The pilocarpine model of epilepsy in mice.

To characterize the acute and chronic behavioral, electrographic and histologic effects of sustained seizures induced by pilocarpine in mice. After status epilepticus, the surviving animals were continuously monitored for 24 h/day for < or = 120 days. The brains were processed by using neo-Timm and Nissl stains. The first spontaneous seizures occurred between 4 and 42 days after status epilepticus. The mean "seizure-silent period" lasted for 14.4 +/- 11.9 days. During the chronic phase, recurrent spontaneous seizures were observed 1-5 times per animal per week and were associated with sprouting in the supragranular layer of the dentate gyrus. Structural brain damage promoted by pilocarpine-induced status epilepticus may underlie or be associated with recurrent spontaneous seizures in mice.