Pilocarpine-Induced Epilepsy in Rats

To induce epilepsy, rats were injected with pilocarpine hydrochloride (380 mg/kg, i.p.; Sigma-Aldrich, UK), a muscarinic cholinergic agonist. In order to prevent the peripheral cholinergic effects of pilocarpine, rats were pre-treated with scopolamine methyl nitrate, as a cholinergic antagonist (1 mg/kg, i.p.; Sigma-Aldrich, UK) 30 minutes before the injection of a single dose of pilocarpine hydrochloride. Then the treated rats were monitored for a period of 3 to 4 hours after injection of pilocarpine, and the seizure severity was graded according to Racine’s criteria[33 (link)]. Only rats were included in the present work if they exhibited stage 4 or 5 seizure score. In order to terminate the sustained seizure that lasted for 3 hours, diazepam (7 mg/kg, i.p.) was injected, and an additional dose of diazepam (3 mg/kg, i.p.) was administered every 2 hours, if needed, and then the animals were cared and fed with Hartmann’s solution till recovery[34 (link)]. Two weeks after pilocarpine injection, the occurrence of spontaneous seizures was recorded during chronic phase using daily video monitoring 8 hours/day for two weeks.