for excellence, therefore they tended to overtrain and fall into be chronic fatigue or depressive state. It is recognized that psychological dysfunction affects sleep strongly. There is also a problem caused from physical characteristic of athlete. Charles FP et al. showed that 92% of the professional football players had large necks and elevated BMI, and the prevalence of sleepdisordered breathing was 14% of them. However, there are only few studies dealing with sleep problems in athletes in the past. For the purpose to evaluate the athletes’ sleep and health, we examined nocturnal sleep, daytime sleepiness, mood and physical condition by the questionnaires, respectively; Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Self-Rating Depression Scale (SDS), General Health Questionnaire-28 (GHQ-28), and MorningnessEveningness Questionnaire (MEQ), for the college athletes of various sport events. The results will be present in the aspects of sleep habits and prevalence of sleep problems in college athletes. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 S-18. Sleep in the ICU: Restless patients and sleepy doctors Chairperson: David Dinges (USA) SCIENCE OF SLEEP LOSS AND PERFORMANCE: IMPLICATIONS FOR THE PHYSICIAN DUTY HOURS DAVID F DINGES Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, U.S.A. Deficits in goal-directed behavior due to total or partial sleep loss are experienced universally and associated with significant social, financial and human cost. Laboratory-based sleep deprivation studies consistently reveal that sleep deprivation negatively impacts mood and a range of neurobehavioral functions, and that it leads to microsleeps, sleep attacks and cognitive deficits, which can pose risks in safety-sensitive activities. Experiments have demonstrated that these effects occur when people remain awake beyond 16 h, and when nightly sleep duration is chronically reduced below 7 h. The consequences of sleep loss associated with work schedules involving prolonged periods awake have become a major public policy issue in recent years. One area of concern in the USA has been the impact of traditionally long duty hours in physicians in training and nurses.1 Current duty hour limits for resident physicians in the USA were promulgated by the Accreditation Council for Graduate Medical Education in 2002. They were intended to reduce the risk of performance errors due to chronic sleep loss by limiting residents to 80 h work per week, and reduce the risk of acute sleep loss be limiting residents 24 h work durations, which can be extended to 30 h for continuity of care and education. They also mandate 1 day in 7 free from duty averaged over 4 weeks, and 10 h rest opportunities between duty periods. However, recent studies of use of these work hour limits by residents reveal that the limits do not prevent acute or chronic sleep loss, and they contribute to medical errors and motor vehicle crash risks. A survey of 3604 first- and second-year resident physicians found that among all subspecialties 66% of residents reported sleeping an average of 6 h or less per night, and 22% reported sleeping an average of 5 h or less per night. Surgical residents reported the least amount of sleep of all subspecialities.2,3 For example, 84% of orthopedic surgery residents reported obtaining 6 h or less sleep per night and 40% reported obtaining 5 h or less. Among all residents, sleep durations of 5 h or less were associated with elevated odds ratios for serious accidents and injuries, working in an impaired condition, and having made significant medical errors.3 Sleep durations were significantly shorter in first-year than in second-year residents, suggesting that impairments would likely be greater in the less experienced house staff, which could further exacerbate risk of serious medical error. Another study4 involving a prospective nationwide, Web-based monthly reporting survey of 2737 first-year residents found that the odds ratios for reporting a motor vehicle crash and a near-miss incident after an extended work shift (i.e. 24–30 h were 2–6 times higher that a shift that was not of extended duration, and that every extended work shift that was scheduled in a month increased the monthly risk of a motor vehicle crash by 9% and increased the risk of a crash during the commute from work by 16%. A recent comprehensive study that relied on physician-based documentation of medical errors confirmed that extended duty periods of 24 h–30 h and 80 h work weeks were associated with significant increases in attentional failures 5 and serious medical errors in intensive care units6 relative to an intervention schedule that limited scheduled work to 16 h per day, and resulted in Sleep and Biological Rhythms 2005; 3: A2–A73 increased sleep time and significantly fewer attentional failures5 and serious medical errors.6 Thus the current duty limits on work hours of resident physicians in the USA do not safeguard against the negative effects of sleep loss on performance and safety, and may actually contribute to increased medical errors and motor vehicle crash risks. More effective approaches to preventing sleep deprivation are needed in resident training. References 1. Rogers A et al. Health Affairs 2004; 23(4): 202–12. 2. Baldwin DC et al. Academic Medicine 2003; 78: 1154–63. 3. Baldwin DC, Daugherty SR. Sleep 2004; 27(2): 217–23. 4. Barger LK et al. New England Journal of Medicine 2005; 352: 125–34. 5. Lockley S et al. New England Journal of Medicine 2004; 351: 1829–37. 6. Landrigan CP et al. New England Journal of Medicine 2004; 351: 1838–48. Financial disclosure: NIH grants NR04281, and NASA cooperative agreement NCC 9–58 with the NSBRI. SLEEP AND CIRCADIAN RHYTHMS IN CRITICALLY ILL PATIENTS HANS PA VAN DONGEN1, JOOST AC GAZENDAM2 AND RICHARD J SCHWAB1 1 Center for Sleep and Respiratory Neurobiology, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A., 2Martini Hospital, Groningen, The Netherlands Intensive care unit (ICU) patients have been documented to show disrupted sleep patterns (Freedman et al. 2001). This may be due to illness, but it is also possible that the ICU environment contributes to poor sleep. Sleep disturbances in the ICU may be secondary to environmental noise, the timing of clinical care, and other factors directly interfering with sleep. Furthermore, it is possible that sleep in the ICU is dysregulated due to disrupted circadian rhythms. We investigated the latter by measuring core body temperature (CBT) in ICU patients. In addition, we investigated light patterns in the ICU as a possible source of circadian disruption. CBT was measured in 21 nonfebrile patients (age 59 ± 11; 13 females) who were in the ICU for medical recovery following renal insufficiency, myasthenia gravis, chronic obstructive pulmonary disease exacerbation, or acute respiratory distress syndrome (APACHE III scores: 49 ± 23; 17 mechanically ventilated). These patients did not receive any medications that would suppress a potential fever during the study period. CBT was measured with a temperature-sensing urinary catheter (11 patients) or rectal probe (10 patients). CBT recordings were made for 48 h at a rate of one sample every 5 min. The CBT data were subjected to harmonic regression analysis to estimate circadian phase. It was observed that circadian phase varied substantially among patients, with the daily minimum of CBT spanning the entire 24 h of the day (Kolmogorov-Smirnov test of nonuniformity: Z = 1.12, P = 0.16). Thus, the minimum of CBT was not consistently anchored in the early morning hours, as is typical for healthy normals. This finding indicates that circadian rhythms were desynchronized, which may have contributed to the disrupted sleep patterns in the ICU. Light exposure was measured in two different ICUs and in a control sample. Time-integrated light levels were recorded at 1-minute intervals for a total duration of 48 h, by means of a portable light meter. In the ICUs, the light meters were affixed to the head of the bed so that they moved in the same plane as the patient’s head. In one ICU, 10 recordings were made in rooms with a window to the outside, and 9 recordings were made in rooms without a window; in the other ICU, A25 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 17 recordings were made in rooms with a window (each recording involved a different patient). The control sample consisted of 12 nonhospitalized subjects who wore the light meter around their neck while engaged in normal activities (including daytime work and nighttime sleep). The light data were subjected to harmonic regression analysis to estimate circadian phase and amplitude. It was found that the amplitude of the 24-h variation in light exposure was more than 50% greater in the control sample than in each of the ICUs (Wald Z > 5.8, P < 0.001). Surprisingly, no significant differences in light levels were detected between ICU rooms with and without windows to the outside (Wald Z = 0.18, P = 0.86). Overall, in comparison with the control sample, there was less light in the ICUs during the day, and more light in the ICUs during the night. Thus, light patterns appeared to be abnormal in the ICU, which may have led to circadian desynchronization in the ICU patients. This finding suggests that light management may provide a strategy for restoring circadian rhythms and thereby improving sleep in the ICU. Reference Freedman NS, Gazendam J, Levan L, Pack AI, Schwab RJ. Abnormal sleep/wake cycles and the effect of environmental noise on sleep disruption in the intensive care unit. Am. J. Respir. Crit. Care. Medical 2001; 163: 451–7. SLEEP DISRUPTION AND MECHANICAL VENTILATION SAIRAM PARTHASARATHY SAVAHCS/University of Arizona There is growing interest in the study of sleep during critical illness. We know that sleep, in all of its measurable aspects, is severely deranged in critically ill patients during mechanical ventilation. There is growing evidence that mode of mechanical ventilation, medications, and acuity of illness may contribute to such sleep derangements and that conventional factors such as noise and health care delivery may be playing a much smaller role than previously thought. Alternatively, changes in sleep-wakefulness state can alter patient–ventilator interaction, which may in turn influence physicians’ decision-making and patient outcome. Additionally, there is growing evidence that poor sleep is an important factor influencing long-term quality of life in survivors of critical illness. The long-term effect on sleep quality due to the continuous infusion of sedatives administered during critical illness, sleep deprivation during the ICU stay, and chronic disease sequelae that ensue acute illnesses need to be identified. A more complete understanding of the etiopathogenesis of sleep derangements during mechanical ventilation may identify new interventions to help improve sleep, and possibly favorably influence short-term and long-term outcomes. A26 S-19. Sleep debt: The search for links between neurobehavioral effects and neurobiological mechanisms Chairperson: Robert W. McCarley (USA) CUMULATIVE DOSE–RESPONSE NEUROBEHAVIORAL EFFECTS OF CHRONIC SLEEP RESTRICTION DAVID F DINGES AND HANS PA VAN DONGEN Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, U.S.A. Early studies on the effects of chronic sleep restriction reported that sleep durations in the range commonly experienced by people (i.e. 4 h– 7 h per night) appeared to increase subjective sleepiness, but had little effect on cognitive functions, and concluded that people adapted to chronic reductions in sleep duration down to 4–5 h per day. Most of these early reports were limited, however, by a lack of experimental control over a number of key variables, including sleep actually obtained each day, the use of caffeine and nicotine, etc. When these factors were controlled in two recent experiments assessing dose-related effects of chronic sleep restriction on neurobehavioral measures1,2 the results were quite different. In one study, truck drivers were randomized to 7 nights of 3 h, 5 h, 7 h or 9 h time in bed (TIB) for sleep per night.1 Performance was assessed using the psychomotor vigilance task (PVT). Subjects in the 3 h and 5 h TIB groups experienced a decrease in performance across the 7 days of the sleep restriction protocol, with increases in response speed, number of lapses and fastest reaction times on the PVT. In the subjects allowed 7 h TIB per night, a significant decrease in mean response speed was also evident, although no effect on lapses was found. In contrast, PVT performance in the group allowed 9 h TIB was stable across the 7 days. Similar to an earlier report examining cognitive performance effects of 7 nights of sleep restricted to 5 h per night3 there appeared to be an adaptation of subjects to the new sleep schedule, such that cognitive deficits did not continue to accumulate beyond approximately 5–6 days of sleep restriction, although neither study statistically evaluated this question, which was resolved in the other recent study.2 In the longest laboratory-controlled study of sleep restriction reported to date, healthy adults had their sleep duration restricted to 4 h, 6 h or 8 h TIB per night for 14 nights. Daytime deficits in cognitive functions (between 09:30 and 23:30) were observed for lapses on the PVT, for a working memory task and for a cognitive throughput task.2 Performance deficits accumulated across the experimental protocol in those subjects allowed less than 8 h TIB for sleep per night. Data from this study demonstrate that deficits induced by sleep restriction continued to accumulate beyond the 7 nights of restriction used in other experiments, with performance deficits still increasing at day 14 of the restricted sleep schedule. In order to quantify the magnitude of cognitive deficits experienced with 14 days of restricted sleep, the findings from the study were compared with cognitive effects of 4 days of total sleep deprivation, revealing that both 4 h and 6 h TIB for sleep per night for 14 nights produced cognitive decrements equivalent to what occurred when healthy adults were kept awake for 36–50 h.2 Collectively, these experiments suggest that when time in bed for sleep is chronically restricted to less than 7 h per night in healthy adults, cumulative deficits in a variety of cognitive performance functions become evident. Other experiments have shown that these cumulative neurobehavioral effects can also be found in sleep propensity (MSLT) and driving crash risk.4 However, subjective assessments of sleepiness and alertness demonstrate near saturating functions Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 across periods of sleep restriction,1–3 with stable levels reached within a few days. It appears therefore that the adverse cognitive effects of chronic sleep restriction are not paralleled by subjective awareness on the part of subjects, which may explain why people subject themselves to chronic sleep restriction, thinking it has little to no consequences for their behavior. These findings will be discussed in relation to theories of sleep need and sleep homeostatic responses. References 1. Belenky G, Wesensten NJ, Thorne DR et al. J. Sleep Res. 2003; 12: 1–12. 2. Van Dongen HPA, Maislin G, Mullington JM et al. Sleep 2003; 26: 117–26. 3. Dinges DF, Pack F, Williams K et al. Sleep 1997; 20: 267–77. 4. Dinges DF et al. In: Kryger MH et al. (Eds.) Principles and Practice of Sleep Medicine, 2005, 67–76. Financial disclosure: NIH grants NR04281 and RR00040, and NASA cooperative agreement NCC 9–58 with the NSBRI. THEORETICAL AND MATHEMATICAL PREDICTIONS OF THE TWO-PROCESS MODEL RELATIVE TO SLEEP DEBT AND EXCESS WAKEFULNESS HANS PA VAN DONGEN AND DAVID F DINGES Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, U.S.A. The two-process model postulates that sleep is regulated by a homeostatic process (Process S) and a circadian process (Process C). Slowwave activity in the non-REM sleep EEG is considered a marker of the homeostasis process (Borbély & Achermann 1999). Across 14 days of chronic partial sleep deprivation (PSD; 6 or 4 h time in bed daily) in our laboratory, this marker showed an immediate increase followed by a rapid saturation, with stabilization at a somewhat elevated level occurring within ~3 days (Van Dongen et al. 2003). This is in good agreement with mathematical predictions from the quantitative version of the two-process model, suggesting that the model accurately describes sleep homeostatic pressure over days of PSD. The two-process model has also been used successfully to predict waking alertness under select circumstances (Borbély & Achermann 1999). In line with the dynamics of sleep homeostasis, the quantitative two-process model would predict a rapid saturation of alertness deficits across days of PSD. However, this is not in agreement with observations in the laboratory, which showed that chronic PSD resulted in progressive deterioration of alertness over days (Van Dongen et al. 2003). The discrepancy between the temporal courses of observed waking alertness and predicted homeostatic pressure suggests that a novel process may be needed to model alertness during chronic PSD. One way to model this unidentified novel process would be to assume that changes in waking alertness over days are the product of the dynamics of the homeostatic process and a much slower additional process (Johnson et al. 2004). In contrast, we posited a more parsimonious hypothesis that views alertness changes across days as the result of accumulated excess wakefulness (EW), defined as hours of wakefulness beyond a postulated biological threshold of ~16 h (in the average individual). Under conditions of chronic PSD, this EW hypothesis is equivalent to the sleep debt (SD) hypothesis, which assumes alertness changes to be a function of cumulative hours of sleep lost relative to a biological sleep need of ~8 h (in the average individual). However, the EW hypothesis considers sleep to be needed daily to prophylacticly supply the next day’s ration of ~16 h of alert wakefulness. Predictions from the EW hypothesis thereby differ relative to predic- Sleep and Biological Rhythms 2005; 3: A2–A73 tions from the SD hypothesis under conditions of total sleep deprivation (TSD) beyond 24 h: while the SD hypothesis would count ~8 h of sleep lost per day of TSD, the EW hypothesis counts 24 h of excess wakefulness per day of TSD (beyond the first ~16 h). The latter prediction is in much better agreement with experimental data (Van Dongen et al. 2003). Additional data sets are being investigated to further validate the EW hypothesis. In addition, sleep dose–response studies are underway to help formulate, within the EW hypothesis, the dynamics of alertness recuperation following recovery sleep. Meanwhile, the observation that alertness deficits accumulate across days of PSD or TSD in proportion to the cumulative amount of excess wakefulness stands, regardless of the conceptual validity of the EW hypothesis. This finding may inform investigations of the brain mechanisms underlying the effects on alertness of chronic PSD. References Borbély AA, Achermann P. J. Biol. Rhythms 1999; 14: 557–68. Johnson ML, Belenky G, Redmond DP et al. Aviat Space Environ Medical 2004; 75: A141–6. Van Dongen HPA, Maislin G, Mullington JM, Dinges DF. Sleep 2003; 26: 117–28. Financial disclosure: NIH grants NR04281 and RR00040, and AFOSR grants F49620-95-1-0388 and F49620-00-1-0266. PHYSIOLOGICAL AND MOLECULAR STUDIES OF ADENOSINE IN SLEEP CONTROL ROBERT W MCCARLEY, VIJAY RAMESH AND RADHIKA BASHEER Department Psychiatry, Harvard Medical School and VA Boston Healthcare System, Brockton, MA 02301 Previously we have shown that the levels of extracellular adenosine increase during waking in the wake-active cholinergic basal forebrain (CBF) leading to increased sleepiness, compatible with a role of adenosine as an endogenous sleep factor. A mechanism for the sleep inducing effects of adenosine was found in the adenosine A1 receptor mediated-hyperpolarization of the wake active neurons, an effect that was mediated by an inwardly rectifying K + conductance in cholinergic neurons and by the blockade of the hyperpolarization-activated current (Ih) in presumptively GABAergic neurons. In addition to the immediate inhibitory effects, recent data lead us to hypothesize that adenosine also acts a mediator of the long-term effects of sleep deprivation. Prolonged sleep deprivation results in a selective accumulation of extracellular adenosine in cholinergic basal forebrain. Our molecular studies have shown that a high level of adenosine induced by sleep deprivation, acting via the A1 adenosine receptor, induces an intracellular cascade. This cascade includes IP3 receptor-mediated endoplasmic reticulum mobilization of intracellular calcium in cholinergic neurons; this, in turn, induces nuclear translocation of transcription factor NF-kB in cholinergic neuron (review in Basheer et al. 2004). We hypothesized that a sleep deprivation-induced increase in extracellular adenosine and transcriptional activation of NFkB might play a role in mediating the long-term effects of sleep deprivation, such as increased sleepiness and decreased attention. One such target of NF-kB activation is the A1 receptor itself and we found A1 mRNA to be up-regulated with sleep deprivation. To determine if nuclear translocation of NF-kB was essential for the up-regulation of A1 mRNA, nuclear translocation of NF-kB was blocked by injecting an inhibitor peptide, SN50, into cholinergic basal forebrain of rats prior to sleep deprivation. A1R mRNA levels increase following 3 and 6 h of SD without any change in the receptor density when compared to undisturbed sleeping controls. However, detectable changes in A1R protein may require longer SD periods. We thus examined the changes in: (a) membrane A27 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 receptor density by using 3H-DPCPX receptor autoradiography of brain sections following 12 and 24 h of SD; (b) total A1R protein (membrane + cytoplasmic stores) using Western blotting of rat CBF & cingulate cortex homogenates following 6 and 12 h SD. The membrane receptor density showed a trend-level increase following 12 h SD & a more profound and statistically significant increase after 24 h SD (P < 0.04, N = 6). Whereas the total A1R protein levels first decreased (–29%, P < 0.05; N = 6) following 6 h SD, they increased to control levels following 12 h SD. All experiments showed no cingulate cortex changes. Together these results suggest that, initially, an increase in extracellular adenosine may result in extensive receptor internalization and subsequent degradation, a process accompanied by an immediate replacement of the membrane receptors from the cytoplasmic reserves. This maintains the membrane receptor density but decreases the total A1R protein following 6 h SD. The increase in mRNA results in increased A1R translation and production of receptor protein by 12 and 24 h SD. This A1R up-regulation would have the functional effect of increasing the sensitivity of the cell to extracellular adenosine, and hence increasing the inhibitory influence and the propensity to sleep for a given extracellular AD level, a resetting of the homeostatic set point. References 1. Basheer R, Strecker RE, Thakkar MM, McCarley RW (2004) Adenosine and sleep-wake regulation. Progress in Neurobiol. 73: 379–96. 2. Porkka-Heiskanen T, Strecker RE, Thakkar M, Bjorkum AA, Green, RW, McCarley RW (1997) Adenosine: A mediator of the sleepinducing effects of prolonged wakefulness. Science 276: 1265–8. Supported by NIMH 39683 (RWM) and a VA Medical Research Service Award (RB). NITRIC OXIDE AS A POTENTIAL MEDIATOR OF THE NEUROBEHAVIORAL CHANGES INDUCED BY SLEEP DEPRIVATION ANNA KALINCHUK AND TARJA PORKKA-HEISKANEN University of Helsinki, Finland Nitric oxide (NO) is a gaseous neurotransmitter, which is implicated in many physiological and pathological processes of the body. Nitric oxide inhibits energy metabolism of cells through inhibition of the electron transport in the mitochondria. We have previously shown that energy depletion, though increase in extracellular adenosine concentration, induces sleep that resembles recovery sleep. In the present work we tested the hypothesis that NO is induced during sleep deprivation and that this increase is essential for the induction of recovery sleep. Rats were provided with EEG electrodes and in vivo microdialysis cannula aimed to the basal forebrain (BF). After recovery the animals were (1) sleep deprived for 3 h (2) during sleep deprivation molecules that decreased NO (NO scavenger cPTIO, L-NAME, L-NPA and 1400 W) were infused through the microdialysis probe while microdialysate was collected for analysis of adenosine (3) during spontaneous sleep-wake cycle a NO donor, DETANONO, was infused for 3 h. EEG was continuously recorded for 24 h (4) induction of the inducible nitric oxide synthase (iNOS) during sleep deprivation was measured in several brain areas using Western blot. Sleep deprivation (SD) induced increase in subsequent nonREM (NREM) sleep = recovery sleep. Adenosine levels were increased during the 3 h deprivation period. cPTIO infusion during SD dose dependently decreased recovery sleep. L-NAME also decreased recovery sleep and inhibited the increase in adenosine during the deprivation. Specific inhibitor of the nNOS, L-NPA, did not prevent recovery sleep or adenosine increase during the deprivation, while specific inhibitor of the iNOS, 1400 W, completely abolished recovery sleep and increased A28 adenosine levels during the deprivation. Infusion of DETANONO increased NREM sleep. iNOS, which under normal condition is not present in the brain, was induced during the 3 h sleep deprivation in the BF but not in other brain areas. We conclude that nitric oxide, through induction of iNOS, is an important regulator of NREM recovery sleep. S-20. Interaction of sleep loss and cognitive work: Does it matter what we do when we are sleepy? Chairperson: David F. Dinges (USA) AMONG COGNITIVE PROCESSES, ATTENTION IS PARTICULARLY SENSITIVE TO SLEEP LOSS DAVID F DINGES Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, U.S.A. Tasks demanding vigilant attention are especially vulnerable to sleep deprivation, which may account for why sleep loss poses a high risk for driving. Studies show that sleep deprivation increases sleep propensity, measured as a reduction in the latency to sleep onset. The increased propensity for sleep to occur quickly, even when being resisted by the sleep-deprived subject, is consistent with evidence suggesting that microsleeps intrude into wakefulness when sleep-deprived subjects fail to respond (i.e. lapse) during cognitive performance.1 Cognitive performance variability involving both errors of omission (i.e. failure to respond in a timely manner to a stimulus) and errors of commission (i.e. responding when no stimulus is present or to the wrong stimulus) are hallmarks of sleep deprivation.2 We have hypothesized that such variability during performance in sleep-deprived subjects reflects ‘state instability’.1,2,3 The difference between the lapse hypothesis and state instability theory involves the explanation for variability in performance during sleep deprivation. The lapse hypothesis posits that cognitive performance during sleep deprivation is essentially ‘normal’ until it becomes disrupted by lapses (transient periods of low arousal). In contrast, state instability theory posits that variability in cognitive performance increases as homeostatic sleep initiating mechanisms become progressively more disinhibited with sleep loss. That is, the brain’s capacity to maintain alertness is hindered by the repeated activation of sleep processes, making cognitive performance increasingly variable and dependent on compensatory mechanisms. Thus, state instability evident in the cognitive performance and biobehavioral signs (e.g. slow eyelid closures) of sleep deprived subjects, and reflected by the occurrence of microsleeps or sleep attacks, is directly related to the increased variability in cognitive performance. Moreover, state instability theory predicts that at any given moment in time the cognitive performance of the sleep-deprived individual is unpredictable, and a product of interactive, reciprocally inhibiting neurobiological systems mediating sleep initiation and wake maintenance.4 However, a failure to understand that sleep deprivation increases variability within subjects (i.e. state instability) and between subjects (i.e. differential vulnerability to the effects of sleep deprivation) can mean that the effects of sleep loss are missed in cognitive measures because less sensitive metrics or data analyses are used. State instability theory also suggests that there are multiple, parallel mechanisms by which waking and sleep states can interact. This is consistent with reports of the growing number of candidate molecules that may be involved in the co-occurrence of sleep and waking. Vigilant attention performance is especially sensitive to Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 state instability induced by sleep deprivation. For example, the psychomotor vigilance task (PVT), a brief performance test of behavioral alertness, is free of aptitude and learning effects and especially sensitive to sleep loss. It’s high signal rate and heavy dependence on vigilant attention are likely the reasons it has proven to be a reliable, valid and sensitive measure of sleep deprivation.3,5 Its sensitivity to sleep loss suggests that the neural mechanisms of attention are among the most vulnerable to sleep deprivation. This may in part be due to the dorsolateral prefrontal cortex (PFC), which is one of the critical structures in a network of anterior and posterior ‘attention control’ areas. The PFC has a unique executive attention role in actively maintaining access to stimulus representations and goals in interference-rich contexts. References 1. Durmer JS, Dinges DF. Seminars in Neurology. 2005; 25(1), 117–29. 2. Doran SM, Van Dongen HP, Dinges DF. Archives of Italian Biology. 2001; 139(3): 253–67. 3. Dorrian J, Rogers NL, Dinges DF. In: Kushida C. (Ed.), Sleep Deprivation. 2005, 39–70. 4. Saper CB, Chou TC, Scammell TE. Trends in Neurosciences 2001; 24: 726–31 5. Balkin TJ et al. J. Sleep Res. 2004; 13: 219–27. Financial disclosure: NIH grants NR04281 and RR00040, and NASA cooperative agreement NCC 9–58 with the NSBRI. EFFECT OF VARIATION IN COGNITIVE WORKLOAD DURING SLEEP DEPRIVATION HANS PA VAN DONGEN, ALLISON B STAKOFSKY AND DAVID F DINGES Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, U.S.A. The effect of varying cognitive workload on cognitive functioning during sleep deprivation has not been systematically studied. This within-subjects investigation aimed to compare moderate vs. high levels of cognitive workload, operationalized as a two-fold difference in neurobehavioral task duration, during repeated exposure to 36 h of total sleep deprivation. 21 healthy subjects (age 28.5 ± 5.5; 11 females) experienced three 36-h periods of total sleep deprivation, each separated by two recovery days, in the laboratory. Every 2 h during the 36-h sleep deprivation periods, subjects completed a neurobehavioral test battery, during which cognitive performance was measured on the Serial Addition Subtraction Task, Digit Symbol Substitution Task, Word Detection Task and Psychomotor Vigilance Task. Subjects underwent moderate workload (0.5-h-test battery) during two of the sleep deprivation periods, and high workload (1.0-h-test battery) during the other sleep deprivation period, in randomized counterbalanced order. To evaluate the effects of moderate vs. high workload on comparable work periods, the test bouts with high workload (i.e. double task duration) were analyzed using only the responses during the first half of each task. For every task, cognitive performance measures were averaged across the last 24 h of sleep deprivation, so as to yield a single subject-specific measure of impairment during each sleep deprivation period. The moderate and high workload conditions were then compared using a mixed-model analysis of variance (ANOVA), controlling for the order of conditions. Cognitive impairment was found to be significantly greater in the high workload condition than in the moderate workload conditions, for all four performance tasks (F[1,39] > 6.0; P < 0.02). This result indicates that higher cognitive workload, operationalized as increased neurobehavioral task duration, negatively affected cognitive performance during sleep deprivation, even when controlling for task duration. This effect of varying cognitive workload has not been instantiated in Sleep and Biological Rhythms 2005; 3: A2–A73 sleep/wake theories and models of cognitive performance impairment due to sleep loss. We hypothesize that maintaining cognitive performance capability in the high workload condition required compensatory recruitment of additional brain resources, which may have presented a cost to the brain causing the increased cognitive impairment during sleep deprivation. Financial disclosure: NIH grants HL70154 and RR00040 supported this work. COGNITIVE NEUROSCIENCE OF SLEEP DEPRIVATION: FMRI STUDIES OF WORKING MEMORY PERFORMANCE AND ATTENTION MICHAEL CHEE, WEI-CHIEH CHOO, WAI-YEN CHAN, LISA CHUAH, JOANNA SZE AND LI-JUAN SHEN Cognitive Neuroscience Laboratory, SingHealth, Singapore Working memory is an important mental capability that is compromised during short-term total sleep deprivation (TSD). Behavioral studies have shown that task difficulty modulates the effect of TSD on task performance but the direction of this effect differs across studies. We evaluated how TSD affects brain regions recruited in the performance of tasks engaging working memory using two different working memory tests. Functional magnetic resonance imaging (fMRI) was used to image healthy young adult volunteers as they performed these tests under conditions of rested wakefulness, 24 and 36 h of sleep deprivation. In all, three experiments were performed. Two experiments involved testing the difference between manipulating and merely maintaining letters in memory. In these experiments, the ‘harder’ of two conditions, resulted in better preserved performance following 24 h TSD in one cohort of volunteers but not in another (under slightly different experimental conditions). In the third study, task difficulty as determined by the number of intervening items kept in mind (n-back test) was associated with performance decline at all levels of item load after 24 h TSD. In many prior functional imaging studies, verbal working memory has been shown to engage frontal and parietal regions. In our studies, the most consistent fMRI finding in all three experiments was that of relatively reduced parietal activation bilaterally following TSD of 24 and 36 h. All experiments showed that left frontal activation increased with task difficulty during rested wakefulness, but just how activation was modulated as a function of TSD differed between studies. The effect of state on frontal activation varied with test and task difficulty. Further, contrary to what might have been predicted from the behavioral data, there was no significant difference in frontal activation when volunteers were tested at 24 and 36 h of TSD. These imaging results which involve a total of 49 different volunteers, concur with the somewhat contrary results obtained from behavioral studies. In concert with a review of existing functional imaging studies of cognition following sleep deprivation we tentatively conclude that how the brain adapts to sleep deprivation is dependant on the tests used and the experimental conditions employed. The extent to which TSD produces reproducible neural responses to different cognitive tasks tapping the same cognitive domain remains a subject of further research. Supported by: NMRC 200/0477, BMRC 014, The Shaw Foundation A29 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 S-21. The science of what patients do not tell and doctors do not ask Chairperson: Deepak Shrivastava (USA) PREVALENCE OF SLEEP-RELATED BREATHING DISORDER SYMPTOMS IN DELHI, INDIA VK VIJAYAN VP Chest Institute, University of Delhi, Delhi 110 007, India A population based survey to know the prevalence of sleep related breathing disorders using a questionnaire has been completed in both rural and urban areas of Delhi. In the rural areas, 19 villages out of a total of 232 villages were randomly selected during the first stage. After ascertaining the population of each village, households were then selected by systematic sampling method to obtain a sample of 350–400 subjects from each village. In the urban areas, 32 municipal wards (as clusters) out of a total of 134 wards of the Municipal Corporation of Delhi were selected by cluster sampling method initially. One polling station from each cluster was then selected by simple random sampling method. Population of each polling station was ascertained and households from each polling station were selected by systematic sampling method to obtain a sample of 225–250 people from each polling station. The field Investigators made house-to-house visits and handed over the study questionnaire to all adult members of over 18 years of age residing in the house. A repeat visit was made by the Investigators to contact the members who were absent during the first visit. The questionnaires were readministered to a sample of 300 respondents to know the agreement between the first and the readministered questionnaires and the agreement as measured by the ‘kappa estimate’ was 0.910. Fifteen multiple-choice questions were given in the questionnaire and each question was scored according to the severity of breathing disorder symptoms by use of a five-point scale. Each subject was asked to choose one of the five alternative answers to each question: 1. ‘never’, 2. ‘less than once a week’, 3. ‘once or twice a week’, 4. ‘three to five nights/day a week’ or 5. ‘almost everyday/night’. The responders were classified as having sleep related breathing disorder symptoms if they had loud snoring (scores 4 or 5) and/or daytime sleepiness (scores 4 or 5). At the time of interview, age, weight (portable scale) and height were recorded. A total of 14 991 subjects (7016 subjects from the rural area and 7975 from the urban area) were studied. There were 7609 (51%) males and 7382 (49%) females. A history of sleep related breathing disorder symptoms was present in 1011 (7%) out of 14991 subjects. Among the males and females, 696 (9%) and 315 (4%) subjects, respectively, had sleep disordered symptoms. Further analysis had shown that subjects with sleep related breathing disorder symptoms were older with significantly higher (P < 0.01) body weight and body mass index (BMI) in both sexes compared to subjects without symptoms. In subjects with sleep related breathing disorder symptoms, snoring was significantly (P < 0.01) more in males as compared to females. (This study was funded by the Department of Science and Technology, Government of India) DANGERS OF NONAWARENESS OF SLEEP DISORDERS ROBERT MONIE Valley Sleep Disorders and Research Center, Stockton, CA 95204, USA Objective of this presentation is to review of the up-to-date data on epidemiology and health consequences of sleep disordered breathing. Over the last decade, data has been progressively being compiled pointing A30 out the potential and real dangers inherent in sleepiness and sleep disordered breathing. Initially it became apparent that the diagnosis of sleep-disordered breathing carried with it a poorer prognosis. Interest in the effects of sleepiness with driving and attended consequences pointed out loss of time, revenues and injury. Cardiovascular complications have developed as the major focus for consequences of sleep disordered breathing. Congestive heart failure is associated with periodic breathing disorder especially Cheyne-stokes respirations and an attendant increased risk of mortality. The incidence of coronary artery disease, hypertension and arrhythmias are higher in sleep-disordered breathing. New evidence suggests the association of sudden death. The American Academy of Sleep Medicine has just released new Practice Parameters for the Indications for Polysomnography and Related Procedures: An Update for 2005. Included are new recommendations as ‘Standards’, ‘Guidelines’ and ‘Options’ specifically for heart failure, coronary heart disease, stroke and arrhythmias. TRICKS OF THE TRADE: IMPROVING SLEEP LABORATORY PERFORMANCE SUSAN EDWARDS San Jaoquin General Hospital Sleep Center, French Camp, CA Sleep disorders are prevalent in the society. However, acceptance of the problem and life style adjustment are common. Health care providers seldom ask questions regarding patient’s sleep health. Similarly, patients rarely volunteer any sleep related information. This combination is deadly at its worse. We introduced the Berlin Questionnaire to the primary care patients in the clinics of a large health care system. Patients filled the questionnaire as they left the clinic after their appointments. The information was reviewed to determine the possibility of an undiscovered sleep disorder. The medical records were then reviewed for sleep related provider notation on the same visit. 2761 questionnaires were given out. 1838 patients (66.5% response rate) completed the questionnaires over four years (1999–2003). Many patients did not complete the questionnaire due to language barrier. There were 1141 men (mean age 57 years) and 697 women (mean age 48 years). Based on the questionnaire criteria, 335 (29.3%, Confidence interval (CI) 25.2–33.4%) men and 206 (29.5%, CI 24.2–34.7%) women were considered high risk for sleep-disordered breathing. No corresponding notations were found in the medical records of sample patients. Screening tools like simple questionnaires help identify highrisk patients. Provider awareness to ask sleep related questions might increase the probability of identifying a sleep related problem. The availability of an interpreter will further increase the yield. The spouse interviews are considered source of valuable information regarding patients’ sleep problems. Preliminary results of our study of spouses (n = 62) suggest significant limitations (positive predictive value 86%) in spouse information when interviews are conducted in separate rooms. Conflicting information, biased opinions and presumptive statements are prevalent. Our current practice is to find conclusive information after reconciling the intrinsic differences prior to polysomnography. Sleep diary is an under-utilized tool in patient evaluation. Sleep diary is a pre-emptive measure to improve sleep study quality by matching patient preferences to the laboratory schedule. We compared variance in the sleep architecture data (n = 155), with results of the sleep diary as predictor. Although statistical significance was not reached, sleep efficiency is most affected, followed by sleep latency and subjective lack of sleep. Use of screening questionnaire in primary care office, understanding the limitations of spouse interview and proper utilization of sleep diary Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 information is likely to improve the case-finding rate and accuracy of the sleep study results. FUTURE OF SLEEP MEDICINE: DEVELOPING LOCAL RESOURCES AND BENEFITS OF NETWORKING DEEPAK SHRIVASTAVA San Joaquin General Hospital, University of California, Davis, CA Objective of this presentation is to do intense review of alternative methods of diagnosing sleep disorders with reference to current AASM (American Academy of sleep medicine) guidelines and discuss the results of original research comparing home diagnostics vs. sleep laboratory based nocturnal polysomnography. In many countries and communities full service, sleep laboratories are lacking. Waiting period for a sleep study exceeds three months. Portable monitoring is used frequently in the screening and diagnosis of sleep disorders. Comparative review of the literature by AASM, American Thoracic Society and American College of Chest Physicians is available. Portable polysomnography including EEG, electrooculogram, EMG, ECG, airflow, respiratory effort and oxygen saturation devices are frequently used. Apnea-hypopnea index can be calculated, as sleep, staging is possible with some devices. Modified monitors with one to four channels are available. These monitors can be used in remote locations, with and without the technician attendance. Monitors with four channels are useful in diagnosis of sleep-disordered breathing (SDB). In a prospective, nonrandomized trial of unselected primary care patients (n = 810). Group with low risk (n = 408) was assigned portable monitoring whereas group with high risk (n = 402) was subjected to in-lab polysomnography. Portable monitoring in low-risk group detected 99/408 (24%, Confidence interval (CI) 20.1–28.4%) patients with SDB. Polysomnography in these patients confirmed SDB in 80/99 (80.8%). Portable monitor had sensitivity of 86.4% and specificity of 80.8%. Interestingly, at one-year follow-up, of the portable monitor negative patients, who developed symptoms, were found to be positive for SDB, 42/309 (13.5%). Overall, 39.4% patients had SDB at one-year. In high-risk group, 52/402 (12.9%, CI 9.7–16.2%) had negative polysomnography. Results suggest that in unselected primary-care population, screening questionnaire can be false negative and is less specific at one year. Low false positive rate was noted in high-risk patients. When portable monitor detected SDB in otherwise low-risk population, polysomnography confirmed the diagnosis in high percent of patients. Patients should be followed for developing symptoms, if portable monitoring is negative even in low-risk population. Once limitations are well understood, the portable devices can be used for initial evaluation of sleep disorders. Many of these devices are easily available and can be used at locations where sleep laboratories are not available. A local network including a base sleep laboratory may be established for full polysomnography in selected patients. Sleep and Biological Rhythms 2005; 3: A2–A73 S-22. Narcolepsy: Quality of life issues and management Chairperson: Meeta Goswami (USA) QUALITY OF LIFE IN NARCOLEPSY AND THE IMPORTANCE OF SOCIAL SUPPORT MEETA GOSWAMI MPH PhD Director Narcolepsy Institute Assistant Professor Albert Einstein College of Medicine The SF 36, an instrument for measuring quality of life (QOL), was used to determine QOL in narcolepsy in a clinical trial of a wake-promoting agent, modafinil (Provigil). Compared to the general population, subjects with narcolepsy were more affected in vitality, social functioning, and performance of usual activities due to physical and emotional problems. People with narcolepsy experienced HRQOL effects as bad as or worse than those with Parkinson’s disease and epilepsy in several HRQOL areas. HRQOL effects were worse among people with narcolepsy than among those with migraine headaches with one exception: bodily pain. Pharmacological intervention may not be sufficient to allay the psychosocial impact of this impairment. Annual evaluations conducted on group attenders at the Narcolepsy Institute indicate that support groups provide a forum for information exchange about the common elements of a condition, acceptance by peers who are similarly affected, shared understanding, and access to valuable resources. Patients feel reassured and develop a positive outlook. Support groups facilitate active involvement by patients in their health care and have a unique value in the total care of a patient and in enhancing their quality of life. SYMPTOMS AND MANAGEMENT OF NARCOLEPSY EVELINE HONIG Narcolepsy Network, 3 Rosehill Road, Briarcliff Manor, New York 10510, USA The two main symptoms of Narcolepsy are Excessive Daytime Sleepiness and Cataplexy. The sleepiness may be in the form of sleep attacks, continual sleepiness or drowsiness, tiredness, no energy, etc. Cataplexy is a sudden loss of control of the voluntary muscles. Emotions can trigger a Cataplexy attack. Other symptoms include sleep paralysis, hypnagogic hallucinations, disturbed nighttime sleep and automatic behavior. The person who has sleep paralysis feels awake, but is unable to move. Hypnagogic hallucinations are when REM sleep begins before a person is fully asleep. People with Narcolepsy have an increased light nighttime sleep (stage 1), so that they are more easily awakened. Automatic behavior is when familiar, routine or boring tasks are performed without full awareness or later memory of them. In most cases of Narcolepsy we see a loss of brain cells that make a chemical called ‘hypocretins’; there is a genetic component and also an autoimmune hypothesis. Treatment options include medications, sleep regulation and diet and counseling. Good management of Narcolepsy is very important and school and workchoices need to made very carefully. Narcolepsy is not yet recognized as a serious illness and the general public should be more educated about Narcolepsy and other sleep disorders, so it can be diagnosed early and the people affected can be treated properly. A31 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 NARCOLEPSY IN MY FAMILY AND PROFESSIONAL LIFE ROBERT L CLOUD Attorney, 2646 Black Hoof Trail, Milford, Ohio, U.S.A. Bob, age 62, is an active attorney. He also has severe narcolepsy, including all symptoms. He understands, from years of painful experience, how this disorder of fragmented sleep in turn fragments life. Narcolepsy-with-cataplexy has threatened his professional career, impacted close friendships, caused injuries and rescues, and challenged family life. Yet he continues to practice law full-time, laughs with his friends, and enjoys most his family time. How? Because his doctors asked the right questions and got the diagnosis right the first time. They studied and used international research data. And they worked together. Bob’s first medications came from France, through Canada, to his home in Ohio, with FDA approval. He is the first and longest user of Xyrem (25 years) in the U.S., and was active in seeking FDA approval of Provigil. Bob believes he’s benefited from the best of sleep disorder research and practice. His family and friends have provided unwavering support. He hopes his story adds flesh and feeling to your research data, and renewed motivation to your clinical practice. SOCIAL WORK INTERVENTION IN NARCOLEPSY MS K BHUVANESHWARI BHAGAT Narcolepsy Institute, Montefiore Medical Center This article describes social work intervention in narcolepsy. The treatment of narcolepsy utilizes a variety of skills, techniques, and activities consistent with its holistic focus on persons and their environments. The interventions range from primarily person-focused psychosocial processes to involvement in social support, planning and development. These include but are not limited to: Counseling, Clinical Social Work including behaviour modification, Group Work, Social Pedagogical Work, Family treatment and therapy, Obtaining services and resources in the community. Finally we will discuss a case study in relation to the above indicators of intervention. The article consequently provides a foundation for better outcomes in the treatment plans for patients with narcolepsy. S-23. Sleep at high altitude Chairperson: W Selvamurthy (India) OVERVIEW OF HIGH ALTITUDE OF SLEEP RESEARCH W SELVAMURTHY CC, R and D (LS and HR), B Wing, Sena Bhavan, New Delhi-110011 An altered quality and quantity of sleep affects the physiological and psychological well being of an individual leading to a reduced physical and cognitive performance. High altitude hypoxia is known to impair sleep function. This aspect has been focus of older and recent studies. Sleep studies started in the middle of the 19th century; during the same period, Stokes and John Cheyne described Periodic breathing at high altitude. The golden age of sleep research began with the discovery in 1937 by the American Physiologist Loomis of different stages of sleep reflected in the EEG changes. Since then sleep studies have been carried out in simulation chambers and actual field condition on sojourners and high altitude natives as well as in experimental animals. Sleep at A32 high altitude is characterized by poor subjective quality, increased awakenings, brief frequent arousals, marked nocturnal hypoxemia and Periodic breathing. Sleep architecture shows changes in NREM and REM sleep. Significant research on mechanism of sleep disrupted breathing at high altitude including chemoreceptor sensitivity studies has been carried out. Respiratory periodicity at altitude reflects alternating respiratory stimulation by hypoxia and subsequent inhibition by hyperventilation induced hypocapnia. It has been demonstrated that the Periodic breathing cycle length decreases with increasing altitude. Sleep deprivation is another important area of research. Improvement in performance following sleep deprivation using pharmacological interventions (Caffeine, Theophylline, Modafinil and others) has been the focus of some recent studies. The mystery of the Neurochemistry of high altitude sleep is still not completely solved. Besides the traditional neurotransmitters involved in sleep regulation, some of the recent work looks at the role of melatonin, cytokines, orexins, leptins and prostaglandins. Recent work is probing the role of NMDA, GABA and kainite receptors and heat shock protein family, C-reactive proteins, ERp 72 and GRp 78. Strategies to device improvement in sleep qualities at high altitude is the need of the day. Some of the recent work talks about oxygen enrichment of room air and pharmacological interventions including acetazolamides and benzodiazepines. With the induction of recent techniques including fMRI, PET,Genomics and Proteomics,the coming few years will be significant in taking us forwards in the area of high altitude sleep research. PERIODIC BREATHING: HOW DOES IT HAPPEN AND DOES IT CAUSE SLEEP DISRUPTION IN HYPOXIA? ANDREW T LOVERING1,2, JIMMY J FRAIGNE1, WITALI L DUNIN-BARKOWSKI1, EDWARD H VIDRUK2 AND JOHN M OREM1 1 Texas Tech University School of Medicine, Department of Physiology, Lubbock, TX, 79430, USA, 2University of Wisconsin Medical School, John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, Madison, WI, 53706, USA Periodic breathing (PB) and sleep disturbance are common occurrences at altitude but the mechanisms of these phenomenon, and their relation to each other, are not completely understood. It seems clear however, that PB does not account entirely for the sleep disruption that occurs at altitude. Our lab investigated (1) the role of hypocapnia on sleep disruption in hypoxic environments and (2) the neural muscular mechanisms of PB in the intact unanesthetized cat. In our sleep studies hypocapnia induced by either hypocapnic hypoxia or mechanical hyperventilation (hypocapnic normoxia) caused a significant reduction in REM sleep. When hypocapnia was prevented during mechanical hyperventilation, REM sleep was not significantly different from control values (1). Similarly when carbon dioxide levels were increased during hypoxia (by increasing inspired CO2, while maintaining end tidal PO2), the amount of REM sleep increased (1). In our studies PB did not occur during exposure to hypoxia but occurred instead as a posthypoxic ventilatory response. We found that diaphragmatic and medullary respiratory neural activity was phasic during the waxing phase and was less phasic and more tonic during the waning phase of PB. These changes were seen even though the period of cycles during the waxing and waning phases was similar. We conclude that reductions in REM sleep in hypoxic environments can occur independently of PB and that these reductions are attributable primarily to hypocapnia rather than hypoxia. Furthermore we conclude that PB is the result of changes in intensity of phasic respiratory neuronal activity that are independent of the period of the cycle. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Reference Lovering AT, Fraigne JJ, Dunin-Barkowski WL, Vidruk EH and Orem JM. Hypocapnia reduces the amount of Rapid Eye Movement sleep in cats. Sleep 26: 961–7, 2003. Financial support: NIH HL-21257, HL-62589, NS-46062, T32 HL07654-16, GAANN P200A80102, ARCS Foundation. SLEEP AT HIGH ALTITUDE: THE INDIAN PERSPECTIVE USHA PANJWANI, L THAKUR, JP ANAND AND PK BANERJEE Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timar pur, Delhi-110054; India In sojourners to high altitude sleep function is considerably compromised. Poor quality of sleep hampers cognitive functions and reduces performance. Sleep studies conducted by DIPAS during the last 3 decades included subjective evaluation of sleep quality, polysomnography, cognitive performance tests including P300 and autonomic functions in sojourners, acclimatized lowlanders and high altitude natives in the Western and Eastern Himalayas. A marked deterioration in subjective evaluation of sleep quality at locations between 3000 m to 6000 m was found. An increase in sleep latency, greater number of awakenings and a deterioration in sleep quality was reported. Polysomnographic data recorded at 3500 m and 4300 m on sojourners showed reduced sleep efficiency and reduced stages 3 and 4 of NREM sleep. Recent studies at 4300 m revealed the presence of Periodic Breathing, increase in Respiratory Distress Index, and increase in Hypopnea counts on day 2 of induction. An increase in P3 latency of the P300 response was observed pointing to an impairment in cognitive function. In acclimatized lowlanders and high altitude natives, there was a similar curtailment of stages 3 and 4 of NREM sleep but no changes in the number of awakenings. Sympathetic hyperactivity and an increase in anxiety levels were observed in sojourners, while acclimatized lowlanders and high altitude natives had reduced sympathetic activity levels. High altitude hypoxia has a detrimental effect on sleep quality, which may be an important factor affecting performance at high altitude. Studies are needed to device strategies to improve the quality of sleep at high altitude. S-24. Pathophysiology of Sleep Apnea Chairperson: Robert W. McCarley (USA) LINKING THE NEUROBIOLOGICAL AND BEHAVIORAL CONSEQUENCES OF SLEEP APNEA ROBERT W MCCARLEY, JAMES MCKENNA, CHRIS WARD, JAIME TARTAR AND ROBERT STRECKER Department Psychiatry, Harvard Medical School and VA Boston Healthcare System, Brockton, MA 02301 USA We have developed a rodent model of obstructive sleep apnea that separates the effects of the hypoxia and sleep interruption seen in episodes of obstructive sleep apnea (OSA). Frequent interruptions of sleep are consequences of OSA episodes and to model these we used sleep interruption (SI) produced by a treadmill that moved for 10 s, and then was still for 30 s. As a result, animals could not readly enter deep (delta) sleep and had more wakefulness compared with each of two control groups: (1) exercise controls (EC), rats on a treadmill that was on for Sleep and Biological Rhythms 2005; 3: A2–A73 10 min and off for 30 min, thus allowing deep sleep; and (2) compared with cage controls (CC), rats that remained on a nonmoving treadmill. The effects of intermittant hyoxia (IH) were evaluated by sinusoidially varying over 2 min the oxygen concentration of inspired air such that 20 s were above 18% and 20 s were below 10%; control animals had a normal atmospheric concentration of inspired oxygen. Polysomnographic measures of wake, NREM and REM states were evaluated following EEG/EMG recording in rats exposed to IH, SI, or control groups. Since our previous work established that the purine adenosine (AD) may facilitate sleepiness by inhibiting wakefulness-active, cortical activation- and wakefulness-promoting neurons of the cholinergic basal forebrain (CBF), we predicted that AD would mediate the sleepiness due to SI. Microdialysis sample collection coupled to microbore HPLC analysis determined extracellular CBF AD levels. Following 6 h of SI, AD levels rose significantly above baseline. AD levels continued to rise during 30 h of SI exposure, where AD levels during the light period of the second day reached approximately 220% of baseline. In a separate group of rats, AD levels and delta activity were also assessed after 5 days of SI. SI-exposed rats experienced shorter sleep bouts, and delta activity was found to increase more as SI exposures progressed. Furthermore, a significant increase in delta activity during NREM was observed in the recovery periods following 6 h of SI. The McCarley abstract in Symposium 21 describes the neurobehavioral consequences of SI. We found that up to 2 days, 10 h per day of IH did not produce a significant elevation in BF AD levels. There was an initial transient increase in wakefulness that was no longer present by day 2. No significant differences of delta activity (a measure of homeostatic sleep pressure) during NREM were observed in the recovery period after either IH exposure day. Based on the delta activity analysis, SI, compared to short-term IH, appears more responsible for the OSA symptom of daytime sleepiness, and this may be mediated by mechanisms involving CBF AD. Supported by: VA Medical Research Service Awards to RES and RWM; MH39683, HL060292, HL07901, MH070156. NADPH OXIDASE MEDIATES HYPERSOMNOLENCE AND BRAIN OXIDATIVE INJURY IN A MURINE MODEL OF SLEEP APNEA G-X ZHAN1, F SERRANO2, P FENIK1, R HSU1, L KONG1, D PRATICO1, E KLANN3 AND SC VEASEY1,2 1 Center for Sleep and Respiratory Neurobiology and Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, 2 Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston TX and 3Center for Experimental Therapeutics, Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA Persons with obstructive sleep apnea may have significant residual hypersomnolence, despite therapy. Long-term hypoxia/reoxygenation events in adult mice, simulating oxygenation patterns of moderatesevere sleep apnea, result in lasting hypersomnolence, oxidative injury and proinflammatory responses in wake-active brain regions. We hypothesized that long-term intermittent hypoxia activates brain NADPH oxidase and that this enzyme serves as a critical source of superoxide in the oxidation injury and hypersomnolence. We sought to determine whether long-term hypoxia/reoxygenation events in mice result in NADPH oxidase activation and whether NADPH oxidase is essential for the proinflammatory response and hypersomnolence. NADPH oxidase gene and protein responses were measured in wakeactive brain regions in wild-type mice exposed to long-term hypoxia/ A33 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 reoxygenation. Sleep, oxidative and proinflammatory responses were measured in adult mice either devoid of NADPH oxidase activity (gp91phox null mice) or in which NADPH oxidase activity was systemically inhibited with apocynin osmotic pumps throughout hypoxia/ reoxygenation. Long-term intermittent hypoxia increased NADPH oxidase gene and protein responses in wake-active brain regions. Both transgenic absence and pharmacological inhibition of NADPH oxidase activity throughout long-term hypoxia/reoxygenation conferred resistance to, not only longterm hypoxia/reoxygenation hypersomnolence, but also to carbonylation, lipid peroxidation injury and the proinflammatory response, including inducible nitric oxide synthase activity in wake-active brain regions. Collectively, these findings strongly support a critical role for NADPH oxidase in the lasting hypersomnolence, oxidative and proinflammatory responses following hypoxia/reoxygenation patterns simulating severe obstructive sleep apnea oxygenation, highlighting the potential of inhibiting NADPH oxidase to prevent oxidation-mediated morbidities in obstructive sleep apnea. CENTRAL AND PERIPHERAL EFFECTS OF CHRONIC INTERMITTENT HYPOXIA ON GLUCOREGULATION VICTOR B FENIK, DENYS V VOLGIN, JENNIFER L SWAN, RICHARD O DAVIES AND LESZEK KUBIN Department of Animal Biology, University of Pennsylvania, Philadelphia, PA 19104–6046, USA Clinical association studies show that obstructive sleep apnea (OSA) is an independent risk factor for insulin resistance (reviewed by Punjabi et al. 2003). However, the mechanisms by which OSA can lead to altered glucose metabolism are unknown. We tested whether one distinct aspects of the disorder, chronic intermittent hypoxia (CIH), which occurs in OSA patients, alters glucose regulation in rodents. Adult, male Sprague-Dawley rats were exposed to CIH (O2: 5.5–10% for 70 s followed by 19–25% for 80 s, 10 h/day), or matching room airflows, for 35 days. After treatment, rats were fasted and either urethaneanesthetized and subjected to the intravenous glucose tolerance test (400 mg/kg) or rapidly sacrificed under deep isoflurane-anesthesia, RNA extracted from the pancreas and distinct hypothalamic regions, and selected mRNAs quantified by RT-PCR. During the exposure period, body weight gain was slower in CIH than in control rats (2.9 g/day ± 0.2(SE), n = 15 vs. 4.2 ± 0.3, n = 17, P < 0.01). In urethane-anesthetized CIH rats, glucose-stimulated insulin releases was reduced (87 ± 13 mU/L vs. 151 ± 26 at 17–25 min after glucose bolus, P < 0.05, n = 9 and 9), and glucose level elevated (265 ± 18 mg/dL vs. 205 ± 19 at 70 min after glucose injection, P < 0.05). Pancreatic levels of two mRNAs involved in the regulation of insulin release, quantified as the number of cDNA copies/g of total RNA (± SE), were lower in CIH rats; Munc-18 350 ± 50 vs. 920 ± 200 (P < 0.03), and Syntaxin-1 A 210 ± 60 vs. 500 ± 100 (P < 0.05). In contrast, the insulin-1 precursor mRNA was higher, 212 000 ± 59 000 vs. 44 000 ± 13 000 (P < 0.01; n = 6–8 in each group). In the hypothalamic perifornical region, mRNA levels for á2A adrenergic receptor and â3 subunit of GABAA receptor were higher in CIH rats (940 cDNA copies/ng total RNA ± 120 vs. 550 ± 95, and 52 000 ± 9000 vs. 21 000 ± 8000, respectively; P < 0.05 for both, n = 5–6). Glucose-stimulated insulin release is suppressed in rats exposed to CIH for 35 days due to an impairment in pancreatic insulin release mechanisms, rather than reduced insulin synthesis; an altered transcription in hypothalamic glucoregulatory regions may contribute to this impairment. Qualitatively similar changes also occur in healthy A34 humans subjected to chronic sleep restriction (Spiegel et al. 1999). This suggests that CIH and chronic sleep loss have additive effects that initially impede the response to carbohydrate load. With time and repeated insulin spikes, this may lead to the development of insulin resistance. References Punjabi NM, Ahmed MM, Polotsky VY, Beamer BA, O’Donnell CP. Sleep-disordered breathing, glucose intolerance, and insulin resistance. Respir. Physiol. Neurobiol. 2003, 136: 167–78. Spiegel K, Leproult R, Van Cauter E. Impact of sleep debt on metabolic and endocrine function. Lancet 1999; 354: 1435–9. Support: NIH grant HL-074385. BEHAVIORAL ABNORMALITIES IN AN EXPERIMENTAL MODEL OF SLEEP DISORDERED BREATHING BARRY W ROW Department of Pediatrics, Kosair Children’s Hospital Research Institute, University of Louisville Obstructive sleep apnea syndrome (OSAS), the most severe form of sleep disordered breathing (SDB), is a frequent medical condition characterized by repeated episodes of upper airway obstruction, intermittent hypoxia (IH), and sleep fragmentation resulting from recurrent arousals from sleep such as to relieve the upper airway obstruction. The morbid consequences of OSAS are substantial, and primarily include cardiovascular and neurocognitive dysfunction. Given the increasing prevalence of OSAS, it is therefore imperative to identify the underlying factors that contribute to the behavioral and neuronal vulnerability of the disease. The recent development of rodent models has permitted exploration of the role and potential mechanisms whereby exposure to intermittent hypoxia (IH) during sleep contributes to the behavioral deficits observed in OSAS. Exposure to IH in the rat is associated with neurodegenerative changes in brain regions involved in learning and memory, as well as alterations in the neural systems underlying attention and locomotor activity in the developing animal. Multiple pathophysiological pathways appear to be involved in the mechanistic aspects of the behavioral and neuronal susceptibility to IH during sleep which include such factors as glutamate excitoxicity, oxidative stress, inflammatory mediators such as COX-2, iNOS, and PAF, as well as altered regulation of pro- and antiapoptotic gene cascades. Collectively, the available data indicate that exposure to IH during sleep is associated with adverse behavioral and neuronal consequences in the rodent, which may have important implications for clinical populations. S-25. Molecular and neural network in sleep-wake regulation Chairperson: Yoshihiro Urade (Japan) MOLECULAR MECHANISM OF SLEEP YOSHIHIRO URADE Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565–0874, Japan In this symposium, we summarize the recent progress in the research of molecular and neuronal networks involved in sleep-wake regulation. We will focus on prostaglandin D2 (PGD2), adenosine, orexin and histamine, all of which are recognized as key molecules for sleep-stage control. PGD2 and adenosine are proposed to be major humoral sleepinducing factors accumulated in the brain during wakefullness. PGD2 Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 stimulates DP receptors localized in the basal forebrain and increases the local extracellular concentration of adenosine. Adenosine activates A2A receptor-possessing neurons in the basal forebrain and/or ventrolateral preoptic area (VLPO). An intracerebroventricular infusion of PGD2 or adenosine A2A receptor-agonists induces non-REM sleep and increases the expression of fos protein in VLPO. The activation of VLPO neurons is associated with a decrease in the fos expression in the histaminergic tuberomammillary nucleus (TMN), one of the arousal centers. The GABAergic inhibition of TMN is involved in the non-REM sleep induction by PGD2 or adenosine A2A receptor-agonists, whereas the activation of TMN neurons by orexin or prostaglandin E2 induces wakefullness. The neural network between VLPO and TMN is considered to play a key role in the regulation of vigilance states. Four leading researchers will discuss somnogenic stimulation with PGD2 and adenosine of the basal forebrain and VLPO (Drs Eguchi and Luppi) and arousal stimulation with orexin and histamine of the posterior hypothalamus (Drs Sakurai and Huang). ALTERATIONS OF SLEEP-WAKE BEHAVIORAL CHARACTERISTICS AND CENTRAL NERVOUS HISTAMINERGIC SYSTEMS IN HISTAMINE H1 RECEPTOR KNOCKOUT MICE ZHI-LI HUANG1,2, TAKATOSHI MOCHIZUKI1,3, WEI-MIN QU1, YOSHIHIRO URADE1 AND OSAMU HAYAISHI1 1 Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565–0874, Japan, 2Department of Pharmacology, Shanghai Medical College of Fudan University, Shanghai 200032, P. R. China, 3Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA Histaminergic neurons have been suggested to play an important role in the regulation of sleep-wake behavior via histamine H1 receptors (H1R). We characterized the sleep-wake behavior in H1R knockout (KO) mice to clarify the contribution of H1R in the regulation of wakefulness. As compared with wild type (WT) mice, H1R KO mice exhibited 16–20% decreases in the histamine content of most brain regions, in the mRNA expression of histidine decarboxylase (HDC) and histamine H3 receptor (H3R), and in HDC activity in the hypothalamus, where the sole source of the histaminergic neurons is located. The KO mice showed essentially identical sleep-wake cycles to those of WT mice but with fewer incidents of brief awakening (<16 s epoch) and prolonged duration of non-REM sleep. An H1R antagonist, pyrilamine, mimicked the reduction of brief awakening in the WT mice. When ciproxifan, an H3 receptor antagonist, was administered intraperitoneally, it increased wakefulness in WT mice but not at all in H1R KO mice. In vivo microdialysis revealed that the ciproxifan application increased histamine release from the frontal cortex in both genotypes of mice with about 30% of reduction of the recovered histamine in H1R KO mice. These results indicate that H1R is important in the regulation of state transitions from non-REM sleep to wakefulness and is essential for the arousal effect of an H3 receptor antagonist ciproxifan. MOLECULAR MECHANISM OF THE SLEEP REBOUND AFTER PROLONGED WAKEFULNESS NAOMI EGUCHI Waseda-Olympus Bioscience Research Institute, Waseda University, Biopolis, Singapore 138667, and Osaka Bioscience Institute, Osaka 565–0874, Japan A person taking a nap after SD shows deep sleep, i.e. non-REM sleep. However, the mechanism involved in these responses remains unclear. Previously, we demonstrated that prostaglandin (PG) D2-induced non-REM sleep was mediated by DP receptor in mice and that PGD2 was produced by lipocalin-type PGD synthase (L-PGDS) in the brain of wild-type (WT) mice and induced the strong rebound of both non-REM and REM sleep in an SD-time dependent manner (0, 3, and 6 h). However, the gene-knockout (KO) mice for L-PGDS or DP receptor did not show any rebound of non-REM sleep after the 6 h SD, indicating PGD2 to be crucial for induction of the non-REM sleep rebound after SD. In situ hybridization with radioisotope-labeled RNA probe and immunohistochemistry revealed that L-PGDS was up-regulated in the leptomeninges and oligodendrocytes in an SD time-dependent manner. The level of L-PGDS-mRNA increased 1.3-fold in the whole brain and especially in perineuronal oligodendrocytes of the thalamus and hypothalamus up to 1.6-fold. Therefore, we propose that PGD2 produced by L-PGDS during SD induces the non-REM sleep rebound to protect neurons against SD-related stress. Next, we investigated the effect of SD on spatial learning and memory, as assessed by the Morris water maze test with the hidden platform for 6 days. The mean escape latency decreased as a function of training days for both WT and L-PGDS-KO mice (n = 12) without SD, suggesting that the learning system is not impaired by the L-PGDS-gene deficiency. However, SD treated before swimming (Day 2 to Day 5) suppressed the decline of the mean escape latency only in WT mice, but not in the KO mice. WT mice showed drowsiness day by day during the SD treatment, whereas KO mice remained active even on Day 6. For the probe test on Day 6, SD treatment resulted in a decrease in the time spent around the platform for WT mice but not for KO mice, indicating that SD induced PGD2-mediated drowsiness and impaired spatial memory. ROLES OF OREXIN-PRODUCING NEURONS IN THE MECHANISM THAT STABILIZES SLEEP/WAKEFULNESS STATES AKIHIRO YAMANAKA AND TAKESHI SAKURAI University of Tsukuba, Ibaraki 305–8575, Japan The implication of orexin in narcolepsy suggests the importance of orexin in the normal regulation and maintenance of vigilance states. Orexin neurons project from the LHA to the monoaminergic and cholinergic nuclei in the brainstem to regulate sleep/wakefulness states as well as feeding. The activity of orexin neurons is inhibited by glucose and leptin, and stimulated by ghrelin. In accordance with the previous report that prepro-orexin mRNA is up-regulated by fasting, this observation suggests that orexin neurons sense the animal’s nutritional state by monitoring humoral factors such as leptin and glucose. We also found that orexin neurons are inhibited by serotonin and noradrenaline, while excited by acetylcholine. We recently found that orexin neurons are innervated by multiple specific brain regions implicated in the regulation of sleep/wakefulness states. This study revealed that orexin neural network ensures ‘gflip-flop’ mechanisms between the POA sleep-active neurons and monoaminergic neurons. Thus, orexin neurons have functional interactions with hypothalamic feeding pathways and monoaminergic/cholinergic centers, and provide a critical link between peripheral energy balance and the CNS mechanisms that coordinate sleep/wakefulness and motivated behavior such as food seeking. Prolonged wakefulness or sleep deprivation (SD) induces fatigue effects, such as drowsiness and a decrease in learning and memory, in humans. Sleep and Biological Rhythms 2005; 3: A2–A73 A35 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 THE ENDOGENOUS SOMNOGEN ADENOSINE EXCITES A SUBSET OF SLEEP NEURONS VIA A2A RECEPTORS IN THE VENTROLATERAL PREOPTIC NUCLEUS PIERRE-HERVÉ LUPPI, THIERRY GALLOPIN AND PATRICE FORT UMR5167 – CNRS, Physio-pathologie des Réseaux Neuronaux du cycle Veille-Sommeil, Lyon-69372, France Recent research has shown that GABA/galanin neurons in the ventrolateral preoptic nucleus (VLPO) are crucial for sleep by inhibiting wakepromoting systems, but the process that triggers their activation at sleep onset remains to be established. Since evidence indicates that sleep induced by the sleep-promoter adenosine requires activation of brain A2AR, we examined the hypothesis that adenosine could directly activate VLPO neurons via A2AR in rat brain slices. Following on from our initial in-vitro identification of the sleep neurons as uniformly inhibited by noradrenaline and acetylcholine arousal transmitters1, we established that the VLPO comprises two intermingled subtypes of neurons, differing in their firing responses to serotonin, either inhibited (Type-1, 47%) or excited (Type-2, 53%). Since both cell types contained galanin and expressed GAD-65/67 mRNAs, they potentially correspond to the sleep neurons inhibiting arousal systems. Besides, adenosine and CPA (A1R agonist) inhibited Type-1 and Type-2 neurons. In contrast, adenosine unmasked a reversible and selective excitation of Type-2 cells, while in presence of DPCPX (A1R antagonist). This effect involved the activation of postsynaptic A2AR since it was reproduced by CGS21680 (A2AR agonist) in synaptic uncoupling conditions and reversed by ZM241385 (A2AR antagonist)2. Hence 3, the present study is the first demonstration of a direct activation of the VLPO sleep neurons by adenosine. Our results further support the cellular and functional heterogeneity of the sleep neurons, which could enable their differential contribution to the regulation of sleep. Adenosine and serotonin progressively accumulate during arousal. We propose thus that Type-2 neurons, which respond to these homeostatic signals by increasing their firing are involved in sleep induction. In contrast, Type-1 neurons would likely play a role in the consolidation of sleep through reciprocal inhibitory interactions with the arousal systems. References 1. Gallopin et al. Effect of the wake-promoting agent modafinil on sleep-promoting neurons from the ventrolateral preoptic nucleus: an in vitro pharmacologic study. Sleep 2004, 27: 19–25. 2. Gallopin et al. The endogenous somnogen adenosine excites a subset of sleep-promoting neurons via A2A receptors in the ventrolateral preoptic nucleus. Neuroscience, 2005 (in press). 3. Fort et al. In vitro identification of the presumed sleep-promoting neurons of the ventrolateral preoptic nucleus (VLPO). In Sleep, Circuits and Functions, 2005 pp. 43–64, CRC Press. S-26. REM sleep: a critical assessment of short and long-term regulatory aspects Chairperson: Roberto Amici (Italy) REMS REGULATION IN THE RAT: TEMPORAL COURSE, CIRCADIAN MODULATION AND RELATIONSHIP WITH NREMS ENNIO A VIVALDI1, ADRIÁN OCAMPO-GARCÉS1 AND ALEJANDRO BASSI2 1 Facultad de Medicina, Universidad de Chile, Santiago, Chile, 2Facultad de Ciencias F’sicas y Matemáticas, Universidad de Chile, Santiago, Chile In addition to the regulatory processes that affect REM sleep expression at a circadian time scale, short-term regulatory effects can be demonstrated in the alternation between a REM sleep episode (REMSE) and the interval separating two episodes, since a shorter or longer REM episode tends to be followed, respectively, by a shorter or longer interval. In the spontaneous sleep-wake cycle a positive correlation exists between REMSEs and their following, but not their preceding, intervals. Under a 12 : 12 light : dark schedule the correlation is present at all phases, when REM sleep is abundant and when it is scarce, except only for the first hour after lights-on. The relationship is better described by a sigmoid function whose parameters are modulated throughout the 24 h, presenting the highest amplitude and earliest rise in the first third of the lights-on phase and the lowest amplitude at the start of lights-off. In intervals of a moderate length, below 7 min, using as the dependent variable the time spent in NREM within an interval, as opposed to the whole length of the interval, did not improve the correlation. A carry-over effect could be demonstrated when two successive REM cycles were considered, since a sequence of a long REMSE followed by a short interval tended to result in an interval longer than expected in the next cycle. A nonlinear logistic regression method was employed to develop a model of the dynamics of REM sleep propensity as an interval evolves. When the factor length of previous REMSE was introduced into the model, it was shown to be significant in lowering the propensity to go back into REM sleep, particularly up to the first 8–10 min of the interval. Further evidence for the existence of a homeostatic REM sleep regulatory mechanism operating at the time scale of spontaneous sleep cycle was obtained from an intermittent REM sleep deprivation protocol consisting of six instances of a 10-minute REM sleep permission window alternating with a 20-minute REM sleep deprivation. An increment of REM sleep pressure could be demonstrated through the deprivation window, as well as a decrease proportional to REM sleep expression at the permission window. Financial disclosure: Grant Fondecyt 1030141. CONTRIBUTION OF THE SLEEP CYCLE FREQUENCY TO THE UNDERSTANDING OF SHORT-TERM REMS REGULATION OLIVIER LE BON Université Libre de Bruxelles, Brussels, Belgium The oscillation between REMS and NREMS is a phenomenon observed in most homeothermic species. One or both of the two components could be under the influence of an oscillator. In the first case, REMS would be permitted in the troughs of a cycling NREMS. In the second case, a cycling REMS would interrupt NREMS as a function of its own internal pressure. Or the ultradian alternation may merely result from A36 Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 physiological interaction between the two components with REMS being a complement to NREMS, necessary for its expression. Although its normal distribution has been established in humans and other species more than 30 years ago, the number of cycles in a night (or sleep cycle frequency) is a variable that has seldom been used in sleep research. Two to seven cycles can be observed in normal nights in healthy humans and up to 125/24 h in small rodents. The different hypotheses described above predict different types of associations between this variable and key standard sleep variables. In studies on healthy humans, mice and rats, associations were found between the number of cycles and total REMS, not total SWS, total SWA nor total NREMS. Inverse relationships were found between the number of cycles and the SWA per cycle in humans. These data indirectly support theories where REMS interrupts NREMS and short-term REMS homeostasis. REMS REGULATION UNDER ENVIRONMENTAL CHALLENGES ROBERTO AMICI, FRANCESCA BARACCHI, PAOLO CAPITANI, MATTEO CERRI, DANIELA DENTICO, CHRISTINE ANN JONES, MARCO LUPPI, PIER LUIGI PARMEGGIANI, EMANUELE PEREZ AND GIOVANNI ZAMBONI Department of Human and General Physiology, Alma Mater StudiorumUniversity of Bologna, Italy Physiological regulation is impaired during REM sleep (REMS) (Parmeggiani 2005). As a consequence, REMS occurrence is affected when body homeostasis is challenged by changes in ambient conditions. In particular, REMS occurrence is depressed in animals kept at low ambient temperature (Ta). In the cat, the return to normal laboratory conditions following cold exposure is characterized by a REMS rebound which is proportional to the degree of the previous REMS loss, showing the presence of a fine long-term regulation of REMS amount. Short-term REMS regulatory aspects have been evidenced under normal laboratory conditions in the rat. In this species, the duration of the interval between two consecutive REMS episodes (REMS-INT) appears to be directly related to the duration of the previous REMS episode, but does not show any relationship with the following episode (Vivaldi et al. 1994). Short and long-term regulatory aspects of REMS have been studied in 24 male Sprague Dawley rats (250 g) during a 24 h-exposure to different low Tas (ranging from –10°C to 10°C) and a 4-day recovery at normal laboratory Ta. A precise long-term regulation was observed for REMS, since REMS amount was greatly depressed during the exposure and increased during the first day of the recovery and both these effects were proportional to the thermal load during the exposure (Cerri et al. 2005). In contrast, it appeared that short-term regulation processes were operating during the recovery but not during the exposure, as suggested by the finding that in the latter condition the duration of the REMS-INT was not related to the duration of the previous REMS episode. References Cerri M, Ocampo-Garces A, Amici R, Baracchi F, Capitani P, Jones CA, Luppi M, Perez E, Parmeggiani PL, Zamboni G. Cold exposure and sleep in the rat: effects on sleep architecture and the electroencephalogram. Sleep 2005; 28: in press. Parmeggiani PL. Physiological regulation in sleep. In: Kryger MH, Roth T, Dement WE (eds.) Principles and practice of sleep medicine. Philadelphia WB. Saunders 2000; 169–78. Vivaldi EA, Ocampo A, Wyeneken U, Roncagliolo M, Zapata AM. Shortterm homeostasis of active sleep and the architecture of sleep in the rat. J. Neurophysiol 1994; 72: 1745–55. Financial disclosure: The research was supported by MIUR, Italy. Sleep and Biological Rhythms 2005; 3: A2–A73 Focus Group Abstracts FG-1. Cardio-respiratory Control in Infant Sleep – Recent Developments, Major Questions, New Controversies Chairperson: Adrian Walker (Australia) POSTNATAL DEVELOPMENT OF CARDIORESPIRATORY CONTROL DURING SLEEP IN HUMAN INFANTS ROSEMARY SC HORNE Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia During the early postnatal period the autonomic control of the respiratory and cardiovascular systems undergoes considerable maturation. Newborn infants spend the majority of their time asleep, and the maturation of sleep architecture and sleep states is one of the outstanding developmental features of the first year of life. Sleep states markedly influence both respiratory and cardiovascular control, and given the immaturity of this control during the postneonatal period, it is not surprising that infants are at increased risk for cardiorespiratory disturbances and hypoxaemia during sleep. Apnoea and hypoxaemia are very common problems in infants, particularly those born preterm, and are often the cause of prolonged hospitalisation. Investigation of the maturation of the cardiorespiratory system during sleep is of particular importance in preterm infants in order to understand why these infants are more vulnerable to cardiorespiratory disorders. Despite the dramatic decline in the incidence of Sudden Infant Death Syndrome (SIDS) it is still the leading cause of death in the western world in the postneonatal period. It has been postulated that SIDS results from an alteration in the neural integration of the cardiovascular and respiratory systems, with a concomitant failure to arouse from sleep. Various epidemiological studies have identified factors, both environmental and infant and maternal related which increase the risk of a baby dying from SIDS. Physiological studies have now shown that these risk factors alter infant physiology during sleep and depress arousability. New methods are now needed to further investigate infant physiology during sleep. Continuous measurements of blood pressure and systemic vascular resistance will provide important knowledge which has previously not been available. SLEEP-RELATED CENTRAL AUTONOMIC COMMANDS AND BAROREFLEX CONTROL IN THE NEWBORN ALESSANDRO SILVANI AND GIOVANNA ZOCCOLI Dipartimento di Fisiologia Umana e Generale, Università di Bologna, Italy In adults, central autonomic commands on heart period (HP) and arterial pressure allow an anticipatory regulation during wakefulness (exercise, defense reaction). However, baroreflex control of HP prevails in wakefulness as well as in non-REM sleep, whereas central commands prevail in REM sleep, when they represent regulatory disturbances. In newborn animals, cardiorespiratory regulation undergoes functional maturation and differs in many respects from that of older animals. A37 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 In order to study the relative contribution of baroreflex control and central autonomic commands during the wake-sleep cycle in newborns, we computed cross-correlation functions between spontaneous fluctuations in HP and mean arterial pressure (MAP) in lambs. The linear correlation between HP and MAP yields an index of the balance between central and baroreflex control of HP. The cross-correlation function allows a more complete description of the system under study, as it yields information on the correlation between two signals as a function of the time shift, i.e. positive or negative time lag, between the signals. Thus, the maximum value reached by the cross-correlation function can quantify the strength of the coupling between HP and MAP. The time shift observed, on the other hand, informs on the time relationship between changes in MAP and changes in HP. The experiments demonstrated that a positive correlation between HP and previous values of MAP characterises all wake-sleep states in newborn lambs. The positive correlation was 60% higher during quiet sleep than in the other states. Central autonomic commands on HP were evident only at the beginning of the phasic hypertensive events (MAP surges) that characterise active sleep, when HP decreased almost simultaneously with the rise in MAP. Later in the course of the MAP surges, HP increased consistently with baroreflex control. In conclusion, the analysis of the relationship between HP and MAP indicates that sleep-related changes occur in the control of heart rhythm in newborn lambs. Heart rhythm is more tightly controlled by the baroreceptor reflex and less dependent on central autonomic commands in quiet sleep than in other wake-sleep states. In active sleep, central autonomic commands do not prevail tonically over baroreflex control of HP, but rather represent phasic regulatory disturbances that mark the onset of hypertensive events. SYMPATHETIC CONTROL OF THE CEREBRAL CIRCULATION IN THE NEWBORN ADRIAN M WALKER Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia. At birth, infants face significant risk as both blood pressure and critical organ flows (e.g. cerebral) are at a lifetime minimum. Infants spend the major part of their life in sleep, and early postnatal life sees dramatic changes in sleep organisation. Coincidently, there are dramatic developmental changes in the infant’s circulatory control systems, and the ability to compensate for stresses such as hypotension. Sympathetic nervous effects in the cerebral vasculature are powerful in the newborn, as functional sympathetic innervation appears during fetal life, when it has important trophic and protective roles for the vessels of the immature brain. Neuro-adrenergic mechanisms are also powerful in cerebral vessels of the neonate, much more so than in adults. Moreover, sympathetic neural activity is known to be stimulated in the systemic (noncerebral) circulation of sleeping adults. Thus, sympathetic neural control of cerebral vessels may be particularly prominent in modifying cerebral blood flow in newborn sleep, but as yet there are no studies (neither newborn nor adult) examining this possibility. New investigative approaches such as continuous beat-beat blood flow monitoring complemented by sympathetic neural recordings will assist in understanding whether cerebral sympathetic innervation assumes an important protective role for cerebral micro vessels during unusual or abnormal conditions, such as acute hypertensive episodes precipitated by stress, particularly during the hypertensive episodes of REM sleep, when arterial pressure rises rapidly to high levels. A38 BAROREFLEX CONTROLS IN HUMAN INFANT SLEEP BARBARA GALLAND Departments of Women’s & Children’s Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand The baroreceptor reflex is important in the regulation of arterial pressure; its primary aim to conserve blood flow to two vital organs, the heart and brain. The reflex minimises any variation in blood pressure (BP) by initiating reflex responses of the autonomic nervous system to alter both heart rate (HR) and arterial vascular tone. Classical techniques for studying the baroreflex in human adult or animal studies cannot be applied to the infant because they require cooperation on part of the individual or involve pharmacological agents considered unethical to use in infants. Studies have been limited to mechanical testing to change BP and provoke changes in HR and vascular tone using head-up/down tilting, or changing upper body pressure using a neck chamber device. Such studies are concerned with the short-term regulation of arterial BP but mathematical analyses of beatto-beat HR and BP have been used to estimate HR variability and baroreflex sensitivity, thus allowing the dynamics of system to be studied. Recently developed noninvasive techniques to measure beat-to-beat BP using the volume-clamp system (developed for adult use) have advanced investigations in this area. Although the technique has been modified for infant use, there are technical limitations associated. Another technique, the measure of pulse transit time, may be a useful estimate of BP, although infant data is scant. Reports from the early 90 s that autonomic dysfunction affecting HR control, or autonomic maturational delay, was a feature of some Sudden Infant Death Syndrome (SIDS) victims, has led to a vast number of research studies in this area. The importance of investigating circulatory control was strengthened by published respiratory recordings of infants that died of SIDS showing a progressive bradycardia with continued breathing movements, suggesting maintenance of circulatory control may be a crucial factor in survival. Pre-natal and postnatal risk factors for SIDS, investigating areas of possible compromise, have been focussed on, revealing deficits of BP control in infants born small weight for gestational age, preterm infants, infants of smoking mothers, and infants sleeping prone. Much knowledge has also been gained from these studies about normal ontogeny of BP control, respiratory control, sleep, and arousal. Undoubtedly much has been learnt within the SIDS research arena as to which infants, and in which situations, infants may be compromised in terms of BP control. However the exact mechanism/s leading to SIDS remain elusive. Advancing our knowledge in this area undoubtedly will depend on development of newer, reliable, noninvasive techniques to measure BP in infants. SLEEP AROUSAL AND MOTOR DEFICITS IN SIDS VICTIMS I KATO1, P FRANCO2, S SCAILLET2, J GROSWASSER2, H TOGARI1 AND A KAHN2 1 Department of Pediatrics, Nagoya City University Medical School, Nagoya, Japan, 2Pediatric Sleep Unit, University Children’s Hospital, Free University of Brussels, Brussels, Belgium Failure to arouse from sleep has been suggested to contribute to sudden infants death syndrome (SIDS). Polysomnographic recordings confirmed that the victims who would succumb to SIDS in the future had fewer body movements and spent less time awake than control subjects. The study was undertaken to determine the characteristics of arousals from sleep in infants who eventually died of SIDS. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Infants who died of SIDS some days or weeks after their night-time sleep was recorded polysomnographically in a sleep laboratory. Their sleep recordings were compared with those of control infants matched for gender, gestational age and age at recording. Sleep states and apneas were scored according to recommended criteria. Arousals were differentiated into subcortical activation or cortical arousal, according to the presence of autonomic and/or EEG changes. SIDS infants were characterized by significantly less frequent total arousals than the control infants. Analyzing the types of arousal responses, SIDS victims had fewer cortical arousals, but more frequent subcortical activation than the control infants. The ratio of cortical arousal to subcortical activation was significantly smaller in the SIDS than in the control infants. The duration of the subcortical activation was significantly greater in the SIDS than in the control infants. The analysis of the time distribution of the arousals across the night showed that, compared to the control infants, the SIDS victims showed significantly more frequent subcortical activation events in the first part of the night, and significantly fewer cortical arousals during the latter part of the night. The arousal process include numerous cellular networks and neuromediators and are under the control of both cortical and cerebellar structures. Changes in brainstem or cerebellar neuromediators in response to repeated hypoxic episodes during sleep might contribute to incomplete arousal responses in some vulnerable infants. Arousal from sleep is believed to be an important survival mechanism that may be impaired in victims of SIDS. By arousing from sleep, heart rate, blood pressure and ventilation are increased, and a behavioural response is evoked allowing movement away from a life-threatening stimulus. Future SIDS victims present subtle physiological deficits in arousal process already some weeks before death, reinforcing a suspicion from prenatal vulnerability. FG-2. Culture and Biology of Children’s sleep Chairpersons: Masako Okawa (Japan)and Judith Owens (USA) INTRODUCTION AND OVERVIEW OF SLEEP HABITS AND PROBLEMS IN JAPANESE ADOLESCENTS MASAKO OKAWA Department Psychiatry, Shiga University of Medical Science, Japan The starting part of this report is aimed to describe the sleep habits and sleep problems in Japanese adolescents using data from an epidemiological survey of 34 high schools in two suburban cities in Japan, meanwhile the final part focuses on one of the common sleep disturbances in Japanese adolescents, the delayed sleep phase syndrome (DSPS). From the 3478 (90.7% response rate) students who completed the Japanese version of the Pittsburgh Sleep Questionnaire Index (PSQI-J), 891 (25.6%) were categorized as short sleepers (i.e. their perceived sleep duration was less than 6 h). The mean bedtime (SD) was 00:03 (01:06) hours, and it was later for the male students than for the female students. The mean bedtime was later as the grade went up. The mean rise time was 06:33 (00:47) hours, and it was later for the male students than for the female students. The mean rise time was also later as the grade went up. The mean perceived sleep duration was 380.0 (66.0) min and it was shorter for the female students than for the male students. The mean perceived sleep duration reduced as the grade went up. The mean perceived sleep latency was 16.8 (19.4) min. Sleep and Biological Rhythms 2005; 3: A2–A73 Multivariate logistic regression analysis revealed that short sleep duration was significantly associated with being female and having a later bedtime, an earlier rise time, a high global PSQI-J score, a long study duration outside school hours, and a long commuting duration. Self-reported sleep problems are common in Japanese adolescents and are associated with multiple factors. Clearly there is a need for health education directed at solving sleep problems in Japanese adolescents. Meanwhile, for one common sleep disorders in Japanese high school students, DSPS (with 0.4% prevalence rate) no treatment has been established yet. We propose treatment regimens in our report based on chronobiology: resetting the daily life schedule, chronotherapy, regulation of the lighting environment, methylcobalamin, and/or melatonin. References Tagaya H et al. Sleep habits and factors associated with short sleep duration among Japanese high-school students: A community study. Sleep and Biological Rhythms 2004; 2(1): 57–64. Ohida T et al. An epidemiologic study of self-reported sleep problems among Japanese adolescents. Sleep 2004 August 1; 27(5): 978–85. CULTURE AND BIOLOGY OF CHILDREN’S SLEEP JUDITH OWENS Brown Medical School Because many of the variables that shape sleep and sleep behaviors (parenting and discipline styles, the physical sleeping environment, lifestyle issues, etc.) are highly influenced by the cultural context in which they exist, it is clear that the cultural and family influence on sleep behaviors in children have a major impact. This impact must be taken into consideration in any cross-cultural assessments of sleep problems and sleep behaviors, as in, for example, comparisons of prevalence rates of sleep problems across different countries. A few examples of sleep issues that are impacted upon by cultural and family values include parenting practices, beliefs, and values that influence sleep behavior and sleep problems; the perceived function of sleep and the relative value and importance of sleep as a health behavior; common cultural practices regarding transitional objects (i.e. pacifiers, blankets, etc.), bedtime routines (i.e. television viewing, reading, degree of parental involvement), sleeping arrangements, and sleeping environment (sleeping surface, room-sharing, etc.); temporal organization of sleep-wake states (napping, sleep duration); culturally based interpretations of other sleep-related behaviors (such as nightmares, night terrors, sleep walking, sleep talking); and the perceived impact of sleep problems and insufficient sleep on children’s health, behavior, learning, etc. Cultural issues must also be taken into consideration as well as in defining optimal culturally sensitive identification and treatment strategies in clinical practice. For example, cosleeping of infants and parents is a common and accepted practice in many countries. In many ‘traditional’ societies, sleep is heavily embedded in social practices, and both the sleeping environment and the positioning of sleep periods within the context of other activities is much less solitary and less rigid than in more ‘Westernized’ cultures. Therefore, the developmental goal of independent ‘self-soothing’ in infants at bedtime and after night wakings may not be shared by all families. Ways in which parents define sleep problems in their children and from whom they seek treatment, assessment and treatment approaches for sleep disorders (who provides care and how?), and cultural practices regarding parental management of sleep problems (i.e. behavioral treatment, medication, complementary and alternative medicine) are also issues directly relevant to clinical practice. Therefore, there are many important reasons to consider an international focus in examining sleep problems in children. Not only are many of the variables that affect sleep patterns and practices highly culturally A39 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 based, but, because sleep problems are almost universally present in childhood and have negative effects on health and well-being common to all children, the impact of sleep problems on children and families transcends all cultures. This presentation will offer an overview of the unique cultural implications of sleep practices around the world in order to share information and experiences among groups of physicians and across cultures. EPIDEMIOLOGY OF SLEEP PROBLEMS AMONG MAINLAND CHINESE CHILDREN AND ADOLESCENTS XIANCHEN LIU1 AND LIANQI LIU2 Department of Family and Human Development and Prevention Research Center Arizona State University, AZ 85287, USA, 2Shandong Mental Health Center, Jinan 250014, P. R. China 1 Using data from two epidemiological surveys of schoolchildren and adolescents in Shandong Province of China, this report was aimed to examine sleep patterns and sleep problems and their correlates in Chinese children and adolescents. Structured questionnaires were used to collect data on children’s sleep patterns, sleep problems, and psychosocial information. Sleep patterns and sleep problems in children (n = 517, mean age = 10.5 years, 47% boys): Average bedtime and wakeup time were 21:06 (SD = 44.4min) and 06:24 (SD = 19.8 min), respectively. As age increased, children stayed up later and woke up earlier. Average sleep duration was 9.1 h, significantly decreasing with age (F = 19.63, P < 0.001). Common sleep problems of this sample were as follows: difficulty falling asleep, fear of sleeping in the dark, sleeptalking, restless sleep, teeth grinding during sleep, and daytime sleepiness. Sleep duration and sleep problems in Chinese adolescents (n = 1365, mean age = 14.6 years, 60% boys): Mean night sleep duration was 7.6 h (SD = 48.0 min). Approximately 10% of adolescents slept less than 7 h at night, 42% slept less than 8 h, and only 13% slept 9 h or over. Sleep duration declined significantly with age (r = -.191, P < 0.001). Of the sample, 16.9% reported insomnia symptoms, including difficulty initiating sleep (10.8%), difficulty maintaining sleep (6.3%), and early morning awakening (2.1%); 22% went to sleep later than 12:00 AM. at least once a week; 48.9% had experience of nightmares sometimes or often; 2.3% had ever taken hypnotic medication during the past month. A series of logistic regression analyses showed that multiple child and family factors were associated with elevated risk for sleep problems in Chinese children and adolescents: life stress, chronic health conditions, psychopathology, lack of physical exercise, cosleeping, poor peer relationships, and adverse family environment. Sleep problems in Chinese children and adolescents are comparable to those reported in western countries. Multiple child and family variables are associated with elevated risk for sleep problems in children and adolescents. Prospective longitudinal studies are warranted to examine sleep duration and sleep problems and their effects on child and adolescent well-being across countries. PREVALENCE OF HABITUAL SNORING AND ASSOCIATED SYMPTOMS IN PRIMARY SCHOOL CHILDREN IN HONG KONG ALBERT MARTIN LI Department of Paediatrics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong Habitual snoring (snoring of more than 3 nights per week) is an important manifestation of obstructive sleep apnoea (OSA) and on its own A40 may be associated with the presence of diurnal symptoms. Our study aimed to determine the prevalence of habitual snoring in primary school children in Hong Kong, and to evaluate the diurnal symptoms and conditions that may be associated with it. A validated questionnaire completed by parents was used to assess the sleep and awake behaviours, sleep problems and demographic data of Hong Kong Chinese children aged 6–13 years. Thirteen primary schools in two representative districts in Hong Kong were randomly selected. A total of 6424 out of 9172 questionnaires (response rate was 70.04%) were completed and analyzed. The prevalence rate of habitual snoring was 7.1%. Habitual snorers had significantly more nighttime symptoms, including breathing difficulty during sleep (odds ratio [OR], 15.24; 95% confidence interval [CI], 10.24–22.69; P < 0.0001), mouth breathing during sleep (OR, 10.49; 95% CI, 8.05–13.67; P < 0.0001), night sweating (OR, 5.91; 95% CI, 4.56–7.67; P < 0.0001), restless sleep (OR, 4.67; 95% CI, 3.75–5.82; P < 0.0001), and night terror (OR, 8.71; 95% CI, 4.26–17.81; P < 0.0001) when compared to nonsnorers. There was also increased prevalence of daytime symptoms; feeling tired during the day (OR, 3.30; 95% CI, 2.53–4.31; P < 0.0001), falling asleep while taking bus or train (OR, 3.45; 95% CI, 2.51–4.73 P < 0.0001), falling asleep while watching television (OR, 2.21; 95% CI, 1.32–3.69; P < 0.05), and hyperactivity (OR, 1.87; 95% CI, 1.46–2.41; P < 0.0001) among the habitual snorers. The presence of asthma (OR, 4.5; 95% CI, 3.0–6.75; P < 0.0001), allergic rhinitis (OR, 3.21; 95% CI, 2.57–4.0; P < 0.0001) and a history of tonsillitis in the last 12 months (OR, 4.35; 95% CI, 3.27–5.79; P < 0.0001) increased the likelihood of habitual snoring. Habitual snoring is a significant and prevalent problem in Hong Kong Chinese children and is associated with diurnal symptoms of OSA. The presence of asthma, allergic rhinitis and a history of tonsillitis in the past 12 months increased the likelihood of habitual snoring. SLEEP BREATHING DISORDERS IN JAPANESE CHILDREN SOICHIRO MIYAZAKI AND MASAKO OKAWA Department of Sleep Medicine, Shiga University of Medical Science Nasal obstruction in children causes severe progressive respiratory disturbance during sleep, because they are obligatory nasal breather and nasal obstruction cannot be compensated by mouth breathing during sleep. Obstructive sleep apnea syndrome (OSAS) in children is most common in preschool-aged children, which is the age when the tonsils and adenoids are the largest in relation to the underlying airway size. Some studies have evaluated the prevalence of childhood OSAS, which was approximately 2%. Recent survey on the OSAS prevalence rate of Japanese children indicated 1.4%. Its symptoms are nightly snoring, observed apnea, restless sleep, diaphoresis, enuresis, cyanosis, excessive daytime sleepiness, and behavior or learning problems including attention-deficit/hyperactivity disorder. Findings on physical examination related to adenotonsillar hypertrophy show mouth breathing, nasal obstruction, adenoidal facies, hyponasal speech and chest deformity, which was induced by highly, elevated negative thoracic pressure during sleep. Maxillofacial growth was also affected by sleep related breathing disorder. It is widely accepted that polysomnography (PSG) and intrasophageal pressure monitoring are gold standard in diagnosis for childhood OSAS. However, PSG and intrasophageal pressure monitoring are highly expensive, time consuming and is not easy to carry out on a child. Some abbreviated methods are necessary. Videotaping and nocturnal pulse oximetry are useful for screening techniques. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 SLEEP PROBLEMS IN INDONESIAN CHILDREN (PRELIMINARY STUDY) RINI SEKARTINI Departmen of Child Health University of Indonesia, Salemba 6 Jakarta 10430, Indonesia Sleep problems are common in children. High prevalence of sleep disorder, its negative effect to children and parents, and the success of education and behavior intervention make the importance of screening in the first three years of life is needed. To find the prevalence of sleep disorders in under three year old children and find the correlation between sleep disorder and sosiodemographic factors of parents. A cross-sectional analytical study with simple random sampling method. The subjects of this research were under three year old children at five city in Indonesia. Data were collected from guided interview by using a questionnaire adapted from BISQ (Brief Infant Sleep Questionnaire). The criteria used to define poor sleepers on the basis of the BISQ measures were as follows (1) the child wakes >3 times per night (2) nocturnal wakefulness is >1 h, or (3) the total sleep time is <9 h. A total of 385 respondents were completed; 83.4% of responder were mother. The mean age of children were 19.8 month, 51.4% were boys and 48.6% were girls, and birth order of the child 43.4% were the oldest. Most of the family have 2 children, most of fathers (49.9%) and mothers (53.0%) were low educated and 66.5% families have low economy levels. Prevalence of poor sleepers was 44.2%. Sleeping arrangement 73.5% in parents’ bed, 43.1% child sleep position on her/his back. Fifty-six point one percentages children fall asleep while feeding especially milk or breastfeed, 22.6% while in bed alone, 20% while being rocked, 23.1% while in bed near parent and 22.6% while being held. The mean for nocturnal sleep duration were 565.80 +104.3 minute, day time sleep duration were 204.28 +104.3 min. Forty-two point three percentages of parents consider child’s sleep not a problem at all. BISQ are tool for children sleep problem. Most of the children sleeping arrangement in parents’ bed, and most of them fall asleep while feeding. While the prevalence of poor sleepers were high, most of parents consider child’s sleep not a problem at all. EPIDEMIOLOGIC METHOD ON SLEEP HABIT AND PROBLEMS FOR JAPANESE CHILDREN YURIKO DOI Department of Epidemiology, National Institute of Public Health, Wako, Japan With respect to sleep for children, it is our agreement that crosscultural comparisons among societies with different cultures are invaluable in better understanding the biology of children’s sleep itself as well as the role of culture influencing their sleep. Epidemiological comparison studies are expected to be as one of the promising study areas in this research topic. The development of culturally sensitive tools to measure children’s sleep is essential. The Child Sleep Habit Questionnaire (CSHQ) (Owens et al. 2000) has been widely used for detecting and diagnosing children’s sleep problems in clinical practice. I was given an opportunity of being involved in a project of developing the Japanese version of CSHQ (CSHQ-J). Thus, my presentation is going to focus on the process of developing the preliminary version of CSHQ-J and the findings obtained from the cognitive debriefing of it. The preliminary CSHQ-J was developed through the following steps, translation of the CSHQ from English to Japanese, back-translation of Sleep and Biological Rhythms 2005; 3: A2–A73 the translated CSHQ from Japanese to English, and comparison the back-translated to the original one on whether or not the instructions, questions and response choices of the two had the same meanings. At the next step, it was applied to 5 Japanese mothers, who graduated from college or high school, with preschool children. After filling it out, they were interviewed to examine whether or not the meanings and wordings were clear and consistent. Overall, all the mothers interviewed agreed the questions were easy to understand, however, some caused them confusing. First, it became clear that since there were many different sleeping arrangements possible in Japan (e.g. futon), some questions could be interpreted in slightly different ways. Second, the question on a problem of the sleep habit was ambiguous, something a problem because parents think it is or because children complain it is. Third, the response choice, ‘not available’, was so unclear that they totally ignored it or answered it based on their own different interpretations. As the results, it would probably be wise to add the item on family’s sleeping arrangements, the definition of a problem of the sleep habit, and the explanations of response choices. Reference Owens JA, Spirito A, McGuinn M. The Children’s Sleep Habits Questionnaire (CSHQ): psychometric properties of a survey instrument for school-aged children. Sleep 2000; 23: 1043–51. PRELIMINARY EPIDEMIOLOGICAL STUDY ON SLEEP PROBLEMS AMONG JAPANESE CHILDREN USING CHILDREN’S SLEEP HABITS QUESTIONNAIRE (CSHQ) YASUNORI OKA AND FUMIE HORIUCHI Japan Somnology Center, Neuropsychiatry Research Institute, Tokyo, Japan, Department of Neuropsychiatry, Ehime University School of Medicine, Ehime, Japan It has been suggested that sleep problems are common in children with psychiatric disorders. However, systematic investigation on this problem has not been conducted in Japan. Children’s Sleep Habits Questionnaire (CSHQ) was designed for the screening of sleep problems and has been validated on both the community population and clinical samples. We used the preliminary Japanese version of CSHQ (CSHQ-J) and made a study on a small number of school-aged children who consulted the university-based child and adolescent neuropsychiatry clinic. The aim of the preliminary study was to investigate the validity of the Japanese version of the questionnaire and to identify the prevalence of possible sleep problems among Japanese children. The CSHQ-J with additional questionnaire items asking about the difficulty in understanding and answering CSHQ-J was given to the parents of 32 patients with psychiatric disorders between the ages of 5 and 11 years (mean age 9.3 SD 1.5 years). Although two subjects who misunderstood the instruction could not answer properly, 30 subjects including seven subjects who reported a difficulty in understanding some questionnaire items could properly answer the questions. Total sleep disturbance score and subscale scores (bedtime resistance, sleep onset delay, sleep duration, sleep anxiety, night walking, parasomnias, sleep disordered breathing and daytime sleepiness) were calculated. Total sleep disturbance score ranged 36–62 (mean 46.8 SD 6.9) and 80.0% of patients had higher than the predetermined threshold of the total score. Subscale scores were higher than the predetermined threshold in 33.3% on bedtime resistance, 16.7% on sleep onset delay, 46.7% on sleep duration, 26.6% on sleep anxiety, 20.0% on night walking, 20.0% on parasomnias, 10.0% on sleep disordered breathing and 50.0% on daytime sleepiness. A41 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Although we have not establish normative value on the Japanese population, CSHQ-J appears to be a useful tool for the screening of sleep problems in children with psychiatric disorders. Subscale score could identify potential sleep disorders. Further studies are needed to establish the cut-off value of total and subscale scores of CSHQ-J in order to enhance its usefulness as a screening tool on the Japanese population. Reference Owens JA, Spirito A, McGuinn M. The Children’s Sleep Habits Questionnaire (CSHQ): Psychometric properties of a survey instrument for school-aged children. Sleep 2000; 23: 1043–51. CHARACTERISTICS OF SLEEP IN CHILDREN: A COMMUNITY BASED STUDY IN SALAYA, NAKHON PATHOM, THAILAND NITTAYA J KOTCHABHAKDI, NOOTCHANART CHAINORIT, JEERANUN JIVASOMBOONKUL, ORAPIN LAOSUWANNAPONG, ATHIWAT PLENGSA-ARD AND NAIPINICH KOTCHABHAKDI National Institute for Child and Family Development (NICFD) and Neuro-Behavioural Biology Center, Institute of Science and Technology for Research and Development, Mahidol University, Buddhamonthol 4 Road, Salaya, Nakornpathom 73170, Thailand This study is a part of the NICFD’s Salaya community based child development project which emphasizes the promotion of child health and development through family and community participation. The objective is to study parental perception of sleep in children under 12 years of age, their sleep arrangement, bedroom environment and the quality of sleep. 95 children, 50 boys and 45 girls, from 66 families in Mu 1, 3 and 5 villages were studied. Parents or principle child caregivers were interviewed on home visit. The children’s growth and development were assessed with physical examination in the baseline survey. Most children (89.4%) were cosleeping on the same mattress with caregivers, and 59.6% sleeping in the parents’ room. Insects were reportedly the most common cause of sleep disturbance (15.8%), while traffic sound caused disturbance in 13.7%. The average latency period to sleep in children was 24.22 +23.12 min. Among 57 young children under the age of 6 years, 38.59% had inadequate sleep duration for age. Bed time ritual included: feet washing in 80%, brushing teeth in 66.3%, drinking and/or eating 41.5%, saying a prayer in 32.9%, story telling in 10.5%, being read to 7.4%, listening to radio in 12.6% and caregiver singing lullaby in 9.5%. The health risk behaviours included falling asleep while watching television in 38.9%, bottle feeding to sleep in 44.3%. Clinging to persons mostly mothers and transitional objects were found in 40% and 37.9%, respectively. Surprisingly, there were only 10% of children under 6 years of age with thumb sucking, 5.5% with self touching. There were 22.1% showing strong opposition going to bed. Among 57.4% who woke up during the night, 30.9% needed feeding. The sleep problems in children, perceived by the caregivers, included excessive movement during sleep in 53.8%, bruxism in 18.2%, difficulty going to sleep in 12.6% and night talking in 11.6%. Nocturnal enuresis was found in 13.2% of children aged 6–12 years. Further analysis showed 6 in 19 or 31.6% of under 6 years old children with suspect delay development had difficulty to sleep compared to 3 in 30 or 10% of those with age appropriate development. However the difference was not statistically significant (P = 0.065). Among 24 reportedly hyperactive children, 17 or 70.8% had excessive movement during sleep, which was significantly different from 33 (47.8%) of 69 children without hyperactivity (P = 0.043). A42 INFANT & YOUNG CHILDREN SLEEP SURVEY IN NORTHERN TAIWAN-A PRELIMINARY REPORT YI-HUNG CHOU Director, Division of Neonatology, Assistant Professor, Chang-Gung Children’s Hospital, Taipei, Taiwan There are many parent-reporting sleeping problems in the young children aged 0–3 years, but no known survey was found in Taipei metropolitan area. We design a specific questionnaire (Infant Sleep Survey Questionnaire-ISSQ) to investigate parent-reporting sleep problems regarding the incidence, the possible causes, and the relationship with age and gender, which was performed in the setting of well-baby clinic. Survey reported problems with sleep and at least one of the following over the preceding 3 months: waking on more than five nights a week, waking more than three times a night, taking more than 30 min to fall asleep, requiring parental presence to fall asleep, reverse of day and night, Medical illness interfere sleep at night, environmental problems, and feeding problems. We plan to enroll 500 infants or more aged 0–3 years within a period of 6 months, part of data of the participants will be presented in the sleep meeting. In the preliminary report, a total of 123 children were enrolled (71 boys and 52 girls) with different age intervals: 32 aged 0–6 months, 56 aged 7–12 months, 23 aged 13–24 months, 12 in aged 25–36 months. The caregivers include mother, babysitter, grandparents, father and day-care center attendants. The results showed: (1) perception of the severity of sleep problems by parents- no problems in 44, mild in 53, moderate in 16, and severe in 10; (2) requiring parental presence, feeding problems, medical illness are cited as the top 3 manifestation; (3) persistence of sleep problems more than one months was observed in 57 out of 123 children (46.3%); (4) the set-up of a sleep routine was done only in 15 children with sleep problems (19%); (5) the major problems were different in each age interval and also in gender; (6) mothers reported higher prevalence rate than other caregivers. We conclude that sleep problems of infants and young children is very common in Taipei metropolitan area, and the complexity of presence of problems in children and variable attitude among the caregivers demand an in-depth study in the future. FG-3. Clinical & Neurophysiological Aspects of Basal Ganglia during Sleep Chairperson: Jean Askenasy (Israel) IRON DEFICIENCY IN THE NIGROSTRAIATAL SYSTEM RICHARD P ALLEN Johns Hopkins University, Department of Neurology, USA Iron is a necessary ingrediant for cell functioning but it also has to be tightly regulated since overload is associated with increased oxidative stress and cell death while deficiency produces abnormal cellular function. The restless legs syndrome (RLS) appears to have iron deficiency in the nigro-striatal system, at least for RLS with an early onset (before age 45) of RLS symptoms. MRI imaging shows decreased iron in the substantia nigra in proportion to the severity of the RLS symptoms. Autopsy studies show decreased iron, H-ferritin and increased Transferrin in both the substantia nigra and the putamen. The results of the decreased iron in these cells is an increase in tyrosine hydroxylase (TH) and in phosphorylated TH (pTH). The animal studies with iron deprivation show a similar result with the added information that the extracellular dopamine is increased along with a major increase in the Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 amplitude of the circadian variation in extra-cellular dopamine. These factors combined with some in-vitro studies provide a model of the response of the nigro-striatal system to iron deficiency that predicts in part the characteristic features of RLS. BASAL GANGLIA AND RLS-PLM WAYNE HENING UMDNJ-RW Johnson Medical School, New Brunswick, New Jersey The pathophysiology of the restless legs syndrome remains a mystery. The highly effective treatment with dopaminergic drugs has pointed to the involvement of dopamine pathways in the pathophysiology of the condition. Attempts in daytime imaging to demonstrate dopamine deficits have been inconclusive, with modest pre- and postsynaptic deficits found in various studies but absent in others. One ioneering functional imaging study (Bucher et al. 1997) found activations during sensory and motor dysfunctions of RLS in the reticular formation of the brainstem, red nucleus, cerebellum, and thalatmus, but not in the basal ganglia. A recent hypothesis is that deficiencies in brain iron transport and storage may impact on dopamine function (Earley et al. 2000), perhaps through abnormalities of synaptic development (Wang et al. 2004). Consistent with this hypothesis, there are abnormalities in the level of iron (Allen et al. 2001) and iron regulating proteins (Connor et al. 2004) in the substantia nigra, a major source of dopaminergic neurons. Other sources of potential involvement of the dopamine system in RLS include the descending dopamine system (A11) which innervates the spinal cord and the enteropenduncular nucleus (Rye, 1997) which mediates between the basal ganglia and the brainstem. The intriguing relationship between RLS and Parkinson disease, the preeminent basal ganglia disease, may also indicate the interrelationship of movement and sleep disorders (Rye 2004). THE UNKNOWN ROLE OF BASAL GANGLIA DURING SLEEP JEAN ASKENASY Department of Neurology, Research Authority Sackler Faculty of Medicine, Tel.Aviv University, Ben Yehuda 79, Herzlya 46403, Israel Electromyographic recordings during sleep reveal isolated phasic potentials, a pattern different from that of the EMG during wakefulness, suggesting different muscle activity during sleep. It is well known that sleep suppress the involuntary movements of Distonya, Myoclonus, Essential Tremor, Tics, Athetosis, Chorea Senile, Chorea Huntington, Chorea Minor, Ataxia Teleangiectasia, Wilson and Parkinson’s disease. But sleep can also initiate involuntary movements such as Periodic leg movements during sleep (PLM), Sleep Walking, Bruxism and REM behavior disorders. The prevalent hypothesis of the involuntary movements in Parkinson’s disease is that the inner segment of the globus pallidus is hyperactive due to reduced Gabaergic influence on the subthalamic nucleus (STN). The suppression of tremor and rigidity during sleep may be the consequence of a different constellation of inputs in the thalamic and cortical areas. Several hypotheses attempted to explain the pathogenesis of involuntary movements during wakefulness. Yet there is no explanation of the duality of suppression and initiation of involuntary movements during sleep. It can be hypothesized that suppression of movements is a consequence of attenuation in activities of neurotransmitter that occur during sleep. Initiation of involuntary movements during sleep remains unexplained. The origin of movements may be in the spinal cord, the basal ganglia, the thalamus and/or the cortex. Sleep and Biological Rhythms 2005; 3: A2–A73 The question about the rhythmic PLM phenomenon remains unanswered as well. Is it a phenomenon suppressed by wakefulness or is it a feature activated by sleep? Is the dopamine receptor wake or sleep effector? Dopamine agonists suppress REM sleep and improve PD. In dopamine transmitter knockout mice, the modafinil arousal effect is diminished, suggesting that the arousal effect is dopaminergic mediated. REM sleep decreasing dopaminergic activity also suppresses involuntary movements? Dopamine agonists suppress REM sleep and REM deprivation improves PD during wakefulness. The little knowledge on the effect of sleep on involuntary movements includes: (a) Involuntary movements originating from more peripheral sites ale less influenced by sleep. (b) Sleep-associated tremor is devoid of it’s alternating pattern. (c) Lesions or stimulation of the STN, Globus pallidum internum, Putamen, Globus Pallidum Externum, Thalamus and Ventral intermediate nuclei of thalamus suppress involuntary movements, mimicking the sleep effect during wakefulness. SLEEP PATTERN IN HUNTINGTON DISEASE: COULD IT BE THE CAUSE FOR BEHAVIORAL DISTURBANCES? MH ANCA1, A BLONDER2, N GILADI3 AND AD KORCZYN3 Department of Neurology, Wolfson1 & Tel Aviv 3Medical Centers, Sackler School of Medicine, Maarag Worldclass Sleep Diagnostic Center2, Tel Aviv, Israel Huntington disease (HD) is an inherited neurodegenerative disease characterized by motor dysfunction, cognitive deterioration and psychiatric symptoms. The early symptoms of the disease reflect frontostriato-limbic dysfunction with selective degeneration of striatal GABAergic neurons of direct & indirect striatal pathways directed to globus palidum, substantia nigra pars reticulata and subthalamic nucleus Over 80% of HD patients complain about sleep disturbances.Also two thirds of the patients with Parkinson’s Disease (PD) reported sleep disorders. Sleep quality might be affected by movements, cognitive decline as well as by mood and psychiatric features. The few sleep studies done on small groups of HD patients were contradictories and nonconclusive. We hypothesize that sleep disturbances are early signs of the disease that might have a prognostic value. To assess the sleep pattern in genetically tested HD patients with mild to moderate disease, and to correlate it with clinical features. To compare this pattern to the pattern of sleep in age matched normal people as well as to patients with other neurodegenerative disease as PD. Ten HD patients (7 female), with a mean disease duration of 6.5 ± 3.06 years, underwent one night polysomnographic (PSG) home assessment.All patients had complex motor and mood disturbances and all of them complained of sleep problems and low daily performances.Six patients are treated with neuroleptic drugs. All patients were assessed in the Movement Disorder Unit for their motor, behavioral, mood and cognition scores using the Unified HD Rating Scale, the Hamilton questionnaire and the Mini-Mental State Examination (MMTE). The sleep quality was assessed using the Epworth Sleep Scale. Other nine ambulatory age matched PD patients (5 female) with sleep complaints underwent home PSG. The PSG was performed in patient’s natural home ambiance, using the Embla system digital recorder of 16 channels. The sleep scoring was done following Rechtschaffen and Kales protocol. The mean age of HD patients was 51.5 ± 13.1 years and the mean CAG repeats was 45.3 ± 2.06. The study population was characterized by a mean daily Functional Capacity of 9.1 ± 2.02, MMSE score of 25.7 ± 5.6, Hamilton score of 18.3 ± 8.9, and Epworth score of A43 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 35.4 ± 11.7. In the PD group the mean age was 63.4 ± 11 and the disease stage h & Y 1–3. All patients completed a whole night PSG assessment without complaints. The sleep architecture in HD patients, compared to standard sleep in normal age-matched subjects revealed signifficantly prolonged NREM1 (P = 0.00009), mild prolonged NREM2 and significantly reduced amount of REM (P = 0.00001). Multiple body heterogenous movements, recorded in HD patients during sleep, appeared mainly (60%– 80%) during the prolonged NREM2 and almost disappeared during SWS and REM stage. The PD patients sleep assessment revealed a trend for mild REM sleep reduction and SWS increment, mostly NREM3/4 with preserved NREM1/2. In one patient REMBD was found.No significant respiratory disturbances were observed during sleep study in HD and PD patients. The HD patients have poor sleep with an abnormal pattern that shows significant reduction of REM sleep. This pattern is different from the sleep pattern of normal subjects and PD patients in the same age group.The presence of movements during sleep does not explain the poor sleep.This sleep pattern seems to be a consistent and intrinsic feature of the disease. Free Communication Abstracts MEDITATION, SLEEP AND PERFORMANCE PRASHANT KAUL, JASON M PASSAFIUME AND BRUCE F O’HARA University of Kentucky, Kentucky, USA Previous studies have documented clear changes in the EEG during meditation, especially an increase in alpha waves (as typically occurs with eyes closed) followed by theta bursts, depending to some extent on the meditator, type of meditation and brain regions monitored. Although this brain state is clearly a form of wakefulness, meditation, like sleep, is also reported to be relaxing and restorative. Again, like sleep, we do not know what is restored, but we can at least use wellvalidated and accepted measures of sleepiness to test whether meditation might be restorative in similar or different ways than sleep. Although many people have used meditation to assist sleep, such as in cases of insomnia, virtually no work has addressed the interactions of meditation, sleep, restoration and performance. Therefore, we have begun a series of studies using the Psychomotor Vigilance Task (PVT) before and after periods of mediation and differing sleep debts. Our first study measured PVT performance in the mid-afternoon (when vigilance typically wanes a bit) before and after 40 minute periods of meditation, sleep, or a control activity. All 10 subjects underwent multiple sessions of each activity and showed a significant improvement in PVT measures five minutes following meditation and a significant decline in performance following a nap (presumably due to sleep inertia). An hour later both of these effects are reduced, but not eliminated. Seven of the 10 subjects were also tested following a fullnight of sleep deprivation which lowered the PVT performance. The relative improvement from this lowered baseline condition was even greater following meditation in this sleep deprived state in six out of the seven subjects and all seven reduced their number of lapses. The subjects in this study had either no prior meditation experience, or moderate prior experience and there was no obvious difference related to prior meditation experience. This suggested that meditation serves a performance-enhancing and perhaps restorative role even in novice A44 meditators. We are now in the process of performing longer term studies in expert meditators who spend several hours a day in meditation to address whether meditation may be able to partially replace sleep. Preliminary data thus far suggests some replacement, but much more work is needed. SLEEP INDUCING FUNCTION OF ALPHA-1ADRENOCEPTORS OF THE MEDIAL PREOPTIC AREA RAMALINGAM VETRIVELAN, HRUDA NANDA MALLICK AND VELAYADHAN MOHAN KUMAR All India Institute of Medical Sciences, New Delhi – 110029 The study was undertaken to ascertain the role of alpha-1adrenoceptors in the medial preoptic area (mPOA) on regulation of sleep-wakefulness (S-W) and body temperature (Tb). Adult male Wistar rats were chronically implanted with electrodes for recording electrooculogram (EOG), electroencephalogram (EEG) and electromyogram (EMG) to assess S-W and a radio transmitter for telemetric recording of Tb. Methoxamine, an alpha-1-agonist and prazosin an alpha-1-antagonist were bilaterally injected at the mPOA through cannulae which were also chronically implanted. The effects of intrapreoptic injection of these drugs were also studied in those animals whose presynaptic noradrenergic terminals were destroyed by injecting 6-OHDA at the trajectory of ventral noradrenergic bundle (VNA). Artificial cerebrospinal fluid was used as a vehicle. Methoxamine injection into the mPOA induced a fall in Tb. But there were no major changes in S-W except an increase in wake period (W) for 10 mins. This short lasting arousal coincided with the maximum fall in Tb. On the other hand, prazosin induced an increase in Tb and an injection bound increase in W for 60 min. Methoxamine injection at the mPOA, in the animals with destroyed presynaptic NE terminals, induced an increase in total sleep time but prazosin did not affect S-W. Methoxamine-induced fall in Tb in these animals was of longer duration and prazosin-induced rise in Tb was relatively short lived. Results suggest that postsynaptic alpha-1-adrenergic receptors of mPOA are hypnogenic and hypothermic. Financial disclosure: This study was supported by Council of Scientific and Industrial Research (CSIR), India. NADPH OXIDASE MEDIATES HYPERSOMNOLENCE AND BRAIN OXIDATIVE INJURY IN A MURINE MODEL OF SLEEP APNEA G-X ZHAN1, F SERRANO2, P FENIK1, R HSU1, L KONG1, D PRATICO3, E KLANN2 AND SC VEASEY1 1 Center for Sleep and Respiratory Neurobiology and Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, 2 Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston TX and 3Center for Experimental Therapeutics, Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA Persons with obstructive sleep apnea may have significant residual hypersomnolence, despite therapy. Long-term hypoxia/reoxygenation events in adult mice, simulating oxygenation patterns of moderatesevere sleep apnea, result in lasting hypersomnolence, oxidative injury and proinflammatory responses in wake-active brain regions. We hypothesized that long-term intermittent hypoxia activates brain NADPH oxidase and that this enzyme serves as a critical source of superoxide in the oxidation injury and hypersomnolence. We sought to determine whether long-term hypoxia/reoxygenation events in mice result in NADPH oxidase activation and whether Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 NADPH oxidase is essential for the proinflammatory response and hypersomnolence. NADPH oxidase gene and protein responses were measured in wakeactive brain regions in wild-type mice exposed to long-term hypoxia/ reoxygenation. Sleep, oxidative and proinflammatory responses were measured in adult mice either devoid of NADPH oxidase activity (gp91phox null mice) or in which NADPH oxidase activity was systemically inhibited with apocynin osmotic pumps throughout hypoxia/ reoxygenation. Main results: Long-term intermittent hypoxia increased NADPH oxidase gene and protein responses in wake-active brain regions. Both transgenic absence and pharmacological inhibition of NADPH oxidase activity throughout long-term hypoxia/reoxygenation conferred resistance to, not only long-term hypoxia/reoxygenation hypersomnolence, but also to carbonylation, lipid peroxidation injury and the proinflammatory response, including inducible nitric oxide synthase activity in wake-active brain regions. Collectively, these findings strongly support a critical role for NADPH oxidase in the lasting hypersomnolence, oxidative and proinflammatory responses following hypoxia/reoxygenation patterns simulating severe obstructive sleep apnea oxygenation, highlighting the potential of inhibiting NADPH oxidase to prevent oxidation-mediated morbidities in obstructive sleep apnea. EFFECT OF CONTINUED COLD EXPOSURES ON SLEEP AND BRAIN TEMPERATURE OF RATS: ROLE OF THE MEDIAL PREOPTIC AREA AMBIKA PRASAD K MAHAPATRA, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Department of Physiology, All India Institute of Medical Sciences, New Delhi – 110029, India Sleep wakefulness (S-W) and brain temperature (Tbr) of normal and the medial preoptic area (mPOA) lesioned male Wistar rats were studied, when they were exposed to a mild cold (18°C) ambient temperature (Ta). Electroencephalogram (EEG), electrooculogram (EOG) and electromyogram (EMG) electrodes (bilateral) were chronically implanted to assess S-W, and a thermocouple above the dura to record the Tbr. Three recordings of S-W and Tbr (24 h each) at 24°C were taken which were found to be comparable. The average of three was taken as the base line or control level. N-methyl D-aspartic acid (NMDA) was injected (5 micro gram in 0.2 micro litre of distilled water, neutralized with NaOH) into the mPOA to destroy the neurons specifically sparing the fibers of passages. S-W and Tbr were recorded for 24 h after 28th days of lesion before exposing the rats to cold (18°C). On 1st, 7th, 14th, 21st, and on 28th day of cold exposure, S-W and Tbr were recorded. There was decreased sleep and increased Tbr after the mPOA lesion. Exposure to the cold produced further decrease in sleep, but it came back to the pre-exposure level by the 14th day. Increase in the durations of sleep episodes was responsible for the restoration of sleep to the pre exposure level. Similarly, on exposure to 18°C, sleep decreased significantly, but it was restored by 21st day of continued exposure, in case of normal rats. Increase in the frequencies of sleep episodes was responsible for the restoration of sleep. The Tbr remained elevated throughout the period of cold exposure. Resetting of the Tbr at a higher level may be a part of the homeostatic readjustment to restore sleep. The magnitude of the changes in Tbr and S-W were less in the lesioned rats, as compared to those observed in the normal rats. On the basis of these observations, it is proposed that the mPOA plays a role in interlinking thermoregulation and sleep regulation. Sleep and Biological Rhythms 2005; 3: A2–A73 AUGMENTED SLEEP APNEA AND STATEDEPENDENT ABNORMALITY OF CHEMOREFLEX IN OREXIN KNOCKOUT MICE TOMOYUKI KUWAKI1, BEN-SHIANG DEN1, AKIRA NAKAMURA2, WEI ZHANG, MASASHI YANAGISAWA3 AND YASUICHIRO FUKUDA2 1 Departments of Molecular & Integrative Physiology and 2Autonomic Physiology, Chiba University Graduate School of Medicine, Chiba, Japan, 3 Department of Molecular Genetics, University of Texas SWMC, Dallas TX, USA Mice would be useful experimental animals in that these animals are frequently used in genetic engineering and there is a possible link between genetics and etiology of sleep-related disorders, such as sudden infant death syndrome. Therefore, we have established a method for measuring ventilation of mice concomitantly with electroencephalography (EEG) and electromyography (EMG) for assessing sleep-wake states (1). Normal wild-type mice developed two types of central sleep apneas, that is, postsigh and spontaneous apneas, as normal humans do. Moreover, postsigh apneas in mice were observed exclusively during slowwave sleep (SWS) while spontaneous apneas were seen in both SWS and rapid-eye-movement (REM) sleep. These characteristics are very similar to those of sleep apneas in healthy human infants and children. Applying this newly developed method to male prepro-orexin knockout mice (2), we examined whether orexin, a recently discovered hypothalamic neuropeptide, participates in the breathing control during sleep. Ventilation, EEG, and EMG were recorded for six hours in the daytime, resting period for nocturnal mice. Recording chamber was continuously flushed with either room air, hypoxic, or hypercapnic gas mixtures. Respiratory frequency, tidal volume, minute volume, and frequencies of apneas and augmented breaths were separately determined during quiet wakefulness, SWS, or REM sleep. Hypercapnic ventilatory responses during quiet wakefulness were attenuated in orexin knockout mice, although hypoxic responses were comparable to those in the wild-type littermates. During SWS and REM periods, however, both of hypercapnic and hypoxic responses were normal in prepro-orexin knockout mice. On the other hand, spontaneous apneas during SWS and REM were more frequent in orexin knockout mice than in wildtype littermates. Our findings suggest that orexin plays a crucial role both for CO2-sensitivity in wakefulness and for preserving ventilation stability during sleep. References 1. Nakamura A, Fukuda Y, Kuwaki T. Sleep apnea and effect of chemostimulation on breathing instability in mice. J. Appl. Physiol. 2003; 94: 525–32. 2. Chemelli RM et al. Narcolepsy in orexin knockout mice: molecular genetics of sleep regulation. Cell 1999; 98: 437–51. Financial disclosure: The Ministry of Education, Culture, Sports, Science and Technology, Japan supported part of this work. EFFECTS OF PROGESTERONE BLOCKADE OVER COCAINE-INDUCED GENITAL REFLEXES OF PARADOXICAL SLEEP DEPRIVED MALE RATS MONICA L ANDERSEN AND SERGIO TUFIK Universidade Federal de São Paulo-UNIFESP, Sao Paulo, SP, Brazil Paradoxical sleep deprivation (PSD) enhances cocaine-induced genital reflexes (penile erection [PE] and ejaculation [EJ]) in male rats and induces a significant increase in progesterone concentration. As progesterone treatment facilitates PE in PSD castrated rats, we may speculate that progesterone appears to be a relevant hormonal factor eliciting genital reflexes in PSD males. In order to expand the latter finding, dif- A45 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 ferent doses of antiprogestin mifepristone (vehicle, 2.5, 5, 10 and 20 mg/kg, s.c.) were administered to PSD rats at the end of a four-day period of PSD one hour prior to cocaine administration (7 mg/kg, i.p.) and placed in observation cages for the evaluation of genital reflexes. Pretreatment with vehicle induced PE in all rats and this effect was significantly reduced by mifepristone at 5–20 mg/kg doses that lowered the proportion to 40% of the rats. The frequency of PE was also significantly reduced for all doses used. There were no significant differences between vehicle and mifepristone in EJ behavior. As for hormone concentrations, mifepristone reduced progesterone concentrations at the 5–20 mg/kg doses compared to vehicle group. At 20 mg/kg it also elevated testosterone concentrations. In addition, mifepristone administration induced a significant decrease in the duration of PS episodes at all doses. These data suggest that progesterone exerts an essential role in erectile response induced by cocaine in PSD male rats. NORADRENERGIC SYSTEM INTERACTS WITH GENITAL REFLEXES-INDUCED BY COCAINE IN PARADOXICAL SLEEP DEPRIVED MALE RATS MONICA L ANDERSEN, ISABELA B ANTUNES AND SERGIO TUFIK Universidade Federal de São Paulo-UNIFESP, Sao Paulo, SP, Brazil It has been shown that paradoxical sleep deprivation (PSD) enhances cocaine-induced genital reflexes (penile erection [PE] and ejaculation [EJ]) in male rats. As PSD induces alteration in noradrenergic receptor sensitivity and cocaine is a noradrenaline reuptake inhibitor, the present study was designed to further examine the noradrenergic mechanism on spontaneous genital reflexes-induced by cocaine in PSD male rats. Different doses of alpha and beta adrenoceptor agonists or antagonists were administered subcutaneously to PSD rats at the end of a four-day period of PSD one hour prior to cocaine administration. In comparison to PSD-vehicle group, the pretreatment with alpha-1adrenoceptor agonist (methoxamine) reduced the percentage of animals displaying PE whereas the antagonist (prazosin) did not. Yohimbine, a alpha-2 adrenoceptor antagonist significantly decreased this percentage. For beta-1 adrenoceptors drugs, both dobutamine (agonist) and atenolol (antagonist) only reduced the percentage at the highest dose and beta2 adrenoceptors drugs had no effect in the number of animals displaying PE. Except for clonidine all drugs significantly reduced the frequency of PE. Ejaculatory behavior was significantly decreased following yohimbine and beta-1 drugs whereas it was completely abolished by prazosin. The results, viewed in the light of other available reports suggest that noradrenergic receptors play an important role in sexual behavior exhibited by male rats, and that genital reflexes were markedly inhibited following an acute cocaine injection in sleepdeprived rats. ACUTE COCAINE EFFECTS IN PARADOXICAL SLEEP DEPRIVED MALE RATS MONICA L ANDERSEN, JULIANA C PERRY AND SERGIO TUFIK Universidade Federal de São Paulo-UNIFESP, São Paulo, SP, Brazil Cocaine is a psychomotor drug known to cause behavioural alterations. This study was conducted to characterize behavioural response to acute cocaine injection (7 mg/kg, ip) in paradoxical sleep deprived (PSD) male rats since sleep deprivation is also associated with several behavioural alterations. Cocaine or vehicle was administered to rats at the end of a 4-day period of sleep deprivation, and in home-cage control animals. Cocaine administration in control and PSD rats induced a significant increase in stereotyped behaviour in relation to saline-injected A46 rats. PSD induced significant but heterogeneous effects in animals by increasing grooming while it had effect neither on stereotyped behaviours, locomotion nor on anxiety-like behaviours but significantly decreased rearing behaviour. PSD potentiates the action of cocaine on stereotyped behaviours suggesting supersensitivity of dopaminergic receptors. Thus, the present study indicated that the behavioural effects of cocaine could be modified by PSD. This in turn may have relevant implications in the cocaine effect in abusers under sleep deprived condition. THE EFFECTS OF DOPAMINERGIC AGONISTS ON GENITAL REFLEXES IN PARADOXICAL SLEEP DEPRIVED MALE RATS MONICA L ANDERSEN AND SERGIO TUFIK Universidade Federal de São Paulo-UNIFESP, São Paulo, SP, Brazil Dopamine (DA) agonists provide evidence that different receptor subtypes in the central nervous system (CNS) have influence in sexual behavior. Sleep deprivation induces supersensibility of DA receptors and previous work has shown that the DA agonist apomorphine enhances spontaneous genital reflexes (penile erection-PE and ejaculation-EJ) in rats deprived of paradoxical sleep. The present study sought to extend the latter finding by assessing the effects of other DA agonists in paradoxical sleep deprived (PSD) male rats. The DA drugs (bromocriptine and piribedil) were acutely administered to rats that had been deprived of sleep for 4 days and to normal controls. Sleep deprivation alone induced PE and this effect was potentiated by piribedil, with maximal effects occurring with the 8 mg/kg dose; whereas only one dose of bromocriptine (8 mg/kg) induced more PE in PSD rats than in nondeprived treated controls. EJs were increased in piribedil PSD groups but this response was absent after bromocriptine treatment in the dose range tested. Our data show the genital reflexes that occurred in PSD rats are potentialized by piribedil and not by bromocriptine. These DA agonists showed distinct effects in sexual response suggesting that these effects are probably due to PSD-induced DA receptor supersensitivity even though different mechanisms are involved. THE STIMULATING EFFECTS OF ECSTASY IN THE GENITAL REFLEXES OF PARADOXICALLY SLEEP DEPRIVED RATS TUFIK S, ANDERSEN ML, BATISTA MC,CALZAVARA MB, COSTA JL AND FRUSSA-FILHO Universidade Federal de São Paulo-UNIFESP, São Paulo, SP, Brazil Ecstasy is a psychostimulant and is a synthetic derivative of amphetamine that, according to its consumers, promotes the enhancement of sexual pleasure. This study sought to investigate the effects of ecstasy in the genital reflexes of paradoxically sleep deprived (PSD) male rats. Distinct groups of PSD rats were administered with saline or different doses of ecstasy. The incidence of genital reflexes was evaluated for 90 min. The four doses that were used induced genital reflexes in PSD animals that significantly differed form their respective treated control groups. Under the influence of two intermediary doses, all animals displayed erection and ejaculation. The frequency of genital reflexes was also significantly greater than in relation to the PSD-saline group. Results showed a great enhancement of the genital reflexes of PSD rats that might have occurred due to serotoninergic alterations induced by this drug of abuse when associated to sleep deprivation. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 DIURNAL VARIATIONS OF CSF HYPOCRETIN & CHANGES IN GENE EXPRESSION AS DETECTED BY MICROARRAYS IN YOUNG & OLD RATS F DÉSARNAUD1, E MURILLO-RODRIGUEZ1, D GERASHCHENKO1, S SHIROMANI1, L LIN2, S NISHINO2, E MIGNOT2 AND PJ SHIROMANI1 1 West Roxbury VA/Harvard Medical School and 2Stanford University, Palo Alto, CA, USA Elderly humans and animals show increased episodes of sleep during the wake-active periods. To test the hypothesis that such sleep episodes might result from a decline in endogenous wake-active factors such as hypocretin/orexin (HCRT/OX), CSF was collected (under anesthetic) from the cisterna magna from young (2 months, n = 9), middle age (12 mos, n = 10), and old (24 mos, n = 10) F344 rats, at 4 h intervals (beginning at ZT0, lights-on). CSF was collected once from each rat every 4 days at one ZT point. The rats were implanted (under anesthetic) with a transmitter to provide a continuous record of core body temperature rhythm. Separate group of similar age rats were killed and the lateral hypothalamus (LH) and other brain regions rapidly extracted for analysis using gene-chip methods. Over a 24-h period, old rats had 10% less CSF HCRT/OX vs. either middle age or young rats (P < 0.002), but no significant difference in core temperature or gross locomotor activity. There was no difference in the phase position or amplitude of the HCRT/OX rhythm. There were no differences in the numbers of HCRT/OX-immunoreactive neurons and in HCRT/OX mRNA. Microarray gene analysis of the LH revealed in old rats a significant change, compared to LH of young rats or cortex of young or old rats, in genes involved in inflammation, neuronal signaling, and oxidative/lipid metabolism, suggesting a modification of the neuronal activity in the LH where the HCRT/OX neurons are localized. The decline in CSF HCRT/OX may prevent the elderly from maintaining sustained bouts of wakefulness. In addition, a decline in the adenosine signal (see Murillo-Rodriguez, Neuroscience, 2004) may not sustain long periods of sleep, thereby leading to the increased sleep fragmentation in the elderly. Supported by DVA Medical Res, NS30140, AG15853, AG09975, MH55772. MILD REGULAR EXERCISE CONSOLIDATES SLEEP-WAKE ARCHITECTURE IN 24 MONTH OLD F344 RATS CARLOS BLANCO-CENTURION AND PRIYATTAM J SHIROMANI West Roxbury VA and Harvard Medical School With aging there is increased sleep fragmentation, decline in sleep homeostasis, increased episodes of sleep during the normally wake active period and a severe loss of delta power. These changes are not due to a loss of sleep-active neurons in the VLPO (3) although a decline in adenosine A1 receptor in the basal forebrain (2) together with a decline in hypocretin levels (1) might be contributing factors. Since the elderly population is expected to double in the next 10 years, interventions that can improve sleep quality are urgently needed. Here we investigate the effects of mild exercise on sleep in old rats. Young (3 month, n = 4) and old (21 month, n = 6) male rats were exercised for one hour daily (at dark onset; 2 m/min) for 45 days. Agematched control rats (young n = 4, old n = 4) were not exercised but kept awake by gentle handling for the hour. A 48 h sleep recording was made immediately after exercise, 2 days later and 2 weeks after the end of exercise. Rats were housed in 12 : 12 LD with food and water available ad libitum. Sleep and Biological Rhythms 2005; 3: A2–A73 Compared to control old rats, old rats that were exercised lost weight and were awake more during the last third of the night, a time when hypocretin levels peak (1). In old rats exercise also significantly reduced nighttime sleep fragmentation by increasing length of wake, SWS and REM bouts. Exercise also lengthened SWS bouts during the light-on sleep period. These changes persisted two weeks after end of exercise. In old rats exercise also significantly increased theta power during REM sleep, and alpha power during waking. However, delta power during SWS was not changed. Exercise had no effect on any sleep parameters in young rats. Here, the rats were exercised for one hour at the start of the normal wake-active period, and they were awake more during the last third of the light-off period. In humans, this would be analagous to exercise in the morning, and we suggest that it should keep them more alert and active during the day. We suggest that the increased waking might result from higher levels of hypocretin secreted as a result of the exercise. Thus, exercise produces weight loss and better sleep in old rats.1. Desarnaud F et al. (2004) Sleep 27: 851.2. Murillo-Rodriguez E et al. (2004) Neuroscience 123: 361.3. Shiromani PJ et al. (2000) Am J Physiol 278: R125. Support (optional): Veteran’s Affairs Merit Award, AG15853, NS30140, MH55772. EFFECTS OF LATERAL HYPOTHALAMIC LESIONS WITH THE NEUROTOXIN HYPOCRETIN2-SAPORIN ON BASAL FOREBRAIN ADENOSINE LEVELS E MURILLO-RODRIGUEZ1, L LING2, M XU1, C BLANCO-CENTURION1, D GERASHCHENKO1, S NISHINO2, E MIGNOT2 AND PJ SHIROMANI1 1 VA Medical Center & Harvard Medical School, West Roxbury, MA and 2 Stanford University Center for Narcolepsy, Palo Alto, CA, USA The human sleep disorder narcolepsy is now considered a neurodegenerative disease, as there is a massive decrease in number of neurons containing the neuropeptide hypocretin (HCRT), also known as orexin. HCRT neurons are localized only in the perifornical region of the lateral hypothalamus (LH) from where they project to major arousal centers. However, it is not known which projection produces what symptom of narcolepsy. One target site is the basal forebrain and it is possible that waking might be due to the HCRT neurons projecting to the BF and activating the cholinergic neurons. As a result of the HCRT activation of the BF, there should be a congruent increase in local sleep factors such as adenosine (AD); lesion of the HCRT neurons should produce a corresponding decrease in AD and increased sleep. Here we test this pathway by measuring AD levels and sleep in rats with lesions of the HCRT neurons. Sprague-Dawley rats (280–300 g) were administered (under deep anesthesia) either saline (control group) or the neurotoxin HCRT2-SAP (90 ng/0.5 mL) into the LH. CSF was collected from all rats at CT0 (36 and 60 days postlesion) and CT8 (40 and 64 days postlesion) in randomized order. On day 70 CSF was collected at CT6 in all rats to serve as a baseline for the total sleep deprivation study. On day 77 the rats were kept awake for 6 h (first six hours of light period) and CSF was collected. HCRT was detected using RIA as described previously. After collecting the CSF, the rats were implanted with sleep recording electrodes and a microdialysis guide cannula into the BF (A = -.35; L = 2.0; h = 8.5. Paxinos and Watson, 1986). Seven days postsurgery, a microdialysis probe was inserted (BAS 1 mm length). ACSF was perfused (flow rate = 0.25 l/min) and after 24 h of stabilization period, samples (5 l) were collected for 2 h and then the rats were kept awake for 6 h. The rats were then allowed to A47 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 sleep undisturbed. Microdialysis samples were collected every hour during the 6 h prolonged waking and during 2 h of recovery sleep. AD levels were determined using HPLC and UV-116 A. The sleep records are still being analyzed but the HCRT and AD analysis is complete. At CT0 and CT8, lesioned animals (n = 6) had a significant decline in HCRT levels compared to saline rats (n = 6) (P < 0.0001). Six hours of prolonged waking increased HCRT levels in saline but not in lesioned rats (P < 0.05). AD levels were significantly lower in lesioned (n = 6) compared to saline (n = 6) animals (P < 0.05). In response to 6 h prolonged waking there was a significant increase in AD in the saline rats (P < 0.05) but not in lesioned rats. Anatomical studies have shown a unilateral HCRT projection to the BF and here we find that it also drives AD levels. Accumulation of AD in the BF as result of this HCRT activation might then serve to gradually inhibit the BF neurons and promote sleep. Support: VA Medical Res, NS30140, AG15853, AG09975, and MH55772. was actually related with a somewhat lower risk for severe sleepiness among the train drivers. Shift scheduling guidelines for irregular shift systems have been developed based on the data. The recommendations focus on the timing of the night and morning shifts, the criteria for the use of ‘quick return’ morning-night and day-night combinations and, the use of napping in different shift combinations. References Härmä M, Sallinen M, Ranta R, Mutanen P, Muller K. The effect of an irregular shift system on sleepiness at work in train drivers and railway traffic controllers. J. Sleep Res. 2004; 48: 137–49. (2002) 11, 141–51. Sallinen M, Härmä M, Mutanen P, Ranta R, Virkkala J, Muller K. SleepWake rhythm in an irregular shift system. J. Sleep. Res. 2003; 12: 103–12 Sallinen M, Härmä M, Mutanen P, Ranta R, Virkkala J, Muller K. Sleepiness in various shift combinations of irregular shift systems. Industrial Health 2005; 43: 114–22. SHIFT SCHEDULING IN IRREGULAR TRAIN TRANSPORTATION SHIFT SYSTEMS EFFECTS OF HIGH FATIGUE ON MOOD AND SLEEP IN BREAST CANCER PATIENTS UNDERGOING CHEMOTHERAPY HÄRMÄ MIKKO AND SALLINEN MIKAEL Brain@Work Research Center, Finnish Institute of Occupational Health, Helsinki, Finland Shift scheduling and sleep has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. A series of field studies were carried out among Finnish train drivers and traffic controllers to develop recommendations for ergonomic shift scheduling and optimal sleep in irregular shift systems. 126 randomly selected male train drivers and 104 railway traffic controllers were investigated by a questionnaire and sleep/work diaries during 21 consecutive days during the irregular shift system. Based on the obtained data of 2482 days, the prevalence of severe sleepiness at work (i.e. Karolinska Sleepiness Scale 7 or higher), the length of main sleep period and napping were modelled by a series of logistic regression analyses for repeated measurements (GEE), using factors related to the shift system, sleep-wakefulness and individual differences as explanatory variables. The odds ratios showed that the risk for severe sleepiness at work was 6–14 times higher in the night shift and about twice as high in the morning shift compared with the day shift. About 50% of both train drivers and traffic controllers had severe sleepiness during the night shifts. The prevalence of severe sleepiness varied between 36 and 62% and that of dozing off at work between 9 and 31% among the train drivers depending on the current shift condition. 28–50% of the traffic controller reported dozed-off the night shifts. The main sleep period before the first night shift shortened by about 2 h when the morning shift immediately preceded the night shift as compared with the combinations containing at least 36 h of free time before the night shift (reference combination). Among the different shift combinations, the main sleep period before the night shift was most curtailed (up to 2.9–3.5 h) between two night shifts. Afternoon napping increased when the morning or the day shift immediately preceded the night shift, the odds being 4.4–4.8 in comparison with the reference combination. The main sleep period before the morning shift became 0.5 h shorter when the evening shift preceded the morning shift in comparison with the sleep period after a free day. The risk of severe sleepiness and dozing-off at work were not significantly related with the preceding shift combination or time-off period before the shift but they were significantly related with the shift length, starting time of the morning shift (severe sleepiness) and the length of the preceding sleep. Individual sleep need increased sleeping time and the risk for severe sleepiness. Aging did not affect sleep before the morning or night shifts or dozing-off at work but A48 SHAMINI JAIN, PAUL J MILLS, LIANQI LIU AND SONIA ANCOLI-ISRAEL University of California, San Diego, CA, USA Fatigue is one of the most common complaints in breast cancer patients and might affect responses to standard treatment. We examined potential effects of fatigue on psychosocial functioning and measures of sleep during chemotherapy. Twenty-seven stage I-IIIA breast cancer patients were studied before chemotherapy and during weeks 1, 2 and 3 of the first and fourth cycles of anthracycline-based chemotherapy. The Multidimensional Fatigue Symptom Inventory short form (MFSI-sf) was used to measure fatigue; cutoff scores for prechemotherapy high and low fatigue groups were based on studies with normative data (above 16 = high fatigue). Subjective sleep reports were obtained via the Pittsburgh Sleep Quality Index (PSQI) & Functional Outcomes of Sleep Quality (FOSQ), and objective (daytime napping and night Total Sleep Time (TST) & Wake After Sleep Onset (WASO), based on actigraphy) sleep data were also collected. Measures of depression (Center for Epidemiological Studies Depression) & quality of life (Functional Outcomes of Cancer Therapy-Breast) were also examined. Data were analyzed using repeated measures ANOVA over six timepoints. Patients with high fatigue prior to chemotherapy reported higher fatigue, higher depression and lower quality of life throughout chemotherapy (P < 0.004 in all cases). Patients also reported higher PSQI daytime disturbance as well as lower total FOSQ scores throughout chemotherapy (P < 0.003 in all cases). A significant group ¥ time of chemotherapy interaction was found for night WASO; high fatigued patients showed increased WASO during the fourth cycle of chemotherapy (P < 0.04). This effect remained significant even when controlling for concurrent depression and QOL ratings. There was also a significant interaction for TST, with high fatigued patients showing steeper declines in TST in response to both cycles 1 and 4 of chemotherapy (P < 0.02). High fatigued patients also reported more daytime napping throughout chemotherapy (P < 0.03). Results indicate that highly fatigued breast cancer patients show poorer psychological outcome as well as more disrupted sleep patterns during chemotherapy. Supported by NCI CA 85264. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 SOURCES OF DISCREPANCY BETWEEN SELF-REPORT AND RECORDED SLEEP IN HEALTHY SENIORS I HAIMOV1, N BREZNITZ2 AND S SHILOH2 Department of Behavioral Science, Emek Yezreel Academic College, Israel, 2 Department of Psychology, Tel Aviv University, Israel 1 It is generally accepted that sleep disturbances figure as one of the most ubiquitous health problems in elderly persons. Although the elderly comprise only about 13% of the US population, between 35 and 40% of all prescriptions for hypnosedatives are written for people over the age of 65 years, and 14% of all elderly people consume these drugs daily. Likewise, it was found that most hypnosedatives are prescribed based on subjective complains. Although literature examining the subjective judgment of the elderly has found that self-report measures adequately represent a person’s personality tendencies with a corresponding decline in reliance on more objective information, only a few studies have examined the credibility of subjective judgments of sleep among healthy seniors. Therefore, in this study we examined the correlation between self-report and recorded sleep among elderly people, and then looked for the sources for the discrepancy we found. The study population comprised 98 elderly subjects (mean age = 72.3, SD = 5.8; 36 males and 62 women). All subjects were living independently in the community and were in good clinical condition. Subjects were asked to fill out several questionnaires concerned with a wide spectrum of issues, such as demographic background, depression, anxiety, life satisfaction, sense of coherence scale and self-esteem scale. In addition, they were questioned extensively about all aspects of their sleep via the Mini Sleep Questionnaire (MSQ) and the Technion Sleep Questionnaire. Subjects: sleep was continuously monitored for one week with a wrist actigraph (Ambulatory Monitoring, Inc.). Analysis revealed substantial discrepancies between the objective and subjective measures of sleep [for example, the correlation for sleep latency was (r = 0.2., NS)]. Conversely, a positive correlation was found between self-esteem and the measure of optimistic discrepancy in sleep (r = 0.42, P < 0.01), and between sense of coherence and size of the discrepancy between objective and subjective measures of sleep (r = 0.30, P < 0.05). In the elderly, subjective judgment of sleep adequately represents a person’s personality tendencies rather than reflecting objective sleep. These findings suggest that particularly in the elderly population, prescriptions for hypnosedatives should not rely on the patient’s subjective judgments of sleep but rather on objective measures. NOCTURNAL SLEEP IS DISRUPTED IN ADHD CHILDREN R SILVESTRI1, I ARICÒ1, G MENTO1, A GAGLIANO2, T CALARESE2 AND C DI PERRI1 1 Sleep Medicine Center, Messina Medical School, 2Pediatric Neurology and Psychiaty, Messina Medical School We recorded over night, 11 ADHD, male children (mean age 9, 3, range 4–13), diagnosed according to international DSM IV criteria. Video-polisomnography included a minimum of 8 to a maximum of 16 leads (in children who had previously displayed epileptic abnormalities on day-time EEG)with 21 electrodes (10–20 system). Focal interictal epileptiform abnormalities were detected in 8/11 patients: centro-temporal bilaterally (rolandic) in 4 patients, bifrontal with left predominance in 2, left anterior temporal in 1, right occipital in 1. Nocturnal focal seizures (rolandic and occipital) were recorded in 2 patients. Sleep and Biological Rhythms 2005; 3: A2–A73 A high PLMs index indicative of nocturnal myoclonus was detected in 7 patients, 4 of which qualified for RLS. Disorders of arousals (DOA) were recorded in 4 patients. Enuresis, bruxism and snoring with SBD were confirmed in 2 patients each. Therapy with Levetiracetam (250–1000 mg depending on body weight) reduced PLMs, suppressed DOAs and seizures and improved over all night quality of nocturnal sleep. SLEEP DISTURBANCES IN NURSES WORKING SHIFTS: LACK OF RELATIONSHIP BETWEEN SUBJECTIVE COMPLAINTS AND OBJECTIVE SLEEP RECORDINGS R EPSTEIN1, O TZISCHINSKY1,2, R NAVEH1, P HERER1, G PILLAR1, H ADAMI3 AND P LAVIE1 1 Sleep Laboratory, Faculty of Medicine, Technion, Haifa, Israel, 2Emek Yezreel Academic College, Emek Yezreel, Israel, 3Director of Nursing, Rambam Medical Center, Haifa, Israel Shift workers and nurses in particular, often suffer from sleep disturbances. Nurses who easily adjust to shift work likely report fewer complaints and sleep better than nonadjusted nurses. In the current study we aimed to assess sleep disturbances subjectively and objectively in a large cohort of nurses working on a rotating shift or days shifts. 700 nurses working in a Medical Center in Israel completed health, life style and the Technion sleep questionnaires (82% shift workers and 18% day workers). Based on the sleep questionnaire three groups were formed: 40 shift workers who complained of ‘difficulties falling asleep’ and ‘multiple mid-sleep awakenings’ (Sleep Disturbed-SD; 27% of shiftworkers); 42 shift workers without sleep complaints (Non Sleep Disturbed-NSD; 73% of shiftworkers), and 27 day working nurses without sleep complaints (Day-D). All groups were investigated overnight with the Watch-PAT 100, a validated unattended ambulatory device that provides objective information on total sleep time, sleep efficiency, apneahypopnea index, oxygen saturation, and arousal index. D-Nurses were older than SD who in turn were younger than NSD nurses (D: 48.2(7)ys, NSD: 41.1 (9.9)ys, SD: 35.6 (8.9)ys, P < 0.0001). There were no group differences in BMI (SD: 26.1 (4.8), NSD: 25.1 (5.0), D: 26.4 (4.6), marital status (married: SD: 73%, NSD: 75%, D: 80%), or smoking habits (never smoked: SD: 89%, NSD: 65%, D: 86%). The SD group also reported early morning awakenings and morning headaches significantly more than the other two groups. However, Watch_PAT (100) recordings revealed no differences between the groups in total sleep time (SD: 6.5 (1.6) h, NSD: 6.4 (1.3) h, D: 6.3 (1.2) h) arousal index (SD: 13.54 (8.24); NSD:13.5 (6.07); D:13.99 (8.39), or sleep efficiency (SD:80.5 (12.9)%, NSD: 80.5 (10.5)%, D: 81.3 (10)%) In spite of an increased rate of sleep complaints, objective recordings revealed no evidence of decreased total sleep time, sleep efficiency or increased mid sleep awakenings. Future research should investigate the causes of subjective sleep complaints in nurses working shifts. REM SLEEP INDUCTION BY ANTAGONISM OF GABAA RECEPTORS IN THE ORAL PONTINE RETICULAR FORMATION OF THE RAT IS BLOCKED BY ATROPINE GERALD A MARKS, OREN SACHS AND CHRISTIAN C BIRABIL Department of Psychiatry, University of Texas South-western Medical Center, Dallas, Texas-75390, USA Antagonism of GABAa receptors in the nucleus pontis oralis (PnO) results in a long-lasting increase in REM sleep in the rat and a short- A49 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 lasting, triggering of REM sleep in the cat. The long-lasting effect in rat may result from secondary influences on other neurotransmitter systems known to have long-lasting effects. Here, we test the hypothesis that inhibiting GABA transmission in PnO increases REM sleep through increases in acetylcholine release. Under anesthesia, Long-Evans Hooded rats were surgically prepared for chronic sleep recording and additionally implanted with guide cannulae aimed at sites in the PnO. After recovery, animals received multiple injections at each site with 60 nL of drug solution within one-half-hour before lights-out. Bicuculline methiodide (BMI, 1 mM), gabazine (GZ, SR95531, 0.01 and 0.1 mM), carbachol (0.1 or 1 mM), atropine (4 mM) and saline-vehicle injections were administered unilaterally at least one-week apart. Following each injection, 24-h electrographic recordings were obtained. Compared to mean control values, both GABAa receptor antagonists, BMI and GZ, produced long-lasting (>8 h) increases in REM sleep. GZ had a greater potency, which is consistent with its higher affinity for the GABAa receptor. At sites in which the cholinergic agonist, carbachol, and GZ were both effective, preinjection of the muscarinic antagonist, atropine, completely blocked the REM sleep increase by GZ. Atropine alone did not decrease REM sleep amounts. GABAa receptor mechanisms operate in the pontine reticular formation in the control of REM sleep. In the rat, blockade of GABAa receptors augments REM sleep through action on the cholinergic system. A different mechanism appears to operate in the cat where it recently has been reported that scopolamine does not affect REM sleep induction by bicuculline. This difference may underlie the species-disparity in the duration of effects on REM sleep by inhibition of GABA transmission. This work was supported by NIH Grant RO1 MH57434. INTER-INDIVIDUAL DIFFERENCES IN SLEEPINESS AMONG STUDENTS: ARE THE EVENING TYPES MORE SOMNOLENT THAN MORNING TYPES? RACHIDA ROKY, BRAHIM BENAJI AND MAJDA TAOUDI BENCHEKROUN Department of Biology, Faculty of Sciences Ain Chock, University Hassan II, Casablanca, Morocco. [email protected] Daytime sleepiness is a very frequent problem in students. These later report higher prevalence of sleepiness than the older adults. Insufficient and fragmented sleep are the most important causes of sleepiness. Eveningness is associated with more insufficient nocturnal sleep than morningness. However, the use of the multiple sleep latency test (MSLT) measure did not demonstrate any difference in the daytime sleepiness across the different chronotypes. The objective of this study was to determine, by the use of the Epworth sleepiness scale, the relation between diurnal sleepiness and chronotype with an emphasis on the gender effect. 540 university students (290 girls and 250 boys) completed a questionnaire including the Epworth sleepiness scale (ESS), the Horne and Ostberg scale for chronotypes characterization, sleep habits, medication intake, coffee and tea consumption. Results indicated that the ESS varied significantly across the different chronotypes in girls but not in boys. Girls reported higher sleepiness score among the evening type (ESS = 8.5) in comparison to the intermediate (ESS = 6.56; p = 0.039) and the morning type (ESS = 6.5; p = 0.033). Moreover, the ESS score was significantly (P = 0.024) higher in girls (6.65 ± 0.19) than in boys (5.99 ± 0.24). The analysis of the eight situations of the ESS showed that the significant gender effect was observed in the situation when the subject is sitting down after a midday meal. The morningness/eveningness scale was also significantly A50 (P = 0.026) higher in girls (54.2 ± 0.43) than in boys (51.95 ± 0.65). The morning type, the intermediate type and the evening type represented, respectively (28%; 65.5% and 4.5%) in girls and (27.7%; 63.5% and 8.8%) in boys. In conclusion, this study showed that the girls present more sleepiness and more morning types than boys. In girls, evening chronotype was associated to higher daytime sleepiness. One of the perspectives of this study is to elucidate the determinants of this gender effect in sleepiness and chronotype. References Levine B, Roehrs T, Zorick F, Roth T. Daytime sleepiness in young adults. Sleep 1988; 11(1): 39–46. Hublin C, Kaprio J, Partinen M, Koskenvuo M. Insufficient sleep – a population-based study in adults. Sleep 2001; 24(4): 392–400. Rosenthal L et al. Sleepiness/alertness among healthy evening and morning type individuals. Sleep Medical 2001; 2(3): 243–8. SLEEP AND SLEEPINESS DURING RAMADAN FASTING RACHIDA ROKY1, FLORIAN CHAPOTOT2, MAJDA TAOUDI BENCHEKROUN1, BRAHIM BENAJI1 AND ALAIN BUGUET2 1 Department of Biology, Faculty of Sciences University Hassan II Ain Choq, Casablanca, Morocco. [email protected], 2Institut de médecine tropicale du service de santé des armées – Le Pharo, Marseille, France During the month of Ramadan, Moslems refrain from drinking, eating and having sexual relations between sunrise and sunset. This study examined the effect of Ramadan fasting on sleep, sleepiness, mood and rectal temperature in 8 healthy young male subjects. Polysomnography including the recording of the electroencephalogram, electrooculogram and electromyogram was performed on the beginning of Ramadan (11th) and the end of this month (25th). The baseline recordings were scheduled two weeks before Ramadan, and the recovery recordings two weeks after this month. The daytime sleepiness was measured by the use of the Multiple Sleep Latency Test (MSLT) combined with a quantitative waking EEG analysis. Mood and subjective alertness were evaluated by the visual analogue scale. The results showed that during Ramadan, the circadian rhythm of body temperature was modified with a 2-h delay in both the acrophase and bathyphase and a decrease in the amplitude. The mesor did not vary. Nocturnal sleep latency increased and total sleep, slow-wave sleep (SWS) and REM sleep duration decreased. Objective sleepiness increased during Ramadan, especially at 10:00 h, 12:00 and 16:00 h. During the MSLT, there was an increase in the duration of stage 1 at 10:00 h and 12:00 h and in the daily mean waking EEG absolute power in the theta (5.5–8.5 Hz) frequency band. Significant correlations were found between sleep latency in the MSLT and rectal temperature, as well as between sleep latency and waking EEG absolute power of the fast alpha (10.5–12.5 Hz), sigma (11.5–15.5 Hz) and beta (12.5–30 Hz) frequency bands. Subjective mood decreased at 16:00 h, both in the beginning and the end of Ramadan. In conclusion, Ramadan fasting induced a delay in the circadian rhythm of body temperature and the sleep wake cycle and it also induced an increase in subjective and objective daytime sleepiness. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 SLEEP AND HPA MARKERS ASSOCIATED WITH DEVELOPMENT OF ADOLESCENT DEPRESSION UMA RAO, RUSSELL E AND POLAND UT South-western Medical Center at Dallas, Texas, USA, Cedars-Sinai Medical Center, Los Angeles, California, USA To identify depression-related EEG sleep and HPA changes in healthy adolescents at high risk for depression, and to examine the relationships among these changes with onset and clinical course of depression. Adolescents with major depressive disorder, controls with no personal history of psychiatric disorder but were at high risk for development of depression by virtue of parental depression, and controls with no personal or family history of psychiatric illness participated in EEG sleep and HPA studies for three consecutive nights. Compared with normal controls, depressed and high-risk adolescents had significantly shorter latency to REM sleep, increased phasic REM sleep and elevated NUFC excretion. Depressed youth also showed evidence of reduced sleep efficiency at baseline. Short REM latency, high REM density and elevated nocturnal urinary free cortisol (NUFC) were associated with the development of depression. Elevated NUFC also was associated with recurrent depressive episode(s). The findings that REM sleep abnormalities and elevated HPA activity occur prior to the onset of depression in adolescents suggest that these variables serve as vulnerability markers for the illness. Sleep and HPA measures also make a differential contribution to our understanding of the pathophysiology and prognosis of mood disorders in adolescent patients. LEGAL ISSUES IN SLEEP MEDICINE K PUVANENDRAN Sleep Disorder Unit. Singapoe General Hospital The interface between medicine and law encompasses many controversies, T.V. and movies dramatise such stories where a persons life or reputation hinges on forensic naunces. Act done by a person asleep cannot be criminal, there being no consciousness. However layman and jury perceive this differently. ‘He did a violent act, so he could not have been sleeping’. Sleep disorder or sleep walking, as a plea is unbelievable to the layman and jury. Forensic issues in sleep medicine is illustrated by cases studied locally and addressed from a scientific, clinical and legal aspect. Singapore, Year 1988 Woman, sleep deprived, drives a car over the leg of a child seated on the road pavement. Charged for negligence (because she should not drive if sleepy). Found to be an act during microsleep. Singapore, Year 1999 Woman alleges – She was raped when she was asleep. Boys says – It was sex with consent Q-Can the woman be raped in sleep? Singapore, Year 2000 A woman alleges – that the man seated next to her in a long haul flight molested her. Plea-Man says he was sleeping and oblivious. Singapore, Year 2002 Man charged for perjury. Found to be inappropriate verbal response from microsleep. Narcolepsy with Automatic Behavior Singapore, Year 2002 Young boy known sleepwalker, loud snorer with catnaps. Woke up in army camp from an afternoon nap and violently strangled an intruder, his friend. Previous similar violence twice. Found to be sleep walking with confusional arousal and narcolepsy. Sleep and Biological Rhythms 2005; 3: A2–A73 PASSIVE BODY HEATING: EFFECTIVE, SAFETY AND CONVENIENT TOOL FOR DETERIORATED SLEEP MAINTENANCE IN DEMENTED PATIENTS YUMIKO MISHIMA1, KAZUO MISHIMA2, SATOSHI HOZUMI1, TETSUO SHIMIZU2 AND YASUO HISHIKAWA1 1 Department of Geriatric Psychiatry, Kyowa Hospital, 2Division of Neuropsychiatry, Department of Neuro and Locomotor Science, Akita University School of Medicine This study investigated the sleep-promoting, thermoregulatory, and circadian phase-shifting actions of passive body heating (PBH) in elderly insomniacs with mild-to-moderate vascular dementia. Thirteen elderly insomniacs with vascular dementia (mean age 76.9 years; male/female ratio 2/11) were subjected to a PBH trial session. This session comprised a 3-day baseline period, 2-day PBH period, and 1-day post-PBH period. In the PBH period, the subjects received PBH (immersion in hot water of 40.0 ± 0.5°C to mid-thorax level) for 30 min beginning 2 h before bedtime. Sleep-waking estimated by actigraph, core body temperature (cBT), and heart rate variability were continuously monitored. Dim light melatonin onset time (DLMO) was determined in the baseline and post-PBH periods. PBH significantly improved subjects’ sleep quality; sleep latency decreased, sleep efficiency increased, and wake time after sleep onset decreased. These trends were more prominent in the latter half of the sleep time. PBH induced a rapid cBT elevation of approximately 0.80°C on average followed by enhanced heat loss (dif cBT, difference in cBT between just after the PBH and bedtime) lasting 1.5 h before sleep. There was a significantly positive correlation between dif cBT and sleep latency. PBH induced no significant phase shift in DLMO. Heart rate variability data showed that PBH induced parasympathomimetic action during sleep time in the subjects. PBH may have a sleep-promoting effect by interventing in the thermoregulatory and autonomic systems in elderly insomniacs with vascular dementia. DIFFERENT COMPONENTS OF PENILE ERECTION EVOKED AFTER ELECTRICAL STIMULATION OF THE MESOPONTINE TEGMENTUM JUAN C TOLEDO1, YOSHIMASA KOYAMA1, YUKIHIKO KAYAMA1, HIROSHI IWASAKI2, AKIHIRO KAWAUCHI2 AND TSUNEHARO MIKI2 1 Department of Physiology II, Fukushima Medical University, School of Medicine. Fukushima Japan, 2Department of Urology, Kyoto Prefectural University Previous studies have shown that neurons of the LDT fire before or during spontaneous penile erections. Lesions of the lateral preoptic area disrupt penile erections only during REM sleep 1. Injection of carbachol into the lateral preoptic area evokes penile erection 2. Trace studies show that cholinergic inputs to the lateral preoptic area come from the LDT. Our aim is to find out whether stimulation of the LDT causes penile erection. Rats were operated and implanted: a telemetric transducer to measure corpus spongiosum pressure (CSP); wires for measuring neck and bulbospongiosum muscle (BS) activities; and screws on their skull for measuring electroencephalogram. Carbon fiber electrodes were used for electrical stimulation of the brainstem. During the stimulation rats were unanaesthetized and head restrained. Spontaneous penile erections consist on a smooth increase in CSP (vascular component) followed by suprasistolic sharp increases in CSP A51 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 (muscular component) with BS activity. Penile erections, which were similar to spontaneous ones, could be evoked from the LDT and its surroundings.When the dorsal raphe nucleus (DR) and the areas lateral to the LDT were stimulated, CSP peaks with no vascular component but with BS activity were evoked. These peaks had lower amplitude than the peaks from LDT evoked or spontaneous erections.An erection pattern, which consisted on many high frequency CSP peaks followed by a normal erection pattern could be evoked after stimulation of areas close to Barrington nucleus but also in the LDT. The present study suggests that the different components of erection can be localized in different regions of the brainstem. The LDT may be involved in both the generation of a vascular component and the muscular component of a penile erection. The DR and lateral to the LDT may be involved only in the generation of the muscular component, since virtually no vascular components could be evoked after DR stimulation. References 1. Schmidt MH, Valax JL, Sakai K, Fort P, Jouvet M. Role of the Lateral preopric area in sleep-related erectile mechanisms and sleep generation in the rat. J. Neuroscience. 2000; 20: 6640–7. 2. Schimdt MH, Gervasoni D, Luppi PH, Fort P. Carbachol administration into the lateral preoptic area induces erections and wakefulness. Abst. Soc. Neurosci. Meeting, 2001. INCIDENCE OF MOTOR VEHICLE ACCIDENTS AMONG PATIENTS WITH OBSTRUCTIVE SLEEP APNEA SYNDROME IN TOKYO HIRONOBU YAEGASHI1,2, YASURO TAKAHASHI3 AND YUICHI INOUE1 1 Japan Somnology Center, Neuropsychiatric Research Institute, 2Matsumoto Kyoritsu Hospital, Sleep Center, 3Sleep Disorder Center, Neuropsychiatric Research Institute Many studies have suggested that patients with obstructive sleep apnea syndrome (OSAS) have an increased risk of motor vehicle accidents (MVAs) more than general population. However, previous studies were from western countries in which traffic situations and symptomatic characteristics of patients are different from Japan. Besides, the relationship between the occurrence of MVAs and severity of the disorder has not well identified. We made questionnaire survey on OSAS drivers living or working in Tokyo area (n = 608, 46}10 years old) who visited outpatient clinic of our sleep disorder center from November 1999 to April 2001 regarding driving habits and MVA history in the preceding 5 years. None of the subjects had any other sleep disorders and/or used drugs, which might act to cause excessive daytime sleepiness. Professional drivers were also excluded from the subjects. The severity of subjective daytime sleepiness of the patients was measured with Epworth sleepiness scale (ESS). Age adjusted 582 control subjects were sampled from male drivers who renew their drivers’ licenses at Kohto driving license center in Tokyo from March to June 2001. 72 of 608 OSAS drivers reported to have one or more MVAs, while 30 of 582 general drivers (odds ratio (OR) = 2.47, 95% confidence interval (CI): 1.59–3.85). The MVA rates of the OSAS patients group with 45/ h or more of apnea hypopnea index (AHI) was significantly higher than general drivers, but the value of the group with less than 30 of AHI did not differ from controls. The MVA rates of the OSAS group with 11 or more of ESS score were also significantly higher than controls (OR = 2.31, 5.52, respectively), but the value of the group with less than 11 of ESS score did not differ from controls. The MVA rate of OSAS drivers with AHI45 and/or ESS11 was 14.0%(63/449), and the A52 rate was significantly higher than controls (OR = 3.00, 95%CI: 1.91–4.73). Our study revealed that OSAS drivers with 45 or more of AHI and/or 11 or more of ESS score have an increased risk of MVAs. This finding may be of practical importance in the management of OSAS drivers. Because it has been well known that the association between AHI and ESS score has been known to be weak, these variables should be investigated simultaneously when evaluating risks of MVAs of drivers with OSAS. AN INTEGRATED MODEL OF HUMAN SLEEP-WAKE RHYTHMS DAIKI ISHIURA, KEISUKE YAMAMOTO, MITSUYUKI NAKAO, NORIHITO KATAYAMA AND MITSUAKI YAMAMOTO Graduate School of Information Sciences, Tohoku University Sleep-wake rhythms are considered to be controlled by the mutually interacting two oscillators, one for circadian pacemaker driving temperature/melatonin rhythm, and the other for sleep-wake rhythm, which are tentatively called oscillators I (Osc I) and oscillator II (Osc II), respectively. The mathematical models have been playing an important role in this field, which help researchers integrate a wide variety of physiological knowledge. So far, we have developed two different mathematical models of human sleep-wake rhythms: one is the thermoregulatory model of sleep control (Model A; Nakao et al. 1995), and the other is the phase dynamics model of human circadian rhythms (Model B; Nakao et al. 2002). Model A consists of two circadian oscillators and thermoregulatory feedback loops mediated by the heat memory, heat load and loss processes associated with sleep-wake patterns, which are modulated by both Osc I and Osc II. This model can reproduce the relationship between body temperature and sleep-wake rhythm and the bimodal distribution of sleepiness. Therefore, it can predict the behavior of sleepiness and body temperature under various situations such as sleep deprivations and transient heat loads. However, it can work only under the externally entrained condition, which is due to the model structure that dynamical interactions between oscillators are not implemented. On the other hand, Model B consists of two pacemakers and an overt sleep-wake oscillator, where the couplings between oscillators change adaptively dependent on correlation between the pacemakers and the selected activity pattern. Owing to this mechanism, Model B can simulate behavior of circadian pacemakers in response to forced rest-activity schedules under free-run situations and time zone flights. However, it cannot provide amplitude information concerning physiological variables such as temperature and sleepiness because its dynamics are restricted only to those of phase. As known from their features, these models are mutually complementary. Therefore, their combination could construct an almighty model. In order to realize this, the two oscillators of Model A are replaced by appropriate sinusoidal functions whose phases are responsible for those of Model B. This integrated model could simulate the sleepiness and sleep-wake patterns even under crucial situations that photic and nonphotic environments dynamically change. References M Nakao et al. (1999) Thermoregulatory Model of Sleep Control:Losing the heat memory. J. Biol. Rhythms. 14: 547–56. M Nakao et al. (2002) A Phase Dynamics Model of Human Circadian Rhythms. J. Biol. Rhythms. 17: 476–89. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 CHRONOBIOLOGICAL PROPERTIES OF CELLULAR IMMUNE ACTIVITIES UNDER SLEEP AND SLEEP DEPRIVED CONDITIONS YASUHIRO MATSUMOTO, KAZUO MISHIMA, KOHTOKU SATOH, TAKUMA TOZAWA, YUMIKO MISHIMA, TETSUO SHIMIZU AND YASUO HISHIKAWA Division of Neuropshychiatry, Department of Neuro and Locomotor Science, Akita University School of Medicine Growing evidence suggests that sleep-waking and immunity systems mutually make functional modification. Various natural and acquired immune activities have been reported to show robust daily variations with diverse functional peak timing, such that some appear during daytime and others appear during sleep. However, it remains to be clarified whether daily variations observed in the immune functions are under sleep- or circadian-dependent regulation. In the present study, we investigated chronobiological properties of several lines of cellular immune functions under sleep and sleep deprived conditions. The subjects were 10 healthy young men (mean age, 20.9 y; age range, 19–23 y). The mean sleep onset time of each subject before starting the study was defined as his .00.00 hours. This study was composed of a sleep session and a sleep-deprived session placed in a cross-over design with 2-week interval between each session. In both sessions, subjects entered the sleep laboratory at 8 h before .00.00 hours (–08.00 hours). At –06.00 hours, they took a 750-Cal meal and spent a habitual night (.00.00 hours –08.00 hours). At 08.00 hours –36.00 hours, subjects were rested in the supine position during the waking time (at 100 lux), and allowed to recline and sleep only at 24.00 hours –32.00 hours (less than 10 lux). They took a 150-Cal snack and 100 cc of water every 2 h during waking. Blood samples to measure cellular immunity (every 4 h) including peripheral WBC subsets, T-cell subsets (CD4+ and CD8+ cell distribution), NK cell activity, and blastogenic responses to PHA and Con-A, and blood samples to measure serum melatonin and cortisol concentration (every hour), were painlessly collected through an indwelling catheter (heparin lock) for consecutive 36 h. Significant daily variations were observed in WBC counts, WBC subsets (neutrophils, lymphocytes and monocytes), CD4+ cell ratio, CD4/CD8 ratio, and NK cell activity in both sessions. Blastogenic responses to mitogenic factors (PHA and Con-A) showed significant daily variations only in the sleep session. Neutrophil subset, monocyte subset, NK cell activity showed acrophases during daytime (timing of peak circulating cell numbers or peak phagocytosis; 08.00 hours –1959 hours), whereas lymphocyte subset, CD4 and CD4/CD8 ratios showed acrophases during nighttime (2.000 hours –0759 hours). These findings support the notion that at least a part of, but not all of, cellular immune fuctions are under circadian control and suggest the possible functional linkages between sleep and host defense systems in human. USING BRIGHT BLUE LIGHT IN THE MORNING FOR THE TREATMENT OF MILD DELAYEDSLEEP-PHASE SYNDROME LEON LACK, TOBY BRAMWELL AND HELEN WRIGHT School of Psychology, Flinders University of South Australia Delayed sleep phase syndrome (DSPS) results in insufficient sleep and daytime tiredness when sufferers attempt to arise early for social or work commitments. DSPS is associated with a delayed circadian rhythm that can be treated with the phase advancing capacity of morning bright light. Moreover, recent research has shown greater efficacy of short wavelength (blue) light than long wavelengths in phase advancing the Sleep and Biological Rhythms 2005; 3: A2–A73 circadian rhythms of normal sleepers. (Wright et al. 2004) The present study evaluated the efficacy of morning blue light stimulation for the treatment of mild DSPS. Seventeen mild DSPS sufferers (about 2 h delayed from normal) participated in a three week protocol: one week baseline, one week treatment with gradual advance of wake-up time from a mean of about 0910 hours to the target 06.00 hours, and one week post-treatment. Participants were randomly allocated either to a group receiving two hours of bright light immediately after awakenings during the gradual advance of wake-up time or a control group without bright light after awakening during the treatment week. For the bright light group blue light (peak wavelength at 470 nm at 65 microW/cm2 irradiance) was administered using a portable light device comprising light emitting diodes mounted on glass frames. The morning bright light group showed a significant 2.7 h advance of dim light melatonin onset compared to 0.3 h advance (n.s.) in the control group. Although there was some advance of sleep onset time during the treatment week, this may have arisen mainly from increased homeostatic sleep drive. During the post-treatment week, freed of any sleep/wake instructions, sleep onset and wake-up times generally reverted back to pretreatment times for both groups. Morning bright blue light normalized the melatonin circadian rhythms of mild DSPS sufferers. However, additional cognitive/behavioral therapy may be necessary to obtain a more lasting advance of sleep onset and wake-up times and a more effective treatment of mild DSPS. Reference Wright HR, Lack LC, Kennaway DJ. Differential effects of light wavelength in phase advancing the melatonin rhythm. J. Pineal Res. 2004; 36: 140–4. CLOSING THE EYES: A SIGNAL FOR THERMOREGULATION AND SLEEP MICHAEL GRADISAR, LEON LACK AND HELEN WRIGHT School of Psychology, Flinders University of South Australia Increases in distal skin temperatures have been associated with the attempt to sleep. (Lack & Gradisar 2002) However, it is not known which aspects of the attempt to sleep are responsible for these increases. This paper presents two studies that investigated specific sleep behaviors, cognitions and events, and their effects on distal skin temperature and sleep onset. Study 1 employed 34 good sleepers (mean age = 26.7 (10) (year) in a counterbalanced, repeated measures design comprising manipulations of four sleep behaviors: laying down, pulling covers up, placing contralateral (left) hand under covers, and closing the eyes. Distal skin finger temperature (FT) was measured from the right fingertip, and this remained outside the covers. Study 2 employed 15 good sleepers (mean age = 19.6 (1.5) year) with three conditions counterbalanced: lights off, close eyes, and attempt sleep. Finger temperature (FT), EEG and EOG were measured in study 2. Sleep onset latency was measured from lights out to Stage 1 sleep onset. In Study 1, laying down and placing the contra-lateral hand under the covers did not significantly increase FT (both p > 0.05), but pulling the covers up, [t(95) = 1.78, P < 0.01], and closing the eyes did, [t(99) = 4.10, P < 0.0001]. In study 2, lights off increased FT [t(164) = 2.79, p = 0.006], with closing the eyes contributing a further FT increase [t(164) = 2.15, p = 0.03]. However, the intention to sleep, and actually falling asleep, did not evoke any further significant FT change (P > 0.05). The likelihood of falling asleep was also affected by conditions, with sleep onset occurring < 1% of trials in the lights off condition, significantly increasing to 36% in the closed eyes condition (P < 0.0001) (despite being instructed in both conditions to remain A53 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 awake). With instructions to attempt sleep, no further significant increase in sleep likelihood occurred (P > 0.05). The stimuli of lights out and closing the eyes evoked thermoregulatory responses, with closing the eyes also increasing sleep propensity. Reference Lack L, Gradisar M. Acute finger temperature changes preceding sleep onsets over a 45-h period. J. Sleep Res. 2002; 11: 275–82. Financial Disclosure: The Faculty of Social Sciences, Flinders University. ABNORMALITIES OF SLEEP EEG IN FIBROMYALGIA P STORRS1, F MCKENNA1 AND K HUME2 1 Rheumatic Diseases Sleep Research Unit, Trafford General Hospital, 2 Dept of Biological Sciences, Manchester Metropolitan University, Manchester, U.K. Fibromyalgia is a disease of unknown aetiology. Subjective disturbance in sleep is commonly reported. Earlier studies in sleep laboratories have found some patients with fibromyalgia to have an abnormal pattern in EEG, with alpha wave intrusion in delta wave sleep. We have investigated 6 patients newly diagnosed with fibromyalgia, presenting consecutively to a rheumatology outpatient clinic. All patients were female with a mean age of 34 (range 31–40 years). All patients fulfilled the ACR criteria for fibromyalgia. None of the patients were taking hypnotic, tricyclic or other antidepressants or psychotropic drug therapy. All patients had domiciliary sleep EEG recordings on two consecutive nights, with simultaneous actigraphy recording of movement during sleep. The computerised recordings were analysed manually and compared with 6 age and sex matched healthy control subjects. All patients reported subjective disturbance in sleep. The actigraphy recordings indicated that all patients had profoundly abnormal sleep patterns. All patients had a similar abnormality in the EEG pattern in comparison with the control subjects. There was significant alpha wave intrusion into the delta wave pattern at the same stage of sleep in all patients on both nights. The pattern of alpha wave intrusion was similar in all patients, indicative of a specific abnormality. These results demonstrate an abnormality in sleep EEG in patients with fibromyalgia and support the hypothesis that fibromyalgia could be a primary sleep disorder. INACTIVATION OF THE EXCITATORY CORTICAL PROJECTIONS TO CAUDATE NUCLEUS DURING SLEEP ALEXANDER A LOSHKAREV, ELENA I RODIONOVA, EKATERINA V LEVICHKINA AND IVAN N PIGAREV Institute for Information Transmission Problems Russian Acad. Sci., Moscow, Russia Studying the neuronal activity in caudate nucleus (CN) in behaving cats we noticed that this activity in wakefulness replicate the properties of cortical neurons projecting to neostriatum. The same was true in drowsiness when CN neurons reproduced for a while bursty pattern of the developing sleep in cortical neurons. However, the picture changed dramatically during slow wave sleep. Instead of the expected burstpause pattern typical for cortical neurons in sleep neurons in CN strongly reduced the firing frequency and often could even stay silent during sleep. Experiments presented here were designed to investigate directly the transfer function of the cortico-caudate projections in sleep-wake cycle. Two cats under general anesthesia were surgically prepared for chronic A54 recordings of EEG and eye movements. One microelectrode recorded neuronal activity in the lower bank of the cruciate sulcus, which is known as having strong projections to CN. This electrode could also be used for electrical micro stimulation of the cortical area around the recorded neuron. Second microelectrode recorded neuronal activity in CN. The first task was to compare the neuronal background activity in the cortex with the activity in CN in sleep and wakefulness. 76 cortical neurons and 76 neurons in the CN were investigated. The ratio of firing frequency in sleep to that one in wakefulness was calculated for every neuron. In the cortex this ratio was sufficiently more than 1, i.e. neurons increased their average activity during sleep with respect to wakefulness. On the contrary, in CN that ratio turned out to be less than 1. Taking into account that projections from the cortex to neostriatum are excitatory we proposed that there should be an active blocking of cortical information transferring to the CN during sleep. To check this hypothesis we compared the responses of neurons in CN to cortical stimulation in wakefulness with those responses in sleep. The activity of 39 neurons in the CN, which in wakefulness responded to the electrical cortical stimulation, was studied. Only during 18 experiments we succeeded in recording the effects of cortical stimulation in CN both in sleep and in wakefulness. Responses of 9 neurons were excitatory, and 9 – inhibitory. The responses to cortical stimulation of all those 18 caudal neurons decreased or entirely disappeared during sleep. Excitatory cortical projections to caudate nucleus are blocked during sleep. THE EFFECT OF NAPPING ON MOOD AMONG WOMEN WITH SIGNIFICANT PREMENSTRUAL SYMPTOMS LYNNE LAMARCHE, GENEVIÈVE FOREST AND JOSEPH DE KONINCK University of Ottawa, Canada Up to 80% of reproductive women suffer from premenstrual syndrome (PMS) (Hamilton, Parry, Alagna, Blumental, & Herz 1984), and between 5%–25% of women experience it to a severe degree (Shaver, 2002; Kessel & Coppen, 1963). Irritability (32.5%) and feelings of depression (31%) are two of the most prevalent symptoms experienced during this phase (Sheldrake & Cormack 1976). It is also known that daytime sleepiness is correlated with the premenstrual phase, and that this is even more pronounced among women with more severe symptoms (Manber & Bootzin 1997). PMS costs millions of dollars every year due to the loss of productivity and costs associated with individual lives (Reid & Yen 1981). For these reasons, treatment options such as dietary supplements and medication have been suggested. However, these interventions are expensive, and studies on their effectiveness remain quite controversial (Mortola 1996). Naps have been found to be effective at improving mood in the general population (Taub 1976). The aim of the current study was to examine the impact of a short mid-afternoon nap on emotional symptoms, more specifically irritability and depression, among women with significant premenstrual symptoms. So far, 6 women have been studied (mean age 26.8 years). All participants had regular and ovulatory cycles, were not taking any contraceptive medication, and were not suffering from any sleep or psychological disorders. Participants came to the sleep laboratory to take a nap during the premenstrual phase, which occurred on average 2.3 days before onset of menses. The timing of the nap was scheduled for approximately 12 h following the mid point of their nocturnal sleep. Participants were allotted 40 min to fall asleep and given a maximum of 30 min to sleep. The Mood Adjective Checklist, containing items measuring aggression (i.e. angry, defiant) and sadness (i.e. regretful, sad), was administered immediately before and 30 min after napping. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Results indicated that aggression (P < 0.05) and sadness (P < 0.05) significantly decreased after napping. In addition, a trend was observed for the decrease in aggression to be positively correlated with the number of minutes spent in slow wave sleep (SWS) (r = 0.71, p = 0.074). These results suggest that napping among women with significant premenstrual symptoms may help prevent or counteract some of their emotional symptoms. EXCESSIVE DAYTIME IN CHILDREN WITH EPILEPSY RAMA MAGANTI AND AMIT BISWAS Marshfield Clinic-Neurology Adults with epilepsy were shown to experience excessive daytime sleepiness (EDS) and poor sleep quality, which may be due to anticonvulsant use, seizures, and or primary sleep disorders (Foldvary, Journal of Clinical Neurophysiology. 19(6): 514–21, 2002). Similar studies however, are lacking in children. We hypothesized that children with epilepsy have worse daytime sleepiness compared to controls. Children with epilepsy (treated with nonbenzodiazepines, nonbarbiturate anticonvulsants) and age/sex matched controls between ages 8 and 18 were recruited for this pilot study. All subjects completed the Pediatric Daytime Sleepiness Scale (PDSS) and parents completed the Pediatric Sleep Questionnaire (PSQ). Two tailed t-tests were used for group comparisons and regression analysis to identify independent predictors of daytime sleepiness among patients. Marshfield Clinic institutional review board approved the study. 50 children with epilepsy (30 male; 20 female), and 30 age/sexmatched controls (18 male; 12 female) were enrolled in the study. Parents of children with epilepsy reported significantly worse daytime sleepiness on PSQ (P = 0.01). Furthermore, these parents more often reported complaints of sleep apnea (P = 0.007) and parasomnias (P = 0.005) compared to controls. On the PDSS, children with epilepsy reported significantly worse daytime sleepiness compared to controls (P = 0.002). Seizure frequency, epilepsy syndrome and anticonvulsants used were not significant predictors of EDS among patients. EDS is common among children with epilepsy, which may be due to an underlying sleep disorder such as sleep apnea or parasomnias. Further studies are needed to determine factors underlying EDS, and whether treatment of underlying sleep disorder improves EDS among children with epilepsy. DISCHARGE PATTERNS OF HYPOCRETIN (OREXIN) NEURONS ACROSS SLEEPWAKEFULNESS CYCLE IN FREELY MOVING RATS LYUDMILA I KIYASHCHENKO1,2, BORIS Y MILEYKOVSKIY1,2 AND JEROME M SIEGEL1,2 1 Department of Psychiatry and Biobehavioral Sciences, University of California, 2VA GLAHS-Sepulveda USA Our recent studies in anesthetized rats showed that hypothalamic hypocretin (Hcrt) neurons have broad spikes with long lasting later positive deflection (LPD) that is significantly broader than the LPDs of adjacent nonHcrt cells. We found that this spike parameter serves as practically unerring criterion for identification of Hcrt neurons responding antidromically to electrical stimulation of the ventral tegmental area (VTA). Using this methodical approach, we identified 11 Hcrt neurons and recorded their activity during different behavioral states. Sleep and Biological Rhythms 2005; 3: A2–A73 Hcrt neurons had spike LPD ranging from 0.55 ms to 0.78 ms with a mean 0.62 ± 0.02 ms (n = 11) and responded antidromically with an average latency of 4.7 ± 0.21 ms during VTA stimulation. Hcrt cells were relatively inactive in quiet wakefulness (1.01 ± 0.13 Hz), but are transiently activated during sensory stimulation. They were silent in slow wave sleep and tonic periods of REM sleep, with weak increasing in firing rate during phasic REM sleep (0.32 ± 0.1 Hz). In active waking, Hcrt neurons had approximately equal levels of the activity during grooming (4.9 ± 0.5 Hz) and eating (4.75 ± 0.0.39 Hz) and maximal activity during exploratory behavior (9.3 ± 0.62 Hz). In addition, Hcrt neurons strongly decreased their firing rate during food aversion despite strong EEG desynchronization and the presence of motor activity. We hypothesize that identified Hcrt cells are involved in the regulation of motivational and/or emotional aspects of the behavior modulating motor activity and cortical arousal. The malfunction of such modulation would be consistent with the symptoms resulting from the loss of Hcrt neurons in human and animal narcoleptics, in particular the inability to maintain waking arousal and the losses of muscle tone during catapleptic attacks induced by emotional stimuli. Study is supported by NIH grants MH071350, MH 064109 and SRC of VA GLAHS Sepulveda. EFFECTS OF MICRODIALYSIS OF ANISOMYCIN INTO LATERAL PREOPTIC AREA ON SLEEP OF RATS MELVI METHIPPARA1,2, SUNIL KUMAR1, 3, NOOR ALAM1,2, RONALD SZYMUSIAK1,3 AND DENNIS MCGINTY1,2 1 VAGLAHS, 16111 Plummer Street, North Hills, CA, 2Psychology, 3 Medicine, UCLA, Los Angeles, CA, USA Sleep is considered to be a restorative process which promotes selective expression of genes involved in protein synthesis (1). Although the effects of systemic inhibition of protein synthesis on sleep has been investigated (2), no study has yet investigated the effects of a localized inhibition of protein synthesis in a sleep promoting area such the as preoptic area (POA) on sleep. Therefore, we studied the effects on sleep of microdialysis of a protein synthesis inhibitor, anisomycin, into the lateral preoptic area (lPOA) in free moving rats. Six male Sprague-Dawley rats were stereotaxically implanted with EEG and EMG electrodes, and a guide cannula directed at the lPOA. After 5–7 days of recovery, microdialysis probes were inserted. Sleep recording started 18 h after probe insertion. One h after lights off, rats were microdialysed with anisomycin (500 nM or 5 mM) or artificial (ACSF) for 2 h followed by 18 h of ACSF perfusion. On any given night, each rat received only one of the three treatments. Data from the first 6 h of recording after beginning of treatments were analysed. Compared to ACSF control, 500 nM of anisomycin significantly (P < 0.05) decreased total wake (52.2 ± 1.8% vs. 69.8 ± 4.7%) and increased total slow wave sleep, SWS (40.3 ± 2.0% vs. 26.2 ± 3.4%) especially SWS 2 (26.9 ± 2.2% vs. 12.2 ± 3.1%). 5 mM of anisomycin significantly (P < 0.05) reduced total wake (48.0 ± 3.3% vs. 69.8 ± 4.7%) particularly active wake (33.8 ± 5.4% vs. 52.9 ± 5.03%), and enhanced total SWS (41.6 ± 0.9% vs. 26.2 ± 3.4%) especially SWS2 (27.9 ± 1.7% vs. 12.2 ± 3.1%). Night time application of anisomycin into the lPOA induced sleep at the expense of wake. This could be due to the inhibition of protein synthesis which may be required for sleep to complete its functional role. References 1. Cirelli C, Gutierrez CM, Tononi G. Extensive and divergent effects of sleep and wakefulness on brain gene expression. Neuron. 41: 35–43, 2004. A55 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 2. Rojas-Ramirez JA, Aguilar-Jimenez E, Posadas-Andrews A, Bernal-Pedraza JG, Drucker-Colin RR. The effects of various protein synthesis inhibitors on the sleep-wake cycle of rats. Psychopharmacology (Berl) 53: 147–50, 1977. EFFECTS OF POSTNATAL AGE ON THE INITIAL HYPOXIC VENTILATORY RESPONSE IN SLEEPING INFANTS HEIDI L RICHARDSON1, PETER M PARSLOW1, ADRIAN M WALKER1, RICHARD HARDING2 AND ROSEMARY SC HORNE1 1 Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, and 2Department of Physiology, Monash University, Melbourne, Australia Previous studies have reported that the hypoxic ventilatory response (HVR) is immature in infants, though the age at which maturation occurs remains controversial. Our aim was to quantify the maturation of the HVR of term infants over the first six months of life, during both active sleep (AS) and quiet sleep (QS), taking hypoxia-induced arousal into account. Fifteen healthy term infants, born at 38–41 week gestational age, were studied longitudinally using daytime polysomnography at 2–5 week, 2–3 month and 5–6 month after birth. Nasal airflow was measured using a miniaturised pneumotachograph attached to a silicone rubber nose-mask. Each infant was challenged with hypoxia (15% O2, balance N2) in both AS and QS. Tests were terminated if the infant aroused, after 5 min if no arousal, or if SpO2 fell below 85%. Mean values of O2 saturation (SpO2) and inspired minute ventilation per kg of body weight (VI/kg) were calculated for the initial 15 s and each subsequent 30 s epoch of the hypoxic test period and expressed as percentage changes relative to baseline values. Data were averaged for each sleep state, taking into account whether or not an arousal occurred and compared using ANOVA. The probability of a failure to arouse was lower in QS at 2–5 week compared with 2–3 month and 5–6 month (P < 0.05). During QS tests which resulted in arousal, the fall in SpO2 was greater and the VI/kg lower at 2–5 weeks when compared with both 2–3 month and 5–6 month. During QS tests when infants failed to arouse the fall in SpO2 was less severe despite VI/kg being lower at 2–5 week compared to the other two ages studied. The HVR in AS did not differ with postnatal age. This is the first longitudinal study to examine hypoxic ventilatory responses in the same infants over the first 6 months of life. Although the response during AS did not change with age, during QS the VI/kg response was impaired at 2–5 week compared with later ages, regardless of whether arousal occurred. This project was supported by the Australian National Health and Medical Research Council and the Sudden Infant Death Research Foundation of South Australia EFFECTS OF SLEEP STATE ON THE INITIAL HYPOXIC VENTILATORY RESPONSE IN SLEEPING TERM INFANTS HEIDI L RICHARDSON1, PETER M PARSLOW1, ADRIAN M WALKER1, RICHARD HARDING2 AND ROSEMARY SC HORNE1 1 Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, and 2Department of Physiology, Monash University, Melbourne, Australia A failure to respond appropriately to hypoxia during sleep may be important in the etiology of Sudden Infant Death Syndrome (SIDS). Pre- A56 viously, the majority of studies of the hypoxic ventilatory response (HVR) have been conducted during quiet sleep (QS) only. Since active sleep (AS) is the dominant sleep state throughout the first six months of life, our aim was to examine the initial HVR in human term infants in both AS and QS. Fifteen healthy term infants, born at 38–41 week gestational age, were studied longitudinally using daytime polysomnography at 2–5 week, 2–3 and 5–6 month after birth. Nasal airflow was measured using a miniaturised pneumotachograph attached to a silicone rubber nose-mask. Each infant was challenged with hypoxia (15% O2, balance N2) in both AS and QS. Tests were terminated if the infant aroused, after 5 min with no arousal, or if SpO2 fell below 85%. Mean values of oxygen saturation (SpO2) and inspired minute ventilation per kg of body weight (VI/kg) were calculated for the initial 15 s and each subsequent 30 s epoch of the hypoxic test period and expressed as percentage changes relative to baseline values. Data were averaged for each sleep state, taking into account whether or not an arousal occurred and compared with ANOVA. All tests in AS initiated an arousal response. In QS infants both aroused and failed to arouse. In both sleep states regardless of arousal responses hypoxia induced a significant decrease in SpO2 (P < 0.05) at each age studied. Furthermore, at 5–6 month this decrease was more severe in AS than QS (P < 0.05). No significant change in VI/kg was observed at 2–5 week or 2–3 month in either sleep state. However, at 5–6 month in both AS and QS tests which resulted in arousal VI/kg was increased significantly above baseline at 30 s and 60 s (P < 0.05), and in non arousal QS tests at 60 s (P < 0.05). This is the first study to examine the initial hypoxic ventilatory response during both AS and QS in term infants, taking arousal responses into account. The finding that VI/kg did not differ between sleep states despite differences in SpO2 requires further investigation. The arousal response always observed in AS is likely to be protective against severe hypoxia. This project was supported by the Australian National Health and Medical Research Council and the Sudden Infant Death Research Foundation of South Australia VALIDATION AND RELIABILITY OF THE PITTSBURGH SLEEP QUALITY INDEX (PSQI) HEBREW TRANSLATION AND COMPARISON WITH THE TECHNION MINI SLEEP QUESTIONNAIRE (MSQ) O TZCHISHINSKY1,2, T SHOCHAT1,2, A NICTREN1, T PORTNOY1 AND R PELED2 1 Emek Yezreel Adademic College, Emek Yezreel, 2Sleep Medicine Center Technion, Rambam Hospital, Haifa, Israel The Pittsburgh Sleep Quality Index (PSQI) is a standardized widely used measure of sleep quality, with proven reliability and validity (1). Nineteen items are scored in 7 domains and a global score, including sleep duration, sleep latency, habitual sleep efficiency, sleep disturbances, daytime dysfunction, overall sleep quality and hypnotic use. It has been translated to several languages, including Japanese and French (2, 3). The Technion Mini Sleep Questionnaire (MSQ) is a validated sleep quality questionnaire used in the clinic and in several studies for Hebrew speaking subjects (4). The MSQ includes 10 items pertaining to insomnia, sleep disordered breathing, excessive daytime sleepiness, excessive movements during sleep and use of hypnotic medication. The global score represents the sum of all items. The purpose of the present study was to validate and compare the PSQI translated to Hebrew with the MSQ. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 The PSQI was translated to Hebrew by two sleep researchers fluent in both Hebrew and English. The translation was then evaluated independently by a sleep clinician and two sleep researchers. One translator then back translated the questionnaire from Hebrew to English. The final Hebrew version (PSQI-H) was administered to 90 consecutive adult patients referred to the Sleep Medicine Center in Rambam Medical Center, in addition to the MSQ used routinely and to 145 students. Questionnaires were collected and scored. The MSQ was sub scored into items referring to insomnia (MSQ-I) and items referring to hypersomnia (MSQ-H), in addition to the global score. Correlations between global and subscores were computed. Alpha Cronbach was computed to assess reliability of both questionnaires. Ninty patients and 145 students (mean age 24.5 (4.7) range 20–45) completed the questionnaires. The patients group included (mean age 42.2 (14.6), range 14–78 years; mean BMI: 28.6 (8.25)), 35 females (mean age 46.1 (16.4)) and 55 male (42.2 (14.6)). A significant correlation was found between global MSQ and global PSQI scores, r = 0.702 (P < 0.001). Significant correlations were also found between MSQ-I and PSQI subscale scores including sleep duration r = 0.50 (P < 0.001), sleep disturbances r = 0.34 (P < 0.006), sleep latency r = 0.42 (P < 0.001), sleep quality r = 0.56 (P < 0.001) habitual sleep efficiency, r = 0.53 (P < 0.001) and use of sleep medications r = 0.45 (P < 0.001). Finally, significant correlations were found between MSQ-H and daytime dysfunction and sleep quality (r = 0.41, r = 0.58, P < 0.001, respectively). Cronbach’s alpha coefficients were calculated for global PSQI (AlphaÑ = 0.58), and global MSQ (Alpha = 0.76). Conclusions: Preliminary results show that the PSQI-H demonstrated moderate reliability on a selected patient population. Further studies on normal adults and other clinical populations should be done using larger sample sizes. The agreement between the PSQI-H and the MSQ suggests that the PSQI-H may be used in clinical studies using Hebrew speaking subjects, particularly when insomnia is the main focus of the study and when international standardization is warranted. References 1. Buysse et al. Psychiatry Res. 1989; 28(2): 193–213. 2. Doi et al. Psychiatry Res. 2000; 97(2–3): 165–72. 3. Blais et al. Encephale. 1997; 23(6): 447–53. 4. Zomer et al. (1985) In WP Kollea (Ed) Sleep (pp. 467–470). RELATIONSHIP BETWEEN DIM LIGHT MELATONIN ONSET AND SLEEP TIMING IN SLEEP ONSET INSOMNIACS HELEN WRIGHT1, LEON LACK1 AND RICHARD BOOTZIN2 1 School of Psychology, Flinders University, South Australia, 2Department of Psychology, University of Arizona, USA Because studies have found a strong relationship between the timing of sleep and the melatonin circadian rhythm, it has been suggested that sleep timing can adequately predict circadian timing. Studies have shown that the midpoint of sleep is highly correlated with dim light melatonin onset (DLMO) in young (20 years) good sleepers, with correlations ranging from r = 0.68 (Burgess et al. 2003) to r = 0.89 (Martin & Eastman 2002). In these studies, the midpoint of sleep was able to predict the DLMO within about 1 h for 75% to 92% of the subjects, respectively. Furthermore, in a group of depressed patients with Seasonal Affective Disorder (mean age 40.4 years) the correlation was r = 0.80 (Terman et al. 2005). The strength of this relationship however, has not been evaluated in an insomnia population. Participants were part of a larger study evaluating the effectiveness of behaviour and light therapy for sleep onset insomnia. Eighty-four participants (mean age 31.1 years) with sleep onset insomnia (mean sleep onset latency 63 mins) completed a 7-day sleep diary. On the eighth Sleep and Biological Rhythms 2005; 3: A2–A73 evening they collected saliva under dim light conditions for melatonin analysis. Their average sleep onset time, wake up time and midpoint of sleep times were 01.00 hours ± 58 mins, 0803 ± 69 mins, and 04.32 ± 56 mins, respectively. The correlation between sleep midpoint and DLMO for the whole group was significant but small at r = 0.48, P < 0.0001. However, when the group was divided into those with sleep midpoint later than 0430 (N = 41) and those with an earlier sleep midpoint (N = 43), there was a significant correlation for the later group (r = 0.50, p = 0.0007) and no relationship for the early group (r = –0.06, p = 0.69). It appears that sleep onset insomniacs in general have a less robust relationship between the timing of their sleep and circadian phase than good sleepers. Furthermore, those insomniacs with earlier timed sleep patterns show no relationship. Therefore caution must be exercised in trying to predict the circadian rhythm timing of insomniacs from their sleep timing. References Burgess H et al. The relationship between the dim light melatonin onset and sleep on a regular schedule in young healthy adults. Behav. Sleep Medical 2003; 1: 102–14. Martin SK, Eastman CI. Sleep logs of young adults with self-selected sleep times predict the dim light melatonin onset. Chronobiol, Int., 2002; 19: 695–707. Terman M. Personal communication. 2005. EFECTS OF INGESTED TRYPTOPHAN ON MONOAMINE METABOLISM IN LACTATING NEONATES S APARICIO1, C GARAU1, RV RIAL1, MC NICOLAU1, M RIVERO2 AND S ESTEBAN1 1 Department Biologia F. I C.S., laboratori de Fisiologia. Universitat de les Illes Balears. 07122 Palma de Mallorca (Spain), 2Laboratorios Ordesa S.L.Barcelona, St. Boi de Llobregat. Barcelona (Spain) Tryptophan is an essential aminoacid, precursor in the synthesis of both serotonin and melatonin, two substances with important effects on sleep control. To test its effects on brain monoamine turnover after the ingestion of tryptophan enriched milk, the contents of NA, DOPA, DOPAC, DA, 5-HIAA, 5-HTP, HVA and 5-HT has been tested by HPLC in the urine of 10 infants aged 12 ± 4 weeks receiving artificial lactation with control (1.5%) and enriched (3.4%) tryptophan contents. Both control and tryptophan enriched formulas fully accomplished the requirements for infant milk formulas according to CEE directives. The two milk types were administered to each infant in a double blind arrangement during three periods of seven days. The different milk types were administered in a 12/12 h schedule and the infants received either two identical standard milks (controls) or dissociated low/high tryptophan containing milks (experimental). Control and experimental formulas were switched in a 12/12 h schedule, from 06:00 to 18:00 and from 18:00 to 06:00. The infants received control milk during one week and dissociated low/high tryptophan milk during two additional seven days periods. The tryptophan enriched milk was administered either during the dark period (18:00–06:00) of the 24 h cycle (experimental week) or during the light period of the 24 h cycle (inverse control week). During the whole 21 days duration of the experiment, the diapers (Moltex®) used by the infants and only containing urination, were daily collected. Shortly after collection, each diaper was weighed and a 100 mg cellulose sample was extracted from the central part of the diaper. The urine contained within each sample was eluted in 1 mL of analytic grade methanol, centrifuged and frozen stored (–80°C) for further HPLC-ED chromatographic analysis. A57 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 No significant differences have been found between control and tryptophan enriched fed infants neither in NA, DOPA, DOPAC, DA and HVA but the metabolites of tryptophan and serotonin showed significant changes in the urine produced during night time and only during the experimental week, the one in which high tryptophan milk was administered during night time. Briefly, the levels of 5-HTP and 5-HIAA were increased, while those of serotonin (5-HT) remained unchanged. The results are interpreted as demonstrative of an increased serotonin synthesis and metabolism. However, the lack of changes in the absolute amount of urinary serotonin, together with the absence of changes during light time, points to an increased use as a substrate in the synthesizing pathway of melatonin. In summary, the metabolism of serotonin and probably that of melatonin during dark time can be manipulated by varying the contents of tryptophan in the ingested food. Acknowledgements: This work has been done under a contract with Ordesa SA. and also in part supported by grants of the Spanish Dirección General de Investigación Cient’fica y Técnica, numbers BFI 2002–04583-C01-02 and BFI 2002–04583-C02-02. ADENOSINE INCREASES REST IN YOUNG RATS BUT NOT IN ADULT ONES C GARAU1, S APARICIO1, S ESTEBAN1, MC NICOLAU1, MC BARRIGA2, M RIVERO3 AND RV RIAL1 1 Department Biologia F. I C.S., laboratori de Fisiologia. Universitat de les Illes Balears. 07122 Palma de Mallorca (Spain), 2Depto de Fisiolog’a, Universidad de Extremadura, 06071 Badajoz, 3Laboratorios Ordesa S.L. Barcelona, St. Boi de Llobregat. Barcelona (Spain) Nucleosides are considered as important components of many foods, serving for instance as boosters of the immune system when added to infant milk formulations. On the other hand, it is well known that adenosine plays a fundamental role on the activity of hypothalamic sleep promoting centres. However, it is believed that the adenosine present in food has no effects on the sleep-wake rhythm because of its extremely rapid turnover, which ranges within a period of few seconds and no significant amounts of dietary adenosine could thus reach the brain. In fact, most of the adenosine present in the brain proceeds from an internal source, namely the degradation of CAMP. However, it is known that many physiological processes are dependent on the maturity of the tissues in which their effect is performed and wide changes in the number of brain adenosine receptors have been found along the maturation process. In addition, it is known that the amount of circulating adenosine is low in the human newborn. Hence, dietary adenosine may also have sleep inducing properties in young animals. To test this possibility, 11 adult and 5 weanling rats received (1) 10 mg/kg of adenosine (2) 0.1 mg/kg of R-PIA (a selective agonist of the A1 adenosine receptors) and (3) 30 mg/kg of caffeine. Adenosine had no effects on the behaviour of adult rats as shown by means infrared actimetry performed in their habitual home cages, On the contrary, both adenosine and R-PIA produced significant activity reductions in young animals, while caffeine caused a significant activity increase in both young and adult rats. In conclusion, artificial milk formulations supplemented with adenosine could be used in the control of sleep disturbances in lactating infants. Acknowledgements: This work has been done under a contract with Ordesa SA. and also in part supported by grants of the Spanish Dirección General de Investigación Cient’fica y Técnica, numbers BFI 2002–04583-C01-02 and BFI 2002–04583-C02-02. A58 THE SLEEP IN BIRDS: TWO STATES OR ONLY ONE? C GARAU, S APARICIO S ESTEBAN, MC NICOLAU AND RV RIAL Department Biologia F. i C.S., laboratori de Fisiologia. Universitat de les Illes Balears. 07122 Palma de Mallorca (Spain) The existence of two sleep phases in birds is well established. However, after reviewing the published bird sleep studies, their two phases seem to have important differences from those of mammals in regulation, in REM duration, in the presence of eye movements during NREM and in the lack of a true muscular atonia during REM. In fact, the most important sign to distinguish between NREM and REM in birds has been the EEG amplitude, a factor of disputable importance in animals different from advanced (placental and metatherian) mammals. To ascertain the real equivalence between the sleep of mammals and birds, 4 turtle doves and 4 rats have been tested by analyzing over 1500 s of unambiguous sleep in each animal. The main results in rats showed: (1) a clear bimodal distribution of EEG amplitudes when they were plotted against the number of seconds spent in each amplitude class (2) a significant negative correlation between EEG amplitude and eye movements and (3) a significant positive correlation between EEG and EMG amplitudes. These results fully agree with the existence of two sleep phases in rats. On the contrary, in turtle doves the distribution of EEG amplitude vs. frequency of seconds spent in each EEG amplitude class was always unimodal. Also, no correlation was found between EEG amplitude and both EOG and EMG. These results points to only one sleep phase in birds in which the EEG, the muscular activity and the eye movements are continuously variable and with no discrete difference between phases. If only one sleep phase exists in birds, it is difficult to recognize whether it can be ascribed to NREM or to REM. However, a cue could be obtained from the sleep of the platypus, a primitive mammal in which evident REM sleep has been recorded concurrently with high amplitude-slow frequency EEG. If the presence of only one sleep phase in birds would be confirmed, they would have a very similar sleep to that of reptiles and the evolution of sleep would be fairly clear. The two phases, REM and NREM, would be exclusive of mammals, and both would have appeared as a consequence of the evolutionary changes in the development of the brain. Acknowledgements: This work has been in part supported by a grant of the Spanish Dirección General de Investigación Cient’fica y Técnica, number BFI 2002–04583-C02-02. CHANGES IN SLEEP ELECTROENCEPHALOGRAM AND NOCTURNAL HORMONE SECRETION AFTER ADMINISTRATION OF THE ANTIDYSKINETIC AGENT SARIZOTAN IN HEALTHY YOUNG MALE VOLUNTEERS. HE KUENZEL, A STEIGER, K HELD, IA ANTONIJEVIC, RM FRIEBOES AND H MURCK Max-Planck-Institute of Psychiatry Munich Sarizotan is a 5-HT(1 A) agonist with high affinity to D(3) and D(4) receptors. In animal experiments, the drug shows a strong anticataleptic effect and suppresses effectively dyskinesias in animal models of L: -dopa-induced dyskinesia and of tardive dyskinesia. Data from an open pilot study in patients with Parkinson’s disease show clear indication of a treatment effect against L: -dopa-induced dyskinesia. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 CNS-active drugs are known to modulate sleep electroencephalogram (EEG) and sleep-related hormone secretion. 5-HT(1 A) agonists suppress rapid-eye movement (REM) sleep and enhance the secretion of ACTH, cortisol, prolactin and growth hormone (GH) at daytime. We hypothesised that sarizotan shares these effects. Furthermore, we were interested in the influence of sarizotan on leptin, which participates in the regulation of the energy balance and is enhanced after various psychoactive drugs. Ten healthy male subjects were investigated twice in a double-blind, placebo-controlled crossover design. Sleep EEG and nocturnal hormone secretion of ACTH, cortisol, prolactin, GH and leptin were examined after oral administration of either placebo or 20 mg of sarizotan at night. After administration of sarizotan, a significant reduction of REM sleep and total sleep time in conventional sleep EEG and a significant reduction of sigma- and theta-power in spectral analysis were observed. The main effect on nocturnal hormone secretion was a significant elevation of prolactin and of ACTH in the first half of the night. While REM sleep was suppressed, the endocrine effects of 20 mg sarizotan at night were weak. Its sleep-endocrine profile is comparable to the effects provoked by selective 5-HT reuptake inhibitors. MEASURING SITUATIONAL SLEEP RESISTANCE TO PREDICT DRIVING PERFORMANCE OLIVIER MAIRESSE1, ELKE DE VALCK2, PETER THEUNS1 AND RAYMOND CLUYDTS2 1 Research Methods and Psychometrics, Vrije Universiteit Brussel, Brussels, Belgium, 2Department of Cognitive and Biological Psychology, Vrije Universiteit Brussel, Brussels, Belgium Subjective sleepiness may be experienced most when fighting sleep. According to Borg’s Range Model (1998), perceptual intensities could be approximately equal for different people permitting interindividual comparisons. Following this rationale, a level-anchored category-ratio scale for measuring perceived effort to stay awake was built. Thirty-six male shift-workers performed a 25 min driving simulator test (DriveSim 3.0) between 5.15 and 6.00 AM after a late-night 7 h shift. Driving performance was assessed using (1) mean speed (2) speed deviation (3) lane drifting and (4) accident liability. State and trait sleepiness were assessed using the Stanford Sleepiness Scale (SSS) and the Epworth Sleepiness Scale (SSS), respectively. Situational sleep resistance was assessed using a modified version of Borg’s CR10 scale (Borg 1998). Conform to Cluydts, De Valck, Verstraeten & Theys (2002), both state and trait sleepiness measures were included in multiple linear regression models in order to predict driving performance. In this study, ESS scores did not contribute to explain the variance of the models significantly and were therefore excluded. The variance accounted for by the model with mean speed as dependent variable and SSS scores as independent categorical variables, corrected for complexity (adj. R2), equaled .418 (P < 0.002). The same model but with CR10 scores as the independent continuous variable showed no important difference: adj. R2 = 0.408 (P < 0.001). However, our data suggest that participants used the CR10 as a category scale, reporting only numbers associated with verbal or numerical anchors in distinct categories. Considering this, CR10 scores were used as independent categorical variables, increasing the adjusted R2 to .634 (P < 0.001). In order to predict accident liability logistic regressions were performed. CR10 scores as independent categorical variables significantly predict deviations from the road or hits with other vehicles (c2 = 9716; P < 0.05), where SSS scores failed to be significant predictors. These results suggest that situational sleep resistance measured by the CR10 could predict driver performance more accurately than the classical measures of subjective sleepiness. Sleep and Biological Rhythms 2005; 3: A2–A73 References Cluydts R, De Valck E, Verstraeten E, Theys P (2002) Daytime sleepiness and its evaluation. Sleep Medicine Reviews, 6(2): 83–96. Borg G (1998) Borg’s perceived exertion and pain scales. Human Kinetics, Leeds, United Kingdom. EXPRESSION OF C-FOS IN THE PREOPTIC AREA DURING ENFORCED VS. SPONTANEOUS WAKING I GVILIA, A TURNER, D MCGINTY AND R SZYMUSIAK 1 Research Service, Veterans Admin., North Hills, CA, USA, 2Department of Medicine, University of California Los Angeles, CA, USA, 3Department of Psychology, University of California Los Angeles, CA, USA, 4I. Beritashvili Institute of Physiology, Tbilisi, Georgia Recent studies implicate the ventral lateral preoptic area (vlPOA) and the median preoptic nucleus (MnPN) of the hypothalamus as sleeppromoting sites. Both the vlPOA and MnPN express sleep-associated Fos immunoreactivity and both nuclei contain sleep-active neurons as demonstrated by unit-recording studies. To examine whether the activation of c-fos in the vlPOA and MnPN is functionally relevant to sleep homeostasis, we quantified waking c-fos expression in these nuclei during conditions of low and high sleep drive. Sleep drive was hypothesized to be low in spontaneously awake rats during the dark/active period and high in the rats kept awake during the light/rest period. Male Sprague-Dawley rats, maintained on a 12/12 L : D cycle, were assigned to two groups (n = 4 in each): one group was allowed 2 h spontaneous sleep-waking behavior (SpSW) at the beginning of dark period, while the other group was sleep-deprived (SD) for 2 h at the beginning of light period by tapping on the cage. EEG/EMG recordings were performed in both groups. At the end of the experiments, rats were perfused and brain tissue was processed for immunostaining for c-Fos protein. The Fos-immunoreactive neurons (Fos-IRNs) were counted in rostral and caudal portions of MnPN (rMnPN and cMnPN) and vlPOA, using standard grids. During the dark period, SpSW rats manifested high percentage of spontaneous waking (>85%). During the light period, SD rats exhibited about 95% of wake. Total numbers of Fos-IRNs in the vlPOA and MnPN of SpSW rats (37.8 ± 4.6 in the rMnPN; 23.3 ± 2.4 in the cMnPN and 15.8 ± 0.4 in the vlPOA) were significantly lower then those in SD rats (73.3 ± 2.9 in the rMnPN; 58.3 ± 2.4 in the cMnPN and 50.5 ± 4.3 in the vlPOA). These findings suggest that the sleep-waking behavior – related activation of c-fos in the vlPOA and MnPN might be correlated with the level of homeostatic sleep drive. Additional work is needed to determine the role of circadian factors. Supported by the Department of Veterans Affairs and MH 63323. STUDY OF SLEEP IN FREELY SWIMMING DOLPHINS OI LYAMIN1,2, LM MUKHAMETOV2, PO KOSENKO2, AL VYSSOTSKI3, JL LAPIERRE1, TM POKIDCHENKO2, HP LIPP3 AND JM SIEGEL1 1 UCLA & VA GLASH Sepulveda, CA, USA, 2Utrish Dolphinarium, Moscow, Russia, 3Institute of Anatomy, University of Zurich, Switzerland Our previous studies have demonstrated the unique nature of Cetacean sleep, namely unihemispheric slow wave sleep (USWS) and the absence of REM sleep in the form it is described in all terrestrial mammals. However, in those studies we used traditional tethered equipment and the dolphins were kept in small pools. The aim of the present study A59 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 was to examine sleep of freely swimming dolphins using a portable recorder to avoid the restrain imposed by recording cables. We designed a programmable digital recorder to register EEG in bottlenose dolphins freely swimming in a 9 ¥ 4 ¥ 1.3 m pool with seawater. The recorder was secured to a harness worn by the dolphin, and it allowed the recording of up to 8 EEG signals digitized at 250 Hz for 3 continuous days. To test the system we recorded EEG from two pairs of symmetrically implanted intracranial electrodes in two adult dolphins. The behavior of dolphins was continuously videotaped and synchronized with the EEG. EEG was successfully recorded for 4 and 6 continuous days in dolphin 1 and 2, respectively. Episodes of USWS occurred beginning from day 2 after the surgery. They lasted 26–98 min and alternated in the two hemispheres. In both dolphins, USWS occurred during slow swimming and floating at the surface as described in the previous studies. For the first time, we documented USWS in a dolphin while quietly lying on the bottom of the pool. Those episodes lasted 150–212 s and were interrupted by arousals when the dolphin surfaced to breath. In each dolphin we documented single and serial muscle jerks (2–27/day), which occurred during quiet waking, USWS and transitions between them. The data collected here using a portable recorder indicates considerable plasticity of sleep behavior in dolphins, specifically their ability to display USWS while lying on the bottom in addition to that seen while slowly swimming or floating at the surface. The preliminary data on the association between muscle jerks, and the pattern of EEG and behavior in freely swimming dolphins do not allow us to draw a conclusion about the presence or absence of REM sleep in dolphins without further, more extensive recordings. Supported by NIH, SNF and NCCR COMPARATIVE STUDY OF EEG ASYMMETRY IN DOLPHINS, FUR SEALS AND RATS TM POKIDCHENKO1, OI LYAMIN1,2, LM MUKHAMETOV1 AND JM SIEGEL2 1 Utrish Dolphinarium, Moscow, Russia, 2UCLA & VA GLASH Sepulveda, CA, USA Dolphins display an unusual form of sleep called ‘unihemispheric sleep’. Fur seals exhibit both ‘bilateral’ and ‘asymmetrical’ SWS. ‘All studied terrestrial mammals display bilaterally symmetrical sleep. The aim of this study was to quantify the degree of EEG asymmetry in different frequency ranges in dolphins and seals in comparison to rats. Two adult bottlenose dolphins, four juvenile northern fur seals, and four adult rats were implanted with EEG electrodes for polygraphic sleep recording. EEG spectral power was computed in symmetrical cortical recordings over 20- s epochs in the ranges of 1.2–4, 4–8, 8–12, and 12–15 Hz. The degree of EEG asymmetry was measured by the asymmetry index (AI = [L - R]/[L + R]; L and R – spectral power in the left and right hemisphere, respectively). In rats on average 88–99% of waking, SWS and REM epochs had absolute AI < 0.3. EEG asymmetry during SWS in rats as measured by the AI was minimally expressed in the range of 1.2–15 Hz (0–12% with AI > 0.3). In contrast to rats, dolphins average 88%, 72% and 36% of SWS epochs with an absolute AI > 0.3 in the range of 1.2–4 Hz, 4–8 Hz and 8–15 Hz, respectively. ‘Moreover, in two studied dolphins on average 62% of SWS epochs had maximal absolute values of AI (0.6–1.0) in the range of 1.2–4 Hz and 35% of SWS in the range of 4–8 Hz. Those epochs represented high voltage unihemispheric sleep. ‘Fur seals while sleeping on land displayed AI intermediate of that in rats and dolphins. Seals had little SWS (<8%) with AI > 0.6 in the range of 1.2–8 Hz. ‘EEG asymmetry in seals was equally expressed during A60 SWS in the entire examined range with absolute AI > 0.3 in 28–36% of epochs. AI allows quantitatively estimating the degree of EEG asymmetry between different species. As measured by the AI, there is a significant difference between ‘bilaterally’ sleeping rats (90% SWS with absolute AI < 0.3), ‘unihemispherically’ sleeping dolphins (>80% SWS with AI > 0.3; > 60% SWS with AI 0.6–1.0), and fur seals, showing both ‘bilateral’ and ‘asymmetrical’ SWS (30–40% of SWS with AI > 0.3 in the range 1.2–4 Hz). In dolphins and seals EEG asymmetry is specific to SWS. In rats EEG asymmetry is subtle with no major difference between the behavioral states. Supported by NIH and NSF. EFFECTS OF SELECTIVE H3 RECEPTOR ANTAGONIST ON PERIODIC LIMB MOVEMENTS DURING SLEEP IN AGED RATS KC HSIEH, D NGUYEN, JM SIEGEL AND YY LAI UCLA/VAGLAHS, North Hills, California 91343 USA The H3 receptor has been proposed as a novel therapeutic target for sleep disorders (Passani et al. 2004). Systemic administration of a H3 antagonist has been shown to promote wakefulness in cats and in rats, however, its effects on spontaneously occurring sleep-related pathological symptoms have not been studied. We implanted the chronic epidural EEG electrodes, bilateral nuchal and femoral EMG electrodes in 18-month-old Sprague-Dawley rats to monitor their behavioral states and muscle activity. Guide cannulas targeted at the lateral ventricle were implanted to allow intracerebroventricular (icv) drug delivery. Two old rats showing periodic limb movements (PLM) during sleep were subject to icv injections of thioperamide, a selective H3 antagonist, at ZT8, and the effects were compared with those of the control injections of artificial cerebrospinal fluid (aCSF) of equal volume (10 l). Before and after all recordings, the cannula placement was verified by eliciting immediate drinking behavior with angiotensin II injection. The animals were individually housed in sound-proof recording chambers with controlled light-dark cycle of 12:12. Sleep was scored and analyzed in 10- s epochs; PLM was scored according to the criteria defined by International Classification of Sleep Disorders for humans. Compared with aCSF injection, the sleep architecture was not changed by the injection of 50 g thioperamide, while 100’g thiopermide promoted wakefulness in the first 8 h post injection to 124.6% of the control at the expense of NREM sleep time (63.0% of the control) without changing REM sleep. The total amount of sleep in 24 h post injection remained unchanged in all injections (n = 3). However, at both dosages, thioperamide strongly suppresses PLM over the period of 24 h recording. At a dose of 50 g, thioperamide elicited a reduction of PLM index (PLMI) from 26.8 (aCSF) to 15.7 after injection, whereas 100 g thioperamide injection produced a decrease of PLMI from 17.2 (aCSF) to 8.2. In conclusion, our present study found that selective H3 antagonists at low doses suppress leg movements during sleep without affecting sleep time. This finding is highly relevant to the development of therapeutic treatment for PLM-related disorders in humans. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 SLEEP DEPRIVATION ALTERS SOD AND GPX ACTIVITIES WITHOUT AFFECTING LIPID OXIDATION IN THE RAT BRAINSTEM LALINI RAMANATHAN AND JEROME M SIEGEL Department Psychiatry and Biobehavioral Sciences, University of California, Los Angeles and VAGLAHS Sepulveda, North Hills We propose that free radicals accumulate during waking as a result of enhanced metabolic activity. This increase in free radical production eventually leads to the physiological and pharmacological changes associated with sleep deprivation. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are the major antioxidative enzymes involved in scavenging free radicals. Free radicals if not removed will lead to oxidation of lipids, proteins and/or nucleic acids, resulting in structural and functional damage to cellular components. We previously reported that short-term (6 h) total sleep deprivation significantly increased SOD and GPx activities in the brainstem, while long-term (5–11 days) total sleep deprivation significantly decreased SOD activity in the brainstem. Here we report that the changes in the activities of SOD and GPx were not correlated with changes in the level of the lipid oxidation product, thiobarbituric acid reactive substances (TBARS). Male Sprague Dawley rats (400–500 g) were subjected to short-term (6 h) total sleep deprivation by gentle handling (n = 6), or to long-term (5–11 days) total sleep deprivation by the disk-over-water method (n = 6). All animals were sacrificed by halothane anesthesia followed by decapitation. The brainstem was quickly dissected on ice and stored at –80C. Samples were homogenized in buffer containing 20 mM phosphate (pH 7.4) to which 1% of 0.5 M butylated hydroxytoluene had been added to prevent oxidation during sample preparation. The homogenate (10%, w/v) was centrifuged at 2900 ¥ g for 10 mins. at 4C. The pellet was discarded and the supernatant was used for determining the level of the lipid oxidation product, TBARS. The paired student’s t-test was used to determine statistical significance at the level of P < 0.05. Neither short-term (YC = 0.31 nmoles TBARS/mg protein, SD = 0.23 nmoles TBARS/mg protein t = 1.023, d.f. = 5, p = 0.35) nor long-term (YC = 0.42 nmoles TBARS/mg protein, SD = 0.43 nmoles TBARS/mg protein t = –0.111, d.f. = 5, p = 0.92) total sleep deprivation significantly altered the level of TBARS in the brainstem. We conclude that the initial increase in free radicals resulting from short-term sleep deprivation increased the activities of SOD and GPx, thereby preventing free radical induced lipid oxidation. Prolonged sleep deprivation further enhanced the production of free radicals, which damaged these enzymes resulting in decreased activity. The increased free radical production did not lead to lipid oxidation but may have resulted in protein and/or nucleic acid oxidation. Research supported by HL41370, 1P50, HL060296 and the VA Medical Research Service. CELL PROLIFERATION IN THE DENTATE GYRUS OF ADULT RATS IS REDUCED BY SLEEP FRAGMENTATION MUHAMMAD-TARIQ BASHIR1,2, RUBEN GUZMAN-MARIN1,3, FENG-XU3, KENG-TEE CHEW1, RONALD SZYMUSIAK1,2 AND DENNIS MCGINTY1,3 Research Service1, VAGLAHS, Sepulveda, California, USA, Departments of Medicine2 and Psychology3, UCLA, California, USA The subgranular cell layer of the dentate gyrus (DG) in the adult hippocampus contains progenitor cells with the potential to differentiate into neurons. Previous studies in humans have shown that if sleep is fragmented by brief awakenings after each minute of sleep, daytime cog- Sleep and Biological Rhythms 2005; 3: A2–A73 nitive performance is impaired the next day to virtually the same extent as after total sleep deprivation (SD) 1. Sleep fragmentation is common to different human conditions including depression, sleep apnea and aging. These conditions are associated with reduced hippocampal volumes and hippocampal-dependent cognitive deficits. In animal models for these conditions a reduction in neurogenesis has been shown to play a key role in the development of the hippocampal pathogenesis. In the present study we evaluate the possibility that sleep fragmentation reduces proliferation of cells in the DG of the hippocampus. Male albino rats were implanted for polysomnographic recording. An intermittent treadmill system was used for sleep fragmentation. In the experimental group (SF) fragmentation was achieved by 3 s treadmill movement every 30 s. In the control group (SFC) the treadmill was continuously on for 15 min and off for 150 min. Sleep fragmentation was conducted in 3 conditions: 1 day, 4 days and 7 days (n = 6, 4, 6, respectively). The thymidine analog BrdU that labels proliferating cells was injected two hours prior to the end of each experimental condition. Control rats continued to have substantial amounts of consolidated NREM sleep whereas the sleep fragmented animals exhibited discontinuous episodes of NREM sleep. The number of BrdU positive cells was reduced by 70.1 and 70.08% (P < 0.05 t-test) in the SF group after 7 and 4 days of experimental conditions whereas no differences were observed after 1 day. The results show that SF induced marked reductions in the number of BrdU positive cells in the DG. This effect was greater than that produced by 4 days of SD 2. References 1. Bonnet et al. J. Appl. Physiol. 1991; 71: 1112–8 2. Guzman-Marin et al. 2003. J. Physiology 549.2: 536–71 Support: MH-47480, MH-47489, HL-60296, MH-63323 and The Research Service of The Veterans Administration. MEASURING SITUATIONAL SLEEP RESISTANCE TO PREDICT DRIVING PERFORMANCE OLIVIER MAIRESSE1, ELKE DE VALCK2, PETER THEUNS1 AND RAYMOND CLUYDTS2 1 Research Methods and Psychometrics, Vrije Universiteit Brussel, Brussels, Belgium, 2Department of Cognitive and Biological Psychology, Vrije Universiteit Brussel, Brussels, Belgium Subjective sleepiness may be experienced most when fighting sleep. According to Borg’s Range Model (1998), perceptual intensities could be approximately equal for different people permitting interindividual comparisons. Following this rationale, a level-anchored category-ratio scale for measuring perceived effort to stay awake was built. Thirty-six male shift-workers performed a 25 min driving simulator test (DriveSim 3.0) between 5.15 and 6.00 AM after a late-night 7 h shift. Driving performance was assessed using (1) mean speed (2) speed deviation (3) lane drifting and (4) accident liability. State and trait sleepiness were assessed using the Stanford Sleepiness Scale (SSS) and the Epworth Sleepiness Scale (SSS), respectively. Situational sleep resistance was assessed using a modified version of Borg’s CR10 scale (Borg 1998). Conform to Cluydts, De Valck, Verstraeten & Theys (2002), both state and trait sleepiness measures were included in multiple linear regression models in order to predict driving performance. In this study, ESS scores did not contribute to explain the variance of the models significantly and were therefore excluded. The variance accounted for by the model with mean speed as dependent variable and SSS scores as independent categorical variables, corrected for complexity (adj. R2), equaled 0.418 (P < 0.002). The same model but with CR10 scores as the independent continuous variable showed no important difference: A61 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 adj. R2 = 0.408 (P < 0.001). However, our data suggest that participants used the CR10 as a category scale, reporting only numbers associated with verbal or numerical anchors in distinct categories. Considering this, CR10 scores were used as independent categorical variables, increasing the adjusted R2 to 0.634 (P < 0.001). In order to predict accident liability logistic regressions were performed. CR10 scores as independent categorical variables significantly predict deviations from the road or hits with other vehicles (c2 = 9716; P < 0.05), where SSS scores failed to be significant predictors. These results suggest that situational sleep resistance measured by the CR10 could predict driver performance more accurately than the classical measures of subjective sleepiness. References Cluydts R, De Valck E, Verstraeten E, Theys P (2002) Daytime sleepiness and its evaluation. Sleep Medicine Reviews, 6(2): 83–96. Borg G (1998) Borg’s perceived exertion and pain scales. Human Kinetics, Leeds, United Kingdom. CEREBRAL SYMPATHETIC NERVE ACTIVITY INCREASES DURING REM SLEEP P CASSAGLIA, R GRIFFITHS AND AM WALKER Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia The cerebral circulation in richly invested with sympathetic nerves arising out of the superior cervical ganglion (SCG). Previous studies have shown that increases in arterial blood pressure (ABP) results in increased sympathetic nerve activity (SNA) from the SCG and removal of the SCG lowers baseline cerebral vascular resistance (CVR) and significantly increases cerebral blood flow (CBF), yet the exact role of the sympathetic innervation of the cerebral circulation during sleep remains uncertain. Rapid increases in SNA, through vasoconstriction may protect the cerebral microcirculation from increases in ABP that occur naturally during REM sleep. In this study we aimed to develop a model for examining SNA, ABP and CVR in sleep, allowing tests of the hypothesis that SNA plays a protective role in the cerebro-vascular bed during natural arterial pressure surges. Lambs (A = 2) were instrumented under general anaesthesia for recording of femoral arterial blood pressure and determination of sleep states (bio-electrodes). SNA was measured using 25 m tungsten microelectrodes, with a 1 mm bared tip inserted into the SCG. The signal was differentially amplified and filtered at 100–2000 Hz, and stored (sampling rate 10 kHz) for offline spectral analysis. Substantially increased SNA (average 30 ± 7%) was recorded in the SCG as ABP rose acutely (average 41 ± 6%) during REM sleep (n = 7). Bilinear regression analysis of these data show an increase in SNA preceding the rise in ABP by 5 s. These studies provide preliminary evidence for a potential protective role for the sympathetic innervation of the cerebro-vascular bed against increased distending pressure in sleep, such as during the large transient rises in arterial blood pressure that are common in REM. OXYGEN: A MAJOR REGULATOR CEREBRAL BLOOD FLOW IN REM? AM WALKER, DA GRANT, G ZOCCOLI AND WILD Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia Rapid-eye-movement (REM) sleep is remarkable for its high basal cerebral blood flow (CBF) which exceeds that in all sleep-wake states, and A62 for the further CBF increases associated with transient blood pressure (BP) surges. It has been proposed that sensitivity of cerebral vessels to low PO2 is a fundamental property that determines the level of CBF (Zoccoli et al. Sleep Medical Rev 2002). If this were to be true, oxygen levels should be a powerful determinant of CBF in all behavioural states, though perhaps not predominant in REM. In specific tests of the hypothesis we: (a) contrasted the response of the cerebral circulation during REM and non-REM sleep to transient, episodic arterial oxygen desaturations designed to mimic sleep apnea (HYPOXIA IN SLEEP); (b) determined the changes of CBF associated with REM and non-REM occurring against a background of continuous hypoxia (SLEEP IN HYPOXIA); and (c) examined CBF increments during episodic blood pressure surges (REM SURGES) in normoxia & hypoxia. Lambs (n = 8) were instrumented to record beat-beat cerebral blood flow (CBF) using a 2 mm diameter TRANSONICS transit time ultrasonic flow probe implanted around the superior sagittal sinus, and implanted with catheters to record cerebral perfusion pressure (CPP) and electrodes to define sleep-wake states. Arterial oxygen saturation (SpO2) was recorded with a NELLCOR pulse oximeter. CBF was contrasted between REM and non-REM sleep occurring naturally during normoxia (FiO2 0.21) and during hypoxia induced by reducing FiO2–0.10 either (a) transiently (60 s) within individual sleep epochs (HYPOXIA IN SLEEP); or (b) continuously (1 h) across repeated sleep epochs (SLEEP IN HYPOXIA). Under baseline (normoxia) conditions, CBF (ml/min) was significantly greater in REM than in non-REM (19 ± 1 vs. 15 ± 1, P < 0.01, mean ± SE, n = 4, t-test). During continuous hypoxia, increases of CBF occurred in REM (24 ± 7%, P < 0.05) and non-REM (14 ± 5%, P < 0.05), and the greater CBF (ml/min) of REM (23 ± 2) compared with non-REM (17 ± 1) was preserved (P < 0.02). Similarly, there was preservation of the significantly greater CBF of REM compared with non-REM under conditions of episodically (60 s) imposed hypoxia (n = 6). During BP surges (?BP~20%. n = 4) peak CBF increased similarly in normoxia (23 ± 6%), continuous hypoxia (19 ± 13%) and episodic hypoxia (22 ± 3%). As the major circulatory features of REM sleep (CBF in REM > NREM; large surges of CBF) are preserved in hypoxia, regardless of its duration, sensitivity of cerebral vessels to PO2 appears to be a fundamental property that powerfully affects the basal level of cerebral blood flow, but not the sleep-wake differences. SLEEP HABITS AND PARENT PERSPECTIVE ON CHILDREN’S SLEEP IN SIX COUNTRIES – AMERICA, ETHIOPIA, INDONESIA, FRANCE, JAPAN AND KOREA NORIKO MATSUURA, NAOMI ADACHI, MEGUMI KAJI AND RYOJI ARITOMI Research Intitute on Sleep and Society, Tokyo, Japan Parents have a considerable impact on children’s sleep. Our previous study in Japan showed that child’s sleep was closely related with parents’, especially mother’s. Furthermore, parent’s care for sleep influenced child’s sleep. This result suggested that parent perspective reflected in care for sleep is important for children’s sleep. It would appear that parent perspective differs in countries because of different cultural and social contexts. In present study, we therefore exploratory investigated parent perspective on children’s sleep in different countries. We conducted a survey on parent who had a child aged 0–3 in America, Ethiopia, Indonesia, France, Japan and Korea. Participants answered about sleep habits of their own, spouse and child and their perspective on children’s sleep. Questionnaire included items about sleep habits of family member, sleep problem and environment of child Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 and perspective on child’s sleep. 557 participants (America = 100, Ethiopia = 97, France = 88, Indonesia = 94, Japan = 80, Korea = 98) completed the questionnaire. Sleep habits of family member were significantly different between countries. However, sleep lengths of mother and child were significantly correlated in all countries. Most parents in Japan (86.3%) and Korea (83.7%) whose child slept shorter thought children need to be early to go to bed and to awake. And about half of them claimed that they had problems with child’s sleep (Japan: 55.0%, Korea: 45.9%). On the other hand, in Ethiopia, children slept longest and only 5.0% of parents thought children should go to bed early and wake up early. Percentage of Ethiopian parents who had problems with child’s sleep was the lowest (17.5%). Percentage of parents who thought it’s natural that children sometimes cry at night (97.0% in America 13.3% in Korea) and sleep in some strange positions (82.0% in America 15.3% in Korea) varied between counties. Sleep environments also differed between countries. 98.9% of children slept alone in their own bed in America, while 6.4% in Indonesia. Only 1.0% of parents in America thought that children should sleep with parents, that is to say parents practiced what they thought. Although most children shared a bed with some family member in Indonesia, parents who thought that children should sleep with parents were 31.9%. Parent perceptions on sleep didn’t always correspond to actual children’s sleep. ETHANOL EFFECTS PARTIALLY PREVENTION BY OPIOID RECEPTORS ANTAGONIST T BASISHVILI, M GOGICHADZE, I RUKHADZE AND N EMUKHVARI Beritashvili Institute of Physiology, Georgian Academy of Sciences, Department of Neurobiology of Sleep-Wakefulness Cycle Ethanol and opiates produce similar subjective effects. Endogenous Opioid peptides act as neuromodulators, which modify the action of other neurotransmitters in the CNS. Opioid peptides can affect certain behaviors, including Ethanol consumption. One of the brain circuits that are activated by opioids and Ethanol is the mesolimbic reward system. Ethanol increases dopaminergic neurons discharging by the activation of m-opioid receptors of Ventral Tegmental Area and d-opioid receptors of Nucleus Accumbens. Blockators of opioid system decrease Ethanol consumption in animals and alcoholism relapse in human subjects. Administration of Ethanol induces release of endogenous opioids in the hypothalamus, a region of the brain involved in the regulation of various physiological states, including mood and sleep. Opioid receptors are found in structures involved in Sleep-Wake Cycle (SWC) regulation. The interaction between Ethanol and endogenous opioid system is not yet completely clear. The aim of the present work was to investigate influence of Ethanol and Ethanol + Naloxone (Naloxone – nonselective opioid antagonist) administration on the SWC of rats. Mongrel adult male rats (n = 10) were implanted with electrodes under Hexobarbital sodium anesthesia (i.p. 3 mg/kg). After recovery the animals were injected with Ethanol (i.p. 4.25 g/kg) and Ethanol (i.p. 4.25 g/kg) + Naloxone (i.p. 20 mg/kg). The EEG recording of SWC (10–12 h) continued until background activity was restored. The data were statistically evaluated by Student’s t-test. Results: Administration of high dose of Ethanol, along with cataplexy, elicits behavioral and EEG dissociation, suppression of amplitude of EEG activity and complete immobilization. During this state normal SWC has not been generated. The administration of Naloxone + Ethanol produced partial restoration of SWC. In the following SWC only slight increase of slow-wave sleep and decrease of paradoxical sleep was demonstrated, wakefulness decreased from 42% to 15%. The state, which we characterized as EEG and behavioral dissociation, was partially preserved. Duration of dissociation occupied approximately 20% of the whole cycle compared to 36% after single Ethanol injection. Sleep and Biological Rhythms 2005; 3: A2–A73 According to our results we suppose that high doses of Ethanol realize its effects by endogenous opioid system. Although the dissociative processes are remained after Naloxone administration, we conclude that Ethanol may act on CNS by other neurotransmitter systems as well. DEVELOPMENT OF SLEEP INDICATOR MEASUREMENT TECHNOLOGY UTILIZING THE FINGER PLETHYSMOGRAM ETSUNORI FUJITA, YUMI OGURA, NAOKI OCHIAI1, KOHJI MURATA2, TSUTOMU KAMEI3, YOSHIYUKI UENO4 AND SHIGEHIKO KANEKO5 1 Deltatooling Co., Ltd.3–1 Taguchi-kenkyu-danchi, Higashi-hiroshima, Hiroshima 739–0038, 2Kanazawa University Graduate School of Medical Science, 13–1 Takaramachi, Kanazawa, Ishikawa 920–0934, 3Shimane Institute of Health Science, 223–7 Enya-cho, Izumo, Shimane 693–0021, 4 Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275–0016, 5School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–8656, Japan The mutual effects of an oscillator and homeostasis, which govern sleeping and waking rhythms, are made apparent in changes in the heartbeat, breathing, and body temperature. Fluctuation occurs within the variation in the heartbeat, breathing, and body temperature, and it was hypothesized that the progression from a waking state to a sleeping state could be observed by way of these fluctuations. In addition, a spectrum analysis done on changes in the heartbeat was divided into low frequency (LF), high frequency (HF), very low frequency (VLF), and ultra low frequency (ULF) areas, and it is said that activity regulating the body temperature is included in this VLF area. On one hand, the amplitude of the finger plethysmogram is governed by the heart’s fluctuation characteristics; so is affected by contraction and expansion, and by variations in blood pressure. Furthermore, fluctuations in the baseline are due to fluctuation in the blood flow, which in turn translates into variations in the diameters of the skin’s blood vessels. This led us to hypothesize that indicators of a subject entering a sleep state are captured in the gradient time series wave form of the square of the amplitude of the finger plethysmogram pressure, and also are captured in the fluctuation in diameters of the blood vessels in the skin as evidenced in the largest Lyapunov value’s gradient time series wave form, and that indicators of entering a sleep state exist in the VLF and ULF. The slide calculation method was used to find the gradient time series waveform, based on a 90% overlap rate with the time frame in which the gradient time series wave form was 180 degrees. This hypothesis was verified in sleep studies on subjects in both lying and sitting positions, and indicators were detected when the subject went from a waking state to the first stage of entering a sleep state. These indicators required a measurement timeframe of 30–50 min, and were captured when the power value’s gradient amplitude, the largest Lyapunov coefficient and the power value’s gradient exhibited a phase difference of 180 degrees. A63 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 POLYSOMNOGRAPHIC FINDINGS FROM A SPANISH FAMILY WITH AUTOSOMAL–RECESSIVE PARKINSON SYNDROME (PARK 6) U VOSS1, I TUIN2, KR KESSLER2, B MORALES3, U ZIEMANN2, H STEINMETZ2 AND G AUBURGER2 1 Erfurt University, Germany, 2Neurological Clinic of the J.W. GoetheUniversität, Frankfurt/Main, 3Neurological Clinic of the University Hospital San Cecilio, Granada, Spain Sleep disorders are a frequent symptom in Ideopathic Parkinson’s Disease (IPD). Regarding PSG findings, patients with IPD show a prolonged sleep onset period, reduced sleep efficiency, increased sleep fragmentation, and poor subjective sleep quality. Only little is known about sleep in patients suffering from familial Parkinson’s Disease such as PARK6, a familial autosomal-recessive form of PD caused by a mutation of the PINK1-gene which codes for a serin-threonin-kinase with mitochondrial localisation. Clinically, PARK6 is characterized by an early onset, slow progression, continuous L-DOPA responsivity and lack of atypical attributes. The present study reports on a Spanish family with PARK 6 Parkinson Syndrome. Of the 7 siblings, 3 were genetically homozygote and severely affected, 3 were heterozygote and clinically asymptomatic and one sibling was unaffected. Research questions concerned possible differences in sleep recordings between homozygote and heterozygote or unaffected siblings and similarities of PARK6 and IPD sleep profiles. Siblings reported no incidence of depression, subjective sleep disturbance, increased daytime somnolence or improvement of motoric symptoms following sleep. Standard PSG was recorded during 2 consecutive nights using a 32channel polysomnograph (Brainlab, Schwarzer, Munich). Records were scored visually by two experienced raters according to R & S criteria. All patients had inconspicuous sleep onset latencies. The homozygote affected patients had increased sleep fragmentation due to elevated arousal indices. Amounts of SWS and REM sleep were significant indicators of disease progression in trend analyses, showing a strongly increased amount of SWS (37%) and reduced REM sleep (6%) in the most affected patient. One asymptomatic sibling suffered from sleep apnea, all other siblings showed no sign of respiratory abnormalities, increased limb movements or RBD-like behavior during sleep. Aside from higher sleep fragmentation and increased arousal frequency in homozygote patients, there was no systematic difference between homozygote and heterozygote siblings. However, it should be noted that disease progression was accompanied by a hightened amount of SWS coinciding with reduced REM sleep, suggesting these parameters to be a potential marker of disease progression. Concerning IPD vs. PARK6, there appear to be marked differences in sleep quality, showing a subjectively satisfactory sleep quality in PARK6 patients and a more intact sleep architecture, independent of dopaminergic medication. Diagnostic implications of these findings are addressed. CHANGING CONCEPTS OF SLEEP AND CONSCIOUSNESS FROM ANCIENT TO MODERN TIMES JPN MISHRA Jain Vishva Bharati Institute (Deemed University) Ladnun-341306, Rajasthan, India Man’s striving to understand the nature of sleep and consciousness which makes him face his cataclysmic nature and provocative behav- A64 iour has also to be as old. The concept of both sleep and consciousness has passed through the era of ‘Uroboros Concept’ in the time span of ‘Creation Myth’, then ‘Hero Myth’, then to ‘Yogic and Kundalini Concept’ of human consciousness as mentioned in Vedic Literature. Consciousness in human being have been studied furthermore in detail in Upnishads where it has been classified in the stages like-Jagrat, Svapna, Sushupti and Turiya. Vedanta Sutras with the commentary by Ramanuja indicates that in the vedic age the presence of two different varieties of sleep were well recognised. One was the stage of dreaming and the other was the stage of dreamless sleep. The Kundalini Yoga or Tantric concepts postulate a slightly modified version and state that Prana Shakti or Cosmic energy negotiates with several vortices, Chakras in the body and produces different states of sleep and/or consciousness. There is another Yogic School of thought which says that sleep may be classified in physical sleep, psychical sleep and sleepless sleep (Yoga Nidra), in close association of Jagrat and Swapna Stage. The Modern concept of consciousness and its various forms in many ways bears a close resemblance with the one described in ancient scriptures. All these need and proposed to be discussed in detail to get clear pathway of mechanism of possible neural substrates operating in both sleep and consciousness. SLEEP AUDITORY INFORMATION PROCESSING MARISA PEDEMONTE, CLAUDIA BENTANCOR AND RICARDO A VELLUTI Neurofisiolog’a, Departamento de Fisiolog’a. Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. Auditory data is continuously present coming from the environment and/or from the body, and it constitutes a first step toward sleep learning. Thus, the unitary firing response to pure tone-bursts exhibited by each auditory specific nucleus or cortex showed to be changing along with the behavioral shifts, i.e. the sleep waking cycle in the guinea pig. Furthermore, no units were silent on entering sleep, while were reported to fire as during wakefulness or increasing/decreasing their discharges (1,2). It is usually admitted that the cortical level is the place where the most relevant processing is carried out. The importance of the inferior colliculus central nucleus (ICc) as a crossroad in the auditory pathway makes this nucleus a suitable place to contribute to higher levels information processing. The hypothesis is that complex sound stimulation, the animal natural call, may be differently processed during wakefulness and in sleep even at the IC level. Animals (n = 6) were prepared for recordings in physiological conditions, i.e. during the sleep-waking cycle. Bipolar cortical, hippocampal and neck muscles electrodes were implanted for behavioral control. Glass micropipettes filled with 3M Sodium acetate were used for extracellular single cell recording. Acoustic stimuli consisted of pure tone-bursts (50 ms) and guinea pig vocalizations (whistle, 750 ms), previously tape recorded, played backwards and forwards. Unitary data obtained during periods of wakefulness and slow wave sleep were analyzed performing peri-stimulus time histograms (PSTH), studying the number of discharges and their temporal distribution. Each ICc unit was characterized as an auditory one using a tone-burst at its best frequency during wakefulness. The PSTH of the recorded response to a whistle showed that, when the natural call was played backwards, i.e. inverted in time, or played direct, the neuronal firing changed in Wakefulness. The played natural call provoked a greater response than the played inverted in time call. On passing to slow wave sleep, the same neuron exhibited a lower discharge number. When played backwards, a net difference in comparison to the response to a direct whistle was exhibited, increasing or decreasing the firing number. In both cases, during wakefulness or slow wave sleep, there was also present a change in the pattern of discharge. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 Vocalizations, being possible significant stimuli, showed a differential processing at the ICc level in comparison with the responses to nonnatural sounds, either in waking or sleep. Two possibilities are open: 1. The natural-inverted call evoke a neuronal change because the natural one may be significant. 2. The difference introduced may be due to the temporal change in the stimulus frequencies presentation, although the first proposition seems to be more probable. References 1. Pedemonte, Pérez-Perera, Peña, Velluti. Sleep Res. Online (2001). 2. Velluti, Pedemonte. Cell. Mol. Neurobiol. (2002). PHASIC REM SLEEP IN NEWBORNS: ROLE OF NITRIC OXIDE IN CEREBROVASCULAR REGULATION GIOVANNA ZOCCOLI1, DANIEL A GRANT2, JENNENE WILD2 AND ADRIAN M WALKER2 1 Department of Human and General Physiology, University of Bologna, Italy, 2Ritchie Centre for Baby Health Research, Monash Medical Centre, Monash University, Clayton, Australia Nitric Oxide (NO) powerfully promotes cerebral vasodilatation during sleep in newborns and it is the major determinant of the cerebral blood flow (CBF) differences between sleep-wake states (Zoccoli et al. 2001). While NO tonically elevates CBF during REM sleep, further large phasic increases of CBF occur during the transient blood pressure surges that characterize this sleep state. In this study we addressed the hypothesis that NO plays a key vasodilating role also in these phasic circulatory disturbances of REM sleep. Newborn lambs (n = 6) were anesthetised and instrumented with electrodes for polygraphic recordings, an ultrasonic flow probe around the superior sagittal sinus to measure CBF and arterial (arterial pressure, Pca), venous (drug infusion) and subdural (intracranial pressure, Pic) catheters. We examined dynamic changes of CBF, Pca, Pic, cerebral perfusion pressure (CPP = Pca – Pic) and cerebral vascular resistance (CVR = CPP/CBF) during spontaneous sleep-wake cycles. REM sleep epochs were recorded for 3-h periods before (control period) and during infusion of N-nitro-L-arginine (L-NNA), an inhibitor of NO synthase (L-NNA infusion period). In control periods an early decrease in CVR, starting 30 s before the onset of blood pressure and CPP surges, begins the phasic CBF increase which is then further incremented as CPP rises. During L-NNA infusion the early onset of the CVR decrease disappears, and the extent of the CBF surge is markedly reduced. Moreover, the CPP elevation and CVR increase are significantly prolonged. During surges Pic was strongly correlated with Pca (control R2 = 0.61, L-NNA R2 = 0.33) but the slope of Pic-Pca regression is much lower (P < 0.05) after L-NNA infusion (Pic/Pca = 0.36) compared with control period (Pic/Pca = 0.91), and Pic reaches much lower levels. In newborns, NO powerfully regulates the cerebral circulation during the phasic events of REM sleep, lowering vascular resistance, elevating blood flow and amplifying intracranial pressure during transient blood pressure surges. NO may exert these actions by promoting vascular distension as well as by dilating resistance vessels. While NO preserves basal cerebral perfusion it may also promote excessive distension and endanger cerebral microvessels of the newborn brain during REM sleep, when large arterial blood pressure surges are common. Reference Zoccoli G, Grant DA, Wild J, Walker AM. Nitric oxide inhibition abolishes sleep-wake differences in cerebral circulation. Am. J. Physiol. 2001; 280: H2598–606. Sleep and Biological Rhythms 2005; 3: A2–A73 CORTICAL EEG TOPOGRAPHY OF THE SLEEPWAKEFULNESS TRANSITION LUIGI DE GENNARO1, GIUSEPPE CURCIO1, FABIANA FRATELLO1, CRISTINA MARZANO1, FABIO MORONI1, MARIA CONCETTA PELLICCIARI1 AND MICHELE FERRARA1,2 1 Department of Psychology, University of Rome La Sapienza, Italy, 2 Department of Internal Medicine and Public Health, University of L’Aquila, Italy The aim of the present study was to assess, for the first time, the EEG correlates of sleep inertia following awakening from a whole night of sleep by means of an Hz-by-Hz EEG spectral power analysis. We hypothesized that a higher power in the low-frequency bands and a lower power in the high-frequency band could characterize the sleep offset period, as compared to the presleep wake. Moreover, the presence of regionally graded differences along the antero-posterior axis in the EEG substratum of the awakening period have been also evaluated. The postsleep waking EEG was compared to that recorded during the presleep wakefulness from four midline derivations (Fz-A1, Cz-A1, Pz-A1, Oz-A1) in 25 normal right-handed females (age = 23.4 ± 1.08 years). Twelve subjects were awakened from stage REM, while 13 subjects were awakened from stage 2. after 7.5 h of accumulated sleep. Power spectra of the four derivations were computed by a Fast Fourier Transform routine for a final 1-Hz resolution (1–24 Hz range). Power spectra were calculated separately for closed-eyes (5 min) and openeyes (5 min) wakefulness. The first 10 min after awakening are characterized by an increase of EEG power in the high-theta and low-alpha frequency range (6–8 Hz) compared to the corresponding presleep waking period, and by a significant decrease of EEG power in the beta range (18–24 Hz). As regards the topographic differences, the postsleep period showed a parietooccipital prevalence in several bins of the delta and theta bands (1–3 Hz and 5–7 Hz). Moreover, the occipital derivation showed a decreased power in the alpha (8 Hz and 10–11 Hz) and even more in the beta range (17–21 Hz) as compared to the other derivations. The EEG substratum of the sleep offset period is characterized by a pattern of increased EEG power in the high-theta and low-alpha bands, and of decreased power in the beta range. This pattern can be considered as the spectral EEG signature of the sleep inertia phenomenon. The state of postsleep EEG hypoarousal does not subside in the first 10 minute period after awakening considered in the present analysis. Finally, according to our results the more posterior scalp locations show stronger EEG signs of sleep inertia, being the last ones to properly wake up. SLEEP STATE MISPERCEPTION: IS IT A TRUE ‘SUBJECTIVE’ INSOMNIA? CRISTINA MARZANO1, EMILIA SFORZA2, GIUSEPPE CURCIO1, FABIANA FRATELLO1, FABIO MORONI1, MARIA CONCETTA PELLICCIARI1, MICHELE FERRARA1 AND LUIGI DE GENNARO1 1 Department of Psychology, University of Rome La Sapienza, Italy, 2 Department of Psychiatry, University Hospital of Geneva, Geneva, Switzerland Sleep state misperception (SSM) is a subtype of primary insomnia (PI) characterized by normal conventional PSG measures in patients having profound and, at times, dramatic sleep complaints. Although this PI subtype has been included into classification systems about 20 years ago (1), little research has been devoted to this subtype (2), and only one study has assessed quantitative EEG changes showing lower delta and greater alpha, sigma, and beta EEG activity in NREM, but not in A65 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 REM sleep (3). The aim of the present study was to assess, for the first time, the EEG correlates of SSM by means of two separate Hz-by-Hz EEG power analyses of the sleep-wake transition and of the whole night. Moreover, the presence of regionally graded EEG differences along the antero-posterior axis have been also evaluated. Standard EEG recordings from four midline derivations (Fz-A1, Cz-A1, Pz-A1, Oz-A1) of 10 patients with a diagnosis of SSM (age = 35.6 ± 13.9 years) were compared to those of 10 normal sleepers. Power spectra of the four derivations were computed by a Fast Fourier Transform routine for a final 1-Hz resolution (1–30 Hz range). Power spectra were calculated for the presleep and the sleep onset periods (5 min samples), and for the whole night, separately for NREM (S2 + SWS) and REM sleep. The two groups showed significant differences in the presleep period only at the occipital site, with higher alpha relative power in normal than in SSM subjects. After sleep onset, a distinct pattern of topographical changes differentiated the two groups: SSM patients showed lower delta relative power over anterior areas (Fz and Cz) and higher beta activity (more pronounced at anterior sites) as compared to normals. NREM sleep of the whole night again showed lower delta and higher beta activity in SSM patients than in normals. A clear dissociation between anterior and posterior areas was found with the SSM patients showing higher beta at the anterior sites and lower beta at Oz as compared to normals. Analyses on REM sleep also confirmed this antero-posterior dissociation for the beta relative power. Although preliminary, these results (a) point to the existence of speciphic physiological correlates of SSM, confuting its definition as subjective insomnia; (b) explain the understimation of sleep latency and of total time in terms of hyperarousal and heightened awareness during the sleep onset process, and continuing across the whole night; (c) localize this mechanism, expressed by lower delta and higher beta EEG activity, at the more anterior areas, mainly at the frontal cortex. References 1. Association of Sleep Disorders Centers. Diagnostic Classification of sleep and arousal disorders. Sleep 1979; 2: 1–137. 2. Edinger JD, Krystal AD. Subtyping primary insomnia: is sleep state misperception a distinct clinical entity? Sleep Medicine Reviews 2003; 7: 203–14. 3. Krystal AD, Edinger JD, Wohlgemuth WK, Marsh GR. Non-REM sleep EEG frequency spectral correlates of sleep complaints in primary insomnia subtypes. Sleep 2002; 25: 630–40. ROLE OF GABAERGIC AND NORADRENERGIC INTERACTIONS IN PEDUNCULOPONTINE TEGMENTUM IN THE REGULATION OF RAPID EYE MOVEMENT SLEEP DINESH PAL AND BIRENDRA NATH MALLICK* School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India Interactions between noradrenergic (NAergic) REM-OFF and cholinergic REM-ON neurons have been proposed (1,2). A role of GABA in mediating such response has also been proposed (3,4). Although the role of GABA in LC has been shown (3,4,5), the role of NA and GABA in pedunculopontine tegmentum (PPT) was not known and hence was investigated in this study. Rats were surgically prepared for sleep-wake recording and a bilateral stainless steel cannula aiming PPT was implanted. After recovery, 200 nL of 0.05% picrotoxin (GABA-A antagonist), 0.01% prazosin (alpha1 antagonist), 0.1% clonidine (alpha2 agonist) or 0.1% propranolol (Beta antagonist), was microinjected bilaterally into the PPT of freely moving normally behaving rats using a remote controlled dual A66 syringe pump. In addition, coinjections of picrotoxin and clonidine were done into PPT using the same method. Saline (N-N diethylamide for prazosin) served as the positive control and was injected into the same site. The site of injection was immunohistochemically confirmed. The effects of these antagonists and agonists on sleep-wakefulness cycle were scored and compared statistically. The results showed that while GABAergic antagonist reduced REM sleep by decreasing the number of REM sleep episodes, noradrenergic antagonists increased REM sleep by increasing the number of REM sleep episodes. Clonidine, which is known to decrease the release of NA from the terminals, enhanced REM sleep by increasing the mean duration of REM sleep per episode. Co-injection of picrotoxin and clonidine did not have any effect on total time spent in REM sleep; however, there was a significant decrease in the number of REM sleep episodes and a significant increase in the mean duration of REM sleep per episode. Based on these results we propose that NA in PPT regulates REM sleep. Further, GABA by acting presynaptically on NAergic terminals projecting onto REM-ON neurons in PPT is modulating REM sleep. Financial support from CSIR & ICMR acknowledged. References 1. Hobson et al. Science (1975) 189: 55–8. 2. Sakai, Arch. Ital. Biol. (1988) 126: 239–57. 3. Mallick et al. In: Rapid Eye Movement Sleep. Marcel Dekker, Inc. (1999) 153–66. 4. Mallick et al. Neuroscience (2001) 104: 467–85. 5. Mallick et al. J. Biosci (2002) 27: 539–51. BENEFITS IN SLEEP-RELATED MEMORY CONSOLIDATION FOLLOWING CHOLINERGIC MEDICATION ARE ASSOCIATED WITH INCREASED DELTA ACTIVITY DURING PHASIC REM SLEEP IN OLDER ADULTS ORLA P HORNUNG1, FRANCESCA REGEN1, HEIDI DANKER-HOPFE1, HANS DORN1, MICHAEL SCHREDL2 AND ISABELLA HEUSER1 1 Department of Psychiatry and Psychotherapy, Charité – University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany, 2Central Institute of Mental Health, Mannheim, Germany Previous research suggests an important role of REM sleep in memory consolidation, with theta and delta oscillations as well as phasic REM sleep components being of particular significance. While memory consolidation during REM sleep has been studied extensively in younger adults, older adults have not been in the focus of many investigations so far. Recent studies have suggested that increases in the amount of REM sleep following administration of an acetylcholineesterase inhibitor (AChE-I) are associated with improved memory consolidation in older adults. Based on these findings, the present study investigated whether benefits in sleep-related memory consolidation following cholinergic medication in old age are associated with higher activity in EEG theta and delta frequency bands during REM sleep. Forty-two participants, male and female, between the ages of 60 and 77 years received 5 mg of the AChE-I donepezil orally 30 min before bedtime in a placebo-controlled, double-blind design. Before and after the study night memory tasks were performed. Mean root mean square (RMS) voltages in EEG delta (1–4 Hz) and theta (4–8 Hz) frequency bands were calculated for total and phasic REM sleep as well as total sleep time. As reported earlier, participants of the medication group showed significant benefits in sleep-related memory consolidation (P < 0.05). Notably, a trend for higher mean delta RMS voltages in the medication group compared to the placebo group was found for total REM sleep Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 (P < 0.10). This effect was even more pronounced in phasic REM sleep, where it proved to be significant (P < 0.05). In contrast, the two experimental groups did not differ significantly with regard to mean delta RMS voltages across total sleep time. Moreover, no significant medication effects were found regarding mean theta RMS voltages in the present study. The AChE-I donepezil enhances EEG delta activity during phasic REM sleep in old age, which may partly explain its beneficial effects on sleep-related memory consolidation in older adults. Acknowledgements: Supported by the German Research Foundation (GEP-HE 1786/2–1: REM Sleep and Cognitive Functions and GK 429: Neuropsychiatry and Psychology of Aging). EVIDENCE FOR THE ACTIVATION OF GLUTAMATERGIC NEURONS DURING WAKING AND GABAERGIC NEURONS DURING SLEEP IN THE PERIFORNICAL LATERAL HYPOTHALAMIC AREA SUNIL KUMAR1,2, RONALD SZYMUSIAK1,2, SEEMA RAI1, MELVI METHIPPARA1,3, DENNIS MCGINTY1,3 AND MD NOOR ALAM1,3 Research Service1, VAGLAHS, Sepulveda, California, USA; Departments of Medicine2 and Psychology3, UCLA, California, USA The perifornical-lateral hypothalamic area (PF-LHA) has been implicated in the regulation of locomotor activity and behavioral arousal. PFLHA contains a mixture of neuronal population including neurons containing hypocretin (HCRT), melanin-concentrating hormone, gamma amino butyric acid (GABA), and glutamate(1, 2). A majority of neurons within PF-LHA are active during waking and exhibit little activity during sleep(3). We hypothesized that increased glutamatergic tone within the PF-LHA contributes to the activation of PF-LHA neurons during waking whereas increased GABAergic inhibition within PF-LHA contributes to the suppression of this wake-promoting system during sleep. Experiments were conducted on six male Sprague-Dawley rats during lights on period. In one group, 3 rats were allowed to sleep normally (13.30–15.30 h) after six h of sleep deprivation (7.30–13.30 h, lightson at 7.00). A second group of rats were kept awake for 2 h (13.30– 15.30 h). At the end of the experiments rats were immediately sacrificed and the brain tissues were immunohistochemically processed for Fos-protein (Fos-IR), and markers for GABAergic and glutamatergic neurons. A larger number of Fos-IR neurons were found in PF-LHA of rats that were kept awake vs. rats that were allowed to sleep normally (162 ± 27 vs. 60 ± 7). However, Fos-IR in GABAergic and glutamatergic neurons showed opposite trends. The percentage of GABAergic neurons exhibiting Fos-IR as compared to total Fos-IR neurons was higher in rats that were allowed to sleep normally as compared to rats that were kept awake (40.8 ± 4.7% vs. 17.3 ± 3.4%). In contrary, the percentage of glutamatergic neurons exhibiting Fos-IR was higher in awake rats as compared to sleeping rats (52 ± 2% vs. 34 ± 2%). These preliminary results suggest that in PF-LHA a substantially higher number of glutamatergic neurons are active during waking while a substantially higher number of GABAergic neurons are active during sleep. These results are consistent with the hypothesis that within PFLHA activation of glutamatergic neurons contributes to arousal whereas activation of GABAergic neurons contributes to sleep. References 1. Ziegler DR, Cullinan WE, Herman JP. 2002. J. Comp. Neurol. 448: 217–29 2. Abrahamson EE, Moore RY. 2001. Brain Res. 889: 1–22. Sleep and Biological Rhythms 2005; 3: A2–A73 3. Alam MN, Gong H, Alam T, Jaganath R, McGinty D, Szymusiak R. 2002. J. Physiol. 538: 619–31. Support: NS-050939, MH-47489, HL-60296, and MH-63323. MICRODIALYSIS OF INTERLEUKIN-1B RECEPTOR ANTAGONIST INTO THE PREOPTIC AREA SUPPRESSES NONREM SLEEP IN FREELY BEHAVING RATS MD NOOR ALAM1,2, MELVI METHIPPARA1,2, SUNIL KUMAR1,3, RONALD SZYMUSIAK1,3 AND DENNIS MCGINTY1,2 Research Service1, VA GLAHS, Sepulveda, California, Departments of Medicine2 and Psychology3, UCLA, California, USA Various pharmacological studies suggest that IL-1b is involved in sleep regulation under both physiological and immunogenic conditions (1,2). The Preoptic area (POA) is a sleep-promoting region. Many in vivo and in vitro studies suggest that POA is one of the potential sites that mediate IL-1b-induced physiological effects including sleep(3,4). However, the localized effects of endogenous IL-1b in POA on sleep is not known. We examined effects of microdialytic perfusion of IL-1b receptor antagonist (IL-1ra) into the POA on sleep to determine the sleep-promoting ability of endogenous IL-1b in the POA. Four male Sprague-Dawley rats were stereotaxically implanted with EEG and EMG electrodes, and a guide cannula directed at the lateral POA. After at least 7 days of recovery, microdialysis probes were inserted. Rast were microdialysed with artificial cerebrospinal fluid (aCSF) or IL-1ra (5 mM and 10 mM) for 2 h followed by 2 h of aCSF perfusion during lights-on period (11.00–15.00 h, lights-on at 7.00). As compared to aCSF control, rats microdialysed with 10 mM of IL-ra into POA spent more time in waking (48.33 ± 8.558% vs. 34.25 ± 8.03), particularly active awaking (31.63 ± 5.30% vs. 22.74 ± 5.21) and less time in nonREM sleep (47.60 ± 8.55% vs. 59.44 ± 9.10%) especially deep nonREM sleep (25.56 ± 7.63% vs. 40.49 ± 9.15%). REM sleep was unaffected (4.06 ± 2.08% vs. 4.74 ± 1.75). 5 mM IL-1b-ra produced only marginal effects. These preliminary results suggest that local application of IL-1ra into the POA during the lights-on period promotes active waking and suppresses deep nonREM sleep. This suggests that the sleep promoting effects of endogenous IL-1b, in part, is mediated via the neuronal substrates within the POA. References 1. Obal F, Jr., Krueger JM. 2003. Front Biosci. 8: d520–50. 2. Opp MR, Krueger JM. 1994. Am. J. Physiol. 266: R688-95. 3. Baker FC, Shah S, Stewart D, Angara C, Gong H et al. 2005. Am. J. Physiol. Regul. Integr. Comp. Physiol. 288: R998–R1005. 4. Nakashima T, Hori T, Mori T, Kuriyama K, Mizuno K. 1989. Brain Res. Bull 23: 209–13. Support: NS-050939, MH-47489, HL-60296, and MH-63323. DISRUPTED SLEEP IS CORRELATED WITH ELEVATED EPINEPHRINE AND INTERLEUKIN-6 KIRSTIN ASCHBACHER1, SONIA ANCOLI-ISRAEL1,2, JOEL E DIMSDALE1, SUSAN CALLERAN1, MICHAEL G ZIEGLER3, PAUL J MILLS1, THOMAS L PATTERSON1,2 AND IGOR GRANT1 1 Department of Psychiatry, University of California, San Diego, 2San Diego Veterans Affairs Healthcare System, La Jolla, California, 3Department of Medicine, University of California, San Diego, USA The chronic stress of caregiving for a spouse with dementia is associated with cardiovascular morbidity. One possible pathway to such morbidity is through disrupted sleep, which frequently accompanies A67 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 caregiving. Studies on the effects of partial sleep deprivation in healthy young men have found daytime elevations in circulating catecholamines and Interleukin-6 (IL-6), two factors believed to contribute to the development of cardiovascular disease. We sought to determine whether disrupted sleep was associated with elevated levels of circulating epinephrine (EPI) and IL-6, a proinflammatory cytokine. 58 caregivers of spouses with Alzheimer’s disease (mean age: 73; 33% men) wore an actigraph (Sleep Watch-L, Ambulatory Monitoring, Inc) for three consecutive days (72 h). Action-W was used to score nighttime sleep/wake activity in terms of minutes, percentages, and the number/duration of awakenings averaged across the three nights. Morning plasma blood samples drawn within several days of the actigraph measurements were assayed for IL-6 and EPI. Partial correlations controlling for the effects of age revealed both biomarkers were positively associated with the mean number of wake minutes (IL-6: r = 0.32, p = 0.016; EPI: r = 0.284, p = 0.032) and wake percent (IL-6: r = 0.35, p = 0.008, EPI:, r = 0.273, p = 0.04). IL-6 but not EPI was associated with the mean duration of night awakenings (r = 0.37, p = 0.004), while neither was significantly associated with the number of night awakenings. Caregivers who spent more of their nighttime sleep periods awake or experienced longer awakenings exhibited elevated levels of epinephrine and proinflammatory activity, physiological alterations that could potentially contribute to the development of cardiovascular disease. POLYSOMNOGRAPHIC FINDINGS IN HEREDITARY SPINOCEREBELLAR ATAXIA (SCA-2) I TUIN1, U VOSS2, J-S KANG1, H STEINMETZ1 AND G AUBURGER1 Neurological Clinic, University Hospital J. W. Goethe-University, Frankfurt, Germany, 2Erfurt University, Germany 1 The study investigated the sleep profile of a homogeneous group of patients suffering from hereditary spinocerebellar ataxia (SCA-2). Unique to this group of patients is the early degeneration of the olivopontocerebellar region of the brainstem. In the course of disease progression, additional structures such as the thalamus, substantia nigra, and the anterior horn are also affected. By contrast, there is no sign of cortical involvement even in the most severely affected patients of this group. The olivopontocerebellar region has been associated with the control of REM sleep initiation. The thalamus, in particular the nucleus reticularis thalami, is regarded as the rhythm generator of NREM sleep. Together with the midbrain, the thalamus is believed to be involved in maintaining muscle atonia. Accordingly, it was expected to find a loss of muscle atonia at an early stage of the disease, accompanied by alterations of REM sleep with reduced to absent REM sleep episodes as a function of disease progression. With regard to SWS, no specific hypotheses were expressed. Standard PSGs (Brainlab, Schwarzer, Munich) were recorded for 9 patients on 2 consecutive nights. Records were scored visually by two experienced raters according to R & S and ASDA criteria. Patients differed only in disease severity and disease progression. Subjectively, all patients slept well. Only the mildly affected patients reported a dream recall. Polysomnographic findings were analysed with regard to disease duration, polyglutamine expansion size (CAG count), age of onset, ataxia score, age, and sex. Sleep efficiency was poor in all 9 patients, due to expansive periods of nocturnal wakefulness. Sleep onset latencies were inconspicuous. The more severely affected patients showed an increase in amount of SWS. REM sleep was strongly reduced or absent in these patients. Trend A68 analyses suggest that an increase in SWS as well as a decrease in REM sleep differentiate well between different stages of disease progression. In spite of subjective reports of good sleep, objectively, SCA2 patients displayed poor sleep efficiency and increased sleep fragmentation. Several sleep parameters compare to those reported for Idiopathic Parkinson’s Disease. SWS and REM sleep appear to be promising progression markers in SCA-2. INFLUENCE OF MODERATE SLEEP RESTRICTION IN OLDER SELF-REPORTED LONG SLEEPERS SD YOUNGSTEDT, CE KLINE, M ZIELINSKI, A LEE, TM DEVLIN AND DF KRIPKE University of South Carolina, Columbia, SC USA Epidemiological studies have consistently shown a ‘U’–shaped association of mortality with self-reported sleep duration, with lowest mortality associated with 7 h of sleep. Since reported long is more common than short sleep it is a greater risk factor. However, even if it could be proven that long sleep causes mortality, many long sleepers would likely be unwilling to curtail their sleep it was too difficult. The aims of our ongoing study are (1) to describe the sleep and mood of older selfreported long sleepers; (2) to examine whether this sample can moderately restrict time-in-bed without negative consequences. Twenty-seven older (50–70 year) adults who report sleeping 8.5 h per night have been assessed. Participants are screened for absence of sleep apnea, severe depression, and excessive daytime sleepiness. Glucose tolerance is assessed before the experiment. During a 2-week baseline, participants follow their usual sleep-wake cycle. Following baseline, participants are randomly assigned to two 8-week treatments: (1) sleep restriction which requires participants to spend 90 min less time-in-bed compared with baseline while following a fixed sleep-wake schedule; (2) a control which requires participants to follow a fixed sleep schedule with time-in-bed equivalent to baseline. Sleep/wake is recorded continuously via actigraphy, supplemented by diaries. Sleepiness is assessed thrice daily with the Stanford Sleepiness Scale. Following baseline and every 2 weeks thereafter, participants are assessed with the Epworth Sleepiness Scale, the Geriatric Depression Scale, the SF-36 health-related quality of life inventory, and the Functional Outcomes of Sleepiness Questionnaires (FOS-Q). A neurobehavioral performance battery (vigilance, reaction time, memory) is also administered following baseline and three times thereafter. Although participants have averaged approximately 9 h in bed during baseline, acigraphic sleep durations have average only approximately 7.5 h. Mood and sleepiness levels have been normal. One of the participants in the sleep restriction treatment dropped out after week 8. Otherwise, there have been essentially no significant differences between treatments in changes in sleepiness, mood, quality-of-life, or glucose tolerance. In qualitative interviews with our ombudsperson, the participants report little difficulty following the protocol. In follow-up assessments up to 8 months postexperiment, some participants report voluntary continuation of sleep restriction. The results suggest that (1) much of the time-in-bed in our sample is spent awake; (2) these self-reported long sleepers are able to moderately restrict their time-in-bed without negative consequence. Research supported by NIH grant HL71560. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 EFFECTS OF TOTAL SLEEP DEPRIVATION ON WAKING ELECTROENCEPHALOGRAM, PUPILLARY UNREST INDEX AND SUBJECTIVE SLEEPINESS F REGEN, H DORN AND H DANKER-HOPFE Department of Psychiatry and Psychotherapy; Charité-University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany In recent years there has been growing interest in the use of pupillography as an objective and time-saving method to measure daytime sleepiness. Previous studies have shown frequency specific changes in the waking EEG as well as an association of subjective sleepiness with waking EEG activity during extended wakefulness. The aim of the present study was to investigate (1) the time course of waking EEG activity, Pupillary Unrest Index (PUI) and subjective sleepiness and (2) the association between PUI, subjective sleepiness and waking EEG during total sleep deprivation. 24 healthy adults (20–35 years old, 9 males, 15 females) participated in the study. Eleven test series including performance tests, subjective sleepiness ratings and infrared video pupillography were performed during 40 h of sustained wakefulness. Subjective sleepiness was assessed by means of the Stanford Sleepiness Scale (SSS) and a Visual Analogue Scale (VAS). Waking EEG activity was recorded continuously using a Vitaport system. 5- s epochs recorded during pupillography were visually inspected for artifacts and subjected to spectral analysis, average spectra were then calculated. The results presented refer to epochs selected from the C4/(A1A2) derivation. Significant variations over time were observed in PUI, SSS, VAS and power in the delta (1.5–5.5 Hz), theta (5.5–8.5 Hz) alpha1 (8.5– 10.5 Hz), beta1 (12–18 Hz) and beta3 (21–30 Hz) frequency range. At time points of maximum PUI a significant increase was found in delta, theta, alpha1 and beta1 power, respectively. Likewise, high levels of subjective sleepiness were associated with significant increases in delta, theta, alpha1 and beta1 power. During extended wakefulness PUI showed a significant association with SSS (r = 0.527; P < 0.0001) and VAS (r = 0.535; P < 0.0001). Correlation between PUI and EEG activity was positive with r = 0.589 (P = 0.0001) for delta power, r = 0.616 (P < 0.0001) for theta power and r = 0.527 (P = 0.0001) for power in the alpha1 band. Similar changes in waking EEG activity were found with increasing levels of subjective sleepiness. SSS and VAS were significantly associated with power in the delta, theta, alpha1, beta1 and beta2 (18–21 Hz) band. The finding of a close association of PUI with measures of subjective sleepiness as well as with distinct changes in waking EEG activity further supports the use of pupillography as a reliable method to measure daytime sleepiness. A DESCRIPTIVE MODEL OF THE TIME-COURSE OF THE PROBABILITY OF TRANSITIONS INTO AND OUT OF REM SLEEP ALEJANDRO BASSI1, ENNIO A VIVALDI2 AND ADRIÁN OCAMPO-GARCÉS2 1 Facultad de Ciencias F’sicas y Matemáticas, 2Facultad de Medicina, Universidad de Chile. Santiago, Chile A model is proposed that describes the processes of going into and out of REM sleep. Behavioral states are expressed as discrete, stable configurations whose discrete character results from rapid transitions when switching from one state to another. The high variability observed in the duration of state bouts suggests that the timing of the switching has an important stochastic component. Although the overt expression of Sleep and Biological Rhythms 2005; 3: A2–A73 behavioral states is discrete, the likelihood of a transition into or out of a given state at any given moment can be assumed to be the result of a continuous underlying process. Our goal was to asses the time course throughout a REM sleep episode (REMSE) of the likelihood that the REMSE ends, and throughout an interval between two REMSEs of the likelihood that new REMSE starts. We call the first variable instability and the second variable propensity. The data base consisted in 15-second epochs scoring of continuous recordings of 16 male Sprague-Dawley rats. Data was fitted into nonlinear logistic regression models to estimate the dynamics of REM sleep propensity and instability under different conditions. REM sleep propensity is described by a curve that starts from a high point at the beginning of the interval and rapidly diminishes to stay at a low level at least for spontaneous intervals up to 20 min in duration. The curve thus represents an inertia effect prompting to go back into REM sleep followed by a stabilization effect. REM sleep instability is described by a curve that also shows the inertia and stabilization effects, but then rises again in a third phase indicative of a saturation effect. Relevant factors for REM sleep expression, such as the phase of light:dark cycle and the short-term homeostatic effects of the previous REM sleep episode were analyzed in terms of their complex effects on the stabilization and saturation stages. The inertia and stabilization processes are consistent with a duality involving rapid changes in the activity patterns of neural ensembles and less abrupt modulations of neurochemical substrates conditioning the neural events. REM sleep occurrence would result from specific neural activity pattern whose all-or-none stochastic occurrence is influenced by a neurochemical substrate undergoing a smoother modulation. BLOOD PRESSURE AND PULSE TRANSIT TIME MEASURES IN RESPONSE TO AUDITORY STIMULATION DURING INFANT SLEEP STUDIES BARBARA GALLAND, EVAN TAN, BARRY TAYLOR AND MARIE GOULDEN Departments of Women’s & Children’s Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand Experimental methods to investigate autonomic cardiovascular control in infants during sleep require noninvasive techniques. Changes in BP have been difficult to measure noninvasively until the advent of measures of finger pulse beat-to-beat BP developed for adult use and modified for application in infants. Pulse transit time (PTT), the time taken for the pulse to travel between two arterial sites, may also be a useful estimate of BP, as in adults, the measure purportedly correlates inversely with BP, but infant data is scant. The aim of this study was to establish a normal range of data in infants profiling beat-to-beat BP changes with simultaneous PTT in response to auditory, stimulation provoking subcortical and cortical arousal. Fifteen healthy infants with no history of maternal smoking were studied during a morning nap in the supine position (mean ± SD age = 10 ± 1 weeks; weight = 6400 ± 894 g). In addition to standard polygraphic recordings, a Portapres finger BP system was modified for wrist application. PTT was measured as the time between the maximum R wave threshold (ECG waveform) and the minimum pulse wave threshold (waveform from piezo-electric transducer on the foot). Infants were exposed to white noise from 50 db to maximum100 db at 10 db increments (twice within REM and NREM states) and dB thresholds for subcortical and cortical arousals established. If the infant failed to arouse at 100 dB intensity, an arbitrary value of 110 dB was assigned. Significantly higher (P = 0.01) intensities were needed to elicit a cortical arousal during NREM sleep (arbitrary value 91.1 ± 2.9 dB) than REM sleep (77.8 ± 1.8 dB). Cortical arousal from NREM sleep resulted A69 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 in a significant –20% rebound overshoot in both systolic and diastolic P 25 s after the stimulus; not apparent in either REM sleep or with subcortical arousals. PTT decreased approximately 20 ms with cortical arousal, significant for REM sleep only (P = 0.03) and tended to be inversely correlated with systolic P (r = –0.69; p = 0.058). The study provides baseline data for future infant studies where predisposition for defective cardiovascular autonomic control is indicated. The potential use of PTT as a possible substitute for BP measures during infant sleep studies is indicated, but further research is needed. VASCULAR ENDOTHELIAL GROWTH FACTOR IN OBSTRUCTIVE SLEEP APNEA SYNDROME NIR PELED, DAVID SHITRIT AND MORDECHAI R KRAMER Pulmonary Institiute, Rabin Medical Center, Beilinson Campus, Petach Tiqva and the Sackler Faculty of Medicin, Tel. Aviv University, Tel. Aviv, Israel Vascular Endothelial Growth Factor (VEGF) is a hypoxia-sensitive glycoprotein stimulating neoangiogenesis. Recent studies have shown that VEGF is elevated in Obstructive Sleep Apnea Syndrome (OSAS). However, the exact association between VEGF and OSAS is not fully understood. In this study we investigated VEGF levels in 100 OSAS patients. VEGF levels were evaluated for 100 OSAS patients. Patients have been grouped according to apnea hypopnea index (AHI) into 4 groups. Mean AHI (STD) were 14.5 (3.8), 30.0 (5.5), 47.1 (6.2), 74.1 (11.9) in groups A-D, respectively (P < 0.001). With OSAS severity, oxygen desaturation was significantly worse. The accumulated time (minutes) with oxygen saturation below 90% was 17.3 (STD:41.1), 18.9 (49.2), 51.2 (72.1) and 118.9 (96.7) minutes in groups A-D, respectively (ANOVA P < 0.001). Despite the variety of OSAS severity and the significant oxygen desaturation, VEGF level was not associated with OSAS severity (VEGF (STD): 455.3 (232.9), 455.5 (265.7), 380.5 (277.4), 504.4 (391.8) ng/mL, respectively; ANOVA p = 0.546). However, VEGF level in our patients was higher than the normal range. VEGF level did not correlate with body mass index, AHI nor with any of the sleep parameters. VEGF is elevated in OSAS, but without an association with OSAS severity. INTERMITTENT AIRWAY OCCLUSION INCREASES SERUM POTASSIUM AND THE INCIDENCE OF CARDIAC ARRHYTHMIAS IN ANAESTHETIZED RATS MARK DUNLEAVY1, DONNCHA LANE1, KEN O’HALLORAN2 AND AIDAN BRADFORD1 1 Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin Ireland and 2Department of Human Anatomy and Physiology, University College Dublin, Dublin, Ireland In obstructive sleep apnoea, the airway becomes occluded intermittently during sleep. It is associated with cardiac arrhythmias (Burack 1984). During occlusion, there are intense contractions of inspiratory muscles and systemic hypoxia. Limb muscle contraction and systemic hypoxia can elevate arterial plasma potassium concentration (Medbo and Sejersted 1990) and elevated potassium is arrhythmogenic. We hypothesize that intermittent airway occlusion causes cardiac arrhythmias and elevated serum potassium. Male Wistar rats were anaesthetized (pentobarbitone, 60 mg/kg I.P.) and breathed spontaneously through a tracheostomy. The electrocardiogram, tracheal pressure, end-tidal CO2 and blood pressure were A70 recorded. Arterial blood samples were measured every hour for serum potassium concentration by flame photometry. The trachea was occluded for 15 s, twice per min for 6 h to mimic human sleep apnoea (n = 7). Controls (n = 5) were treated identically except that the trachea was not occluded. There was a progressive increase in serum potassoum in the occlusion group (3.94 ± 0.21 and 4.77 ± 0.24 mM, 0 and 6 h, respectively, mean ± SEM, ANOVA, P < 0.05) but not in the controls. At 5.5–6 h, there was no significant difference in blood pressure (79.7 ± 4.9 vs. 115.0 ± 14.3 mmHg, control and occlusion, respectively). There were no arrhythmias in the controls but ventricular premature beats occurred in 5 out of 6 of the occlusion group (13.5 ± 7.2 events in 30 min). Therefore, mimicking human obstructive sleep apnoea by intermittent airway occlusion in rats causes an increase in serum potassium and arrhythmias. Similar changes occurring during sleep apnoea would be of considerable clinical significance. References Burack B. The hypersomnia–sleep apnea syndrome: its recognition in clinical cardiology Am. Heart J. 1984; 107: 543–8. Medbo JL, Sejersted OM. Plasma potassium changes with high intensity exercise. J. Physiol. Lond. 1990; 421: 105–22. REM FEATURES IN WAKE-SLEEP TRANSITION MELINDA SVERTECZKI, LÁZÁR ALPÁR SÁNDOR, HAVRÁN LINDA, KIS TAMÁS, RIGÓ PÉTER, CSÓKA SZILVIA AND BÓDIZS ROBERT Semmelweis University, Institute of Behavioural Sciences, H-1089 Budapeat, Nagyvárad Tér 4, Hungary Based on our previous studies on epyleptic patients and the literature we expected increased 1.5–3 Hz power spectra activity in REM sleep compared to stage 2 NREM sleep (S2). Based on the covert-REM hypothesis REM features were expected to occure in a greater extend during wake-sleep transition than in S2 sleep. Eight individuals’ polysomnography have been performed and Fourier transformed. The sleep transition was separeted into three stages: 1, one minute alpha activity, 2, alpha drop out and 3, one minute stage 2 sleep. As a comparassion, each individuals own full night REM and S2 sleep were utilized. The following frequency bands were analized in all cases: slow oscillation (0.5–1.25 Hz), delta/theta frequencies (1.5–3, 3.25–4.5, 4.75–6.25, 6.5–7.75 Hz), alpha (8–12 Hz) and sigma (12.25–15 Hz) bands. For each individual, in each stages of the sleeptransition their own power spectra density were compared to the whole night REM and S2 sleep. In variancy analysis the similarity to REM/S2 sleep were expressed as a distance from 1, which shows the REM/S2 likeliness in a logarithmic form: log(1/|1-x|). In contrast to the hippocampal 1.5–3 Hz oscillation in sleep onset we detected in the wake-sleep transition increased activity in the slow oscillation, delta and theta frequency bands. Specific REM-likeliness occured in the fast delta and fast theta frequencies. In alpha frequency band we found similarity to the S2 sleep during sleep transition possibly due to the slow spindling. Changes in the sleep onset period call attention to reduced thalamic, thalamo-cortical activity in contrast to the expected parahippocampalhippocampal activity. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 ADENOSINE AS A CANDIDATE MEDIATOR OF SLEEP HOMEOSTASIS, SLEEP DEBT, AND THE NEUROBEHAVIORAL CHANGES OF SLEEP REDUCTION ROBERT W MCCARLEY, RADHIKA BASHEER, ROBERT E STRECKER Department Psychiatry, Harvard Medical School and VA Boston Healthcare System, Brockton, MA 02301 USA The major evidence for adenosine’s (AD) role in sleep homeostasis can be summarized as (1) a progressive increase in the wakefulnesspromoting region of cholinergic basal forebrain (CBF) with each hour of sleep deprivation; (2) pharmacologically induced increases in AD in CBF promotes sleep; (3) antisense knockdown of the AD A1 receptor in CBF markedly blunts sleep deprivation-induced increases in nonREM sleep and delta activity; (4) In vivo, AD inhibits wakefulnessactive neurons in the CBF while, in vitro, postsynaptic inhibition occurs in both cholinergic and presumptively GABAergic CBF neurons and is mediated by the A1 receptor (A1R). We reason that sleep debt must involve transcriptional alterations, since sleep debt is cumulative over days and depends on continued sleep restriction (or, alternatively expressed, increased wakefulness). New data support our theory that AD may mediate sleep debt by a positive feedback mechanism whereby increased CBF adenosine concentrations leads to increased A1 receptor production. The increased concentration of the A1 receptor (A1R) leads to a ‘resetting’ of the homeostatic set point, whereby a given concentration of AD produces a greater inhibition of wakefulness-active neurons and thus increased sleepiness. A summary of the events leading to increased AD A1R is: adenosine acting at the A1R in cholinergic neurons leads to an intracellular cascade that activates the transcription factor NFkB which promotes the transcription of A1R mRNA. Very recent data indicate this leads to increased A1R protein and ligand binding. The next step will be to look at neurobehavioral effects of sleep restriction (wakefulness increase). Our rodent model of sleep interruption (SI) may be a highly useful for looking at cumulative effects of sleep loss. SI via a slowly moving treadmill (on for 10 s, off for 30 s) produces increased wakefulness and decreased delta sleep. SI produces increases in CBF adenosine that are progressive over two days; we think that the increased AD makes it likely that this paradigm, like total sleep deprivation, will increase A1R protein and binding and that this increased sensitivity to AD may mediate some of the effects. We are now undertakng a systematic investigation of the cognitive/behavioral effects of SI in the rodent, and here present initial findings; mediating mechanisms, such as AD, have yet to be determined. We find SI, like sleep deprivation, blunted long-term potentiation in hippocampus, more so with 3 days of SI than with a single day. Moreover, SI of one day decreased the retention of the hippocampusdependent Morris water maze learning. Furthermore, 24 h SI impaired complex learning in an extra-dimensional set-shifting task (a ‘rat Wisconsin Card Sorting Task’). On a direct test of vigilance and attention, rats progressively increased errors of omission and total errors on the 5 choice serial reaction time test with increasing sleep deprivation; effects of SI are currently being examined. Our goal is to develop a complete battery of animal behavioral tests that will allow comparability with human measures of decreased performance with sleep restriction and deprivation while allowing mechanistic determination of their basis. Supported by VA Medical Research Service (RB & RWM), NIMH (39683, 70156), NHLBI (60292). Sleep and Biological Rhythms 2005; 3: A2–A73 REM-LIKE SCALP EEG FEATURES IN WAKE-SLEEP TRANSITION MELINDA SVERTECZKI, LÁZÁR ALPÁR SÁNDOR, HAVRÁN LINDA, KIS TAMÁS, RIGÓ PÉTER, CSÓKA SZILVIA AND BÓDIZS RÓBERT Semmelweis University, Institute of Behavioural Sciences, H-1089 Budapest, Nagyvárad Tér 4, Hungary The covert-rapid-eye-movement (REM) sleep hypothesis of dreaming suggests that elements of REM sleep emerge during sleep onset, leading to vivid hypnagogic imagery. Based on parahippocampal electrocorticography (EEG) of epileptic patients previously we found an increase in REM-like 1.5–3.0 Hz parahippocampal activity followed alpha dropout during wake-sleep transition. Hypothesis: Scalp EEG features of REM sleep are enhanced during wake-sleep transition. Eight subjects’ polysomnography have been performed and Fourier transformed (Cz electrode). The sleep transition was categorised in three stages: 1, one minute alpha activity, 2, alpha dropout (50%) and 3, one minute stage 2 sleep. The following frequency bands were analysed: slow oscillation (0.5–1.25 Hz), delta/theta frequencies (1.5–3, 3.25–4.5, 4.75–6.25, 6.5–7.75 Hz), alpha (8–12 Hz) and sigma (12.25–15 Hz) bands. For each individual, in each stages of the wakesleep transition power spectral densities of the above frequency bands were divided by the respective values of the whole night REM and NREM stage 2 sleep (S2) power spectra. The similarity to REM/S2 sleep were expressed as a distance of the ratio (transition/REM, transition/S2) from 1, which shows the REM/S2 likeness in a logarithmic form: log(1/|1-x|). In contrast to the parahippocampal 1.5–3 Hz oscillation in sleep onset we detected increased activity in the slow oscillation, delta (1.5–4.5 Hz) and theta (4.75–7.75 Hz) frequency bands in wake-sleep transition (1st, 2nd stages of the sleep transition). Specific REM features appeared in the fast delta (3.25–4.5 Hz) and fast theta (6.5–7.75 Hz) frequencies followed alpha dropout during wake-sleep transition. Regarding alpha frequency band wake-sleep transition (alpha dropout) was similar to S2 sleep possibly due to the slow spindling during S2 sleep. Changes in the sleep onset period call attention to reduced thalamic, thalamo-cortical activity which is reflected scalp EEG as opposed to parahippocampal-hippocampal activity detected by medio-temporal electrocorticography. References 1. Bódizs R, Kántor S, Szabó Sz, Szûcs A, Er’ss L, Halász P. Rhythmic hippocampal slow oscillation characterizes REM sleep in humans. Hippocampus 2001; 11(6): 747–53. 2. Bódizs R, Sverteczki M, Lázár AS, Halász P. Human parahippocampal activity: non-REM and REM elements in wake-sleep transition. Brain Research Bulletin 2005; 65(2): 169–76. EFFECT OF GLUTAMATE INJECTION AT THE MEDIAL PREOPTIC AREA ON SLEEPWAKEFULNESS IN MALE RATS AUSAF A FAROOQUI, KAMALESH K GULIA, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Departmet of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India The medial preoptic area (mPOA) is one of the important neural sites for regulation and maintenance of sleep (Kumar 2004). Lesions of the mPOA result in a decrease in total sleep duration (John and Kumar 1998). A recent report has shown activation of the mPOA during the slow wave sleep (Khubchandani et al. 2005). Noradrenaline, A71 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 acetylcholine and GABA in the mPOA have been shown to influence sleep-wakefulness. The role of glutamate in the mPOA with regard to sleep regulatory function has not been studied, although an abundance of glutamate receptors has been reported in this area (Eyigor et al. 2001). To assess sleep-wakefulness, electrodes for EEG, EOG, and EMG were chronically implanted in male Wistar rats (wt 220–280 g) under sodium pentobarbital anesthesia. A bilateral guide cannula for drug injection was implanted 2 mm above the mPOA. After a recovery period of 1 week, three baseline sleep recordings for 4 h (12.00 hours to 16.00 hours) were taken to ensure normal sleep-wakefulness pattern. Glutamate at a dose of 40 ng in 200 nL was injected in the mPOA bilaterally. Sleep-wakefulness patterns were studied for subsequent four hours. Changes in wakefulness, slow wave sleep, and rapid eye movement sleep were analyzed in one-hour bins. Total duration of sleep increased in the first 3 h of recording after injection. This increase was found to be maximum during 2nd and 3rd hours of sleep recording. The findings corroborate with other studies on the role of the mPOA in normal sleep-wakefulness. These also hint at the possible involvement of glutamate receptors in the mPOA in sleep regulation. References Eyigor O, Centers A, Jennes L. Distribution of ionotropic glutamate receptor subunit mRNAs in the rat hypothalamus. J Comp Neurol 2001; 434: 101–24. John J, Kumar VM. Effect of NMDA lesion of the medial preoptic neurons on sleep and other functions. Sleep. 1998 15; 21: 587–98. Khubchandani M, Jagannathan NR, Mallick HN, Kumar VM. fMRI shows activation of the medial preoptic area during sleep. Neuroimage. 2005; 26: 29–35. Kumar VM. Why the medial preoptic area is important for sleep regulation. Indian J. Physiol Pharmacol. 2004; 48: 137–49. THE PREVALENCE OF SNORING IN MADRAS, INDIA D BALAKRISHNAN, S THIRUNAVUKKARASU, R EDWIN AND BS VIRUDHAGIRINATHAN Kanchi Kamakoti Childs Trust Hospitals, The Tamilnadu Dr MGR Medical University, Institute of Neurology, Madras Medical College There is an urgent need in India, for reliable data on sleep disorders and snoring. The data from the west cannot be confidently extrapolated to the south, as the social parameters are very different. The aim of this study is to gather reliable data on the prevalence of snoring, through a partially administered questionnaire and observational survey. 1133 visitors of all ages to a medical exhibition constituted the study population. Of these, 58 were deleted from the study because they were less than two years of age. Physical parameters like age, height, weight and economic levels were recorded. A simple questionnaire was administered to each of them. The results were analysed critically. The over all prevalence of snoring was 19.5%. Of children below 12 years, 22 percent had snoring. The adults showed a higher prevalence of 24%; the elder group had even a higher prevalence with nearly one half reporting snoring. This positive association of snoring with increasing age was found to be significant. The percentage of snorers was found to be higher in the males than in the females –24.4% in males vs. 13% of females. This gender bias was further analysed with reference to particular age groups. The male predominance was found to significant only in the adult category and not in the other age groups. The BMI increased the snoring prevalence only in the adults. Snoring in children and in adolescents was found to be independent of BMI. A history of sore throat was positively associ- A72 ated with snoring only in children less than 12 years of age. In a significant proportion of snorers, a lack of concern was noted. This survey broadly indicates the profile of snorers in this part of the world. In a first attempt to gather data about the prevalence of snoring in this part of the world, a partially administered questionnaire survey was conducted in Chennai, India. Across all ages, the percentage of snoring was 19.5. The male gender and affluence had a positive association with snoring. The BMI increased the snoring prevalence only in the adults. A history of sore throat was positively associated with snoring significantly in the children less than 12 years of age only. This survey broadly indicates the profile of snorers in this part of the world. Acknowledgements: The authors gratefully acknowledge the help and encouragement rendered by the Medical Director of Kanchi Kamakoti Childs Trust Hospital in carrying out this study. CHANGES IN THERMAL PREFERENCE, SLEEP-WAKEFULNESS AND BODY TEMPERATURE IN ADULT RATS WITH IMPAIRED WARM RECEPTORS DEEPENDRA KUMAR, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Department of Physiology, All India Institute of Medical Sciences, New Delhi-110029, India Ambient temperature (Ta) is one of the important environmental parameters influencing sleep-wakefulness (S-W), and body temperature (Tb). Central thermoreceptors in the brain and peripheral thermoreceptors in the skin convey information about the thermal status of the body and environment to the preoptic area for regulation of Tb. The preoptic area plays a major role in regulation of S-W, Tb and thermal preference(Ray et al. 2005). In the present study we investigated the effect of elevated and lower Ta on S-W, and Tb in rats with impaired warm receptors. The S-W and Tb were recorded for 24 h at 27°C and 6 h at 18, 21, 24, 27, 30, 33, and 36°C before and after destruction of warm receptors at 27°C. Thermal preferences of rats were studied by putting the animals into a three interconnected environmental chamber where they could choose 27, 30 and 33°C. The central and peripheral warm sensitive receptors were destroyed after control recordings by the systemic injection of capsaicin (8-Methyl-N-Vanillyl-6-Nonenamide, 375 mg/kg BW, Sigma, USA). Normal rats preferred Ta of 27°C while rats with impaired warm receptors chose Ta of 30 and 33°C. The S-W of the normal and rats after destruction of warm receptors did not differ significantly. Though the sleep aws increased at high Ta in normal rats, it had no signifficant effect after destruction of warm receptors. Lowering Ta produced reduction in sleep in both normal and lesioned rats.The rats with impaired warm receptors showed slightly higher body temperature when compared with controls at 27°C. These rats showed increase in body temperature when exposed to elevated Ta, but when exposed to lower Ta, it did not produce any significant change. Warm sensitive receptors are important for thermoregulation and increase sleep at higher Ta. Normal thermal preferenceof the animal is also dependent on the inputs from the warm receptors. Reference Ray B, Mallick HN, Kumar VM. Changes in sleep-wakefulness in the medial preoptic area lesioned rats: Role of thermal preference Behav. Brain. Res. 2005; 158: 43–52. Financial support: Defence Research and Development Organization, India. Sleep and Biological Rhythms 2005; 3: A2–A73 Interim Congress of the World Federation of Sleep Research and Sleep Medicine Societies 2005 THE INHIBITORY ROLE OF THE MEDIAL SEPTUM IN PARADOXICAL SLEEP IN RATS RAJAGOPALAN SRIVIDYA, HRUDA NANDA MALLICK AND VELAYUDHAN MOHAN KUMAR Department of Physiology, All India Institute of Medical Sciences, New Delhi-110029, India The effects of the destruction of the medial septal neurons (MS) with N-methyl-D-aspartic acid on sleep-wakefulness (S-W), body temperature (Tb), locomotor activity (LMA) and thermal preference were studied in male Wistar rats. When these rats were given a choice of three ambient temperatures (Tamb) of 24°, 27°, and 30°C, they preferred 27°C before the lesion. But they chose 30°C during the initial days and 24°C by the third week after the MS lesion. The MS lesion produced an increase in paradoxical sleep (PS) though this change was Sleep and Biological Rhythms 2005; 3: A2–A73 not very evident when the rats were not allowed to choose their Tamb. Though there was a decrease in slow wave sleep (SWS), it recovered considerably, when the lesioned rats chose their preferred Tamb. However, the frequency of SWS episodes did not show any recovery. There was a decrease in both Tb and LMA by the third week after the MS lesion. It can therefore be concluded that the MS lesion affected the initiation of SWS, as there was a decrease in the frequency of SWS episodes. Study of S-W in the rats that were given freedom to select Tamb helped to demonstrate the role of the MS in the inhibition of PS. It also showed that the thermostat of the rats was reset at a lower level by the third week after the MS lesion. Decrease in heat production resulting from a decrease in LMA, could have contributed towards the animals’ efforts to maintain a lower Tb. A73