A mean-field model of gamma-frequency oscillations in networks of excitatory and inhibitory neurons

Abstract

Gamma oscillations are widely seen in the cerebral cortex in different states of the wake-sleep cycle and are thought to play a role in sensory processing and cognition. Here, we study the emergence of gamma oscillations at two levels, in networks of spiking neurons, and in a mean-field model. At the network level, we consider two different mechanisms to generate gamma oscillations and show that they are best seen if one takes into account the synaptic delay between neurons. At the mean-field level, we show that introducing a delay in the mean-field also produces gamma oscillations. The mean-field matches the mean activity of excitatory and inhibitory populations, as well as the oscillation frequency, for both mechanisms. This mean-field model of gamma oscillations should be a useful tool to investigate large-scale interactions through gamma oscillations in the brain.