吗啡点燃条件位置性偏爱重现大鼠海马CA1区多巴胺递质的变化

目的检测吗啡（morphine，Mor）点燃条件位置性偏爱（conditioned plac epreference，cPP）重现大鼠海马CA1区多巴胺（dopamine，DA）递质的变化，揭示海马CA1区DA递质的变化与吗啡点燃诱发cPP重现的关系．方法用恒量法（10mg／kg）给大鼠连续颈背部皮下注射（subcutaneous，SC）吗啡8d建立CPP模型；用生理盐水替代吗啡训练大鼠10d，使形成的CPP逐渐消退；单次SC2．5mg／kg吗啡点燃已消退的CPP．用荧光分光光度法检测吗啡点燃CPP重现大鼠海马CA1区DA递质的变化．结果SC10mg／kg吗啡8d建立CPP，生理盐水训练10d使已形成的CPP消退，小剂量吗啡（2．5mg／kg）使消退的CPP重现；吗啡点燃CPP重现大鼠海马CA1区DA含量与对照组比较显著增加（P〈0．05）．结论吗啡点燃CPP重现时大鼠海马CA1区DA增加，小剂量吗啡诱发大鼠CPP重现行为可能与海马CA1区中DA含量增加有关．

The Changes of Dopamine in Hippocampal CA1 in CPP Activition Model Induced by Morphine in Rats

Objective To detect the changes of dopamine in hippocampal CA1 in CPP activition model induced by morphine in rats and to reveal the relationship between dopamine changes in hippocampal CA1 and CPP recurrence induced by morphine. Methods Morphine was administered via subcutaneous injection at constant dose （10 mg/kg） for 8 days to establish morphine CPP. The rats were administered saline instead of morphine to induce CPP extinction for 10 days. CPP was reinstated following a single priming injection of morphine （2.5 mg/kg） to kindle CPP. The changes of dopamine in hippocampal CA1 in CPP activition model induced by morphine in rats were detected by fluorospectrophotometer. Results Injecting morphine （10 mg/kg） for 8 d induced CPP successfully. After 10 days training with saline, CPP failed to be induced. A single priming injection of morphine （2.5 mg/kg） kindled CPP. The contents of dopamine in hippocampal CA1 in the activition CPP model induced by morphine in rats were higher than control group （P 〈 0.05）. Conclusion The contents of dopamine in hippocampal CA1 in the activition CPP model induced by morphine in rats increase, CPP recurrence induced by morphine is probably related to the increase of dopamine in hippocampal CA1.