Dept. of Rehabilitation Medicine, Keio Univ. School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
J Appl Physiol (1985). 2010 Oct;109(4):1086-95. doi: 10.1152/japplphysiol.00869.2009. Epub 2010 Aug 5.
It has been well documented that the 15- to 35-Hz oscillatory activity of the sensorimotor cortex shows coherence with the muscle activity during weak to moderate steady contraction. To investigate the muscle dependency of the corticomuscular coherence and its training-related alterations, we quantified the coherence between electroencephalogram (EEG) from the sensorimotor cortex and rectified electromyogram (EMG) from five upper limb (first dorsal interosseous, flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) and four lower limb muscles (soleus, tibialis anterior, biceps femoris, rectus femoris), while maintaining a constant force level at 30% of maximal voluntary contraction of each muscle, in 24 untrained, 12 skill-trained (ballet dancers), and 10 strength-trained (weightlifters) individuals. Data from untrained subjects demonstrated the muscle dependency of corticomuscular coherence. The magnitude of the EEG-EMG coherence was significantly greater in the distally located lower limb muscles, such as the soleus and tibialis anterior, than in the upper or other lower limb muscles in untrained subjects (P < 0.05). These results imply that oscillatory coupling between the sensorimotor cortex and spinal motoneurons during steady contraction differs among muscles, according to the functional role of each muscle. In addition, the ballet dancers and weightlifters showed smaller EEG-EMG coherences than the untrained subjects, especially in the lower limb muscles (P < 0.05). These results indicate that oscillatory interaction between the sensorimotor cortex and spinal motoneurons can be changed by long-term specialized use of the muscles and that this neural adaptation may lead to finer control of muscle force during steady contraction.
已有大量文献记载,感觉运动皮层在 15-35Hz 范围内的震荡活动与弱至中度稳定收缩期间的肌肉活动具有相干性。为了研究皮质肌相干性的肌肉依赖性及其与训练相关的变化,我们量化了脑电图(EEG)来自感觉运动皮层和五个上肢(第一背间骨间、桡侧腕屈肌、桡侧腕伸肌、肱二头肌、肱三头肌)和四个下肢肌肉(比目鱼肌、胫骨前肌、股二头肌、股直肌)的肌电图(EMG)之间的相干性,同时保持每个肌肉 30%最大自主收缩力的恒定力水平,在 24 名未经训练的、12 名技能训练(芭蕾舞演员)和 10 名力量训练(举重运动员)个体中。来自未经训练的受试者的数据表明皮质肌相干性具有肌肉依赖性。在未经训练的受试者中,EEG-EMG 相干性的幅度在位于远端的下肢肌肉(如比目鱼肌和胫骨前肌)中明显大于上肢或其他下肢肌肉(P <0.05)。这些结果表明,在稳定收缩期间,感觉运动皮层与脊髓运动神经元之间的震荡耦合根据每个肌肉的功能作用而在不同肌肉之间有所不同。此外,芭蕾舞演员和举重运动员的 EEG-EMG 相干性比未经训练的受试者小,尤其是在下肢肌肉中(P <0.05)。这些结果表明,感觉运动皮层与脊髓运动神经元之间的震荡相互作用可以通过肌肉的长期专门使用来改变,这种神经适应可能导致在稳定收缩期间对肌肉力量的更精细控制。