BASAL GANGLIA MOTOR CONTROL .3. PALLIDAL ABLATION - NORMAL REACTION-TIME, MUSCLE COCONTRACTION, AND SLOW MOVEMENT
BASAL GANGLIA MOTOR CONTROL .3. PALLIDAL ABLATION - NORMAL REACTION-TIME, MUSCLE COCONTRACTION, AND SLOW MOVEMENT
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DOI：
10.1152/jn.1991.65.2.330
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发表时间：
1991-02-01
影响因子：
2.5
通讯作者：
THACH, WT
中科院分区：
文献类型：
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作者：
MINK, JW;THACH, WT
1. 在两只恒河猴中，通过显微注射蝇蕈醇（暂时性）和红藻氨酸（永久性）实现了苍白球内侧部（GPi）中含有最大浓度的腕部相关神经元的部分的失活。 蝇蕈醇注射后，在30 s内出现以下情况：1）腕屈肌和伸肌的强直性和阶段性共激活; 2）屈肌的激活略大，在姿势保持和运动终点时产生屈肌偏倚; 3）所有运动缓慢，运动时间延长。 然而，4）通过减少先前负荷的肌肉活动（沿负荷方向移动）所做的运动比通过增加肌肉活动（逆负荷方向移动）所做的运动慢。 尽管所有的动作都明显变慢，但对动作的反应时间是正常的。 最后，大多数动作的幅度都降低了。 开放房间行为包括行走时在病变对侧盘旋。 效果是可重复的（12次注射），在7-8小时内明显，通常在第二天的测试中完全消失。3. 在红藻氨酸注射后，有一段时间的混合效应，随后是一段时间的永久性缺陷（观察长达24天），复制了蝇蕈醇的临时效应。 相比之下，蝇蕈醇失活小脑齿状核导致1）反应时间延长和2）运动轨迹的可变性增加，但3）运动时间或峰值速度没有变化。 开放房间行为包括用注射同侧的前肢够水果时的过冲。 从正常的苍白球神经元的火灾不断，苍白球神经元抑制其目标神经元，蝇蕈醇的效果是即时的事实，我们得出结论，从紧张性抑制释放的目标神经元，使他们火的模式，促进维持状态的激动剂和拮抗剂肌肉的共收缩。从运动时间延长的事实，我们得出结论，维持状态的神经活动，导致肌肉共同收缩干扰的命令，自愿运动，这是由其他机制产生的。 从运动开始的反应时间是正常的这一事实，我们得出结论，苍白球神经元可能发挥很少或根本没有作用，这些运动，而不是由其他结构，包括前大脑皮层和小脑外侧的自发启动。
1. Inactivation of the portions of globus pallidus pars interna (GPi) containing the greatest concentration of wrist-related neurons was achieved in two rhesus monkeys with microinjections of muscimol (temporary) and kainic acid (permanent).2. After muscimol injection, there was onset within 30 s of 1) tonic and phasic coactivation of wrist flexors and extensors; 2) slightly greater activation of the flexors, giving a flexor bias in postural holds and the endpoint of movements; and 3) slowness of all movements with a prolonged movement time. Nevertheless, 4) movements made by lessening prior loaded muscle activity (to move in the direction of the load) were slower than movement made by increasing muscle activity (to move against the direction of the load). Despite marked slowing of all movements, there was 5) a normal reaction time for movement onset. Finally, there was 6) a reduced amplitude of most movements. Open room behavior included 7) spiraling contralateral to the lesion while walking. Effects were reproducible (12 injections), were apparent for 7-8 h and were usually completely gone by the next day's testing.3. After kainic acid injection, there was a period of mixed effects, followed by a period of permanent defects (observed for up to 24 days) that duplicated the temporary effects of muscimol.4. By contrast, muscimol inactivation of the cerebellar dentate nucleus resulted in 1) a prolonged reaction time and 2) an increased variability of movement trajectory, but 3) without change in movement time or peak velocity. Open room behavior included overshoot in reaching for fruit with the forelimb ipsilateral to the injection.5. From the facts that normal pallidal neurons fire constantly, that pallidal neurons inhibit their target neurons, and that the muscimol effect was immediate, we conclude that the release of the target neurons from the tonic inhibition allowed them to fire in patterns that promoted a maintained state of cocontraction of agonist and antagonist muscles. From the fact the movement time was prolonged, we conclude that the maintained state of neural activity that caused the muscle cocontraction interfered with the commands for voluntary movement, which were generated by other mechanisms. From the fact that reaction time for movement onset was normal, we conclude that the pallidal neurons may play little or no role in the voluntary initiation of these movements, which are instead generated by other structures that include the anterior cerebral cortex and the lateral cerebellum.