Cunningham C L, Niehus J S, Noble D
Department of Medical Psychology, Oregon Health Sciences University, Portland 97201-3098.
Alcohol. 1993 Mar-Apr;10(2):97-102. doi: 10.1016/0741-8329(93)90087-5.
Recent research suggests that rats and mice differ in their sensitivity to ethanol's rewarding effect in the place conditioning paradigm. However, these species have not previously been examined in a comparable manner. The present study compared genetically heterogeneous rats and mice using an identical place conditioning procedure. Each animal received four pairings of a distinctive tactile floor stimulus with injection of ethanol (1.5 g/kg); a different tactile stimulus was paired with saline injection. Ethanol suppressed activity in rats but elevated activity in mice. As in most previous studies with drug-naive animals, rats showed aversion whereas mice showed preference for the ethanol-paired stimulus. This difference cannot be attributed to differences in housing conditions, apparatus, stimuli, or temporal parameters. Rather, it appears to represent a species difference in initial sensitivity to ethanol's hedonic effects. If one assumes that ethanol is both rewarding and aversive, this outcome might be explained by a species difference in tolerance/sensitization, the time-course of the biphasic hedonic response to a single ethanol exposure, or selective association. Together with other recent studies from this laboratory, the present findings suggest the mouse may well be the species of choice for studying preferences conditioned by ethanol.
最近的研究表明，在位置条件反射范式中，大鼠和小鼠对乙醇奖赏效应的敏感性存在差异。然而，此前尚未以可比较的方式对这些物种进行研究。本研究使用相同的位置条件反射程序，对基因异质的大鼠和小鼠进行了比较。每只动物接受四次将独特的触觉地板刺激与注射乙醇（1.5克/千克）配对；将不同的触觉刺激与注射生理盐水配对。乙醇抑制了大鼠的活动，但提高了小鼠的活动。与之前大多数对未接触过药物的动物的研究一样，大鼠表现出厌恶，而小鼠则表现出对与乙醇配对的刺激的偏好。这种差异不能归因于饲养条件、实验装置、刺激或时间参数的差异。相反，这似乎代表了对乙醇享乐效应初始敏感性的物种差异。如果假设乙醇既有奖赏性又有厌恶性，那么这一结果可能可以用耐受性/敏感性的物种差异、对单次乙醇暴露的双相享乐反应的时间进程或选择性关联来解释。结合该实验室最近的其他研究，目前的研究结果表明，小鼠很可能是研究由乙醇形成的偏好的首选物种。
