Mayfield R D, Randall P K, Spirduso W W, Wilcox R E
Department of Kinesiology, University of Texas at Austin 78712.
Pharmacol Biochem Behav. 1993 Dec;46(4):769-75. doi: 10.1016/0091-3057(93)90199-4.
Apomorphine, a nonselective, direct-acting dopamine agonist, and amphetamine, a nonselective indirect-acting dopamine agonist, were compared for their effects on the reaction time response in rats. Animals were shaped to release a lever in response to an auditory/visual stimulus to avoid mild foot shock. The characteristics of the reaction time response of primary interest were percent successful avoidance and response latency. Apomorphine (0, 1, and 5 mg/kg, IP) significantly decreased successful avoidance, but had no effect on response latencies. Thus, the decrease in successful avoidance was not a direct result of longer latencies. Amphetamine (0, 0.5, and 1 mg/kg, IP) produced a different pattern of effects on the reaction time response. Successful avoidance was not affected by amphetamine treatment. However, response latencies were dose-dependently decreased in response to amphetamine. These results demonstrate that dopamine receptor stimulation by different dopamine agonists produces a different pattern of effects on the characteristics of the reaction time response. In addition, these results demonstrate that successful avoidance can be modulated independently of response latencies.
阿扑吗啡是一种非选择性的直接作用多巴胺激动剂，苯丙胺是一种非选择性的间接作用多巴胺激动剂，研究人员比较了它们对大鼠反应时间的影响。训练动物在听到听觉/视觉刺激时按下杠杆以避免轻微的足部电击。主要关注的反应时间特征为成功回避百分比和反应潜伏期。阿扑吗啡（0、1和5毫克/千克，腹腔注射）显著降低了成功回避率，但对反应潜伏期没有影响。因此，成功回避率的降低并非潜伏期延长的直接结果。苯丙胺（0、0.5和1毫克/千克，腹腔注射）对反应时间产生了不同的影响模式。苯丙胺处理对成功回避率没有影响。然而，反应潜伏期随着苯丙胺剂量的增加而呈剂量依赖性缩短。这些结果表明，不同的多巴胺激动剂刺激多巴胺受体会对反应时间特征产生不同的影响模式。此外，这些结果表明成功回避可以独立于反应潜伏期进行调节。
