PERSISTENT ELEVATION OF NOCTURNAL ACTIVITY IN RODENTS FOLLOWING APPARENT RECOVERY FROM LITHIUM PILOCARPINE-INDUCED LIMBIC SEIZURES/

The nocturnal and day-time activity of rats was monitored continuously after the induction of seizures by a single systemic injection of lit hium followed 4 hr, later by the muscarinic agent pilocarpine. Althoug h there was a transient increase in activity during the day cycle shor tly after the seizure induction, this behavior returned to baseline le vels: however, nocturnal activity increased and remained elevated two to three times above the baseline levels. Implications for the enhance ment of nocturnal melatonin levels within the brains of these chronica lly epileptic rats are discussed.