吗啡诱导条件性位置偏爱大鼠伏隔核壳区遥测电活动分析

Wireless telemetry electrical activity of nucleus accumbens shell in morphine-induced CPP rats

目的：记录吗啡诱导条件性位置偏爱（CPP）大鼠伏隔核（NAc）壳区电活动变化,分析其与觅药行为之间的关系。方法：SD大鼠40只,于NAc壳区脑立体定位电极埋藏后,随机分为手术对照组和吗啡诱导CPP组（n=20）,后者制作吗啡依赖模型。利用CPP视频系统结合脑电无线遥测技术,记录各组大鼠在黑、白箱停留、黑-白箱穿梭和白-黑箱穿梭时大鼠NAc壳区电活动变化,分析其各频段百分比的差异。结果：与手术对照组比较,吗啡诱导CPP组大鼠黑箱停留时,左右侧NAc壳区电活动0-10 Hz频段百分比减少（P〈0.05）,10-20 Hz与30-40 Hz频段百分比增加（P〈0.05,P〈0.01）;白箱停留时,0-10 Hz与30-40 Hz频段百分比减少（P〈0.05,P〈0.01）,10-20 Hz增加（P〈0.05,P〈0.01）;黑-白箱穿梭时,0-10 Hz频段百分比增加（P〈0.05,P〈0.01）,10-30 Hz减少（P〈0.05）;白-黑箱穿梭时,0-10 Hz频段百分比减少（P〈0.05）,10-30 Hz增加（P〈0.05）,进一步将吗啡诱导CPP组大鼠穿梭时NAc壳区电活动与停留状态下相比较,白箱与白-黑箱穿梭比较其脑电无明显差异,但相对于黑箱停留,黑-白箱穿梭时左右NAc壳区电活动0-10 Hz与40-50 Hz频段百分比增加（P〈0.05）,10-20 Hz和30-40 Hz频段百分比减小（P〈0.05）。结论：吗啡诱导CPP大鼠黑-白箱穿梭觅药时,NAc壳区电活动发生特异性改变,这种改变可能与觅药行为的动机发生相关。

Objective： To analyse the relationship between the electrical activity changes of nucleus accumbens（ NAc） shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference（ CPP） rats induced by morphine.Methods： Forty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model（ n = 20）. A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively,which included staying in black or white chamber of video box,shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave. Results： When the morphine-induced rats staying in black chamber,compared with the operation-only control group,the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased（ P〈 0. 05）,meanwhile,those of 10 - 20 Hz and 30- 40 Hz were reduced（ P〈 0. 05,P 〈0. 01）; when the morphine-induced rats staying in white chamber,the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased（ P 〈0. 05,P 〈0. 01）,that of 10 - 20 Hz was reduced（ P〈 0. 05,P 〈0. 01）; when the morphine-induced rats in black-white shuttling status,the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased（ P 〈0. 05,P 〈0. 01）,that of 10 - 30 Hz was reduced（ P〈 0. 05）; and in the white-black shuttling status,the electrical activity showed that the percentage of 0 - 10 Hz was reduced（ P 〈0. 05）,that of 10 - 30 Hz was increased（ P 〈0. 05）; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However,when rats in black-white shuttling status,compared with staying in black chamber,the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased（ P〈 0. 05）,meanwhile,those of 10 - 20 Hz and 30 - 40 Hz were reduced（ P 〈0. 05）. Conclusion： The electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group,and these changes might be associated to the rat＇s drug-seeking behavior.