apamin对日龄雏鸡长时记忆的影响  

Effect of apamin on the long-term memory in one-trial passive avoidance learning task of day-old chick

作　　者：赵希武[1,2] 王倩[1] 张旭[1] 徐慕玲[1] 蒋锦昌[1] 李兵[1] 

机构地区：[1]中国科学院生物物理研究所,脑与认知科学国家重点实验室,北京100101 [2]中国科学院研究生院,北京100049

出　　处：《中国科学：生命科学》2010年第6期501-508,共8页Scientia Sinica(Vitae)

基　　金：国家自然科学基金(批准号:30400090);国家高技术研究发展计划(批准号:2007AA02Z313);中国科学院知识创新工程(批准号:KSCX1-YW-R-32)资助项目

摘　　要：日龄雏鸡的一次性被动回避学习任务模型被广泛应用于记忆机制研究,具有多方面的优势和便利性.apamin是SK通道(钙离子激活的小电导钾离子通道)的一种选择性阻断剂,以往研究显示其可能增进记忆.但人们对其作用机制的了解不是很充分.使用颅内微量注射方法,在雏鸡中枢记忆相关核团IMM施加apamin,研究其对记忆形成和保持的影响.实验结果显示,雏鸡在弱刺激条件下的被动回避任务中本不能形成稳定的长时记忆,但在训练前短时间内或训练后立即注射适量apamin,可以易化长时记忆的形成.然而,apamin对记忆随时间衰退的过程几乎没有影响,即对记忆保持没有增进作用.此外,在左、右脑IMM单侧注射apamin都可促进记忆形成,但所需剂量高于双侧注射时,且在左侧产生效应的时间早于右侧,这体现了两侧IMM在记忆加工中作用的不对称性.这些结果提示,apamin可能通过阻断中枢记忆相关核团内的SK通道,影响由训练诱发的、与记忆形成有关的某些分子或细胞事件,在一定程度上起到改善记忆的作用.The one-trial passive avoidance learning task of the day-old chick,with distinct advantages in many aspects,is widely used as a behavioral model in studies of learning and memory.Apamin is a selective blocker of small conductance Ca2＋-activated K＋ （SK） channel.Previous studies have shown that apamin may improve the memory performance,but the understanding is limited and the underlying mechanism remains unclear.In the present study,apamin was administered into IMM,a primary memory-related nucleus in the chick brain,by intracerebral injection,and the effect on memory formation and retention was examined.After weakly reinforced training,the sham-control chicks did not exhibit clear long-term memory;but the administration of an appropriate dose of apamin shortly before the training or immediately after the training could facilitate the formation of long-term memory.However,there was hardly any change in the time course of memory decaying,in other words,the memory retention was not enhanced by apamin.In addition,the memory formation could be promoted by unilateral injection of apamin in either hemisphere,but a higher dose was required than that for bilateral injection.The effective time of apamin was earlier in the left hemisphere than in the right,indicating the asymmetrical involvement of bilateral IMMs in memory processing.These results suggest that,by blocking the SK channels in the memory-related nuclei in the brain,apamin can affect some training-triggered molecular and cellular events which are related to memory formation,and hence may improve the memory function to some extent.

关 键 词：日龄雏鸡 一次性被动回避学习任务 长时记忆 APAMIN SK通道 

分 类 号：R33[医药卫生—人体生理学]