Central Glutamatergic and Monoaminergic Systems of Rats in Morphine Dependence and Withdrawal: A Microdialysis Study

• Main Authors: Hwang Nei Gwei, 黃乃瑰
• Other Authors: Tung C. S.
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/64830208832070134105

碩士 === 國防醫學院 === 生理學研究所 === 81 === The mechanisms of morphine dependence and withdrawal are multiple; however, morphine dependence is mostly correlated wtih the mesocorticolimbic system for its reinforcement and reward, while morphine withdrawal is primarily dependent upon the locus coeruleus for its alertness and averse. Recently, EAAs, especially the glutamate (Glu), have been proposed as contri- butors to the physiology of morphine withdrawal. NMDA receptor antagonists applied prior to the precipitation of morphine withdrawal in the morphine dependent rat attenuate the with- drawal syndrome. Furthermore, the striatal DA and Glu receptor stimulation produce opposite behaviors, although their inter- actions and anatomic locations in the corticostriatal and nigrostriatal pathway are not clearly defined. With the aid of HPLC and microdialysis, we detected changes of monoamines and Glu in nucleus accumbens (which represents the reward system) and the striatum (which represents motor function) which help define their roles and interactions in morphine dependence and withdrawal. It appears that in morphine dependent rat, DOPAC and 5-HIAA significantly increase in the nucleus accumbens and striatum, while Glu decreases; on the other hand, in the morphine with- drawal rat, DOPAC and 5-HIAA will significantly decrease, while Glu tends to increase.