【摘要】 目的:分析海洛因诱导条件性位置偏爱(CPP)大鼠的伏隔核(NAc)脑电活动在海洛因依赖不同时期的变化特征,探讨其在药物依赖形成过程中的作用。方法:通过立体定位向大鼠NAc埋藏电极,建立海洛因依赖大鼠模型,用无线遥测方法分别记录海洛因给药前、给药后即刻及戒断状态3个时期内大鼠NAc神经元放电活动,分析NAc神经元脑电活动的频率(0.5 Hz~30 Hz)分布及波幅。结果:CPP系统建立海洛因依赖模型有效,大鼠戒断症状明显。海洛因给药5~10 d,大鼠陆续出现白箱CPP,戒断2 d时戒断症状达高峰。各时期内大鼠NAc脑电活动δ波比例皆最高,α2波比例最低,不同频段脑电的分布梯度相似。与给药前和戒断期相比,给药后即刻状态NAc低频放电(δ波)比例明显升高(P<0.01),高频放电(β波)比例明显降低(P<0.01);戒断期α1波比例明显小于其它各期(P<0.01)。与给药前相比,给药后即刻和戒断期NAc脑电活动平均波幅均显著增大(P<0.01),但戒断期的平均波幅比给药后即刻期的明显降低(P<0.01)。结论:海洛因依赖不同时期内大鼠NAc的脑电活动出现明显变化,提示NAc神经元活动可能参与药物依赖的调节。更多还原

【Abstract】 Objective: To analyze the electrical activity property changes in nucleus accumbens( NAc) of heroin-induced conditioned place preference( CPP) rats during different stages of heroin dependence and to explore NAc’s roles in the formation of drug dependence. Methods: Recording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus,followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence,including heroin pre-exposure,immediate post-exposure and heroin withdrawal,were respectively recorded using EEG wireless telemetry techniques. The frequency distribution( ranging from 0. 5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured. Results: Heroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference( CPP) for the white box after 5 ~ 10 days of heroin-exposure,and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence,the NAc electrical activity contained the highest proportion of δ rhythm and the lowest proportion of α2rhythm. The discharge frequence band was similar across different stages.There was a significantly increased ratio of low-frequency discharges( δ rhythm) and decreased ratio of high-frequency discharges( βrhythm) in NAc of rats during the immediate post-heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage,the ratio of α1rhythm was significantly lower than during pre-and post-heroin exposure stages( P < 0. 01). Further,the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However,the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage. Conclusion: The electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence,which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.更多还原