Kazennikov O V
Kharkevich Institute of Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
Neurosci Behav Physiol. 2010 Jul;40(6):645-51. doi: 10.1007/s11055-010-9307-3. Epub 2010 Jun 12.
Electromyographic activity and synchronous discharges in the muscles of the wrist induced by transcranial magnetic stimulation of the motor cortex as the thumb and index finger were used to hold a handle bearing a weight were studied during performance of a number of motor tasks. When the subject increased grip force, for example, in response to increases in the weight of the attached load or by voluntarily squeezing the handle, the evoked response increased proportionally to muscle activity. If the subject moved the hand holding the handle up and down with an amplitude of 10 cm and a frequency of 0.5-1 Hz, grip force changed in accordance with the predicted inertial loading. The muscle response in the adductor pollicis muscle increased to a greater extent than the activity in the muscle. The response to sudden inertial loading consisted of a reflex increase in grip force, the muscle response increasing to a lesser extent than activity in the muscle. This suggests that larger increases in evoked muscle responses on up and down movement of the hand with a load are associated with anticipatory changes in grip force. These results are assessed from the point of view of the involvement of the motor cortex in generating anticipatory changes in muscle activity in the distal muscles.
在进行一系列运动任务时，研究了经颅磁刺激运动皮层诱发的腕部肌肉肌电图活动和同步放电情况，此时拇指和食指握住一个带有重物的手柄。例如，当受试者增加握力时，无论是因附加负载重量增加还是通过主动挤压手柄，诱发反应都与肌肉活动成比例增加。如果受试者以10厘米的幅度和0.5 - 1赫兹的频率上下移动握住手柄的手，握力会根据预测的惯性负荷而变化。拇收肌的肌肉反应比该肌肉的活动增加幅度更大。对突然惯性负荷的反应包括握力的反射性增加，肌肉反应的增加幅度小于该肌肉的活动。这表明，手部负载上下移动时诱发肌肉反应的更大增加与握力的预期变化有关。从运动皮层参与产生远端肌肉活动预期变化的角度对这些结果进行了评估。
