Seizure induction
Three days after surgery, rats were treated with pilocarpine (380 mg/kg, i.p.; Sigma-Aldrich Co., St. Louis, MO) at 20 min after methylscopolamine (5 mg/kg, i.p.; Sigma-Aldrich Co., St. Louis, MO). Using this treatment paradigm, behavioral seizures typically began within 20-40 min. Approximately 80% of pilocarpine treated rats showed acute behavioral features of SE (including akinesia, facial automatisms, limbic seizures consisting of forelimb clonus with rearing, salivation, masticatory jaw movements, and falling). We applied the 2 hr-SE rat model, because > 90% of the rats that we monitored in our previous studies [25] displayed spontaneous, recurrent seizures within 1-3 months after pilocarpine-induced status epilepticus. Diazepam (10 mg/kg, i.p.; Hoffman Ia Roche, Neuilly sur-Seine) was administered 2 hours after onset of SE and repeated, as needed. The rats were then observed 3 - 4 hours a day in the vivarium for general behavior and occurrence of spontaneous seizures. Non-experienced SE (non-SE) rats (showing only acute seizure behaviors during 10 - 30 min, n = 8) and age-matched normal rats were used as controls (n = 7).