In different species, REM sleep (REMS) occurrence appears to be finely regulated on either a shor... more In different species, REM sleep (REMS) occurrence appears to be finely regulated on either a short (Vivaldi E, 1994) or a long-term basis (Parmeggiani PL, 1980). However, the hypothesis that REMS amount is homeostatically regulated is challenged by data on humans which show that a scarce REMS rebound follows REMS deprivation (Horne J, 2000). Further analysis was carried out on data from an experiment in which 24 male Sprague-Dawley rats (250g) were exposed for 24h to different low ambient temperatures (Tas, ranging from \u201310\ub0C to 10\ub0C) and then allowed to recover for 4 days at normal laboratory Ta (Cerri M, 2005). REMS decreased proportionally with cold exposure, but a quick compensatory REMS rebound occurred during the first day of recovery when the previous loss went beyond an \u201calarm\u201d threshold (AT) corresponding to 22% of the REMS daily need. By using data from literature we have calculated that AT for cats (Parmeggiani PL, 1980) and humans (Endo T, 1998) should correspond to 72% and 234% of the REMS daily need. Examining the three species together, AT appears to increase proportionally to the average duration of the REMS episode. It also appears to be positively related to their brain mass (Kg) according to a power function: y = 226.03x 0.36 , r2=0.986. This would suggest that, in analogy to what has been observed regarding the body\u2019s energy needs, small mammals have a smaller capacity to buffer their REMS need than large ones
Tau protein is of primary importance for many physiological processes in neurons, where it affect... more Tau protein is of primary importance for many physiological processes in neurons, where it affects the dynamics of the microtubule system. When hyperphosphorylated (PP-Tau), Tau monomers detach from microtubules and tend to aggregate firstly in oligomers, and then in neurofibrillary tangles, as it occurs in a group of neurodegenerative disorders named thauopathies. A hypothermia-related accumulation of PP-Tau, which is quickly reversed after the return to normothermia, has been shown to occur in the brain of hibernators during torpor. Since, recently, in our lab, a hypothermic torpor-like condition (synthetic torpor, ST) was pharmacologically induced in the rat, a non-hibernator, the aim of the present work was to assess whether ST can lead to a reversible PP-Tau accumulation in the rat brain. PP-Tau was immunohistochemically assessed by staining for AT8 (phosphorylated Tau) and Tau-1 (non-phosphorylated Tau) in 19 brain structures, which were chosen mostly due to their involvement in the regulation of autonomic and cognitive functions in relation to behavioral states. During ST, AT8 staining was strongly expressed throughout the brain, while Tau-1 staining was reduced compared to control conditions. During the following recovery period, AT8 staining progressively reduced close to zero after 6 h from ST. However, Tau-1 staining remained low even after 38 h from ST. Thus, overall, these results show that ST induced an accumulation of PP-Tau that was, apparently, only partially reversed to normal during the recovery period. While the accumulation of PP-Tau may only depend on the physicochemical characteristics of the enzymes regulating Tau phosphorylation, the reverse process of dephosphorylation should be actively regulated, also in non-hibernators. In conclusion, in this work a reversible and widespread PP-Tau accumulation has been induced through a procedure that leads a non-hibernator to a degree of reversible hypothermia, which is comparable to that observed in hibernators. Therefore, the physiological mechanism involved in this process can sustain an adaptive neuronal response to extreme conditions, which may however lead to neurodegeneration when particular intensities and durations are exceeded.
Fluorescent Neuronal Cells v2 is a collection of fluorescence microscopy images and the correspon... more Fluorescent Neuronal Cells v2 is a collection of fluorescence microscopy images and the corresponding ground-truth annotations, designed to foster innovative research in the domains of Life Sciences and Deep Learning. This dataset encompasses three image collections in which rodent neuronal cells' nuclei and cytoplasm are stained with diverse markers to highlight their anatomical or functional characteristics. Alongside the images, we provide ground-truth annotations for several learning tasks, including semantic segmentation, object detection, and counting. The contribution is twofold. First, given the variety of annotations and their accessible formats, we envision our work facilitating methodological advancements in computer vision approaches for segmentation, detection, feature learning, unsupervised and self-supervised learning, transfer learning, and related areas. Second, by enabling extensive exploration and benchmarking, we hope Fluorescent Neuronal Cells v2 will catalyze breakthroughs in fluorescence microscopy analysis and promote cutting-edge discoveries in life sciences. The data are available at: https://amsacta.unibo.it/id/eprint/7347. In response to these challenges, we present a large archive comprising high-resolution fluorescent microscopy images, encompassing different markers and cell types. Furthermore, the data are shared as easily accessible PNG files, and the corresponding annotations are provided in various types and formats, enabling the exploration of different learning approaches and tasks, thereby significantly expanding the scope of potential applications.
Despite some difficulties in interpretation, results are also satisfactory with respect to the co... more Despite some difficulties in interpretation, results are also satisfactory with respect to the counting task, as testified by mean and median absolute error of, respectively, 0.8 and 1.
In different species, REM sleep (REMS) occurrence appears to be finely regulated on either a shor... more In different species, REM sleep (REMS) occurrence appears to be finely regulated on either a short (Vivaldi E, 1994) or a long-term basis (Parmeggiani PL, 1980). However, the hypothesis that REMS amount is homeostatically regulated is challenged by data on humans which show that a scarce REMS rebound follows REMS deprivation (Horne J, 2000). Further analysis was carried out on data from an experiment in which 24 male Sprague-Dawley rats (250g) were exposed for 24h to different low ambient temperatures (Tas, ranging from \u201310\ub0C to 10\ub0C) and then allowed to recover for 4 days at normal laboratory Ta (Cerri M, 2005). REMS decreased proportionally with cold exposure, but a quick compensatory REMS rebound occurred during the first day of recovery when the previous loss went beyond an \u201calarm\u201d threshold (AT) corresponding to 22% of the REMS daily need. By using data from literature we have calculated that AT for cats (Parmeggiani PL, 1980) and humans (Endo T, 1998) should correspond to 72% and 234% of the REMS daily need. Examining the three species together, AT appears to increase proportionally to the average duration of the REMS episode. It also appears to be positively related to their brain mass (Kg) according to a power function: y = 226.03x 0.36 , r2=0.986. This would suggest that, in analogy to what has been observed regarding the body\u2019s energy needs, small mammals have a smaller capacity to buffer their REMS need than large ones
Tau protein is of primary importance for many physiological processes in neurons, where it affect... more Tau protein is of primary importance for many physiological processes in neurons, where it affects the dynamics of the microtubule system. When hyperphosphorylated (PP-Tau), Tau monomers detach from microtubules and tend to aggregate firstly in oligomers, and then in neurofibrillary tangles, as it occurs in a group of neurodegenerative disorders named thauopathies. A hypothermia-related accumulation of PP-Tau, which is quickly reversed after the return to normothermia, has been shown to occur in the brain of hibernators during torpor. Since, recently, in our lab, a hypothermic torpor-like condition (synthetic torpor, ST) was pharmacologically induced in the rat, a non-hibernator, the aim of the present work was to assess whether ST can lead to a reversible PP-Tau accumulation in the rat brain. PP-Tau was immunohistochemically assessed by staining for AT8 (phosphorylated Tau) and Tau-1 (non-phosphorylated Tau) in 19 brain structures, which were chosen mostly due to their involvement in the regulation of autonomic and cognitive functions in relation to behavioral states. During ST, AT8 staining was strongly expressed throughout the brain, while Tau-1 staining was reduced compared to control conditions. During the following recovery period, AT8 staining progressively reduced close to zero after 6 h from ST. However, Tau-1 staining remained low even after 38 h from ST. Thus, overall, these results show that ST induced an accumulation of PP-Tau that was, apparently, only partially reversed to normal during the recovery period. While the accumulation of PP-Tau may only depend on the physicochemical characteristics of the enzymes regulating Tau phosphorylation, the reverse process of dephosphorylation should be actively regulated, also in non-hibernators. In conclusion, in this work a reversible and widespread PP-Tau accumulation has been induced through a procedure that leads a non-hibernator to a degree of reversible hypothermia, which is comparable to that observed in hibernators. Therefore, the physiological mechanism involved in this process can sustain an adaptive neuronal response to extreme conditions, which may however lead to neurodegeneration when particular intensities and durations are exceeded.
Fluorescent Neuronal Cells v2 is a collection of fluorescence microscopy images and the correspon... more Fluorescent Neuronal Cells v2 is a collection of fluorescence microscopy images and the corresponding ground-truth annotations, designed to foster innovative research in the domains of Life Sciences and Deep Learning. This dataset encompasses three image collections in which rodent neuronal cells' nuclei and cytoplasm are stained with diverse markers to highlight their anatomical or functional characteristics. Alongside the images, we provide ground-truth annotations for several learning tasks, including semantic segmentation, object detection, and counting. The contribution is twofold. First, given the variety of annotations and their accessible formats, we envision our work facilitating methodological advancements in computer vision approaches for segmentation, detection, feature learning, unsupervised and self-supervised learning, transfer learning, and related areas. Second, by enabling extensive exploration and benchmarking, we hope Fluorescent Neuronal Cells v2 will catalyze breakthroughs in fluorescence microscopy analysis and promote cutting-edge discoveries in life sciences. The data are available at: https://amsacta.unibo.it/id/eprint/7347. In response to these challenges, we present a large archive comprising high-resolution fluorescent microscopy images, encompassing different markers and cell types. Furthermore, the data are shared as easily accessible PNG files, and the corresponding annotations are provided in various types and formats, enabling the exploration of different learning approaches and tasks, thereby significantly expanding the scope of potential applications.
Despite some difficulties in interpretation, results are also satisfactory with respect to the co... more Despite some difficulties in interpretation, results are also satisfactory with respect to the counting task, as testified by mean and median absolute error of, respectively, 0.8 and 1.
Uploads
Papers by Marco Luppi