Papers by Roberto De Pasquale
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 20, 2018
Metaplasticity is the regulation of synaptic plasticity based on the history of previous synaptic... more Metaplasticity is the regulation of synaptic plasticity based on the history of previous synaptic activation. This concept was formulated after observing that synaptic changes in the visual cortex are not fixed, but dynamic and dependent on the history of visual information flux. In visual cortical neurons, sustained synaptic stimulation activate the enzymatic complex NOX2, resulting in the generation of reactive oxygen species (ROS). NOX2 is the main molecular structure responsible for translating neural activity into redox modulation of intracellular signaling pathways involved in plastic changes. Here, we studied the interaction between NOX2 and visual experience as metaplastic factors regulating synaptic plasticity at the supergranular layers of the mouse visual cortex. We found that genetic inhibition of NOX2 reverses the polarizing effects of dark rearing from LTP to LTD. In addition, we demonstrate that this process relies on changes in the NMDA receptor functioning. Altogeth...
, 385 (2008); 320 Science et al. José Fernando Maya Vetencourt Cortex The Antidepressant Fluoxeti... more , 385 (2008); 320 Science et al. José Fernando Maya Vetencourt Cortex The Antidepressant Fluoxetine Restores Plasticity in the Adult Visual This copy is for your personal, non-commercial use only. clicking here. colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to others here. following the guidelines can be obtained by Permission to republish or repurpose articles or portions of articles ): November 13, 2013 www.sciencemag.org (this information is current as of The following resources related to this article are available online at http://www.sciencemag.org/content/320/5883/1588.1.full.html A correction has been published for this article at: http://www.sciencemag.org/content/320/5874/385.full.html version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/content/suppl/2008/06/10/320.5874.385.DC1.html can be found at: Supporting Online Material http://www.sciencemag.org/content/320/5874/385.full.html#related found at: can be related to this article A list of selected additional articles on the Science Web sites http://www.sciencemag.org/content/320/5874/385.full.html#ref-list-1 , 8 of which can be accessed free: cites 27 articles This article 50 article(s) on the ISI Web of Science cited by This article has been http://www.sciencemag.org/content/320/5874/385.full.html#related-urls 41 articles hosted by HighWire Press; see: cited by This article has been http://www.sciencemag.org/cgi/collection/psychology Psychology subject collections: This article appears in the following
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 17, 2014
Reactive oxygen species (ROS) are signaling factors involved in many intracellular transduction p... more Reactive oxygen species (ROS) are signaling factors involved in many intracellular transduction pathways. In the nervous system, ROS are thought to modulate various mechanisms of synaptic plasticity. One important source of ROS production in the brain is the NADPH oxidase complex. Stimulation of NMDA receptors activates NADPH oxidase, which provides selective oxidative responses accompanying the induction of synaptic changes. The activity of NADPH oxidase is known to be crucial for the induction of LTP in the hippocampus. However, the involvement of this complex in cortical synaptic plasticity is still unclear. Here we provide evidence that genetic ablation of NOX2 (the prototypical member of NADPH oxidase family of proteins) suppresses LTP and LTD in the primary visual cortex of the mouse. We also found that the involvement of NOX2 on LTP is partially age-dependent, as the activity of this complex is not critical for mechanisms of synaptic potentiation occurring in immature animals...
Neuroscience, 2011
Increasing evidence suggests that plastic changes underlying skill learning may occur at early st... more Increasing evidence suggests that plastic changes underlying skill learning may occur at early stages of neural processing. However, whether visual perceptual learning (PL) is accompanied by neuronal plasticity phenomena in the primary visual cortex (V1) is yet unknown. Here, we provide the first evidence that practice with specific visual stimuli (gratings) induces long-term potentiation (LTP) of synaptic responses in the rat V1. We report that in rats which have improved through practice their ability to discriminate between two gratings of different spatial frequency, the input/output curves of field potentials evoked in layers II-III of V1 slices by stimulation of either vertical and horizontal connections are shifted leftward compared to controls. Thus, visual PL is followed by potentiation of synaptic transmission both in vertical and horizontal connections (mimicry). We next show that this increase in intracortical connectivity gain is paralleled by LTP-like phenomena caused by the learning process: indeed, visual PL occludes further LTP (occlusion). Mimicry and occlusion are not present in the primary somatosensory cortex of rats trained with PL. These results demonstrate that LTP accompanies PL and highlight the notion that learning can occur at processing stages as early as the primary sensory cortices.
Journal of Neuroscience, Jan 1, 2010
Experience-dependent plasticity in the cortex is often higher during short critical periods in po... more Experience-dependent plasticity in the cortex is often higher during short critical periods in postnatal development. The mechanisms limiting adult cortical plasticity are still unclear. Maturation of intracortical GABAergic inhibition is suggested to be crucial for the closure of the critical period for ocular dominance (OD) plasticity in the visual cortex. We find that reduction of GABAergic transmission in the adult rat visual cortex partially reactivates OD plasticity in response to monocular deprivation (MD). This is accompanied by an enhancement of activity-dependent potentiation of synaptic efficacy but not of activity-dependent depression. We also found a decrease in the expression of chondroitin sulfate proteoglycans in the visual cortex of MD animals with reduced inhibition, after the reactivation of OD plasticity. Thus, intracortical inhibition is a crucial limiting factor for the induction of experience-dependent plasticity in the adult visual cortex.
Neuron, Jan 1, 2012
the cortex into LTP-only or LTD-only states, which allows the potentiation or depression of targe... more the cortex into LTP-only or LTD-only states, which allows the potentiation or depression of targeted synapses with visual stimulation. The pull-push regulation of LTP/LTD occurs via direct control of the synaptic plasticity machinery and it is independent of changes in NMDAR activation or neuronal excitability. We propose these simple rules governing the pull-push control of LTP/LTD form a general metaplasticity mechanism that may contribute to neuromodulation of plasticity in other cortical circuits.
The Journal of Neuroscience, Jan 1, 2011
Despite the importance of corticocortical connections, few published studies have investigated th... more Despite the importance of corticocortical connections, few published studies have investigated the functional, synaptic properties of such connections in any species, because most studies have been purely anatomical or aimed at functional features other than synaptic properties. We recently published a study of synaptic properties of connections between the primary and secondary cortical auditory areas in brain slices from the mouse, and, in the present study, we aimed to extend this by performing analogous studies of the primary and secondary visual areas (V1 and V2). We found effectively the same results. That is, connections between V1 and V2 in both directions were quite similar; in each case, the glutamatergic inputs could be classified as one of two types, Class 1B (formerly "driver") and Class 2 (formerly "modulator"). There is a clear laminar correlation for these different inputs, in terms of both the laminae of origin and those in which the recorded cells were located. Our data suggest a common pattern to the functional organization of corticocortical connectivity in the mouse cortex.
Frontiers in …, Jan 1, 2011
ERK 1,2 pathway mediates experience-dependent gene transcription in neurons and several studies h... more ERK 1,2 pathway mediates experience-dependent gene transcription in neurons and several studies have identified its pivotal role in experience-dependent synaptic plasticity and in forms of long term memory involving hippocampus, amygdala, or striatum. The perirhinal cortex (PRHC) plays an essential role in familiarity-based object recognition memory. It is still unknown whether ERK activation in PRHC is necessary for recognition memory consolidation. Most important, it is unknown whether by modulating the gain of the ERK pathway it is possible to bidirectionally affect visual recognition memory and PRHC synaptic plasticity. We have first pharmacologically blocked ERK activation in the PRHC of adult mice and found that this was sufficient to impair long term recognition memory in a familiarity-based task, the object recognition task (ORT). We have then tested performance in the ORT in Ras-GRF1 knock-out (KO) mice, which exhibit a reduced activation of ERK by neuronal activity, and in ERK1 KO mice, which have an increased activation of ERK2 and exhibit enhanced striatal plasticity and striatal mediated memory. We found that Ras-GRF1 KO mice have normal short term memory but display a long term memory deficit; memory reconsolidation is also impaired. On the contrary, ERK1 KO mice exhibit a better performance than WT mice at 72h retention interval, suggesting a longer lasting recognition memory. In parallel with behavioral data, LTD was strongly reduced and LTP was significantly smaller in PRHC slices from Ras-GRF1 KO than in WT mice while enhanced LTP and LTD were found in PRHC slices from ERK1 KO mice.
Neuroscience, Jan 1, 2010
Increasing evidence suggests that plastic changes underlying skill learning may occur at early st... more Increasing evidence suggests that plastic changes underlying skill learning may occur at early stages of neural processing. However, whether visual perceptual learning (PL) is accompanied by neuronal plasticity phenomena in the primary visual cortex (V1) is yet unknown. Here, ...
Journal of …, Jan 1, 2010
Neuron, Jan 1, 2010
Endocannabinoids are widely regarded as negative modulators of presynaptic release. Here, we pres... more Endocannabinoids are widely regarded as negative modulators of presynaptic release. Here, we present evidence that in visual cortex endocannabinoids are crucial for the maturation of GABAergic release. We found that between eye opening and puberty, release changes from an immature state with high release probability, short-term depression (STD), and high release variability during irregular patterned activity, to a mature state with reduced release probability, STD, and variability. This transition requires visual experience and stimulation of CB1 cannabinoid receptors as it is mimicked by administration of CB1 agonists, blocked by antagonists, and is absent in CB1R KO mice. In immature slices, activation of CB1 receptors induces long-term depression of inhibitory responses (iLTD) and a reduction in STD and response variability. Based on these findings, we propose that visually induced endocannabinoid-dependent iLTD mediates the developmental decrease in release probability, STD, and response variability, which are characteristic of maturation of cortical GABAergic inhibition.
The Journal of …, Jan 1, 2010
Experience-dependent plasticity in the cortex is often higher during short critical periods in po... more Experience-dependent plasticity in the cortex is often higher during short critical periods in postnatal development. The mechanisms limiting adult cortical plasticity are still unclear. Maturation of intracortical GABAergic inhibition is suggested to be crucial for the closure of the critical period for ocular dominance (OD) plasticity in the visual cortex. We find that reduction of GABAergic transmission in the adult rat visual cortex partially reactivates OD plasticity in response to monocular deprivation (MD). This is accompanied by an enhancement of activity-dependent potentiation of synaptic efficacy but not of activity-dependent depression. We also found a decrease in the expression of chondroitin sulfate proteoglycans in the visual cortex of MD animals with reduced inhibition, after the reactivation of OD plasticity. Thus, intracortical inhibition is a crucial limiting factor for the induction of experience-dependent plasticity in the adult visual cortex.
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Papers by Roberto De Pasquale