Presti Michael F, Powell Susan B, Lewis Mark H
Department of Psychiatry, University of Florida, 100 South Newell Drive, PO Box 100256, Gainesville, FL 32610, USA.
Physiol Behav. 2002 Mar;75(3):347-53. doi: 10.1016/s0031-9384(02)00641-8.
Stereotyped behavior is repetitive, topographically invariant motor activity that lacks an obvious function. We have previously characterized the spontaneous and persistent stereotypies that occur in deer mice housed in standard laboratory cages. Providing these animals with enriched environments markedly reduces their vulnerability to develop stereotypic behavioral repertoires, thus enabling us to generate behaviorally distinct (stereotypic and nonstereotypic) mice of the same species. As stereotypic behaviors are readily induced by systemic administration of a dopamine (DA) agonist, the present study tested whether apomorphine would induce stereotypies in environmentally enriched (nonstereotypic) deer mice that were topographically similar to the stereotypies that are spontaneously emitted by standard-caged (stereotypic) deer mice. The effects of apomorphine were also evaluated in the standard-caged (stereotypic) deer mice. DA agonist-induced behaviors in nonstereotypic mice included stereotypies that were largely topographically distinct from spontaneously emitted stereotypies; apomorphine failed to produce statistically significant elevations in two of the three stereotypic behaviors typical of standard-caged deer mice. Furthermore, there was no evidence of increased DA receptor sensitivity in stereotypic mice. Thus, environmentally related stereotypy is distinct from systemically administered DA agonist-induced stereotypy, and is not exacerbated by such drug treatment. The results obtained do provide support, however, for a limited involvement of the DA system in the mediation of these behaviors.
刻板行为是一种重复的、在地形上不变的运动活动，缺乏明显的功能。我们之前已经描述了饲养在标准实验室笼子里的鹿鼠中出现的自发且持续的刻板行为。为这些动物提供丰富的环境会显著降低它们发展出刻板行为模式的易感性，从而使我们能够培育出同一物种中行为不同（刻板和非刻板）的小鼠。由于系统性给予多巴胺（DA）激动剂很容易诱发刻板行为，本研究测试了阿扑吗啡是否会在环境丰富（非刻板）的鹿鼠中诱发刻板行为，这些刻板行为在地形上与标准笼养（刻板）鹿鼠自发产生的刻板行为相似。同时也评估了阿扑吗啡在标准笼养（刻板）鹿鼠中的作用。DA激动剂在非刻板小鼠中诱发的行为包括在很大程度上与自发产生的刻板行为在地形上不同的刻板行为；阿扑吗啡未能使标准笼养鹿鼠典型的三种刻板行为中的两种产生具有统计学意义的增加。此外，没有证据表明刻板小鼠中DA受体敏感性增加。因此，与环境相关的刻板行为不同于系统性给予DA激动剂诱发的刻板行为，并且不会因这种药物治疗而加剧。然而，所获得的结果确实为DA系统在这些行为的介导中有限的参与提供了支持。
