Induction of Epileptic Seizures in Mouse Models of Chronic Restraint Stress

Abstract

Objective To investigate the sensitivity of mouse models of chronic restraint stress to conditions that induce epileptic seizures.Methods Male C57BL/6J mice were randomized into chronic restraint stress(CRS)group and normal control(NC)group. The modeling results were evaluated by sucrose preference test and forced swimming test. Kainic aicd(KA)was intraperitoneally injected to induce acute seizures. Seizure onset time,duration,and scores were recorded and compared.Results During the forced swimming test,the immobility time was(120.9±13.5)s in CRS group and only(59.1±9.8)s in NC group(t=3.700,P=0.0019). During the sucrose preference test,the water consumption proportion at 0-24 h and 0-48 h were(64.7±4.7)% and(73.3±3.0)%,respectively,in CRS group,significantly lower than those[(77.2±2.5)%(t=2.672,P=0.0167)and(83.0±2.8)%(t=2.386,P=0.0297)] in NC group. Although there was no significant difference in the total number of acute seizures[(11.5±1.1)times vs.(13.7±2.1)times;t=0.9767,P=0.3465],mice in CRS group had significantly higher severe seizure score than in control group[(66±10)scores vs.(37±5)scores;t=2.777,P=0.0157]. The seizure onset time was(138±26)s in CRS group,which was significantly shorter than that in NC group[(234±28)s;t=2.485,P=0.0274]. The seizure duration of the CRS group was(61±16)min,which was significantly longer than that of the NC group[(37±5)min;t=3.342,P=0.0053].Conclusion CRS mice are more susceptible to KA-induced acute epileptic seizures.