吗啡成瘾大鼠边缘下区脑电活动的无线遥测及分析

 目的：遥测并分析吗啡成瘾大鼠条件性位置偏爱（conditioned place preference，CPP）模型制备前后边缘下区（infralimbic cortex, IL）脑电活动的实时变化。方法：选用雄性SD大鼠随机分2组（吗啡戒断组和盐水对照组，每组各12只），进行脑立体定位埋植电极手术，采用吗啡注射结合CPP训练制备吗啡成瘾大鼠CPP模型，对照组注射生理盐水。利用CPP视频系统和脑电无线遥测系统，检测造模前后大鼠CPP行为的变化及IL区脑电活动的改变。结果：分别与造模前和对照组白箱内停留时间比较，戒断组大鼠戒断1~3 d在白箱内停留时间延长（均P<0.01）。与对照组比较，戒断组大鼠戒断3 d在白箱停留时，IL区脑电δ波明显减少，β波（β 2）明显增加（P<0.05或P<0.01），α波及θ波变化无显著差异（P>0.05）；戒断组大鼠由黑箱向白箱穿梭时，IL区脑电表现为δ波显著增加（P<0.01），α波（α 1、α 2）及β波（β 1、β 2）显著减少（均P<0.01），θ波无明显变化（P>0.05）；戒断组大鼠在黑箱停留或由白箱向黑箱穿梭时，IL区脑电各波与对照组比较无显著差异（P>0.05）。结论：吗啡成瘾大鼠穿梭觅药与停留在药物相关环境中引发的IL区脑电活动的改变机制可能不同；IL区神经元功能可能存在双重性。

Wireless telemetry and analysis of electrical activity of infralimbic cortex in morphine-addicted rats

AIM：To telemeter and analyze the real-time changes of electrical activity of infralimbic cortex (IL) before and after preparation of the conditioned place preference (CPP) model in morphine-addicted rats. METHODS：The male SD rats were selected and randomly divided into morphine withdrawal group and normal saline control group (12 rats per group). An operation of brain stereotaxic electrode embedding was made. The CPP model of morphine-addicted rats was prepared by morphine injection and CPP training. The rats in control group received normal saline. The changes of CPP and electrical activity of IL in the rats were detected before and after modeling by CPP video system and electroencephalogram (EEG) wireless telemetry system. RESULTS：Compared with before modeling and control group, the time of withdrawal group staying in white box was prolonged significantly on withdrawal 1~3 d. Compared with control group, when the rats in withdrawal group stayed in white box on withdrawal 3 d, the electrical activity of IL showed that δ wave decreased obviously, and β wave (β 2) increased obviously, but no significant change of α wave and θ wave was observed. However, when the rats in withdrawal group shuttled from black box to white box, δ wave increased significantly, and α wave (α 1, α 2) and β wave (β 1, β 2) decreased significantly, but  θ wave had no evident change. When the rats stayed in black box or shuttled from white box to black box, no significant difference of the electrical activity of IL between the 2 groups was detected. CONCLUSION：The change mechanism of electrical activity of IL may be different, when morphine-addicted rats shuttle to seek drug and stay in drug-related environment. There is possibly duality in neuronal function of IL.