Induction of epileptiform activity in hippocampal slices by trains of electrical stimuli

In this paper we present an in vitro model of epileptogenesis based on electrical stimulation rather than pharmacological or ionic manipulations. Hippocampal slices given a series of stimulus trains similar to those used in kindling exhibited 3 types of epileptiform activity in CA3: afterdischarges immediately following the trains; spontaneous bursts of multiple population spikes; and bursts triggered by single stimuli. The afterdischarges and spontaneous bursts may be comparable to those seen in vivo during kindling; also, the progression of these features in this model was similar to their progression during kindling. All epileptiform activities were long-lasting, persisting for up to 3.5 h following the last train. This stimulus train-induced population bursting should be valuable as an acute model of hippocampal epileptogenesis, and may also help elucidate hippocampal participation in the kindling process.