The variability and mean of the firing rate of Hodgkin-Huxley and FitzHugh-Nagumo neurons subjected to random synaptic input are only weakly dependent on the level of inhibitory input, unlike integrate-and-fire neurons. For the latter model, substantial inhibitory input is essential to ensure output variability close to Poissonian firing. It cannot therefore be used routinely in stochastic network modeling in place of biophysical models without first checking that the network behavior is not seriously compromised.

• Received 2 October 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.4731