Effect of Exercise on Inhibition Ability during Nicotine Abstinence Period in Rat and Its Mechanism

Objective:To explore the effect of exercise on inhibition ability and the expression of a7 nicotinic acetylcholine receptors(nAChRs)during nicotine abstinence in rats,and discuss the relevant relationships between them.Methods:30 four-week-old male Sprague-Dawley rats were randomly divided into sedentary group and moderate intensity exercise group.It was performed with conditioned place preference(CPP)to establish nicotine dependence model in rats.The study applied Go/NoGo task to evaluate inhibition ability during nicotine abstinence periods,and the expression of a7 nAChRs in prefrontal cortex and hippocampus were detected by Western blotting.Results:1)Go/NoGo paradigm and nicotine-induced CPP were established successfully.2)Compared to the sedentary group,the preferred values of rat nicotineCPP(secs)from exercise group was significantly reduced(156.27±12.07 vs 83.6±14.85,P<0.01);The accuracy ratio of Go task(%)did not change,while the accuracy ratio of NoGo task(%)increased observably(42.67±3.53 vs 63.43±3.92,P<0.01).3)The expression of a7 nAChRs in both groups did not change in the hippocampus,but it was significantly up-regulated in the prefrontal cortex in exercise group(0.7±0.06 vs 1.23±0.1,P<0.01).4)The inhibition ability of rats during nicotine abstinence periods was negatively correlated with the preferred values of CPP(R2=0.64,P<0.01),and positively correlated with the prefrontal cortex a7 nAChRs expression(R2=0.44,P<0.05).Conclusion:10-day moderate intensity treadmill running can promote rats inhibition ability during nicotine abstinence period,and reduce dependence of nicotine.These effects of exercise may be due to the up-regulation of a7 nAChRs.