Ketamine prevents ECS-induced synaptic enhancement in rat hippocampus.

Electrical induction of seizure activity profoundly impairs hippocampal long-term potentiation (LTP) in rats. A similar effect may account for the memory dysfunction observed after electroconvulsive stimulation in humans and other species. The co-administration of ketamine with the induction of electroconvulsive seizures (ECS) was evaluated as a possible method for reducing the impact of ECS on hippocampal synaptic plasticity in rats. Electrophysiological studies in vivo showed that both the enhancement of the EPSP slope and the subsequent reduction of experimentally induced LTP in the dentate gyrus by repeated, spaced ECS were significantly attenuated by ketamine anaesthesia. The findings suggest that ketamine may protect against ECS-induced memory impairment and thus prove useful in reducing the transient cognitive impairment following electroconvulsive therapy (ECT).