戒断对吗啡依赖小鼠自发活动及场景性恐惧条件化表达的影响  

Effects of abstinence on locomotor activity and contextual fear conditioning in morphine-dependent mice

作　　者：宋赠[1] 宋娟[2] 欧阳新平[1] 高军[1] 付爱文 田绍文[1] 

机构地区：[1]南华大学医学院生理学教研室,衡阳421001 [2]第二军医大学基础医学部神经生物学教研室,上海200433 [3]山东省阳信县计划生育服务站,阳信251800

出　　处：《第二军医大学学报》2007年第4期385-388,共4页Academic Journal of Second Military Medical University

基　　金：湖南省教育厅优秀青年基金(05B045)~~

摘　　要：目的:研究不同戒断期对吗啡依赖小鼠自发活动及场景性恐惧条件化表达的影响。方法:以剂量递增法连续皮下注射(sc)盐酸吗啡7 d建立吗啡依赖小鼠模型,随机分成吗啡戒断1 d、吗啡戒断7 d、吗啡戒断21 d组,并设立生理盐水戒断1、7、21 d组作为对照,每组12～13只。戒断后采用旷场实验观察小鼠自发活动(检测穿梭格数、直立次数、理毛时间、中央区活动时间、进入中央次数及外周时间等指标);随后对小鼠进行场景性恐惧条件化,并于24 h后进行恐惧反应(僵直)的检测。结果:与生理盐水对照组相比,吗啡戒断1 d、7 d组小鼠的水平活动度(P<0．001,P<0．001)和进入中央区次数(P<0．001, P<0．05)明显降低;戒断1 d组小鼠垂直运动也显著下降(P<0．001);吗啡戒断1 d组的理毛行为增加(P<0．05);但各吗啡戒断组的中央区、外周活动时间无显著差异。吗啡处理还选择性损害了戒断1 d组小鼠的场景性恐惧条件化表达(P<0．05)。结论:戒断早期降低了吗啡依赖小鼠部分自发活动,同时损害了场景性恐惧条件化表达。Objective： To study the impact of different abstinence periods on locomotor activity and contextual fear conditioning in morphine-dependent mice. Methods： Morphine hydrochloride was administrated （sc） to mice at a gradually increasing dose for 7 d to establish morphine-dependent model. After the last injection, animals were divided into MW1 d （Morphine Withdrawal for 1 d）, MW7 d, MW21 d, SW1 d（Saline Withdrawal for 1 d）,SW7 d and SW 21 d groups randomly; the spontaneous activities of mice, including the numbers of crossing and rearing, grooming times, the number of center entries and time spent in center area, and the time spent in peripheral area, were observed in the open field box after different periods of abstinence. After the observation, the mice were trained using eight unconditioned stimulus （0.5 s; 0.5 mA foot shock） and contextual fear conditioning was tested 24 h later. Results.. The times of crossing and center entries decreased in MWl d and MW7 dmice （WI d： P〈0.001, P〈0.001;W7 d： P〈0.001,P〈0.05）; the time of rearing in MWI d group was also decreased significantly （P〈0. 001）. mice in MW1 d group had more grooming behaviors （P〈0.05）. The periods spent in the center and peripheral areas were not significantly different between all the 3 morphine-dependent groups and their corresponding saline withdrawal groups. In addition, a history of morphine injection selectively impaired the contextual fear conditioning in mice of MW1 d group （P〈0. 05）. Conclusion： During the early period of morphine abstinence, mice have a decreased spontaneous activity and an impaired contextual fear conditioning.

关 键 词：吗啡依赖 物质戒断综合征 自发活动 恐惧 

分 类 号：R971.2[医药卫生—药品]