Yoshida Takashi, Masani Kei, Zabjek Karl, Chen Robert, Popovic Milos R
Rehabilitation Engineering Laboratory, Toronto Rehabilitation Institute, University Health NetworkToronto, ON, Canada.
Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto, ON, Canada.
Front Hum Neurosci. 2017 Apr 4;11:155. doi: 10.3389/fnhum.2017.00155. eCollection 2017.
In humans, the midline primary motor cortex is active during walking. However, the exact role of such cortical participation is unknown. To delineate the role of the primary motor cortex in walking, we examined whether the primary motor cortex would activate leg muscles during movements that retained specific requirements of walking (i.e., locomotive actions). We recorded electroencephalographic and electromyographic signals from 15 healthy, young men while they sat and performed bilateral, cyclical ankle movements. During dorsiflexion, near-20-Hz coherence increased cyclically between the midline primary motor cortex and the co-contracting antagonistic pair (i.e., tibialis anterior and medial gastrocnemius muscles) in both legs. Thus, we have shown that dynamic increase in corticomuscular coherence, which has been observed during walking, also occurs during simple bilateral cyclical movements of the feet. A possible mechanism for such coherence is corticomuscular communication, in which the primary motor cortex participates in the control of movement. Furthermore, because our experimental task isolated certain locomotive actions, the observed coherence suggests that the human primary motor cortex may participate in these actions (i.e., maintaining a specified movement frequency, bilaterally coordinating the feet, and stabilizing the posture of the feet). Additional studies are needed to identify the exact cortical and subcortical interactions that cause corticomuscular coherence and to further delineate the functional role of the primary motor cortex during bilateral cyclical movements such as walking.
在人类中，行走时中线初级运动皮层是活跃的。然而，这种皮层参与的确切作用尚不清楚。为了阐明初级运动皮层在行走中的作用，我们研究了在保留行走特定要求（即运动动作）的运动过程中，初级运动皮层是否会激活腿部肌肉。我们记录了15名健康年轻男性在坐着并进行双侧周期性踝关节运动时的脑电图和肌电图信号。在背屈过程中，中线初级运动皮层与双腿共同收缩的拮抗肌对（即胫骨前肌和腓肠肌内侧头）之间近20赫兹的相干性呈周期性增加。因此，我们已经表明，在行走过程中观察到的皮质-肌肉相干性的动态增加，在双脚简单的双侧周期性运动中也会出现。这种相干性的一种可能机制是皮质-肌肉通信，其中初级运动皮层参与运动控制。此外，由于我们的实验任务分离了某些运动动作，观察到的相干性表明人类初级运动皮层可能参与这些动作（即维持特定的运动频率、双侧协调双脚以及稳定双脚姿势）。需要进一步的研究来确定导致皮质-肌肉相干性的确切皮层和皮层下相互作用，并进一步阐明初级运动皮层在诸如行走等双侧周期性运动中的功能作用。
