Schechter M D
Department of Pharmacology, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Pharmacol Biochem Behav. 1991 Jan;38(1):7-11. doi: 10.1016/0091-3057(91)90582-m.
The purpose of this study was to examine whether first training rats to discriminate the stimulus cues produced by an indirect dopamine agonist, cathinone, would influence a subsequent test of preference. The conditioned place preference (CPP) paradigm was used to evaluate the reinforcing effects of l-cathinone in four differently treated groups of rats. Half of the animals were trained to discriminate the interoceptive cues produced by 0.8 mg/kg cathinone in a two-lever, food-motivated operant task. The other animals were equally divided between two groups, one receiving saline and noncontingent reinforcements on the same schedule as those trained to discriminate cathinone; the other group, the "yoked-control" rats, received the same cathinone and saline regimen of administration as the discrimination-trained animals. Results of CPP testing indicate that cathinone produced a statistically significant conditioned place preference only in the group trained to discriminate cathinone and not in the saline or yoked control groups. Furthermore, when half of the cathinone discrimination-trained rats were pretreated with the dopamine release inhibitor CGS 10746B, the conditioned place preference to cathinone was attenuated. The results would indicate that pairing cathinone with a nonpreferred environment tended to make the rat spend more time in that environment and the amount of time spent in the cathinone-associated environment can be increased by prior discrimination training and decreased by diminished dopamine function in the brain.
本研究的目的是检验首先训练大鼠辨别间接多巴胺激动剂卡西酮产生的刺激线索是否会影响随后的偏好测试。条件性位置偏爱（CPP）范式用于评估左旋卡西酮在四组不同处理的大鼠中的强化作用。一半的动物在双杠杆、食物驱动的操作性任务中接受训练，以辨别0.8毫克/千克卡西酮产生的内感受性线索。其他动物平均分为两组，一组接受生理盐水和与训练辨别卡西酮的动物相同时间表的非条件强化；另一组，即“配对对照组”大鼠，接受与接受辨别训练的动物相同的卡西酮和生理盐水给药方案。CPP测试结果表明，卡西酮仅在训练辨别卡西酮的组中产生了具有统计学意义的条件性位置偏爱，而在生理盐水组或配对对照组中未产生。此外，当一半接受卡西酮辨别训练的大鼠用多巴胺释放抑制剂CGS 10746B预处理时，对卡西酮的条件性位置偏爱减弱。结果表明，将卡西酮与非偏好环境配对往往会使大鼠在该环境中花费更多时间，并且在与卡西酮相关的环境中花费的时间量可以通过先前的辨别训练增加，而通过大脑中多巴胺功能的减弱而减少。
