手指の複雑動作課題が同側皮質運動野興奮性に及ぼす影響

概要

論文の詳細を見る
In the present study, we examined the effect of certain hand movement tasks on the excitability of the ipsilateral hand-motor cortex. In the first experiment, an isometric abduction (IA) task more than 30% of maximum voluntary contraction (MVC) using the left index finger increased the motor evoked potential (MEP) amplitudes evoked by transcranial magnetic stimulation (TMS) of the contralateral first dorsal interosseous (FDI). Meanwhile, the F-wave amplitudes of the contralateral FDI were significantly increased more than 50% of MVC. These findings indicate that the IA task increased the excitability of the ipsilateral hand-motor cortex without enhancement of spinal motoneuron excitability at less than 50% of MVC, suggesting that the excitability of the ipsilateral hand-motor cortex could be modulated via the transcallosal pathway. As a sensorimotor task in the second experiment, a complex movement (CM) task involving the use of chopsticks to pick up and transport glass balls significantly increased the MEP amplitudes of the contralateral FDI in comparison to those during a pseudo-CM (pCM) task. In addition, amount of background EMG signals (bEMG) during the period 100ms prior to TMS recorded from the left FDI while performing these tasks were about 8% of MVC. Taking into account the result of F-wave during the IA task, CM task-induced MEP facilitation of the contralateral FDI could be attributed to the cortical neural mechanism, not to the spinal mechanism. Furthermore, the CM task-induced MEP facilitation was not dependent on the amount of bEMG recorded from FDI performing these tasks. These findings suggest that differences between the effects of CM and pCM task on the excitability of ipsilateral hand-motor cortex were the results of the different properties of these tasks, i.e., sensorimotor task or not. The CM task was a sensorimotor task and therefore strongly affected the excitability of the ipsilateral hand-motor cortex via the transcallosal pathway.
2010-03-31

手指の複雑動作課題が同側皮質運動野興奮性に及ぼす影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク