吗啡成瘾大鼠脑内核团毁损后的行为学研究及形态学变化

目的研究脑内核团毁损对吗啡成瘾大鼠戒断症状及行为学方面的影响．以及毁损前后的脑形态学变化。方法将120只雄性SD大鼠随机分成对组、吗啡成瘾组、伏核毁损组、海马毁损组及伏核、海马假毁损组，通过旷场实验和隔离残杀实验观察大鼠目的性探究行为和攻击行为的变化．并在光镜和电镜下观察脑内伏核、海马的形态学变化。结果成瘾组和毁损组在自然戒断症状、旷场实验、隔离残杀实验方面经统计学分析，组间差异有统计学意义（P〈0．05）；成瘾大鼠伏核、海马的神经元细胞器减少、线粒体肿胀、染色质边集、核固缩甚至坏死。结论长期使用吗啡可导致脑内神经元超微结构损害：毁损伏核、海马后可改善成瘾大鼠的戒断症状．使其探索行为和攻击性行为发生变化。

Ethological and morphological observations after stereotactic lesioning in morphine-addicted rats

Objective To study effects of stereotaxic lesioning on abstinence symptom and ethology,and observe brain morphological changes after the lesioning in morphine-addicted rats.Methods One hundred and twenty male Sprague-Dawley rats were divided randomly into control group,morphine-addicted group,nucleus accumbens-lesioned group,hippocampus-lesioned group,and nucleus accumbens and hippocampus pseudo-lesion group.Exploratory behavior and isolation-induced aggression in rats were observed by open-field test and killing(muricide) test respectively.The morphological changes of the nucleus accumbens and hippocampus in morphine-addicted and hippocampus-lesioned rats were observed and compared under light and electron microscope.Results The scores of the abstinence symptom and muricide behavior were higher in the addicted group than in lesion groups(P<0.05).The light and electron microscopic changes in the nucleus accumbens and hippocampus were found in addicted group,including organelle decrease,mitochondrial swelling,chromatin margination,karyopyknosis and even necrosis.Conclusion Long-term morphine exposure can lead to damage of neuron ultrastructure in the brain.Stereotactic lesioning can relieve morphine withdrawal syndrome,and change aggressive behavior and exploratory behavior of morphine-addicted rats.