Postsynaptic modulation of electrical EPSP size investigated using a compartmental model

The mormyrid electric fish displays extremely fine temporal resolution as measured in behavioral studies. The first stage of sensory processing, the sensory afferents, also display very precise temporal responses to electrical stimulation. The afferents are connected through gap junctions to the granular cells, which in addition receive a corollary discharge signal at the time of the electric pulse. The granular cells have a relatively long time constant, seemingly at odds with their presumed role as coincidence detectors. We use experimental data to build a compartmental model that investigates the mechanism by which the relative timing of the two inputs to the granular cells determines the effect of the afferent spike through the electrical synapse.