Download Accumulative evidence indicates that microglial cells influence the

Séminaires Grenoblois de Neurosciences
Jeudi 25 Avril à
16h00
Björn Kampa
Junior Group Leader, Vision Lab,
Brain Research Institute, University of Zurich
A Multi-Scale Approach to Cortical
Representation of Visual Scenery
How is our visual environment represented and processed in the brain? In my lab, we seek
answers to this fundamental question with a multi-scale approach combining two-photon imaging
with electrophysiological recordings. Neurons in the visual cortex have a receptive field like a
keyhole through which they look at the scenery in front of the eyes. Visual input from the area
surrounding the receptive field fails to induce neuronal firing but can modulate the neuronal
responses to receptive field stimulation. Recent studies have shown that natural movie
stimulation beyond the receptive field leads to reduced but more precise neuronal responses.
We have established this paradigm in mouse visual cortex where we investigate the interaction
of incoming sensory evidence with internal feedback from surrounding and higher visual areas.
We find precise and sparse responses to presentations of different visual scenes. Our results
suggest a population code, where the visual environment is dynamically represented in the
activation of distinct functional sub-networks. Furthermore, we find higher visual areas to be
well tuned to the characteristics of natural scenes indicating the role of their feedback in visual
perception. Integrated studies at multiple scales from neuronal dendrites to populations of
neurons together with their input from higher visual areas will assemble the puzzle of local
computation in visual cortex revealing the picture of how we perceive and interpret visual
scenes.
Invité par Marco Canepari (Centre de Recherche U836, Equipe 3).
Lieu: Salle de conférences, Grenoble Institut des Neurosciences (GIN).
Bât. Edmond J. Safra, Chemin Fortune Ferrini CHU, La Tronche. Arrêt de tram : Hôpital A. Michallon, à
côté des urgences et on accède au Bâtiment E.J. Safra en longeant les urgences et l’entrée Chartreuse de
l’Hôpital. Stationnement possible sur le parking du restaurant universitaire Le Chantourne
Contact: [email protected]