Effect of vagus nerve stimulation on status epilepticus in rats / 中华神经医学杂志

ABSTRACT

Objective To study the acute effect of vagus nerve stimulation (VNS) on status epilepticus (SE) in rats.Methods Forty-eight male Wistar rats were randomly divided into 4 groups:Group A (VNS preconditioning group),accepted VNS at 2 h before pilocarpine injection,Group B (VNS treatment group),accepted VNS immediately after pilocarpine injection,Group C (negative control group),implanted with electrode without stimulation,and Group D (SE model group),without electrode implantation (n=1 2).Lithium-pilocarpine was used to kindle the rats to establish SE models.Stimulation parameters used in the procedure of VNS were as follows:frequency,30 Hz; pulse width,0.5 ms; current,1 mA; and duty cycle,on-30 s,off-30 s.Behavior changes were observed and caspase-3 expression in dentate gyrus was detected 72 h after pilocarpine injection.Results (1) The seizure frequencies of grade Ⅳ and Ⅴ (Racine grading) in group A and B were significantly fewer than those in group C and D (P＜0.05); the seizure frequency of grade Ⅴ in group A was significantly fewer than that of group B (P＜0.05); SE latency in group A was significantly longer than that in other groups (P＜0.05).(2) Expressions of caspase-3 in the dentate gyrus of group A and B were significantly lower than those of group C and D (absorbancy values being 5854.7±856.5,6244.8±806.0,11957.0±1948.1 and 11543.2±1734.7,P＜0.05).Conclusion VNS has an acute seizure-suppressing effect on SE in rats and it can also reduce neuronal apoptosis induced by SE in hipocampus.