The kinetics of the IPSC, the heterogeneity and the noise affect the firing coherence of a population of inhibitory interneurons

The Fast Spiking interneurons are coupled by both inhibitory and electrical synapses and the experimental findings suggest they operate as clockworks affecting the neural information processing. At present, the functional role of the electrical synapses in a network of inhibitory interneurons is not well understood. In this paper, this issue is investigated by using a single compartment biophysical interneuron model of a Fast Spiking cell. In particular, the parameter values leading to the emergence of synchronous regimes in a network model of inhibitory interneurons coupled by chemical and electrical synapses are determined theoretically in the weak-coupling limit. Moreover, the effects on the firing coherence, arising from heterogeneity and noise, are studied by means of numerical simulations, both for a pair of Fast Spiking cells and for larger size networks.