伏隔核与腹侧被盖区毁损对药物诱导大鼠吗啡觅药行为的影响.doc

1 伏隔核与腹侧被盖区毁损对药物诱导大鼠吗啡觅药行为的影响【关键词】吗啡 Lesion effects of nucleus accumbens and ventral tegmental area on drug priminginduced reactivation of extinguished conditioned place preference in rats 论文联盟 。【 Abstract 】 AIM: To examine the possible role of nucleus accumbens (NAc) and ventral tegmental area (VTA) in drug priminginduced reactivation of extinguished conditioned place preference (CPP). METHODS: After the rats were essfully trained with morphine (10 mg/kg, sc.) bya CPP paradigm, NAc and VTA were lesioned with a DC current passing through the location. After a 15day abstinence period, drug priming (morphine 1 mg/kg, sc.) was given and the place preference score was recorded. RESULTS: Drug priming reactivated the place preference in sham lesion rats. However , the effect of drug priminginduced reactivation of extinguished CPP could be pletely abolished by lesion of NAc and VTA. CONCLUSION: The se results indicate that NAc and VTA play an important role in drug priminginduced reactivation of extinguished CPP. 【 Keywords 】 morphine ; relapse ; nucleus accumbens ; ventral tegmental area ; conditioned place preference 【摘要】目的: 研究定向毁损伏隔核( nucleus accumbens, NAc ) 与腹侧被盖区(ventral tegmental area , VTA) 对药物诱导戒断大鼠吗啡觅药行为的影响, 分析 NAc 和 VTA 在大鼠成瘾行为中的作用. 方法: 雄性 SD 大鼠通过吗啡强化形成条件性位置偏爱后, 使用直流电分别毁损 NA c 与 d 后给予 sc 吗啡诱导大鼠恢复位置偏爱行为,测量并比较毁损组与对照组的位置偏爱得分. 结果: NAc 毁损组和与 VTA 毁损组大鼠在注射吗啡诱导下未恢复对吗啡的条件性位置偏爱[ NA c 毁损组(471 ± 52) s, NA c 对照组(673 ± 53) s; VTA 毁损组(482 ± 49) s, VTA 对照组(700 ± 46) s]. 结论:毁损 NA c和 VT A 能阻断注射吗啡诱导戒断大鼠恢复觅药行为. 在成瘾药物诱导戒断动物觅药行为中, NAc 和 VTA 起重要作用. 3 【关键词】吗啡; 复吸; 伏核; 腹侧被盖区; 条件性位置偏爱 0 引言复吸是药物成瘾的主要特征之一,也是治疗药物成瘾要解决的主要问题[1]. 研究发现成瘾药物可以有效地诱发复吸. 以往研究证明,中脑边缘多巴***系统( mesolimbic dopamine system, MLDS )在药物精神依赖性中起重要作用, 其中, 伏隔核( nucleus accumbens, NAc ) 与腹侧被盖区(ventral tegmental area , VTA) 在药物渴求的建立中起关键性作用[2]. 但 NA c和 VT A 在药物诱发复吸中的作用目前还不清楚[3]. 我们利用条件性位置偏爱(conditioned place preference,CPP) 实验模型, 研究戒断后的吗啡依赖大鼠在吗啡注射诱导下的位置偏爱行为, 并毁损 NAc 和 VTA 观察其对大鼠 CPP 的影响,研究 NAc 和 VTA 在药物诱发复吸中的作用. 1 材料和方法 11 材料