Epileptogenesis in immature rats following recurrent status epilepticus

Strong evidences link; status epilepticus (SE) in childhood with the later development of epilepsy. Pilocarpine-induced SE in developing rats leads to late appearance of spontaneous epileptic seizures only when SE is induced after the 18th day of life. We examined the possibility that 3 consecutive episodes of pilocarpine-induced SE on postnatal days 7, 8 and 9 could induc e behavioral, electrographic and histological epileptic changes in adult li fe. The animals also underwent behavioral tests (inhibitory step-down avoid ance, skinner box, rota-rod, open field and elevated plus-maze). EEG record ings made at the age of 30, 60 and 90 days showed the occurrence of several episodes of spikes and/or polyspikes appearing simultaneously in hippocamp us and cortex. Only three isolated spontaneous seizures were observed durin g the whole period of observation (120 days). The long-term effects of thre e consecutive episodes of SE include increased spontaneous exploratory acti vity, learning impairment, and reduced anxiety when tested on P60. Our find ings provide evidence for EEG changes and cognitive deficits in adult life following recurrent SE on postnatal days 7-9. (C) 2000 Elsevier Science B.V . All rights reserved.