Gerloff C, Richard J, Hadley J, Schulman A E, Honda M, Hallett M
Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-1428, USA.
Brain. 1998 Aug;121 ( Pt 8):1513-31. doi: 10.1093/brain/121.8.1513.
We studied the activation and interaction of cortical motor regions during simple, internally paced and externally paced right-hand finger extensions in healthy volunteers. We recorded EEGs from 28 scalp electrodes and analysed task-related coherence, task-related power and movement-related cortical potentials. Task-related coherence reflects inter-regional functional coupling of oscillatory neuronal activity, task-related power reflects regional oscillatory activity of neuronal assemblies and movement-related cortical potentials reflect summated potentials of apical dendrites of pyramidal cells. A combination of these three analytical techniques allows comprehensive evaluation of different aspects of information processing in neuronal assemblies. For both externally and internally paced finger extensions, movement-related regional activation was predominant over the contralateral premotor and primary sensorimotor cortex, and functional coupling occurred between the primary sensorimotor cortex of both hemispheres and between the primary sensorimotor cortex and the mesial premotor areas, probably including the supplementary motor area. The main difference between the different types of movement pacing was enhanced functional coupling of central motor areas during internally paced finger extensions, particularly inter-hemispherically between the left and right primary sensorimotor cortexes and between the contralateral primary sensorimotor cortex and the mesial premotor areas. Internally paced finger extensions were also associated with additional regional (premovement) activation over the mesial premotor areas. The maximal task-related coherence differences between internally and externally paced finger extensions occurred in the frequency range of 20-22 Hz rather than in the range of maximal task-related power differences (9-11 Hz). This suggests that important aspects of information processing in the human motor system could be based on network-like oscillatory cortical activity and might be modulated on at least two levels, which to some extent can operate independently from each other: (i) regional activation (task-related power) and (ii) inter-regional functional coupling. We propose that internal pacing of movement poses higher demands on the motor system than external pacing, and that the motor system responds not only by increasing regional activation of the mesial premotor system, including the supplementary motor area, but also by enhancing information flow between lateral and mesial premotor and sensorimotor areas of both hemispheres, even if the movements are simple and unimanual.
我们研究了健康志愿者在进行简单的、内部起搏和外部起搏的右手手指伸展过程中，皮质运动区域的激活和相互作用。我们从28个头皮电极记录脑电图，并分析与任务相关的相干性、与任务相关的功率以及与运动相关的皮质电位。与任务相关的相干性反映了振荡神经元活动的区域间功能耦合，与任务相关的功率反映了神经元集合的区域振荡活动，与运动相关的皮质电位反映了锥体细胞顶树突的总和电位。这三种分析技术的结合能够全面评估神经元集合中信息处理的不同方面。对于外部和内部起搏的手指伸展，与运动相关的区域激活在对侧运动前区和初级感觉运动皮层中占主导地位，并且在两个半球的初级感觉运动皮层之间以及初级感觉运动皮层与内侧运动前区（可能包括辅助运动区）之间发生了功能耦合。不同类型运动起搏之间的主要差异在于，在内部起搏的手指伸展过程中，中央运动区的功能耦合增强，特别是在左右初级感觉运动皮层之间以及对侧初级感觉运动皮层与内侧运动前区之间的半球间耦合增强。内部起搏的手指伸展还与内侧运动前区额外的区域（运动前）激活有关。内部和外部起搏的手指伸展之间最大的与任务相关的相干性差异出现在20 - 22赫兹的频率范围内，而不是在与任务相关的功率差异最大的范围（9 - 11赫兹）内。这表明人类运动系统中信息处理的重要方面可能基于类似网络的振荡皮质活动，并且可能在至少两个层面上受到调节，这两个层面在某种程度上可以相互独立运作：（i）区域激活（与任务相关的功率）和（ii）区域间功能耦合。我们提出，与外部起搏相比，运动的内部起搏对运动系统提出了更高的要求，并且运动系统不仅通过增加内侧运动前系统（包括辅助运动区）的区域激活来做出反应，还通过增强两个半球外侧和内侧运动前区以及感觉运动区之间的信息流来做出反应，即使运动是简单的单手运动。
