Activity of coupled excitatory and inhibitory neural populations with dynamic synapses

We investigated the dynamics of localized excitatory and inhibitory populat ions coupled by dynamic synapses. The synaptic connections exhibit fast dep ression and facilitation as recently observed in neocortex. Phase plane ana lysis and numerical simulations are used to investigate population response s to various stimuli. In particular, we analyze the fixed point structure, their stability as a function of input currents. We find parameter sets for which the system exhibits anomalous behavior, by decreasing the activity o f both excitatory and inhibitory populations in response to an increase of the inhibitory input current. (C) 2000 Elsevier Science B.V. All rights res erved.