Miller A D, Brooks V B
Exp Brain Res. 1981;41(2):146-58. doi: 10.1007/BF00236604.
This study was conducted to determine which supraspinal structures, if any, are essential for generation of late (M2 and M3) EMG responses to perturbations. EMGs were recorded during active arm movements made by Cebus monkeys trained to resist perturbations applied to a handle and/or during passive movements imposed on sedated or anesthetized animals. EMGs were tested during active movements after ablation of the arm areas of the sensory and caudal motor cortices, during cooling part of the sensorimotor cortex along the central sulcus, and during cooling the arm area in the ventral lateral (VL) thalamus. EMG responses to passive movements were tested after decerebration and decerebellation, after lesions of the motor and/or sensory cortices, during surface cooling the same, and during cooling the VL arm area and the cerebellar dentate nucleus. M1, M2, and M3 were not abolished in any monkey. Decreases in the magnitudes of these responses occurred in some animals, but no reproducible changes in the sizes of M2 and M3 (in comparison to M1) were observed following any procedure. The effects of cortical lesions on M1, M2, and M3 responses to passive movements were found to depend on the level of arousal of the animal. These results demonstrate that M1, M2, and M3 can be produced in the primate spinal cord and brainstem and that the sensorimotor cortex can facilitate these responses.
本研究旨在确定对于对扰动产生晚期（M2和M3）肌电图（EMG）反应而言，哪些脊髓上结构（若有的话）是必不可少的。在受过训练以抵抗施加于手柄的扰动的卷尾猴进行主动手臂运动期间，以及在对镇静或麻醉动物施加被动运动期间，记录肌电图。在感觉皮层和尾侧运动皮层的手臂区域被切除后、在沿着中央沟对感觉运动皮层的一部分进行冷却期间、以及在对腹外侧（VL）丘脑的手臂区域进行冷却期间，测试主动运动期间的肌电图。在去大脑和去小脑后、在运动和/或感觉皮层受损后、在对相同区域进行表面冷却期间、以及在冷却VL手臂区域和小脑齿状核期间，测试对被动运动的肌电图反应。在任何猴子中，M1、M2和M3均未被消除。在一些动物中，这些反应的幅度有所降低，但在任何操作后，均未观察到M2和M3（与M1相比）大小有可重复的变化。发现皮层损伤对M1、M2和M3对被动运动反应的影响取决于动物的觉醒水平。这些结果表明，M1、M2和M3可在灵长类动物的脊髓和脑干中产生，并且感觉运动皮层可促进这些反应。
