Effects of Environmental Enrichment on Hippocampal Electrophysiological Changes in the Pentylenetetrazole Model of Epilepsy

Objectives: Epilepsy is a neurological disorder characterized by functional/morphological changes in the hippocampus. These functional changes arise as increase or decrease in synaptic plasticity in experimental animals. The present study was an investigation of the effect of enriched environment on hippocampal functional changes in epileptic rats. Methods: The pentylenetetrazole (PTZ) kindling model was used on young male Wistar rats. Rats in the epileptic and control groups were reared for 1 month in standard cage or enriched cage (EC). Subsequently, all animals were given Morris water maze (MWM) test and in vivo recording of long-term potentiation (LTP) in medial perforant pathway-dentate gyrus synapses in hippocampus was made. Results: Statistically significant earlier kindling epileptogenesis in rats housed in EC was observed. Epileptic rats had poor performance in MWM, but enriched environment improved their performance. However, according to electrophysiological recordings, environmental enrichment did not provide positive effect on LTP in epileptic rats. Conclusion: Enriched environment with ongoing PTZ-induced kindling procedure may lead to exaggeration of seizures due to stress as result of corruption of safe, familiar environment.