Expression of c-fos protein in the experimental epilepsy induced by pilocarpine.

The expression of the c-fos proto-oncogene, as estimated by immunohistochemistry of the FOS nuclear protein, was studied in both focal and generalized seizures induced in rats by systemic administration of pilocarpine. Focal seizures, as indicated by the occurrence of stereotyped oral movements, chewing and sniffing, were evoked by either a subconvulsant dose of pilocarpine (200 mg/kg) or the association of a convulsant dose of pilocarpine (400 mg/kg) with SCH 23390, a selective D-1 dopamine receptor antagonist. This seizure pattern resulted in FOS accumulation in certain limbic areas, namely, the piriform cortex, amygdala, and olfactory tubercle.