Spain J W, Newsom G C
Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford 61107.
Psychopharmacology (Berl). 1991;105(1):101-6. doi: 10.1007/BF02316870.
Chronic morphine impaired acquisition of two dissimilar behavioral tasks. In the radial maze, the performance of saline-treated and morphine-treated groups diverged with the latter failing to improve despite extensive training. In contrast, rats treated with naltrexone became skilled in the procedure 2-4 times as rapidly as saline controls. Withdrawal of treatment significantly improved performance of morphine-treated rats, with no change for rats treated with saline or naltrexone. When a second group of rats was extensively trained prior to instituting chronic morphine treatment, performance scores were not affected, suggesting that morphine does not impair spatial working memory despite subjective evidence of other gross behavioral effects, such as ataxia. In the Y-maze choice escape task, acquisition of a response strategy was significantly impaired in rats that had been previously treated with morphine for 17-21 days, despite clear indications that morphine-treated rats were sensitive to the aversive stimulus.
慢性吗啡损害了两种不同行为任务的习得。在放射状迷宫实验中，生理盐水处理组和吗啡处理组的表现出现差异，尽管经过大量训练，吗啡处理组的表现仍未改善。相比之下，接受纳曲酮治疗的大鼠熟练掌握该实验流程的速度比生理盐水对照组快2至4倍。停止治疗后，吗啡处理组大鼠的表现显著改善，而生理盐水处理组和纳曲酮处理组大鼠的表现则无变化。当第二组大鼠在开始慢性吗啡治疗之前接受大量训练时，其表现分数并未受到影响，这表明尽管有诸如共济失调等其他明显行为效应的主观证据，但吗啡并不损害空间工作记忆。在Y型迷宫选择逃避任务中，先前接受吗啡治疗17至21天的大鼠，其反应策略的习得显著受损，尽管有明确迹象表明吗啡处理组大鼠对厌恶刺激敏感。
