Introduction

There is growing interest in the possible application of external stimulation to terminate epileptic seizures. Investigations have shown that epileptic afterdischarges in humans can be terminated by external stimuli (Lesser et al., 1999). However, stimulation of excitatory pathways in a slice preparation of rat hippocampus do not terminate the epileptiform discharge (Motamedi et al., 2000). We have studied possible conditions for termination of bursting activity in a model neural network.

Epileptic seizures in human terminates spontaneously, typically lasting only seconds or minutes. In addition, in many instances, regional seizure activity stops simultaneously in all channels. The actual mechanisms for this spontaneous termination are not well established. To study this phenomena under controlled conditions, we have studied burst termination in model neural networks of purely excitatory neurons.

Our previous simulations (Franaszczuk et al., 1999) have shown that propagation of synchronous epileptiform activity can be terminated when two waves of bursting activity collide. In another earlier study (Kudela et. al., 1997) we have shown that bursting activity in a loop of two excitatory neurons can be terminated by additional excitatory input. In this current study we examine the termination of bursting activity with an excitatory stimulus or increased background activity in networks of multiple neurons having both excitatory and inhibitory synaptic connections.