Alain Destexhe, Laboratory for Computational Neuroscience, UNIC, CNRS, Gif-sur-Yvette, France | Propagating Waves and their Collisions in Visual Cortex

Abstract

Propagating waves have been found in cerebral cortex during anesthesia, sleep or in awake animals. We show here that such waves are found in the primary visual cortex of awake monkey, and could be demonstrated from voltage-sensitive dye (VSD) imaging. Further experiments showed that the collision of two propagating waves produces a combined wave which is less than the sum of the individual waves, so the propagating wave exerts a suppressive effect. We use mean-field models based on conductance-based spiking networks to show possible mechanisms for this suppression. We found that the suppressive effect of propagating waves can be explained by two mechanisms, the fact that inhibitory neurons have a higher gain than excitatory neurons, and the fact that these two contributions combine non-linearly with conductances. We speculate on possible roles of such suppressive propagating waves.