Seminars & Colloquia Calendar

Abstract:  In this talk I would like to focus on a simple (yet not so unrealistic) model of a group of interacting neurons similar to that occurring in local circuits in many parts of cortex. Local neuronal systems have some of the flavor of statistical mechanical systems of interacting particles, except that there are two kinds of neurons, excitatory and inhibitory, that provide opposite-signed inputs to their postsynaptic neurons. In this large dynamical system  defined by coupled ODEs, it has been observed that collectively, the population produces irregular yet clearly present rhythms in the gamma band. This is an emergent phenomenon well documented in experiments but not easily deduced from the rules governing the dynamics of individual neurons. Gamma rhythms are ubiquitous in the whole brain and many specific functions for them have been proposed, but I am inclined to think they are just by-products of neuronal processes.