Repeated morphine treatment influences operant and spatial learning differentially  

作　　者：Mei-Na WANG Zhi-Fang DONG Jun CAO Lin XU 

机构地区：[1]Key Laboratory of Animal Models and Human Disease Mechanisms, Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, and Graduate School of Chinese Academy of Sciences, Beijing 100039, China [2]Mental Health Institute, the 2^nd Xiangya Hospital of Central South University, Changsha 410011, China

出　　处：《Neuroscience Bulletin》2006年第3期137-143,共7页神经科学通报（英文版）

基　　金：This work was supported by grants from the National Natural Science Foundation of China （No. 30470549）;the National Basic Research Priorities Programme （973） of China （No.2006CBS00800）

摘　　要：Objective To investigate whether repeated morphine exposure or prolonged withdrawal could influence operant and spatial learning differentially. Methods Animals were chronically treated with morphine or subjected to morphine withdrawal. Then, they were subjected to two kinds of learning: operant conditioning and spatial learning. Results The acquisition of both simple appetitive and cued operant learning was impaired after repeated morphine treatment. Withdrawal for 5 weeks alleviated the impairments. Single morphine exposure disrupted the retrieval of operant memory but had no effect on rats after 5-week withdrawal. Contrarily, neither chronic morphine exposure nor 5-week withdrawal influenced spatial learning task of the Morris water maze. Nevertheless, the retrieval of spatial memory was impaired by repeated morphine exposure but not by 5-week withdrawal. Conclusion These observations suggest that repeated morphine exposure can influence different types of learning at different aspects, implicating that the formation of opiate addiction may usurp memory mechanisms differentially.Objective To investigate whether repeated morphine exposure or prolonged withdrawal could influence operant and spatial learning differentially. Methods Animals were chronically treated with morphine or subjected to morphine withdrawal. Then, they were subjected to two kinds of learning： operant conditioning and spatial learning. Results The acquisition of both simple appetitive and cued operant learning was impaired after repeated morphine treatment. Withdrawal for 5 weeks alleviated the impairments. Single morphine exposure disrupted the retrieval of operant memory but had no effect on rats after 5-week withdrawal. Contrarily, neither chronic morphine exposure nor 5-week withdrawal influenced spatial learning task of the Morris water maze. Nevertheless, the retrieval of spatial memory was impaired by repeated morphine exposure but not by 5-week withdrawal. Conclusion These observations suggest that repeated morphine exposure can influence different types of learning at different aspects, implicating that the formation of opiate addiction may usurp memory mechanisms differentially.

关 键 词：MORPHINE ADDICTION WITHDRAWAL CONDITIONING spatial learning 

分 类 号：R338.64[医药卫生—人体生理学] R996[医药卫生—基础医学]