The pilocarpine model of epilepsy in mice

Purpose: To characterize the acute and chronic behavioral, electrographic and histologic effects of sustained seizures induced by pilocarpine in mice. Methods: After status epilepticus, the surviving animals were continuously monitored for 24 h/day for less than or equal to 120 days. The brains were processed by using neo-Timm and Nissl stains. Results: 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. Conclusions: Structural brain damage promoted by pilocarpine-induced status epilepticus may underlie or be associated with recurrent spontaneous seizures in mice.