Pilocarpine-Induced Epilepsy Model in Rats

Figure 1 illustrates the design of the drug trial methodology, which was a modified protocol based on Ko and Kang [25 (link)]. Animals were intraperitoneally (i.p.) given LiCl (127 mg/kg) 24 h before the pilocarpine treatment. Animals were treated with pilocarpine (30 mg/kg, i.p.) 20 min after atropine methylbromide (5 mg/kg i.p.). Two hours after SE on-set, animals were administered diazepam (Valium; Hoffman la Roche, Neuilly sur-Seine, France; 10 mg/kg, i.p.) and dosage was repeated, as needed. Control animals received saline in place of pilocarpine. Animals were video-monitored 8 h a day for general behavior and occurrence of spontaneous seizures by 4 weeks after SE induction. Behavioral seizure severity was evaluated according to Racine’s scale [26 (link)]: 1, immobility, eye closure, twitching of vibrissae, sniffing, facial clonus; 2, head nodding associated with more severe facial clonus; 3, clonus of one forelimb; 4, rearing, often accompanied by bilateral forelimb clonus; and 5, rearing with loss of balance and falling accompanied by generalized clonic seizures. We classified chronic epilepsy rats that showed behavioral seizures with seizure score ≥3 more than once.