Kindling procedure

Ten days after surgery (Fig. 1), the afterdischarge (AD) threshold was determined in basolateral amygdala via a train of monophasic square waves (1 ms pulse duration at the frequency of 50 Hz for 3 s). Briefly, the stimulating currents were initially delivered at 30 μA and then the stimulus intensity was increased in steps of 10 μA at 10 min intervals until ADs were recorded for at least 8 s [31]. Animals were stimulated according to the chronic kindling protocol (1 stimulation/day). All epileptiform ADs were continuously recorded from the basolateral amygdala using a PC-based electromodule system (D3107; ScienceBeam Co., Tehran, Iran). The behavioral seizure severity was rated according to Racine’s scores [32]: stage 0, no convulsion; stage 1, facial automatism; stage 2, head nodding; stage 3, unilateral forelimb clonus; stage 4, bilateral forelimb clonus; and stage 5, rearing, falling, and generalized convulsions. The animals were considered as fully kindled when they exhibited stage 5 seizure in three consecutive days. The animals achieved a stage 5 seizure after 10–15 days. Afterdischarge duration (ADD), latency to stage 4 seizure (S4L; as an index of latency to start of generalized seizures), stage 5 seizure duration (S5D), total seizure duration (SD) and the behavioral seizure stage were calculated following each kindling stimulation.

Time line diagram showing the experimental protocol used in kindled groups