吗啡成瘾大鼠的行为学及脑内核团形态学改变的研究

Changes of ethology and brain morphology in morphine-addicted rats

目的研究吗啡成瘾对大鼠学习、记忆、情感等行为学的影响及脑内核团的形态学变化。方法将64只大鼠随机分成吗啡成瘾组和对照组,应用Morris水迷宫、开野实验、隔离残杀实验,观察大鼠学习、记忆、攻击性等行为学变化和脑内海马、伏核及内侧额前皮质在光镜和电镜下的形态学变化。结果成瘾组和对照组部分实验项目中存在统计学差异(P<0.05);在成瘾大鼠伏核、海马、内侧额前皮质观察到细胞器减少、线粒体肿胀、染色质边集、核固缩甚至坏死等形态学变化。结论长期使用吗啡可导致脑内结构的损害,同时可导致大鼠的探索行为及攻击性等行为变化。

Objective To observe the changes of learning-memory, felling and brain morphology in morphine-addicted rats. Methods Sixty-four male Sprague-Dawlay rats were randomly assigned to experimental or control groups. The ability of learning-memory in rats was tested with Morris water maze. Exploratory behavior in rats was observed with open-field test. The isolation-induced aggression in rats was observed with muricide behavior test. The morphological changes in the nucleus accumbens, hippocampus and medial prefrontal cortex in morphine-addicted rats and controls were observed and compared under light or electron microscope. Results The scores of withdrawal signs on abstinence in experimental group were higher than that in control group （P〈0.05）. The learning-memory ability in Morris water maze and exploratory behavior in open-field test were significantly different between the 2 groups （P〈0.05）. The muricide behavior in rats was more obvious in experimental group than that in control group （P〈0.05）. The light and electron microscopic observation revealed the changes in nucleus accumbens, hippocampus and medial prefrontal cortex, including cellular organelle decrease, chondriosome edema, chromatin margination, karyopycnosis and necrosis. Condusion Long-term morphine exposure can lead to the damage in different brain regions and decrease exploratory behavior, but increase aggressive behavior.