伏隔核毁损对药物和应激诱导大鼠吗啡觅药行为重建的影响

Effects of lesion of nucleus accumbens on drug priming or footshock-induced reactivation of extinguished conditioned place preference

目的 分析伏隔核 (nucleusaccumbens ,NAc)在药物和应激诱导大鼠吗啡觅药行为中的作用 ,研究定向毁损NAc对大鼠成瘾行为重建的影响。方法 雄性SD大鼠通过吗啡强化形成条件性位置偏爱 (conditionedplacepreference ,CPP)后 ,使用直流电毁损NAc。 1 5天后给予皮下注射吗啡或间断足击应激诱导CPP ,测量并比较毁损组与对照组的CPP得分。结果 无论在注射吗啡诱导还是在间断足击应激诱导中 ,NAc毁损组的CPP得分均显著低于对照组。

Objective To examine the possible role of nucleus accumbens(NAc) in drug priming and footshock-induced reactivation of extinguished conditioned place preference(CPP).Method After male rats were successfully trained with morphine(10mg/kg,sc.)through a CPP paradigm(8 sessions of daily pairing of morphine with one of the two compartments),NAc was lesioned with a direct current(DC) passing through the location.After a 15-day abstinence period, random intermittent footshock(DC square wave,0.5mA,0.5s width,off time 10-70s)or drug priming(morphine 1mg/kg,sc.)was given and the place preference score was recorded.Result Drug priming or footshock reactivated the placepreference in sham lesion rats.However,the effect of drug priming and footshock-induced reactivation of extinguished CPP could be significantly abolished by lesion of NAc.Conclusion These results indicate an important role for the NAc in both drug priming and footshock stress induced reactivation of extinguished CPP.