Signal Transmission and Synchrony Detection in a Network of Inhibitory Interneurons

Fast Spiking GABAergic interneurons, also coupled through gap junctions too, receive excitatory synaptic inputs from pyramidal cells and a relevant problem is to understand how their outputs depend on the timing of their inputs. In recent experiments it was shown that Fast Spiking interneurons respond with high temporal precision to synaptic inputs and are very sensitive to their synchrony level. In this paper this topic is investigated theoretically by using biophysical modelling of a pair of coupled Fast Spiking interneurons. In particular it is shown that, in agreement with the experimental findings, Fast Spiking interneurons transmit presynaptic signals with high temporal precision. Moreover, they are capable of reading and transferring high frequency inputs while preserving their relative timing. Lastly, a pair of Fast Spiking interneurons, coupled by both inhibitory and electrical synapses, behaves as a coincidence detector.