50 results on '"Gervasoni D"'
Search Results
2. Melting of nanostructured drugs embedded into a ploymeric matrix
- Author
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Bergese, P., Colombo, I., Gervasoni, D., and Depero, Laura E.
- Subjects
Chemistry, Physical and theoretical -- Research ,Thermal analysis -- Methods ,Chemicals, plastics and rubber industries - Abstract
The melting behavior of nanostructured organic materials (drugs) embedded into a cross-linked polymeric matrix is studied. The complex microstructure of these nanocomposites, yielded by the polymer matrix in which molecular clusters and nanocrystals of drug plus a cospiquous fraction of water are confined, demanded synergic application of thermal analysis and temperature resolved X-ray diffraction.
- Published
- 2004
3. The supramammillary nucleus activates cortical structures during paradoxical (REM) sleep: S301
- Author
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RENOUARD, L., FORT, P., OGAWA, K., CLÉMENT, O., BILLWILLER, F., CAMARGO, N., ABDELKARIM, M., GERVASONI, D., GAY, N., SCOTÉ, C., LIBOUREL, P.-A., RAVASSARD, P., SALVERT, D., PEYRON, C., CLAUSTRAT, B., LÉGER, L., SALIN, P.-A., MALLERET, G., and LUPPI, P.-H.
- Published
- 2012
4. REM sleep generating mechanisms: S85
- Author
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LUPPI, P., SAPIN, E., LAPRAY, D., GOUTAGNY, R., LÉGER, L., GERVASONI, D., and FORT, P.
- Published
- 2008
5. The gamma-aminobutyric acid (GABA) transmitter pathway: its key-role in the regulation of NREM and REM sleep: S51
- Author
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LUPPI, P., GERVASONI, D., SAPIN, E., LEGER, L., LAPRAY, D., and FORT, P.
- Published
- 2008
6. The melanin-concentrating hormone receptor 1 plays a key role in the regulation of sleep and the wake-promoting effect of modafinil: P113
- Author
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FORT, P., GERVASONI, D., LAKAYE, B., SALVERT, D., GRISAR, T., LUPPI, P., and ADAMANTIDIS, A.
- Published
- 2006
7. Mapping sleep-wake states with the dynamics of large-scale neural signals in rodents: P104
- Author
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GERVASONI, D., GOUTAGNY, R., SALVERT, D., FORT, P., and LUPPI, P.
- Published
- 2006
8. Microstructural investigation of nimesulide–crospovidone composites by X-ray diffraction and thermal analysis
- Author
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Bergese, P, Bontempi, E, Colombo, I, Gervasoni, D, and Depero, L.E
- Published
- 2003
- Full Text
- View/download PDF
9. Effect of chronic treatment with milnacipran on sleep architecture in rats compared with paroxetine and imipramine
- Author
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Gervasoni, D, Panconi, E, Henninot, V, Boissard, R, Barbagli, B, Fort, P, and Luppi, P.H
- Published
- 2002
- Full Text
- View/download PDF
10. La carta della vegetazione del SIC Alta Valle del Sestaione (Pistoia, Toscana Nord-Occidentale)
- Author
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Foggi, B., Gennai, M., Gervasoni, D., Ferretti, G., Viciani, D., and Venturi, E.
- Published
- 2007
11. Brainstem structures responsible for paradoxical sleep onset and maintenance
- Author
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Luppi, P. -H, Gervasoni, D., Boissard, R., Verret, L., romain goutagny, Peyron, C., Salvert, D., Leger, L., Barbagli, B., Fort, P., Centre de recherche en neurosciences de Lyon (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Team Physiopathologie des Réseaux Neuronaux Responsables du Cycle Veille-Sommeil, Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Verret, Laure, Physio-pathologie des réseaux neuronaux du cycle veille-sommeil, Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Department of Neurobiology, Duke University [Durham], Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
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Neurotransmitter Agents ,MESH: Humans ,MESH: Rats ,Reticular Formation ,MESH: Neural Pathways ,[SDV]Life Sciences [q-bio] ,Models, Neurological ,Sleep, REM ,Neural Inhibition ,MESH: Neural Inhibition ,MESH: Neurotransmitter Agents ,MESH: Sleep, REM ,MESH: Reticular Formation ,Rats ,MESH: Models, Neurological ,Neural Pathways ,MESH: Brain Stem ,Animals ,Humans ,MESH: Animals ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,[SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,Brain Stem - Abstract
International audience; This paper is dedicated to our mentor, Michel Jouvet who inspired our career and transmitted to us his passion for the study of the mechanisms responsible for paradoxical sleep genesis and also that of its still mysterious functions. We expose in the following the progresses in the knowledge in this field brought during 40 years by Michel Jouvet and his team and more recently by the members of a new CNRS laboratory in which we aim to pursue in the path opened by Michel Jouvet.
- Published
- 2004
12. Microwave generated nanocomposites for making insolubile drugs solubile
- Author
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Bergese, Paolo, Colombo, I, Gervasoni, D, and Depero, Laura Eleonora
- Published
- 2003
13. Anatomical demonstration of a medullary enkephalinergic pathway potentially implicated in the oro-facial muscle atonia of paradoxical sleep in the cat
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Fort, P., Rampon, C., Gervasoni, D., Christelle Peyron, and Luppi, P. H.
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Male ,Neurons ,Medulla Oblongata ,Reticular Formation ,Facial Muscles ,Sleep, REM ,Enkephalins ,Immunohistochemistry ,Methionine ,Muscle Tonus ,Neural Pathways ,Cats ,Animals ,Female - Abstract
The present study was aimed to compare in detail the distribution within the rostral ventromedial medulla of Methionin-Enkephalin-immunoreactive neurons with efferent projections to the facial or trigeminal motor nuclei, using a double immunostaining technique in colchicine-treated cats. Following cholera toxin B subunit injections in the facial or trigeminal motor nuclei, we found that respectively 55% and 65% of the medium to large-sized retrogradely labeled cells in the lateral part of the nucleus reticularis magnocellularis were Methionin-Enkephalin-positive. For both motor nuclei, the double-labeled neurons had similar morphology and size and were located exactly in the same area. They could therefore belong to the same population of reticular enkephalinergic neurons. Based on these and previous anatomical and electrophysiological data, we propose that these enkephalin-containing neurons could participate in the hyperpolarization of brainstem and spinal somatic motoneurons during paradoxical sleep.
- Published
- 2001
14. Origins of the glycinergic inputs to the rat locus coeruleus and dorsal raphe nuclei: a study combining retrograde tracing with glycine immunohistochemistry
- Author
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Rampon, C., Christelle Peyron, Gervasoni, D., Pow, D. V., Luppi, P. H., Fort, P., Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Team Physiopathologie des Réseaux Neuronaux Responsables du Cycle Veille-Sommeil, Centre de recherche en neurosciences de Lyon (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and University of Queensland [Brisbane]
- Subjects
[SDV]Life Sciences [q-bio] ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1999
15. Role of the dorsal paragigantocellular reticular nucleus in paradoxical (rapid eye movement) sleep generation: a combined electrophysiological and anatomical study in the rat
- Author
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Goutagny, R., primary, Luppi, P.-H., additional, Salvert, D., additional, Lapray, D., additional, Gervasoni, D., additional, and Fort, P., additional
- Published
- 2008
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16. Neuronal Activity in the Primary Somatosensory Thalamocortical Loop Is Modulated by Reward Contingency during Tactile Discrimination
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Pantoja, J., primary, Ribeiro, S., additional, Wiest, M., additional, Soares, E., additional, Gervasoni, D., additional, Lemos, N. A. M., additional, and Nicolelis, M. A. L., additional
- Published
- 2007
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17. Microwave generated nanocomposites for making insoluble drugs soluble
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Bergese, P., primary, Colombo, I., additional, Gervasoni, D., additional, and Depero, L.E., additional
- Published
- 2003
- Full Text
- View/download PDF
18. Assessment of the X-ray diffraction–absorption method for quantitative analysis of largely amorphous pharmaceutical composites
- Author
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Bergese, P., primary, Colombo, I., additional, Gervasoni, D., additional, and Depero, Laura E., additional
- Published
- 2003
- Full Text
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19. Effects of amphetamine and modafinil on the sleep/wake cycle during experimental hypersomnia induced by sleep deprivation in the cat
- Author
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Lin, J. S., primary, Gervasoni, D., additional, Hou, Y., additional, Vanni-Mercier, G., additional, Rambert, F., additional, Frydman, A., additional, and Jouvet, M., additional
- Published
- 2000
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20. Rôle de la glycine dans les mécanismes de genèse du sommeil paradoxal: approches neuroanatomiques et électrophysiologique chez le rat
- Author
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Fort, P., primary, Rampon, C., additional, Gervasoni, D., additional, Peyron, C., additional, and Luppi, P.H., additional
- Published
- 1998
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21. Rôle du GABA dans l'inactivation des neurones monoaminergiques au cours du sommeil
- Author
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Luppi, P.H., primary, Gervasoni, D., additional, Peyron, C., additional, Rampon, C., additional, and Fort, P., additional
- Published
- 1998
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22. Electrophysiological evidence that noradrenergic neurons of the rat locus coeruleus are tonically inhibited by GABA during sleep
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Gervasoni, D., primary, Darracq, L., additional, Fort, P., additional, Soulière, F., additional, Chouvet, G., additional, and Luppi, P‐H., additional
- Published
- 1998
- Full Text
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23. X-ray diffraction analysis of the polymorphic behaviour of nimesulide loaded into crospovidone
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Bergese, Paolo, Elza Bontempi, Colombo, I., Gervasoni, D., and Laura Eleonora Depero
24. EMD-based analysis of rat EEG data for sleep state classification
- Author
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Baykut, S., Goncalves, P., Luppi, P. -H, Patrice Abry, Souza Neto, E. P., Gervasoni, D., Laboratoire de l'Informatique du Parallélisme (LIP), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), Physio-pathologie des réseaux neuronaux du cycle veille-sommeil, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), Hôpital neurologique et neurochirurgical Pierre Wertheimer [CHU - HCL], Hospices Civils de Lyon (HCL), Department of Neurobiology, Duke University [Durham], Centre National de la Recherche Scientifique (CNRS)-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École normale supérieure - Lyon (ENS Lyon), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, and Gonçalves, Paulo
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[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,[INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing ,[SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing ,ComputingMilieux_MISCELLANEOUS ,[SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing - Abstract
International audience
25. Improving Stereotaxic Neurosurgery Techniques and Procedures Greatly Reduces the Number of Rats Used per Experimental Group-A Practice Report.
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Ferry B and Gervasoni D
- Abstract
Techniques of stereotaxic surgery are commonly used in research laboratories by a range of students, technicians, and researchers. To meet the evolving requirements imposed by international legislation, and to promote the implementation of 3R rules (replacement, reduction, and refinement) by reducing experimental error, animal morbidity, and mortality, it is essential that standard operating procedures and proper conduct following such complex surgeries be precisely described and respected. The present report shows how refinements of our own neurosurgical techniques over decades, have significantly reduced the number of animals (rats) used in experiments and improved the animals' well-being during the post-surgical recovery period. The current pre-, per-, and post-surgical procedures used in our laboratory are detailed. We describe the practical aspects of stereotaxic neurosurgery that have been refined in our laboratory since 1992 and that cover various areas including appropriate anesthesia and pain management during and after surgery, methods to determine the stereotaxic coordinates, and the best approach to the target brain structure. The application of these optimal surgical methods that combine reliable and reproducible results with an acute awareness of ethics and animal welfare leads to a significant reduction in the number of animals included in experimental research in accordance with ethical and regulatory rules as required by the European Directive on laboratory animal welfare.
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- 2021
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26. Adaptive quantization of local field potentials for wireless implants in freely moving animals: an open-source neural recording device.
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Martinez D, Clément M, Messaoudi B, Gervasoni D, Litaudon P, and Buonviso N
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- Animals, Equipment Design instrumentation, Equipment Design methods, Equipment Design trends, Male, Rats, Rats, Sprague-Dawley, Telemetry methods, Telemetry trends, Wireless Technology trends, Adaptation, Physiological physiology, Brain physiology, Electrodes, Implanted trends, Neurons physiology, Telemetry instrumentation, Wireless Technology instrumentation
- Abstract
Objective: Modern neuroscience research requires electrophysiological recording of local field potentials (LFPs) in moving animals. Wireless transmission has the advantage of removing the wires between the animal and the recording equipment but is hampered by the large number of data to be sent at a relatively high rate., Approach: To reduce transmission bandwidth, we propose an encoder/decoder scheme based on adaptive non-uniform quantization. Our algorithm uses the current transmitted codeword to adapt the quantization intervals to changing statistics in LFP signals. It is thus backward adaptive and does not require the sending of side information. The computational complexity is low and similar at the encoder and decoder sides. These features allow for real-time signal recovery and facilitate hardware implementation with low-cost commercial microcontrollers., Main Results: As proof-of-concept, we developed an open-source neural recording device called NeRD. The NeRD prototype digitally transmits eight channels encoded at 10 kHz with 2 bits per sample. It occupies a volume of 2 × 2 × 2 cm
3 and weighs 8 g with a small battery allowing for 2 h 40 min of autonomy. The power dissipation is 59.4 mW for a communication range of 8 m and transmission losses below 0.1%. The small weight and low power consumption offer the possibility of mounting the entire device on the head of a rodent without resorting to a separate head-stage and battery backpack. The NeRD prototype is validated in recording LFPs in freely moving rats at 2 bits per sample while maintaining an acceptable signal-to-noise ratio (>30 dB) over a range of noisy channels., Significance: Adaptive quantization in neural implants allows for lower transmission bandwidths while retaining high signal fidelity and preserving fundamental frequencies in LFPs.- Published
- 2018
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27. Neuronal dynamics supporting formation and recombination of cross-modal olfactory-tactile association in the rat hippocampal formation.
- Author
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Boisselier L, Gervasoni D, Garcia S, Ferry B, and Gervais R
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- Animals, Beta Rhythm, Discrimination, Psychological physiology, Entorhinal Cortex physiology, Male, Piriform Cortex physiology, Rats, Wistar, Theta Rhythm, Hippocampus physiology, Neurons physiology, Olfactory Perception physiology, Reward, Touch Perception physiology
- Abstract
The present study is aimed at describing some aspects of the neural dynamics supporting discrimination of olfactory-tactile paired-associated stimuli during acquisition of new pairs and during recombination of previously learned pairs in the rat. To solve the task, animals have to identify one odor-texture (OT) combination associated with a food reward among three cups with overlapping elements. Previous experiments demonstrated that the lateral entorhinal cortex (LEC) is involved in the processes underlying OT acquisition, whereas the dorsal hippocampus (DH) is selectively involved in the recombination processes. In the present study, local field potentials were recorded form the anterior piriform cortex (aPC), LEC, and DH in freely moving rats performing these tasks. Signal analysis focused on theta (5-12 Hz)- and beta-band (15-40 Hz) oscillatory activities in terms of both amplitude and synchrony. The results show that cue sampling was associated with a significant increase in the beta-band activity during the choice period in both the aPC and the LEC, and is modulated by level of expertise and the animal's decision. In addition, this increase was significantly higher during the recombination compared with the acquisition of the OT task, specifically when animals had to neglect the odor previously associated with the reward. Finally, a significant decrease in coherence in the theta band between LEC and DH was observed in the recombination but not in the acquisition task. These data point to specific neural signatures of simple and complex cross-modal sensory processing in the LEC-DH complex. NEW & NOTEWORTHY This study is the first to describe electrophysiological correlates of cross-modal olfactory-tactile integration in rats. Recordings were sought from the lateral entorhinal cortex and the dorsal hippocampus because previous studies have shown their role in the formation and in the recombination of previously learned associations. We identified specific oscillatory-evoked neural responses in these structures in the theta and beta bands, which characterize acquisition and recombination of cross-modal olfactory-tactile pairs.
- Published
- 2018
- Full Text
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28. Unsupervised online classifier in sleep scoring for sleep deprivation studies.
- Author
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Libourel PA, Corneyllie A, Luppi PH, Chouvet G, and Gervasoni D
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- Algorithms, Animals, Bayes Theorem, Male, Rats, Rats, Sprague-Dawley, Sensitivity and Specificity, Sleep Deprivation diagnosis, Electroencephalography methods, Polysomnography methods, Sleep physiology, Sleep Deprivation physiopathology, Wakefulness physiology
- Abstract
Study Objective: This study was designed to evaluate an unsupervised adaptive algorithm for real-time detection of sleep and wake states in rodents., Design: We designed a Bayesian classifier that automatically extracts electroencephalogram (EEG) and electromyogram (EMG) features and categorizes non-overlapping 5-s epochs into one of the three major sleep and wake states without any human supervision. This sleep-scoring algorithm is coupled online with a new device to perform selective paradoxical sleep deprivation (PSD)., Settings: Controlled laboratory settings for chronic polygraphic sleep recordings and selective PSD., Participants: Ten adult Sprague-Dawley rats instrumented for chronic polysomnographic recordings., Measurements: The performance of the algorithm is evaluated by comparison with the score obtained by a human expert reader. Online detection of PS is then validated with a PSD protocol with duration of 72 hours., Results: Our algorithm gave a high concordance with human scoring with an average κ coefficient > 70%. Notably, the specificity to detect PS reached 92%. Selective PSD using real-time detection of PS strongly reduced PS amounts, leaving only brief PS bouts necessary for the detection of PS in EEG and EMG signals (4.7 ± 0.7% over 72 h, versus 8.9 ± 0.5% in baseline), and was followed by a significant PS rebound (23.3 ± 3.3% over 150 minutes)., Conclusions: Our fully unsupervised data-driven algorithm overcomes some limitations of the other automated methods such as the selection of representative descriptors or threshold settings. When used online and coupled with our sleep deprivation device, it represents a better option for selective PSD than other methods like the tedious gentle handling or the platform method., (© 2015 Associated Professional Sleep Societies, LLC.)
- Published
- 2015
- Full Text
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29. Role of the lateral paragigantocellular nucleus in the network of paradoxical (REM) sleep: an electrophysiological and anatomical study in the rat.
- Author
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Sirieix C, Gervasoni D, Luppi PH, and Léger L
- Subjects
- Animals, Brain Stem cytology, Brain Stem pathology, Disorders of Excessive Somnolence pathology, Disorders of Excessive Somnolence physiopathology, Male, Motor Neurons cytology, Motor Neurons pathology, Nerve Net cytology, Nerve Net pathology, Rats, Rats, Sprague-Dawley, Brain Stem anatomy & histology, Brain Stem physiology, Electrophysiological Phenomena, Nerve Net anatomy & histology, Nerve Net physiology, Sleep, REM physiology
- Abstract
The lateral paragigantocellular nucleus (LPGi) is located in the ventrolateral medulla and is known as a sympathoexcitatory area involved in the control of blood pressure. In recent experiments, we showed that the LPGi contains a large number of neurons activated during PS hypersomnia following a selective deprivation. Among these neurons, more than two-thirds are GABAergic and more than one fourth send efferent fibers to the wake-active locus coeruleus nucleus. To get more insight into the role of the LPGi in PS regulation, we combined an electrophysiological and anatomical approach in the rat, using extracellular recordings in the head-restrained model and injections of tracers followed by the immunohistochemical detection of Fos in control, PS-deprived and PS-recovery animals. With the head-restrained preparation, we showed that the LPGi contains neurons specifically active during PS (PS-On neurons), neurons inactive during PS (PS-Off neurons) and neurons indifferent to the sleep-waking cycle. After injection of CTb in the facial nucleus, the neurons of which are hyperpolarized during PS, the largest population of Fos/CTb neurons visualized in the medulla in the PS-recovery condition was observed in the LPGi. After injection of CTb in the LPGi itself and PS-recovery, the nucleus containing the highest number of Fos/CTb neurons, moreover bilaterally, was the sublaterodorsal nucleus (SLD). The SLD is known as the pontine executive PS area and triggers PS through glutamatergic neurons. We propose that, during PS, the LPGi is strongly excited by the SLD and hyperpolarizes the motoneurons of the facial nucleus in addition to local and locus coeruleus PS-Off neurons, and by this means contributes to PS genesis.
- Published
- 2012
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30. Brainstem mechanisms of paradoxical (REM) sleep generation.
- Author
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Luppi PH, Clement O, Sapin E, Peyron C, Gervasoni D, Léger L, and Fort P
- Subjects
- Animals, Humans, Models, Neurological, Nerve Net physiology, Brain Stem physiology, Sleep, REM physiology
- Abstract
Paradoxical sleep (PS) is characterized by EEG activation with a disappearance of muscle tone and the occurrence of rapid eye movements (REM) in contrast to slow-wave sleep (SWS, also known as non-REM sleep) identified by the presence of delta waves. Soon after the discovery of PS, it was demonstrated that the structures necessary and sufficient for its genesis are restricted to the brainstem. We review here recent results indicating that brainstem glutamatergic and GABAergic, rather than cholinergic and monoaminergic, neurons play a key role in the genesis of PS. We hypothesize that the entrance to PS from SWS is due to the activation of PS-on glutamatergic neurons localized in the pontine sublaterodorsal tegmental nucleus. The activation of these neurons would be due to a permanent glutamatergic input arising from the lateral and ventrolateral periaqueductal gray (vlPAG) and the removal at the onset of PS of a GABAergic inhibition present during W and SWS. Such inhibition would be coming from PS-off GABAergic neurons localized in the vlPAG and the adjacent deep mesencephalic reticular nucleus. The cessation of activity of these PS-off GABAergic neurons at the onset and during PS would be due to direct projections from intermingled GABAergic PS-on neurons. Activation of PS would depend on the reciprocal interactions between the GABAergic PS-on and PS-off neurons, intrinsic cellular and molecular events, and integration of multiple physiological parameters.
- Published
- 2012
- Full Text
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31. The neuronal network responsible for paradoxical sleep and its dysfunctions causing narcolepsy and rapid eye movement (REM) behavior disorder.
- Author
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Luppi PH, Clément O, Sapin E, Gervasoni D, Peyron C, Léger L, Salvert D, and Fort P
- Subjects
- Amygdala physiopathology, Animals, Brain Mapping, Cataplexy physiopathology, Emotions physiology, Glutamine physiology, Glycine physiology, Humans, Hypothalamus physiopathology, Medulla Oblongata physiopathology, Motor Neurons physiology, Muscle Tonus physiology, Neurodegenerative Diseases physiopathology, Neurons physiology, Parkinson Disease physiopathology, Pedunculopontine Tegmental Nucleus physiopathology, Pons physiopathology, Wakefulness physiology, gamma-Aminobutyric Acid physiology, Brain physiopathology, Narcolepsy physiopathology, Nerve Net physiopathology, REM Sleep Behavior Disorder physiopathology, Sleep, REM physiology
- Abstract
Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by the loss of muscle atonia during paradoxical (REM) sleep (PS). Conversely, cataplexy, one of the key symptoms of narcolepsy, is a striking sudden episode of muscle weakness triggered by emotions during wakefulness, and comparable to REM sleep atonia. The neuronal dysfunctions responsible for RBD and cataplexy are not known. In the present review, we present the most recent results on the neuronal network responsible for PS. Based on these results, we propose an updated integrated model of the mechanisms responsible for PS and explore different hypotheses explaining RBD and cataplexy. We propose that RBD is due to a specific degeneration of a sub-population of PS-on glutamatergic neurons specifically responsible of muscle atonia, localized in the caudal pontine sublaterodorsal tegmental nucleus (SLD). Another possibility is the occurrence in RBD patients of a specific lesion of the glycinergic/GABAergic pre-motoneurons localized in the medullary ventral gigantocellular reticular nucleus. Conversely, cataplexy in narcoleptics would be due to the activation during waking of the caudal PS-on SLD neurons responsible for muscle atonia. A phasic glutamatergic excitatory pathway from the central amygdala to the SLD PS-on neurons activated during emotion would induce such activation. In normal conditions, the glutamate excitation would be blocked by the simultaneous excitation by the hypocretins of the PS-off GABAergic neurons localized in the ventrolateral periaqueductal gray and the adjacent deep mesencephalic reticular nucleus, gating the activation of the PS-on SLD neurons., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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32. Sleep architecture of the melanin-concentrating hormone receptor 1-knockout mice.
- Author
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Adamantidis A, Salvert D, Goutagny R, Lakaye B, Gervasoni D, Grisar T, Luppi PH, and Fort P
- Subjects
- Animals, Homeostasis genetics, Male, Mice, Mice, Knockout, Mice, Transgenic, Receptors, Somatostatin antagonists & inhibitors, Receptors, Somatostatin deficiency, Receptors, Somatostatin genetics, Sleep genetics, Wakefulness genetics, Receptors, Somatostatin physiology, Sleep physiology
- Abstract
Growing amounts of data indicate involvement of the posterior hypothalamus in the regulation of sleep, especially paradoxical sleep (PS). Accordingly, we previously showed that the melanin-concentrating hormone (MCH)-producing neurons of the rat hypothalamus are selectively activated during a PS rebound. In addition, intracerebroventricular infusion of MCH increases total sleep duration, suggesting a new role for MCH in sleep regulation. To determine whether activation of the MCH system promotes sleep, we studied spontaneous sleep and its homeostatic regulation in mice with deletion of the MCH-receptor 1 gene (MCH-R1-/- vs. MCH-R1+/+) and their behavioural response to modafinil, a powerful antinarcoleptic drug. Here, we show that the lack of functional MCH-R1 results in a hypersomniac-like phenotype, both in basal conditions and after total sleep deprivation, compared to wild-type mice. Further, we found that modafinil was less potent at inducing wakefulness in MCH-R1-/- than in MCH-R1+/+ mice. We report for the first time that animals with genetically inactivated MCH signaling exhibit altered vigilance state architecture and sleep homeostasis. This study also suggests that the MCH system may modulate central pathways involved in the wake-promoting effect of modafinil.
- Published
- 2008
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33. Novel experience induces persistent sleep-dependent plasticity in the cortex but not in the hippocampus.
- Author
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Ribeiro S, Shi X, Engelhard M, Zhou Y, Zhang H, Gervasoni D, Lin SC, Wada K, Lemos NA, and Nicolelis MA
- Abstract
Episodic and spatial memories engage the hippocampus during acquisition but migrate to the cerebral cortex over time. We have recently proposed that the interplay between slow-wave (SWS) and rapid eye movement (REM) sleep propagates recent synaptic changes from the hippocampus to the cortex. To test this theory, we jointly assessed extracellular neuronal activity, local field potentials (LFP), and expression levels of plasticity-related immediate-early genes (IEG) arc and zif-268 in rats exposed to novel spatio-tactile experience. Post-experience firing rate increases were strongest in SWS and lasted much longer in the cortex (hours) than in the hippocampus (minutes). During REM sleep, firing rates showed strong temporal dependence across brain areas: cortical activation during experience predicted hippocampal activity in the first post-experience hour, while hippocampal activation during experience predicted cortical activity in the third post-experience hour. Four hours after experience, IEG expression was specifically upregulated during REM sleep in the cortex, but not in the hippocampus. Arc gene expression in the cortex was proportional to LFP amplitude in the spindle-range (10-14 Hz) but not to firing rates, as expected from signals more related to dendritic input than to somatic output. The results indicate that hippocampo-cortical activation during waking is followed by multiple waves of cortical plasticity as full sleep cycles recur. The absence of equivalent changes in the hippocampus may explain its mnemonic disengagement over time.
- Published
- 2007
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34. Fast modulation of prefrontal cortex activity by basal forebrain noncholinergic neuronal ensembles.
- Author
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Lin SC, Gervasoni D, and Nicolelis MA
- Subjects
- Animals, Autonomic Nervous System cytology, Cell Size, Data Interpretation, Statistical, Electric Stimulation, Electrodes, Implanted, Electrophysiology, Female, Microelectrodes, Neurons ultrastructure, Prefrontal Cortex cytology, Principal Component Analysis, Prosencephalon cytology, Rats, Sleep physiology, Sleep, REM physiology, Wakefulness physiology, Autonomic Nervous System physiology, Neurons physiology, Prefrontal Cortex physiology, Prosencephalon physiology
- Abstract
Traditionally, most basal forebrain (BF) functions have been attributed to its cholinergic neurons. However, the majority of cortical-projecting BF neurons are noncholinergic and their in vivo functions remain unclear. We investigated how BF modulates cortical dynamics by simultaneously recording =50 BF single neurons along with local field potentials (LFPs) from the prefrontal cortex (PFCx) in different wake-sleep states of adult rats. Using stereotypical spike time correlations, we identified a large (roughly 70%) subset of BF neurons, which we named BF tonic neurons (BFTNs). BFTNs fired tonically at 2-8 Hz without significantly changing their average firing rate across wake-sleep states. As such, these cannot be classified as cholinergic neurons. BFTNs substantially increased the spiking variability during waking and rapid-eye-movement sleep, by exhibiting frequent spike bursts with <50-ms interspike interval. Spike bursts among BFTNs were highly correlated, leading to transient population synchronization events of BFTN ensembles that lasted on average 160 ms. Most importantly, BFTN synchronization occurred preferentially just before the troughs of PFCx LFP oscillations, which reflect increased cortical activity. Furthermore, BFTN synchronization was accompanied by transient increases in prefrontal cortex gamma oscillations. These results suggest that synchronization of BFTN ensembles, which are likely to be formed by cortical-projecting GABAergic neurons from the BF, could be primarily responsible for fast cortical modulations to provide transient amplification of cortical activity.
- Published
- 2006
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35. Paradoxical (REM) sleep genesis: the switch from an aminergic-cholinergic to a GABAergic-glutamatergic hypothesis.
- Author
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Luppi PH, Gervasoni D, Verret L, Goutagny R, Peyron C, Salvert D, Leger L, and Fort P
- Subjects
- Animals, Brain Stem cytology, Brain Stem physiology, Humans, Neural Networks, Computer, Neural Pathways physiology, Neurons physiology, Acetylcholine metabolism, Amines metabolism, Glutamic Acid metabolism, Models, Biological, Sleep, REM physiology, gamma-Aminobutyric Acid metabolism
- Abstract
In the middle of the last century, Michel Jouvet discovered paradoxical sleep (PS), a sleep phase paradoxically characterized by cortical activation and rapid eye movements and a muscle atonia. Soon after, he showed that it was still present in "pontine cats" in which all structures rostral to the brainstem have been removed. Later on, it was demonstrated that the pontine peri-locus coeruleus alpha (peri-LCalpha in cats, corresponding to the sublaterodorsal nucleus, SLD, in rats) is responsible for PS onset. It was then proposed that the onset and maintenance of PS is due to a reciprocal inhibitory interaction between neurons presumably cholinergic specifically active during PS localized in this region and monoaminergic neurons. In the last decade, we have tested this hypothesis with our model of head-restrained rats and functional neuroanatomical studies. Our results confirmed that the SLD in rats contains the neurons responsible for the onset and maintenance of PS. They further indicate that (1) these neurons are non-cholinergic possibly glutamatergic neurons, (2) they directly project to the glycinergic premotoneurons localized in the medullary ventral gigantocellular reticular nucleus (GiV), (3) the main neurotransmitter responsible for their inhibition during waking (W) and slow wave sleep (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 in the deep mesencephalic reticular nucleus (DPMe). We also showed that the tonic inhibition of locus coeruleus (LC) noradrenergic and dorsal raphe (DRN) serotonergic neurons during sleep is due to a tonic GABAergic inhibition by neurons localized in the dorsal paragigantocellular reticular nucleus (DPGi) and the ventrolateral periaqueductal gray (vlPAG). We propose that these GABAergic neurons also inhibit the GABAergic neurons of the DPMe at the onset and during PS and are therefore responsible for the onset and maintenance of PS.
- Published
- 2006
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36. Localization of the neurons active during paradoxical (REM) sleep and projecting to the locus coeruleus noradrenergic neurons in the rat.
- Author
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Verret L, Fort P, Gervasoni D, Léger L, and Luppi PH
- Subjects
- Animals, Cholera Toxin metabolism, Locus Coeruleus metabolism, Male, Neural Pathways metabolism, Neurons cytology, Proto-Oncogene Proteins c-fos metabolism, Rats, Rats, Sprague-Dawley, Sleep Deprivation, Locus Coeruleus cytology, Neural Pathways anatomy & histology, Neurons metabolism, Norepinephrine metabolism, Sleep, REM physiology
- Abstract
Locus coeruleus (LC) noradrenergic neurons are active during wakefulness, slow their discharge rate during slow wave sleep, and stop firing during paradoxical sleep (PS). A large body of data indicates that their inactivation during PS is due to a tonic GABAergic inhibition. To localize the neurons responsible for such inhibition, we first examined the distribution of retrogradely and Fos double-immunostained neurons following cholera toxin b subunit (CTb) injection in the LC of control rats, rats selectively deprived of PS for 3 days, and rats allowed to recover for 3 hours from such deprivation. We found a significant number of CTb/Fos double-labeled cells only in the recovery group. The largest number of CTb/Fos double-labeled cells was found in the dorsal paragigantocellular reticular nucleus (DPGi). It indeed contained 19% of the CTb/Fos double-labeled neurons, whereas the ventrolateral periaqueductal gray (vlPAG) contained 18.3% of these neurons, the lateral paragigantocellular reticular nucleus (LPGi) 15%, the lateral hypothalamic area 9%, the lateral PAG 6.7%, and the rostral PAG 6%. In addition, CTb/Fos double-labeled cells constituted 43% of all the singly CTb-labeled cells counted in the DPGi compared with 29% for the LPGi, 18% for the rostral PAG, and 10% or less for the other structures. Although all these populations of CTb/Fos double-labeled neurons could be GABAergic and tonically inhibit LC neurons during PS, our results indicate that neurons from the DPGi constitute the best candidate for this role., (Copyright 2006 Wiley-Liss, Inc.)
- Published
- 2006
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37. GABAergic control of hypothalamic melanin-concentrating hormone-containing neurons across the sleep-waking cycle.
- Author
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Goutagny R, Luppi PH, Salvert D, Gervasoni D, and Fort P
- Subjects
- Animals, Electroencephalography methods, GABA Antagonists pharmacology, GABA-A Receptor Antagonists, Hypothalamus drug effects, Male, Neurons drug effects, Rats, Rats, Sprague-Dawley, Sleep Stages drug effects, Wakefulness drug effects, Hypothalamic Hormones physiology, Hypothalamus physiology, Melanins physiology, Neurons physiology, Pituitary Hormones physiology, Receptors, GABA-A physiology, Sleep Stages physiology, Wakefulness physiology
- Abstract
The perifornical-lateral hypothalamic area is implicated in regulating waking and paradoxical sleep. The blockade of GABAA receptors by iontophoretic applications of bicuculline (or gabazine) into the perifornical-lateral hypothalamic area induced a continuous quiet waking state associated to a robust muscle tone in head-restrained rats. During the effects, sleep was totally suppressed. In rats killed at the end of a 90 min ejection of bicuculline, Fos expression was induced in approximately 28% of the neurons immunoreactive for hypocretin and in approximately 3% of the neurons immunostained for melanin-concentrating hormone within the ejection site. These results suggest that neurons containing melanin-concentrating hormone are not active during waking and that the lack of a potent GABAergic influence during waking is consistent with their role in sleep regulation.
- Published
- 2005
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38. Global forebrain dynamics predict rat behavioral states and their transitions.
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Gervasoni D, Lin SC, Ribeiro S, Soares ES, Pantoja J, and Nicolelis MA
- Subjects
- Animals, Hippocampus physiology, Male, Membrane Potentials physiology, Neostriatum physiology, Rats, Rats, Long-Evans, Somatosensory Cortex physiology, Ventral Thalamic Nuclei physiology, Behavior, Animal physiology, Prosencephalon physiology, Sleep physiology, Wakefulness physiology
- Abstract
The wake-sleep cycle, a spontaneous succession of global brain states that correspond to major overt behaviors, occurs in all higher vertebrates. The transitions between these states, at once rapid and drastic, remain poorly understood. Here, intracranial local field potentials (LFPs) recorded in the cortex, hippocampus, striatum, and thalamus were used to characterize the neurophysiological correlates of the rat wake-sleep cycle. By way of a new method for the objective classification and quantitative investigation of all major brain states, we demonstrate that global brain state transitions occur simultaneously across multiple forebrain areas as specific spectral trajectories with characteristic path, duration, and coherence bandwidth. During state transitions, striking changes in neural synchronization are effected by the prominent narrow-band LFP oscillations that mark state boundaries. Our results demonstrate that distant forebrain areas tightly coordinate the processing of neural information during and between global brain states, indicating a very high degree of functional integration across the entire wake-sleep cycle. We propose that transient oscillatory synchronization of synaptic inputs, which underlie the rapid switching of global brain states, may facilitate the exchange of information within and across brain areas at the boundaries of very distinct neural processing regimens.
- Published
- 2004
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39. Brainstem structures responsible for paradoxical sleep onset and maintenance.
- Author
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Luppi PH, Gervasoni D, Boissard R, Verret L, Goutagny R, Peyron C, Salvert D, Leger L, Barbagli B, and Fort P
- Subjects
- Animals, Brain Stem anatomy & histology, Humans, Models, Neurological, Neural Inhibition physiology, Neural Pathways anatomy & histology, Rats, Reticular Formation anatomy & histology, Reticular Formation physiology, Brain Stem physiology, Neural Pathways physiology, Neurotransmitter Agents physiology, Sleep, REM physiology
- Abstract
This paper is dedicated to our mentor, Michel Jouvet who inspired our career and transmitted to us his passion for the study of the mechanisms responsible for paradoxical sleep genesis and also that of its still mysterious functions. We expose in the following the progresses in the knowledge in this field brought during 40 years by Michel Jouvet and his team and more recently by the members of a new CNRS laboratory in which we aim to pursue in the path opened by Michel Jouvet.
- Published
- 2004
40. Long-lasting novelty-induced neuronal reverberation during slow-wave sleep in multiple forebrain areas.
- Author
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Ribeiro S, Gervasoni D, Soares ES, Zhou Y, Lin SC, Pantoja J, Lavine M, and Nicolelis MA
- Subjects
- Animals, Behavior, Animal, Cerebral Cortex metabolism, Electrophysiology, Hippocampus metabolism, Male, Models, Neurological, Models, Statistical, Neurons metabolism, Putamen metabolism, Rats, Rats, Long-Evans, Statistics as Topic, Thalamus metabolism, Time Factors, Prosencephalon metabolism, Sleep, Sleep, REM
- Abstract
The discovery of experience-dependent brain reactivation during both slow-wave (SW) and rapid eye-movement (REM) sleep led to the notion that the consolidation of recently acquired memory traces requires neural replay during sleep. To date, however, several observations continue to undermine this hypothesis. To address some of these objections, we investigated the effects of a transient novel experience on the long-term evolution of ongoing neuronal activity in the rat forebrain. We observed that spatiotemporal patterns of neuronal ensemble activity originally produced by the tactile exploration of novel objects recurred for up to 48 h in the cerebral cortex, hippocampus, putamen, and thalamus. This novelty-induced recurrence was characterized by low but significant correlations values. Nearly identical results were found for neuronal activity sampled when animals were moving between objects without touching them. In contrast, negligible recurrence was observed for neuronal patterns obtained when animals explored a familiar environment. While the reverberation of past patterns of neuronal activity was strongest during SW sleep, waking was correlated with a decrease of neuronal reverberation. REM sleep showed more variable results across animals. In contrast with data from hippocampal place cells, we found no evidence of time compression or expansion of neuronal reverberation in any of the sampled forebrain areas. Our results indicate that persistent experience-dependent neuronal reverberation is a general property of multiple forebrain structures. It does not consist of an exact replay of previous activity, but instead it defines a mild and consistent bias towards salient neural ensemble firing patterns. These results are compatible with a slow and progressive process of memory consolidation, reflecting novelty-related neuronal ensemble relationships that seem to be context- rather than stimulus-specific. Based on our current and previous results, we propose that the two major phases of sleep play distinct and complementary roles in memory consolidation: pretranscriptional recall during SW sleep and transcriptional storage during REM sleep., Competing Interests: The authors have declared that no conflicts of interest exist.
- Published
- 2004
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41. Localization of the GABAergic and non-GABAergic neurons projecting to the sublaterodorsal nucleus and potentially gating paradoxical sleep onset.
- Author
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Boissard R, Fort P, Gervasoni D, Barbagli B, and Luppi PH
- Subjects
- Animals, Cholera Toxin metabolism, Electroencephalography, Electromyography, Immunohistochemistry, Iontophoresis, Male, Medulla Oblongata anatomy & histology, Medulla Oblongata physiology, Neural Pathways metabolism, Neurons classification, Phytohemagglutinins pharmacokinetics, Rats, Rats, Sprague-Dawley, Sleep, REM drug effects, gamma-Aminobutyric Acid metabolism, Glutamate Decarboxylase metabolism, Medulla Oblongata metabolism, Neural Pathways anatomy & histology, Neurons metabolism, Sleep, REM physiology
- Abstract
We recently determined in rats that iontophoretic application of bicuculline or gabazine [two GABAa antagonists] and kainic acid (a glutamate agonist) in the sublaterodorsal nucleus (SLD) induces with a very short latency a paradoxical sleep-like state. From these results, we proposed that GABAergic and glutamatergic inputs to the SLD paradoxical sleep (PS)-executive neurons gate the onset of PS [R. Boissard et al. (2002) Eur. J. Neurosci., 16, 1959-1973]. We therefore decided to determine the origin of the GABAergic and non-GABAergic inputs to the SLD combining ejection of a retrograde tracer [cholera-toxin B subunit (CTb)] with glutamate decarboxylase (GAD) immunohistochemistry. The presence of GAD-immunoreactive neurons in the SLD was confirmed. Then, following CTb ejections centred on the SLD, combined with GAD and CTb immunohistochemistry, double-labelled cells were observed in the mesencephalic and pontine reticular nuclei and to a lesser extent the parvicellular reticular nucleus. A large number of GAD-negative retrogradely labelled cells was also seen in these structures as well as in the primary motor area of the frontal cortex, the central nucleus of the amygdala, the ventral and lateral bed nucleus of the stria terminalis, the lateral hypothalamic area, the lateral and ventrolateral periaqueductal grey and the lateral paragigantocellular reticular nucleus. From these results, we propose that the activation of PS-executive neurons from the SLD is due to the removal of a tonic inhibition from GABAergic neurons localized in the SLD, and the mesencephalic and pontine reticular nuclei. Strong non-GABAergic inputs to the SLD could be excitatory and responsible for the tonic glutamatergic input on the PS-on neurons we have previously described. They could also terminate on SLD GABAergic interneurons and be indirectly responsible for the inhibition of the PS-on neurons during waking and slow-wave sleep.
- Published
- 2003
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42. The rat ponto-medullary network responsible for paradoxical sleep onset and maintenance: a combined microinjection and functional neuroanatomical study.
- Author
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Boissard R, Gervasoni D, Schmidt MH, Barbagli B, Fort P, and Luppi PH
- Subjects
- Animals, Bicuculline pharmacology, Carbachol pharmacology, Choline O-Acetyltransferase analysis, Cholinergic Agonists pharmacology, Efferent Pathways anatomy & histology, Electroencephalography, Electromyography, Excitatory Amino Acid Agonists pharmacology, Excitatory Amino Acid Antagonists pharmacology, GABA Antagonists pharmacology, Immunohistochemistry, Kainic Acid pharmacology, Kynurenic Acid pharmacology, Male, Medulla Oblongata drug effects, Phytohemagglutinins analysis, Pons drug effects, Proto-Oncogene Proteins c-fos analysis, Pyridazines pharmacology, Rats, Rats, Sprague-Dawley, Tegmentum Mesencephali anatomy & histology, Tegmentum Mesencephali physiology, Wakefulness drug effects, Medulla Oblongata anatomy & histology, Medulla Oblongata physiology, Pons anatomy & histology, Pons physiology, Sleep, REM drug effects, Sleep, REM physiology
- Abstract
The neuronal network responsible for paradoxical sleep (PS) onset and maintenance has not previously been identified in the rat, unlike the cat. To fill this gap, this study has developed a new technique involving the recording of sleep-wake states in unanaesthetized head-restrained rats whilst locally administering pharmacological agents by microiontophoresis from glass multibarrel micropipettes, into the dorsal pontine tegmentum and combining this with functional neuroanatomy. Pharmacological agents used for iontophoretic administration included carbachol, kainic acid, bicuculline and gabazine. The injection sites and their efferents were then identified by injections of anterograde (phaseolus vulgaris leucoagglutinin) or retrograde (cholera toxin B subunit) tracers through an adjacent barrel of the micropipette assembly and by C-Fos immunostaining. Bicuculline, gabazine and kainic acid ejections specifically into the pontine sublaterodorsal nucleus (SLD) induced within a few minutes a PS-like state characterized by a continuous muscle atonia, low voltage EEG and a lack of reaction to stimuli. In contrast, carbachol ejections into the SLD induced wakefulness. In PHA-L, glycine and C-Fos multiple double-labelling experiments, anterogradely labelled fibres originating from the SLD were seen apposed on glycine and C-Fos positive neurons (labelled after 90 min of pharmacologically induced PS-like state) from the ventral gigantocellular and parvicellular reticular nuclei. Altogether, these data indicate that the SLD nuclei contain a population of neurons playing a crucial role in PS onset and maintenance. Furthermore, they suggest that GABAergic disinhibition and glutamate excitation of these neurons might also play a crucial role in the onset of PS.
- Published
- 2002
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43. The switch of subthalamic neurons from an irregular to a bursting pattern does not solely depend on their GABAergic inputs in the anesthetic-free rat.
- Author
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Urbain N, Rentéro N, Gervasoni D, Renaud B, and Chouvet G
- Subjects
- Action Potentials drug effects, Action Potentials physiology, Animals, Circadian Rhythm physiology, Electroencephalography drug effects, Electromyography, GABA Agonists pharmacology, GABA Antagonists pharmacology, GABA-A Receptor Agonists, GABA-A Receptor Antagonists, GABA-B Receptor Agonists, GABA-B Receptor Antagonists, Iontophoresis, Male, Neurons drug effects, Periodicity, Rats, Rats, Sprague-Dawley, Receptors, GABA-A metabolism, Sleep physiology, Subthalamic Nucleus cytology, Subthalamic Nucleus drug effects, Synaptic Transmission drug effects, Wakefulness physiology, gamma-Aminobutyric Acid administration & dosage, Neurons physiology, Subthalamic Nucleus physiology, Synaptic Transmission physiology, gamma-Aminobutyric Acid metabolism
- Abstract
The subthalamic nucleus (STN) powerfully controls basal ganglia outputs and has been implicated in movement disorders observed in Parkinson's disease because of its pathological mixed burst firing mode and hyperactivity. A recent study suggested that reciprocally connected glutamatergic STN and GABAergic globus pallidus (GP) neurons act in vitro as a generator of bursting activity in basal ganglia. In vivo, we reported that GP neurons increased their firing rate in wakefulness (W) compared with slow-wave sleep (SWS) without any change in their random pattern. In contrast, STN neurons exhibited similar firing rates in W and SWS, with an irregular pattern in W and a bursty one in SWS. Thus, the pallidal GABAergic tone might control the STN pattern. This hypothesis was tested by mimicking such variations with microiontophoresis of GABA receptor ligands. GABA agonists specifically decreased the STN firing rate but did not affect its firing pattern. GABA(A) (but not GABA(B)) antagonists strongly enhanced the STN mean discharge rate during all vigilance states up to three to five times its basal activity. However, such applications did not change the typical W random pattern. When applied during SWS, GABA(A) antagonists strongly reinforced the spontaneous bursty pattern into a particularly marked one with instantaneous frequencies reaching 500-600 Hz. SWS-W transitions occurring during ongoing antagonist iontophoresis invariably disrupted the bursty pattern into a random one. Thus GABA(A) receptors play a critical, but not exclusive, role in regulating the excitatory STN influence on basal ganglia outputs.
- Published
- 2002
44. Unrelated course of subthalamic nucleus and globus pallidus neuronal activities across vigilance states in the rat.
- Author
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Urbain N, Gervasoni D, Soulière F, Lobo L, Rentéro N, Windels F, Astier B, Savasta M, Fort P, Renaud B, Luppi PH, and Chouvet G
- Subjects
- Animals, Circadian Rhythm physiology, Conditioning, Psychological physiology, Electroencephalography, Electromyography, Male, Neurons physiology, Rats, Rats, Sprague-Dawley, Restraint, Physical instrumentation, Sleep physiology, Sleep, REM physiology, Wakefulness physiology, Arousal physiology, Globus Pallidus cytology, Globus Pallidus physiology, Subthalamic Nucleus cytology, Subthalamic Nucleus physiology
- Abstract
The pallido-subthalamic pathway powerfully controls the output of the basal ganglia circuitry and has been implicated in movement disorders observed in Parkinson's disease (PD). To investigate the normal functioning of this pathway across the sleep-wake cycle, single-unit activities of subthalamic nucleus (STN) and globus pallidus (GP) neurons were examined, together with cortical electroencephalogram and nuchal muscular activity, in non-anaesthetized head-restrained rats. STN neurons shifted from a random discharge in wakefulness (W) to a bursting pattern in slow wave sleep (SWS), without any change in their mean firing rate. This burst discharge occurred in the 1-2 Hz range, but was not correlated with cortical slow wave activity. In contrast, GP neurons, with a mean firing rate higher in W than in SWS, exhibited a relatively regular discharge whatever the state of vigilance. During paradoxical sleep, both STN and GP neurons increased markedly their mean firing rate relative to W and SWS. Our results are not in agreement with the classical 'direct/indirect' model of the basal ganglia organization, as an inverse relationship between STN and GP activities is not observed under normal physiological conditions. Actually, because the STN discharge pattern appears dependent on coincident cortical activity, this nucleus can hardly be viewed as a relay along the indirect pathway, but might rather be considered as an input stage conveying corticothalamic information to the basal ganglia.
- Published
- 2000
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45. Single-unit and polygraphic recordings associated with systemic or local pharmacology: a multi-purpose stereotaxic approach for the awake, anaesthetic-free, and head-restrained rat.
- Author
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Soulière F, Urbain N, Gervasoni D, Schmitt P, Guillemort C, Fort P, Renaud B, Luppi PH, and Chouvet G
- Subjects
- Action Potentials drug effects, Action Potentials physiology, Anesthesia, Animals, Conditioning, Psychological, Electroencephalography instrumentation, Electromyography methods, Habituation, Psychophysiologic, Iontophoresis, Locus Coeruleus physiology, Male, Rats, Rats, Sprague-Dawley, Restraint, Physical instrumentation, Substantia Nigra physiology, gamma-Aminobutyric Acid pharmacology, Arousal physiology, Electroencephalography methods, Electromyography instrumentation, Stereotaxic Techniques
- Abstract
In order to avoid any artifactual pharmacological interferences with anaesthetic agents, a procedure has been developed for working on the awake, anaesthetic-free rat in a head-restrained condition. It allows, on the same animal and over several consecutive days, single-unit recordings in combination with systemic or local pharmacology (microiontophoresis or micropressure ejections), as well as monitoring vigilance states via the electroencephalogram and the electromyogram. After the cementing of a special "U"-shaped device on its skull under general anaesthesia, the animal is progressively habituated to stay daily, for several hours, under a painless corresponding stereotaxic restraint. This system can be easily adapted to different stereotaxic frames and, because of its spatial flexibility for targetting the desired rostrocaudal or lateral positions, allows access to a large number of cerebral structures. Experiments performed on Globus Pallidus, Substantia Nigra, and Locus Coeruleus neurons, combining the different possibilities of this system, are reported. They demonstrate, on the awake anaesthetic-free head-restrained rat, and under suitable ethical conditions, the feasibility of single-unit recordings of identified neurons associated with the study of their pharmacological reactivity after systemic or local drug administrations without any other drug interferences, and in physiologically relevant conditions such as the spontaneous alternance of vigilance states., (Copyright 2000 Wiley-Liss, Inc.)
- Published
- 2000
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46. Role and origin of the GABAergic innervation of dorsal raphe serotonergic neurons.
- Author
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Gervasoni D, Peyron C, Rampon C, Barbagli B, Chouvet G, Urbain N, Fort P, and Luppi PH
- Subjects
- Animals, Bicuculline, Cholera Toxin pharmacology, Electroencephalography drug effects, Electromyography drug effects, Electrophysiology, GABA Antagonists, Glutamate Decarboxylase metabolism, Immunohistochemistry, Iontophoresis, Male, Neurons metabolism, Patch-Clamp Techniques, Raphe Nuclei metabolism, Rats, Rats, Sprague-Dawley, Receptors, GABA-A drug effects, Sleep drug effects, Sleep physiology, Sleep, REM drug effects, Sleep, REM physiology, gamma-Aminobutyric Acid metabolism, gamma-Aminobutyric Acid pharmacology, Neurons physiology, Raphe Nuclei cytology, Raphe Nuclei physiology, Serotonin physiology, gamma-Aminobutyric Acid physiology
- Abstract
Extracellular electrophysiological recordings in freely moving cats have shown that serotonergic neurons from the dorsal raphe nucleus (DRN) fire tonically during wakefulness, decrease their activity during slow wave sleep (SWS), and are nearly quiescent during paradoxical sleep (PS). The mechanisms at the origin of the modulation of activity of these neurons are still unknown. Here, we show in the unanesthetized rat that the iontophoretic application of the GABA(A) antagonist bicuculline on dorsal raphe serotonergic neurons induces a tonic discharge during SWS and PS and an increase of discharge rate during quiet waking. These data strongly suggest that an increase of a GABAergic inhibitory tone present during wakefulness is responsible for the decrease of activity of the dorsal raphe serotonergic cells during slow wave and paradoxical sleep. In addition, by combining retrograde tracing with cholera toxin B subunit and glutamic acid decarboxylase immunohistochemistry, we demonstrate that the GABAergic innervation of the dorsal raphe nucleus arises from multiple distant sources and not only from interneurons as classically accepted. Among these afferents, GABAergic neurons located in the lateral preoptic area and the pontine ventral periaqueductal gray including the DRN itself could be responsible for the reduction of activity of the serotonergic neurons of the dorsal raphe nucleus during slow wave and paradoxical sleep, respectively.
- Published
- 2000
47. Origins of the glycinergic inputs to the rat locus coeruleus and dorsal raphe nuclei: a study combining retrograde tracing with glycine immunohistochemistry.
- Author
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Rampon C, Peyron C, Gervasoni D, Pow DV, Luppi PH, and Fort P
- Subjects
- Animals, Antibody Specificity, Cholera Toxin, Glycine immunology, Immunohistochemistry, Male, Neural Inhibition physiology, Neural Pathways, Norepinephrine analysis, Norepinephrine physiology, Periaqueductal Gray chemistry, Periaqueductal Gray cytology, Rats, Rats, Sprague-Dawley, Reticular Formation chemistry, Reticular Formation cytology, Serotonin analysis, Serotonin physiology, Sleep, REM physiology, Glycine analysis, Locus Coeruleus chemistry, Locus Coeruleus cytology, Raphe Nuclei chemistry, Raphe Nuclei cytology
- Abstract
The amino acid glycine is a major inhibitory neurotransmitter in the brainstem and is likely involved in the tonic inhibition of the monoaminergic neurons during all sleep-waking stages. In order to determine the neurons at the origin of the glycinergic innervation of the two principal monoaminergic nuclei, the locus coeruleus and the dorsal raphe of the rat, we applied a double-labelling technique, combining retrograde transport of cholera-toxin B subunit with glycine immunohistochemistry. Using this technique, we found that the locus coeruleus and dorsal raphe nuclei receive a common glycinergic innervation from the ventral and ventrolateral periaqueductal grey, including the adjacent deep mesencephalic reticular nucleus. Small additional glycinergic inputs to these nuclei originated from the lateral paragigantocellular nucleus and the rostral ventromedial medullary reticular formation. The potential role of these glycinergic inputs in the control of the excitability of the monoaminergic neurons of the locus coeruleus and dorsal raphe nuclei is discussed.
- Published
- 1999
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48. Anatomical demonstration of a medullary enkephalinergic pathway potentially implicated in the oro-facial muscle atonia of paradoxical sleep in the cat.
- Author
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Fort P, Rampon C, Gervasoni D, Peyron C, and Luppi PH
- Subjects
- Animals, Cats, Enkephalins metabolism, Female, Immunohistochemistry, Male, Methionine metabolism, Neural Pathways anatomy & histology, Neurons metabolism, Reticular Formation cytology, Facial Muscles innervation, Medulla Oblongata anatomy & histology, Medulla Oblongata physiology, Muscle Tonus physiology, Sleep, REM physiology
- Abstract
The present study was aimed to compare in detail the distribution within the rostral ventromedial medulla of Methionin-Enkephalin-immunoreactive neurons with efferent projections to the facial or trigeminal motor nuclei, using a double immunostaining technique in colchicine-treated cats. Following cholera toxin B subunit injections in the facial or trigeminal motor nuclei, we found that respectively 55% and 65% of the medium to large-sized retrogradely labeled cells in the lateral part of the nucleus reticularis magnocellularis were Methionin-Enkephalin-positive. For both motor nuclei, the double-labeled neurons had similar morphology and size and were located exactly in the same area. They could therefore belong to the same population of reticular enkephalinergic neurons. Based on these and previous anatomical and electrophysiological data, we propose that these enkephalin-containing neurons could participate in the hyperpolarization of brainstem and spinal somatic motoneurons during paradoxical sleep.
- Published
- 1998
49. Effect of strychnine on rat locus coeruleus neurones during sleep and wakefulness.
- Author
-
Darracq L, Gervasoni D, Soulière F, Lin JS, Fort P, Chouvet G, and Luppi PH
- Subjects
- Anesthesia, Animals, Electroencephalography, Electromyography, Electrophysiology, Iontophoresis, Locus Coeruleus drug effects, Polysomnography, Rats, Rats, Sprague-Dawley, Restraint, Physical, Glycine Agents pharmacology, Locus Coeruleus cytology, Neurons drug effects, Sleep physiology, Strychnine pharmacology, Wakefulness physiology
- Abstract
The noradrenergic neurones of the locus coeruleus (LC) discharge tonically during wakefulness, decrease their activity during slow wave sleep and are virtually quiescent during paradoxical sleep. We recently demonstrated an inhibitory glycinergic input to the locus coeruleus and proposed that this could be responsible for inhibition of the LC during paradoxical sleep. To test this proposal, we developed a method combining polygraphic recordings, iontophoresis and single-unit extracellular recordings in the unanaesthetized head-restrained rat. Iontophoretically applied strychnine, a specific glycine antagonist, induced strong excitation of LC neurones during paradoxical sleep, but also during slow wave sleep and wakefulness. These results suggest that glycine tonically inhibits noradrenergic LC neurones throughout the entire sleep-waking cycle and not only during paradoxical sleep.
- Published
- 1996
- Full Text
- View/download PDF
50. Origin of the glycinergic innervation of the rat trigeminal motor nucleus.
- Author
-
Rampon C, Peyron C, Petit JM, Fort P, Gervasoni D, and Luppi PH
- Subjects
- Animals, Cholera Toxin, Immunohistochemistry, Iontophoresis, Male, Rats, Rats, Sprague-Dawley, Trigeminal Nuclei anatomy & histology, Glycine physiology, Motor Neurons physiology, Trigeminal Nuclei physiology
- Abstract
In order to determine the localization of the glycinergic neurones responsible for the hyperpolarization of the rat trigeminal motoneurones during paradoxical sleep, we developed a new double immunohistochemical method combining the b subunit of the cholera toxin (CTb), a very sensitive retrograde tracer, with glycine immunohistochemistry. After iontophoretic injections of CTb into the trigeminal motor nucleus (Mo5), a large number of double-labelled cells was observed bilaterally in the parvocellular reticular nucleus alpha, dorsolateral to the descending branch of the facial nerve. A moderate number of double-labelled neurones was found in the ipsilateral parvocellular reticular nucleus at the level of the facial nucleus, and bilaterally in the raphe magnus and the gigantocellular reticular alpha nuclei. These results suggest that the glycinergic neurones hyperpolarizing the trigeminal motoneurons during paradoxical sleep might be localized in the parvocellular reticular nucleus alpha.
- Published
- 1996
- Full Text
- View/download PDF
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