Effects of correlated input and electrical coupling on synchrony in fast-spiking cell networks

Fast-spiking (FS) cells in layer IV of the somatosensory cortex receive direct thalamocortical (TC) input and provide feed-forward inhibition onto layer IV excitatory cells. The level of synchronous firing of FS cells will affect the shape of this feed-forward output. Two factors that contribute to the synchrony are correlated TC input and electrical coupling between FS cells. Using a cell-pair model, we show that these two factors act synergistically to increase synchrony, and we examine the underlying mechanism.