Teitti S, Määttä S, Säisänen L, Könönen M, Vanninen R, Hannula H, Mervaala E, Karhu J
Clinical Neurophysiology, NBS Laboratory, Kuopio University Hospital, Finland.
Neuroimage. 2008 Apr 15;40(3):1243-50. doi: 10.1016/j.neuroimage.2007.12.065. Epub 2008 Jan 17.
Structural studies in primates have shown that, in addition to the primary motor cortex (M1), premotor areas are a source of corticospinal tracts. The function of these putative corticospinal neuronal tracts in humans is still unclear. We found frontal non-primary motor areas (NPMAs), which react to targeted non-invasive magnetic pulses and activate peripheral muscles as fast as or even faster than those in M1. Hand muscle movements were observed in all our subjects about 20 ms after transcranial stimulation of the superior frontal gyrus (Brodmann areas 6 and 8). Stimulation of NPMA could activate both proximal and distal upper limb muscles with the same delay as a stimulation of the M1, indicating converging motor representations with direct functional connections to the hand. We suggest that these non-primary cortical motor representations provide additional capacity for the fast execution of movements. Such a capacity may play a role in motor learning and in recovery from motor deficits.
对灵长类动物的结构研究表明，除初级运动皮层（M1）外，运动前区也是皮质脊髓束的一个来源。这些假定的皮质脊髓神经元束在人类中的功能仍不清楚。我们发现额叶非初级运动区（NPMAs），其对靶向非侵入性磁脉冲有反应，并且激活外周肌肉的速度与M1中的区域一样快甚至更快。在经颅刺激额上回（布罗德曼6区和8区）后约20毫秒，我们所有受试者均观察到手部肌肉运动。刺激NPMA可以激活近端和远端上肢肌肉，其延迟与刺激M1相同，表明与手部有直接功能连接的汇聚运动表征。我们认为，这些非初级皮层运动表征为快速执行运动提供了额外的能力。这种能力可能在运动学习和运动功能障碍恢复中发挥作用。
