Voltage-dependence of synaptic time course reduces excitation at a diphasic synapse

At a diphasic excitatory-inhibitory synapse of Aplysia, the time constant of decay of the early excitatory synaptic conductance is decreased by depolarization. As a consequence of this reduced excitation, the amplitude of the inhibitory phase is increased and its rise time shortened, and inhibitory charge transfer is greater than excitatory charge transfer at potentials more depolarized than -53 mV. Functional consequences of voltage-dependent time course can thus be identified at a central synapse.