6-羟多巴胺损毁中脑边缘多巴胺能系统抑制药物点燃诱导的大鼠吗啡条件性位置偏爱消退后重建(英文)

Effect of 6-OHDA lesions of the dopaminergic mesolimbic system on drug priming induced reinstatement of extinguished morphine CPP in rats

目的 :考察中脑边缘多巴胺能系统在小剂量吗啡点燃诱导吗啡觅药行为重建中的作用。方法 :将小剂量儿茶酚胺能神经毒素 6 羟多巴胺微量注射到双侧伏核 (1g·L-1)或腹侧背盖区 (5g·L-1) ,观察其对已消退的吗啡条件性位置偏爱之点燃重建的作用。结果 :6 羟多巴胺微量注射到腹侧背盖区选择性地损毁多巴胺能神经元的胞体 ,或注射到伏核以损毁多巴胺能纤维的末梢 ,均可完全消除小剂量吗啡 (0 .2 5mg·kg-1,s.c.)的点燃效应。结论 :中脑边缘多巴胺能系统功能的完整性是药物点燃导致条件位置偏爱重建的必要条件。

Objective: To evaluate the role played by mesolimbic dopaminergic system in the reinstatement of drug seeking behavior induced by priming injections of morphine. Methods: After the extinguishment of morphine conditioned place preference (CPP), low dose catecholaminergic neurotoxin 6 hydroxydopamine (6 OHDA) was bilaterally injected into ventral tegmental area (VTA, 1 g·L -1 ) and nucleus accumbens (NAc, 5 g·L -1 ) before being primed with low dose morphine. Results: the effects of drug priming to induce reinstatement of morphine CPP could be completely abolished by 6 OHDA microinjected into VTA to damage the perikaryon of dopaminergic neurons, or into NAc to lesion the terminal field of the dopaminergic pathyway. Conclusion:The functional integrality of the mesolimbic dopaminergic system is indispensable for drug priming induced reinstatement of conditioned place preference.