Chaos in neural networks with dynamic synapses

We investigated the activity of localized excitatory and inhibitory populat ions coupled by dynamic synapses. Using numerical simulations, we analyzed the Liapunov exponents as well as fractal dimension of the network for vari ous sets of parameters in order to find regimes of periodic and chaotic beh avior. We found that chaotic behavior usually develops when external inputs are near threshold, and that chaos develops through a series of period dou blings. It is robust and stable over considerable volume in parameter space . Within chaotic regimes intermittent behavior is exhibited. We investigate d the average behavior of the network and shown that the response of the ne twork is approximately linear to the excitatory input across various dynami cal regimes. (C) 2000 Elsevier Science B.V. All rights reserved.