Effects of neonatal status epilepticus on rat brain development.

A single, 2-hour episode of status epilepticus induced by flurothyl (1,500 mul) in 4-day-old rats irreversibly curtailed brain weight and brain DNA. Status epilepticus inhibited DNA synthesis but did not increase DNA breakdown and produced no histologic lesions. Rats with status epilepticus showed delayed behavioral milestones and reduced seizure thresholds several weeks after status. After milder convulsions (flurothyl 750 mul, bicuculline), brain DNA was curtailed at 7 days but returned to normal at 30 days. These results suggest that, in the immature brain, epileptic seizures too mild to cause cell necrosis can inhibit DNA synthesis and permanently curtail brain DNA content. This may account for the great vulnerability of the immature brain to epileptic seizures.