A5082726463- Neuroscience and Neuropharmacology Research
- Vestibular and auditory disorders
- Ion channel regulation and function
- Neural dynamics and brain function
- Hearing, Cochlea, Tinnitus, Genetics
- Photoreceptor and optogenetics research
- Advanced Fluorescence Microscopy Techniques
- Nicotinic Acetylcholine Receptors Study
- Neuroscience and Neural Engineering
- Photoacoustic and Ultrasonic Imaging
- Cellular transport and secretion
- Neuroscience of respiration and sleep
- Digital Holography and Microscopy
- Optical Coherence Tomography Applications
- Cell Image Analysis Techniques
- Retinal Development and Disorders
- Lipid Membrane Structure and Behavior
- Mechanical and Optical Resonators
- Random lasers and scattering media
- Electrochemical sensors and biosensors
- EEG and Brain-Computer Interfaces
- Parasites and Host Interactions
- Epilepsy research and treatment
- Photonic and Optical Devices
- Mitochondrial Function and Pathology
Centre National de la Recherche Scientifique
2014-2024
Institut de Biologie de l'École Normale Supérieure
2014-2024
Inserm
2014-2024
Université Paris Sciences et Lettres
2018-2024
École Normale Supérieure - PSL
2012-2024
École Normale Supérieure
2012-2021
École Normale Supérieure d'Abidjan
2012-2021
Laboratoire de Géologie de l’École Normale Supérieure
1992-2008
Laboratoire de Neurobiologie Cellulaire et Moléculaire
2002-2007
Neurocentre Magendie
2000
Genetically encoded voltage indicators are emerging tools for monitoring dynamics with cell-type specificity. However, current enable a narrow range of applications due to poor performance under two-photon microscopy, method choice deep-tissue recording. To improve indicators, we developed multiparameter high-throughput platform optimize microscopy. Using this system, identified JEDI-2P, an indicator that is faster, brighter, and more sensitive photostable than its predecessors. We...
Corelease of GABA and glycine by mixed neurons is a prevalent mode inhibitory transmission in the vertebrate hindbrain. However, little known functional organization networks. Golgi cells, main interneurons cerebellar granular layer, have been shown to contain glycine. We show here that, vestibulocerebellum, cells contact both granule unipolar brush which are excitatory relay for vestibular afferences. Whereas IPSCs mediated A receptors only, cell inhibition dominated glycinergic currents....
1. Activation and desensitization of N‐methyl‐D‐aspartate (NMDA) receptors were studied in large outside‐out patches excised from cultured embryonic neurones dissociated mouse forebrain. The exposed to rapid changes NMDA or L‐glutamate concentrations the presence glycine at (10‐20 microM) saturating modulatory site receptor. 2. Immediately after formation patch responses showed a slow small desensitization, even with high agonist. During following hour, peak response either decreased...
Berger, Albert J., Stéphane Dieudonné, and Philippe Ascher. Glycine uptake governs glycine site occupancy at NMDA receptors of excitatory synapses. J. Neurophysiol. 80: 3336–3340, 1998. At central synapses occupation binding sites N-methyl-d-aspartate (NMDA-Rs) is a necessary prerequisite for the neurotransmitter glutamate to activate these receptors. There conflicting evidence as whether normally are saturated. If they not, then alterations in local concentration could modulate synaptic...
Significance The inferior olive, one of the major source inputs to cerebellum, sends climbing fibers Purkinje cells, key processing units cerebellar-dependent motor control. Using an optogenetic strategy, we demonstrate that cells disinhibit their climbing-fiber afferents via a poly-synaptic circuit. These findings identify functional closed-loop organization in olivo-cerebellar circuits is potentially important for cerebellar learning.
The cerebellum, a crucial center for motor coordination, is composed of cortex and several nuclei. main mode interaction between these two parts considered to be formed by the inhibitory control nuclei cortical Purkinje neurons. We now amend this view showing that GABA-glycinergic neurons cerebellar (CN) project profusely into cortex, where they make synaptic contacts on GABAergic subpopulation Golgi cells. These spontaneously firing cells are inhibited optogenetic activation nucleo-cortical...
An inhibitor causes neuronal excitation Glycine is thought to be primarily an inhibitory neurotransmitter. However, it also acts as a coagonist on excitatory N -methyl-D-aspartate (NMDA) receptors. Otsu et al. examined the function of NMDA receptor subunit combination GluN1/GluN3A in medial habenula (MHb) adult mice. This MHb neurons activated by glycine released from astrocytes. Activation receptors depolarization and increased spiking neurons. Reducing GluN3A levels blocks conditioned...
In the rat cerebellum, Golgi cells receive serotonin-evoked inputs from Lugaro (L-IPSCs), in addition to spontaneous inhibitory (S-IPSCs). present study, we analyze pharmacology of these IPSCs and show that S-IPSCs are purely GABAergic events occurring at basket stellate cell synapses, whereas L-IPSCs mediated by GABA glycine. Corelease two transmitters synapses is suggested fact both GABA(A) glycine receptors open during individual L-IPSCs. Double immunocytochemical stainings demonstrate...
The whole‐cell configuration of the patch clamp technique was used to record from Golgi cells in thin slices rat cerebellum (P12‐P25). Their active membrane properties and input that they receive parallel fibres were characterized. Most filled with biocytin morphologically identified by presence a large axonal arbor restricted granular layer. morphological parameters eighteen best‐preserved quantified. A slow capacitive current transient, characteristic cell axon, identify whenever their...
Disturbances of the serotoninergic neuromodulation in cerebellar cortex have been involved several types ataxia, but physiological action serotonin this structure remains poorly understood. We report that slices rat vermis, triggers firing an inhibitory interneuron presynaptic to Golgi cells. The Lugaro cell, a neglected interneuronal type, satisfies expected criteria for input, whereas basket cells, stellate or cells do not. are selectively excited by serotonin, and their behavior...
T-type voltage-gated calcium channels are expressed in the dendrites of many neurons, although their functional interactions with postsynaptic receptors and contributions to synaptic signaling not well understood. We combine electrophysiological ultrafast two-photon imaging demonstrate that mGluR1 activation potentiates cerebellar Purkinje cell Ca v 3.1 currents via a G-protein- tyrosine-phosphatase-dependent pathway. Immunohistochemical electron microscopic investigations on wild-type gene...
The function of inhibitory interneurons within brain microcircuits depends critically on the nature and properties their excitatory synaptic drive. Golgi cells (GoCs) cerebellum inhibit cerebellar granule (GrCs) are driven both by feedforward mossy fiber (mf) feedback GrC excitation. Here, we have characterized inputs to GoCs in rats mice. We show that, during sustained mf discharge, synapses from local GrCs contribute equivalent charge as synapses, arguing for importance inhibition....
In cerebellar Purkinje cell dendrites, heterosynaptic calcium signaling induced by the proximal climbing fiber (CF) input controls plasticity at distal parallel (PF) synapses. The substrate and regulation of this long-range dendritic are poorly understood. Using high-speed imaging, we examine role active conductances. Under basal conditions, CF stimulation evokes T-type displaying sharp proximodistal decrement. Combined mGluR1 receptor activation depolarization, two activity-dependent...
Synaptic currents display a large degree of heterogeneity their temporal characteristics, but the functional role such heterogeneities remains unknown. We investigated in rat cerebellar slices synaptic Unipolar Brush Cells (UBCs), which generate intrinsic mossy fibers relaying vestibular inputs to cortex. show that UBCs respond sinusoidal modulations sensory input with heterogeneous amplitudes and phase shifts. Experiments modeling indicate this variability results both from kinetics...
At the cerebellar synapse between parallel fibers (PFs) and Purkinje cells in cerebellum, we have found that application of N-methyl-d-aspartate (NMDA) reversibly depresses postsynaptic current. We present evidence this depression involves NMDA receptors located on presynaptic axons requires be combined with action potentials PFs. Unexpectedly, unlike other modulations mediated by receptors, NMDA-induced inhibition does not involve a transmitter release. Because it is blocked both nitric...
Numerous studies have shown that cerebellar function is related to the plasticity at synapses between parallel fibers and Purkinje cells. How specific input patterns determine outcomes, as well biophysics underlying of these synapses, remain unclear. Here, we characterize activity lead postsynaptically expressed LTP using both in vivo vitro experiments. Similar requirements LTD, find high-frequency bursts are necessary trigger this burst-dependent depends on presynaptic NMDA receptors nitric...
Acousto-optic deflection (AOD) devices offer unprecedented fast control of the entire spatial structure light beams, most notably their phase. AOD modulation ultra-short laser pulses, however, is not straightforward to implement because intrinsic chromatic dispersion and non-stationarity acousto-optic diffraction. While schemes exist compensate dispersion, remains an obstacle. In this work we demonstrate efficient modulator for stable phase using time-locked generation frequency-modulated...
The principal neurons of the cerebellar nuclei (CN), sole output olivo-cerebellar system, receive a massive inhibitory input from Purkinje cells (PCs) cortex. Morphological evidence suggests that CN are also contacted by interneurons, but properties this connection unknown. Using transgenic, tracing, and immunohistochemical approaches in mice, we show interneurons form large heterogeneous population with GABA/glycinergic phenotypes, distinct GABAergic olive-projecting neurons. found to...
Climbing fibers (CFs) provide instructive signals driving cerebellar learning, but mechanisms causing the variable CF responses in Purkinje cells (PCs) are not fully understood. Using a new experimentally validated PC model, we unveil ionic underlying CF-evoked distinct spike waveforms on different parts of PC. We demonstrate that voltage can gate both amplitude and spatial range Ca2+ influx by availability K+ currents. This makes energy consumed during complex (CS) also dependent. dendrites...
Significance Although membrane composition and tension modulate the activity of ion channels transporters, this protein–membrane coupling has been challenging to study due difficulty controlling properties in cells technical limitations existing vitro systems. This work demonstrates that whole-cell patch-clamp technique is stabilized by a dynamic passivation mechanism can be used control measure current voltage intact giant unilamellar vesicles (GUVs), cell-sized model biomimetic system...