摘要目的 观察在经历特定剂量吗啡前期用药后的停药状态下,大鼠空间学习和反应学习过程的改变.方法 在前期用药阶段,戒断组及持续给药组皮下注射吗啡5 mg·kg-1·d-1,连续6 d,盐水组在相同时间注射生理盐水,之后,各组进行水迷宫空间学习任务或反应学习任务.在训练期间,戒断组和盐水组每天注射盐水,持续给药组连续给药.结果 空间学习任务中,在训练第3轮,各组正确率分别为戒断组[(97.0±6.0)%]、持续给药组[(79.9±20.1)%]、盐水组[(61.0±20.6)%],戒断组显著高于盐水组( P <0.01 post-hoc LSD test),重复测试显示,戒断组空间学习显著优于盐水组( P <0.05),在空间反向任务中,戒断组表现亦显著优于盐水组.反应学习任务及反应反向学习任务中,各组间差异无显著性.结论 本研究提示在吗啡戒断状态下大鼠空间学习过程增强.

abstractsObjective To investigate the effects of morphine withdrawal on place learning and response learning in rat. Methods 48 wistar rats were divided into morphine-withdrawal group,morphine-maintenance group and saline group. First,the morphine-withdrawal group and morphine-maintenance group both received morphine pretreatment (SC 5mg.kg-1.day-1) for 6 days,and the saline group received saline injection in the same time. Then all the animals were trained with the place learning task or the response learning task in water plus maze. The morphine-maintenance group received morphine daily between two trains,and the morphine-withdrawal groups and saline group received saline in the same time. Results In the place learning task ,the correction rate of the morphine-withdrawal group,morphine-maintenance group and saline group was (97.0±6.0)%,(79.9±20.1)% and (61.0±20.6)% respectively .The difference between morphine-withdrawal group and saline group was significantly ( P <0.01 ).Accordingly,the difference in training effect was significant between these two groups by repeated measure with analysis of variance ( F =31.196,P <0.01). Resemble results were found in the place reverse learning task. There was no significant difference in three groups in response learning task and response reverse learning task. Conclusion Morphine withdrawal may increase place learning,with no significant improvement in response learning.