场景熟悉度对慢性吗啡处理诱导小鼠行为敏化的影响

目的 探求场景熟悉度对慢性吗啡处理诱导小鼠行为敏化的影响.方法 (1)实验一:分别在新颖场景(测试箱)和熟悉场景(鼠笼)中连续7天给予小鼠吗啡处理(10 mg/kg,皮下注射,1次/d);撤药后第7天,在测试箱中给予10 mg/kg吗啡点燃后观察其行为敏化效应.(2)实验二:连续7天给予小鼠吗啡处理(10 mg/kg,皮下注射,1次/d);撤药后第7 d,检测行为敏化的表达,其中配对组检测场景为伴药场景,非配对组检测场景为非伴药场景.结果 (1)实验一:吗啡注射与新颖场景配对能够诱导小鼠行为敏化,而与熟悉场景配对不能诱导小鼠行为敏化.(2)实验二:吗啡注射与新颖场景配对诱导的敏化行为只在吗啡配对的新颖场景中表达而在非配对的新颖场景中不表达.结论 小鼠行为敏化的建立与吗啡注射配对场景的熟悉度相关,并且其表达是场景依赖性的.

Effects of Contextual Familiarity on Behavioral Sensitization Induced by Chronic Morphine Administration in Mice

Objective To investigate the effects of contextual familiarity on behavioral sensitization induced by chronic morphine administration in mice. Methods (1) Experiment 1: Mice were administrated subcutaneously morphine(10 mg/kg,once per day) for consecutive 7 days either in the test chamber(novel context) or home cage(familiar context).After a 6-day washout period,the mice were challenged with 10 mg/kg morphine and then put into the test chambers to measure their locomotor activity for 1 h.(2) Experiment 2: Mice were administrated subcutaneously morphine(10 mg/kg,once per day) for consecutive 7 days.After a 6-day washout period,the mice were challenged with 10 mg/kg morphine and then put into the test chambers to measure their locomotor activity for 1 h.The paired groups were measured for their locomotor activity in the context in which morphine or saline was administrated,however,the unpaired groups were measured for their locomotor activity in the context in which no morphine or saline was administrated.Results (1) Experiment 1: Pairing morphine administration to the novel context,not the familiar context,induced behavioral sensitization in mice.(2) Experiment 2: The expression of behavioral sensitization was only observed in the context in which morphine was administrated. Conclusion The induction of morphine behavioral sensitization in mice is related to the contextual familiarity,and this expression of behavioral sensitization is context-dependent.