Neural mechanisms underlying the changes in ipsilateral primary motorcortex excitability during unilateral rhythmic muscle contraction
Neural mechanisms underlying the changes in ipsilateral primary motorcortex excitability during unilateral rhythmic muscle contraction
复制标题
单侧节律性肌肉收缩过程中同侧初级运动皮层兴奋性变化的神经机制
DOI：
10.1016/j.bbr.2012.10.053
复制
发表时间：
2013
影响因子：
2.7
通讯作者：
Kozo Funase
中科院分区：
文献类型：
--
作者：
Kazumasa Uehara;Takuya Morishita;Shinji Kubota;Kozo Funase
本研究的目的是探讨在单侧节律性肌肉收缩的第一背骨间肌（FDI）（节律性收缩）与三种不同频率的听觉线索（1，2，和3 Hz）引起的同侧初级运动皮层（同侧M1）兴奋性的变化的神经机制。使用单脉冲经颅磁刺激（TMS）技术，当受试者根据每个听觉提示频率进行单侧节律性收缩时，评估不同频率的单侧节律性收缩对同侧M1兴奋性变化的影响。在此之后，使用成对脉冲TMS技术来评估同侧M1内的短皮质内抑制（SICI）/易化（ICF）、长皮质内抑制（LICI）和半球间抑制（IHI）以及背侧运动前皮层到M1（PMd-M1）和背外侧前额叶皮层到M1（DLPFC-M1）的连接的变化。记录右侧FDI诱发的运动诱发电位（MEP）。结果表明，与1Hz和3 Hz条件相比，2 Hz条件下单脉冲TMS诱导的同侧M1兴奋性显著降低。此外，PMd-M1的连接和LICI显着调制取决于单侧节律性收缩的频率。相反，SICI、ICF、IHI和DLPFC-M1的变化与心律频率无直接相关性。这些结果表明，PMd-M1连接和LICI内的ipsi-M1可能优先操作，以调节ipsi-M1的兴奋性，在不同频率的单侧节律性收缩的性能。
The aim of this study was to investigate the neural mechanisms underlying the changes in the ipsilateral primary motor cortex (ipsi-M1) excitability induced during the unilateral rhythmic muscle contraction of the first dorsal interosseous (FDI) (rhythmic contraction) muscle with three different frequencies of auditory cues (1, 2, and 3Hz). The effect of different frequencies of unilateral rhythmic contraction on changes in the ipsi-M1 excitability was assessed using a single-pulse transcranial magnetic stimulation (TMS) technique when subjects were performing the unilateral rhythmic contractions according to each auditory cue frequency. After that, the changes in short intracortical inhibition (SICI)/facilitation (ICF), long intracortical inhibition (LICI) within the ipsi-M1, and interhemispheric inhibition (IHI), as well as dorsal premotor cortex to M1 (PMd–M1), and dorsolateral prefrontal cortex to M1 (DLPFC-M1) connectivity from the contralateral hemisphere to the ipsi-M1 were assessed using paired-pulse TMS techniques. The motor evoked potentials (MEP) induced in the right FDI were recorded. In the results, the ipsi-M1 excitability induced in response to single-pulse TMS was significantly decreased in the 2Hz conditions, compared with the 1Hz and 3Hz conditions. Furthermore, PMd–M1 connectivity and LICI were significantly modulated depending on the frequency of the unilateral rhythmic contraction. In contrast, the changes in the SICI, ICF, IHI, and DLPFC–M1 were not directly associated with the rhythm frequency. These results suggest that PMd–M1 connectivity and LICI within the ipsi-M1 are likely to preferentially operate to modulate ipsi-M1 excitability during the performance of unilateral rhythmic contraction with different frequencies.