Wilcox R E, Spirduso W W
Department of Pharmacology and Toxicology, College of Pharmacy, University of Texas, Austin 78712.
Psychopharmacology (Berl). 1988;95(2):276-9. doi: 10.1007/BF00174524.
Previously, several studies in our laboratories have linked the ability to initiate movement rapidly (reactive capacity) in several rat strains to markers of nigrostriatal dopamine function. In the present investigation we wished to determine the extent to which fast-reacting (FR) and slow-reacting (SR) rats responded differentially to the effects of dopamine agonist (apomorphine) administration. Fisher 344 rats were operantly conditioned on a shock-avoidance, reactive capacity task which requires extremely fast, ballistic, lever release responses. In FR, but not in SR rats, significant dose-dependent decreases in the per cent of successful avoidance trials were observed in response to apomorphine doses. Moreover, apomorphine brought responding in the FR animals to levels below that of the SR rats. Performance of the SR rats was unaffected by drug treatments. A number of interpretations are consistent with these preliminary data, including the idea that basal differences in speed of reaction and differential responses to a dopamine agonist, antiparkinsonian agent may both be associated with a similar mechanism: differential activation of compartmentalized striatal efferent systems.
此前，我们实验室的多项研究已将几种大鼠品系中快速发起运动的能力（反应能力）与黑质纹状体多巴胺功能的标志物联系起来。在本研究中，我们希望确定快速反应（FR）大鼠和慢速反应（SR）大鼠对多巴胺激动剂（阿扑吗啡）给药效果的反应差异程度。将Fisher 344大鼠进行操作性条件反射训练，使其完成一项避免电击的反应能力任务，该任务需要极快的、弹道式的杠杆释放反应。在FR大鼠而非SR大鼠中，观察到阿扑吗啡剂量导致成功避免试验百分比出现显著的剂量依赖性下降。此外，阿扑吗啡使FR动物的反应水平低于SR大鼠。SR大鼠的表现不受药物治疗影响。许多解释与这些初步数据一致，包括反应速度的基础差异和对多巴胺激动剂（抗帕金森病药物）的不同反应可能都与类似机制有关的观点：纹状体传出系统分区的差异激活。
