Amalric M, Koob G F
Department of Basic and Clinical Research, Research Institute of Scripps Clinic, La Jolla, CA 92037.
Brain Res. 1989 Apr 3;483(2):389-94. doi: 10.1016/0006-8993(89)90186-8.
A major function of the dopamine in the striatum is to control the activity of its efferent systems which contain primarily GABAergic neurons. Direct intracerebral injections of haloperidol into the corpus striatum impaired the performance of rats trained to depress a lever in a sensitive reaction time task. Rats were trained to depress a lever until the presentation of a visual conditioned stimulus and then to release the lever within a time limit of 500 ms to obtain a food reward. The increase in reaction time produced by dopamine blockade of the corpus striatum was mimicked by injection of a GABA agonist muscimol in nanogram quantities into the region of the dorsal pallidum, but not into the substantia nigra reticulata. Injections of a GABA agonist into the substantia nigra impaired performance by increasing the number of anticipatory responses (increased number of lever releases before the conditioned stimulus). These results suggest that the dorsal pallidum may play an important role in the response initiation associated with activation of the corpus striatum, and that the dorsal pallidum may form a significant part of parallel striatal outputs that have different functional significance.
纹状体中多巴胺的一个主要功能是控制其传出系统的活动，该传出系统主要包含γ-氨基丁酸（GABA）能神经元。向大鼠纹状体内直接注射氟哌啶醇，会损害经过训练在敏感反应时任务中按压杠杆的大鼠的表现。大鼠经过训练，在视觉条件刺激出现前按压杠杆，然后在500毫秒的时间限制内松开杠杆以获得食物奖励。纹状体多巴胺阻断所导致的反应时间增加，可通过向背侧苍白球区域注射纳克量的GABA激动剂蝇蕈醇来模拟，但向黑质网状部注射则不能。向黑质注射GABA激动剂会通过增加预期反应的数量（条件刺激出现前杠杆松开次数增加）来损害大鼠表现。这些结果表明，背侧苍白球可能在与纹状体激活相关的反应启动中起重要作用，并且背侧苍白球可能构成具有不同功能意义的平行纹状体输出的重要组成部分。
