Badry Reda, Mima Tatsuya, Aso Toshihiko, Nakatsuka Masahiro, Abe Mitsunari, Fathi Dina, Foly Nageh, Nagiub Hamdy, Nagamine Takashi, Fukuyama Hidenao
Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Kawaahara-cho, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan.
Clin Neurophysiol. 2009 Sep;120(9):1717-23. doi: 10.1016/j.clinph.2009.06.027. Epub 2009 Aug 15.
To investigate whether motor suppression is an active process, and to clarify its somatotopic organization, we investigated cortico-motoneuronal excitability using transcranial magnetic stimulation (TMS) during the Stop-signal task.
Subjects were asked to press a button following a Go cue; a Stop-signal followed the Go cue by a certain time delay in 25% of trials, indicating to subjects that they were not to press the button. TMS was given to the primary motor area of the left or right-hand or leg at variable time delays. Motor evoked potentials (MEPs) were recorded from the hand and leg muscles bilaterally.
When TMS was delivered 400 ms after the Go cue, there was significant suppression of the MEPs of the bilateral hand and leg muscles during successful Stop trials, but not during failed Stop trials.
The voluntary stopping of movement in the Stop-signal task is an active process, which likely suppresses not only the cortico-motoneuronal excitability of the task-performing hand, but also causes the widespread suppression of the motor system.
Studies in the normal physiology of response inhibition would be of help in understanding the pathophysiology of neuro-psychiatric disorders associated with deficits in motor suppression.
为了研究运动抑制是否是一个主动过程，并阐明其躯体定位组织，我们在停止信号任务期间使用经颅磁刺激（TMS）研究了皮质-运动神经元兴奋性。
要求受试者在“开始”信号出现后按下按钮；在25%的试验中，“停止”信号在“开始”信号出现后的一定时间延迟后出现，向受试者表明他们不应按下按钮。在不同的时间延迟下，对左手或右手或腿部的初级运动区给予TMS。从双侧的手部和腿部肌肉记录运动诱发电位（MEP）。
当在“开始”信号出现后400毫秒给予TMS时，在成功的停止试验期间，双侧手部和腿部肌肉的MEP有显著抑制，但在失败的停止试验期间没有。
停止信号任务中运动的自愿停止是一个主动过程，它可能不仅抑制执行任务的手部的皮质-运动神经元兴奋性，还会导致运动系统的广泛抑制。
对反应抑制正常生理学的研究将有助于理解与运动抑制缺陷相关的神经精神疾病的病理生理学。
