Dynamique de l'activité corticale et mécanismes de codage

Leader

Research center

45 rue d’Ulm
75230 Paris
Marc Mézard

Institution

Ecole Normale Supérieure
Inserm
CNRS
ED158
Université Pierre et Marie Curie

Laboratory

Institut de Biologie de l'ENS IBENS
U1024 UMR8197
Labex Memolife, Programme France Bio-Imaging, NIH Brain Initiative 2017

Mots clefs

Neurosciences intégratives Modalité sensorielle tactile Cortex à tonneaux Microscopie de fluorescence à deux photons Optique adaptative
Available to host a PhD student

publications

L. Estebanez, J. Bertherat, D.E. Shulz, L. Bourdieu, J.-F. Léger, High order statistics of naturalistic stimuli are orderly mapped in the primary somatosensory cortex, (2016) Nature Comm. 7:13528.

J. Wang, J.-F. Leger, J. Binding, C. Boccara, S. Gigan and L. Bourdieu, Measuring aberrations in the rat brain by coherence-gated wavefront sensing using a Linnik interferometer, Biomed. Opt. Exp. (2012) 3(10) 2510-25.

V. Szabo*, C. Ventalon*, V. De Sars, J. Bradley, and V. Emiliani, “Spatially selective photoactivation with computer generated holography and functional fluorescence imaging in freely behaving mice with a fiberscope”, Neuron, 84 (6), 1157-1169. (2014) * Equal contribution.

S. Schott, J. Bertolotti, J.F. Léger, L. Bourdieu and S. Gigan, Characterization of the angular memory effect of scattered light in biological tissues. Opt. Exp. 23(10) (2015) 13505-16, arXiv:1502.00270.

W. Akemann, J.-F. Léger, C. Ventalon, B. Mathieu, S. Dieudonné and L. Bourdieu, Fast spatial beam shaping by acousto-optic diffraction for 3D non-linear microscopy, Opt. Express 23(22), 28191-28205 (2015).

 

Fields of research

Neurophysiology / systems neuroscience

Research Theme

Nous étudions la représentation de l’information sensorielle dans une colonne corticale en enregistrant optiquement l’activité de centaines de neurones. Nous nous intéressons en particulier à la représentation de l’information tactile collectée par les vibrisses des rongeurs et représentée dans le cortex somato-sensoriel primaire à tonneaux. Notre travail porte sur le codage de stimuli élémentaires à l’échelle d’une seule vibrisse et sur l’effet sur cette intégration du contexte sensoriel, qui peut être modulé par exemple par les corrélations spatio-temporelles des déflections de l’ensemble des vibrisses

Pour aborder ces questions, notre groupe développe différents outils permettant d’enregistrer de façon optimale en microscopie de fluorescence à deux photons l’activité de larges populations neuronales in vivo sur l’animal anesthésié ou en comportement : optique adaptative pour optimiser la profondeur d’imagerie, balayage ultra-rapide acousto-optique pour améliorer la précision temporelle des enregistrements et leur rapport signal sur bruit, couplage avec la tomographie optique cohérente pour l’observation sans marquage de la myéline corticale.

 

Membres de l'équipe

Wang Jinyu
Paresys Gérard
Léger Jean François
Ventalon Cathie

Lab rotation

Adaptive changes in neuronal receptive fields during different conditioning strategies

Chercheur responsable: 

BOURDIEU Laurent

Dates: 

2 January 2018 - 29 June 2018

Date limite de candidature: 

29 June 2018

Period

~ Jan-March 2018

~ April-June 2018 (to be discussed)

Project

We propose to study how cortical receptive fields  in the primary auditory cortex (A1) can be rapidly reshaped by behavioral conditioning. We will use multi-electrodes (Silicon probes) to record neuronal activity in anaesthetized and in awake mice. We will focus on adaptive plasticity in receptive fields of A1 neurons, and explore how operant conditioning for a single tone can change the receptive field properties of both inhibitory interneurons and excitatory pyramidal cells, and how this process depends on cortical layers.

Experiments will consist in (i) implanting electrodes over the auditory cortex of naive mice, (ii) measuring neuronal receptive fields in a large ensemble of neurons, (iii) training animals on an auditory task, (iv) measuring changes in the receptive fields of the same cells following conditioning. An important aspect of these experiments is that we will use two different reinforcement strategies during training – one group of mice will receive aversive (negative reinforcement) conditioning and a second group of mice will receive appetitive (positive reinforcement) conditioning. This will allow us to analyze the effects of reward valence, as well as tone conditioning, on neuronal receptive field plasticity. In parallel, a PhD student in the team is currently studying the effect of conditioning in the upper layers of A1 (layers I-III) with two-photon microscopy calcium imaging. The comparison of the observed changes in supragranular, granular and subgranular layers of A1 will provide a complete view of the circuit rearrangements taking place in this cortex during learning. This is a collaborative project between our group and Dr. Shihab Shamma’s group at the DEC department (ENS). The supervision of this project will be done by Jean-François Léger in Laurent Bourdieu’s team at IBENS and Yves Boubenec in Shihab Shamma’s team at the DEC. These experiments will provide a better understanding of the cellular basis of adaptive neuronal changes during classical conditioning, and also yield new insights into the effects of learning and reward on early sensory processing.

Contact

Ecole Normale Supérieure - IBENS - 46, rue d’Ulm 75005 Paris - +33 1 44 32 37 34 - leger@biologie.ens.fr

Superviseur: 

LEGER Jean-François