Cortical and subcortical neural interactions between trunk and upper-limb muscles in humans
Cortical and subcortical neural interactions between trunk and upper-limb muscles in humans
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人类躯干和上肢肌肉之间的皮质和皮质下神经相互作用
DOI：
10.1016/j.neuroscience.2020.10.011
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发表时间：
2020
期刊：
影响因子：
3.3
通讯作者：
Matija Milosevic and Kimitaka Nakazawa
中科院分区：
文献类型：
--
作者：
Atsushi Sasaki;Matija Milosevic and Kimitaka Nakazawa
日常生活活动需要躯干和上肢节段同时协调激活，涉及中枢神经系统内复杂的肢间相互作用。尽管许多研究已经报道了在功能性任务中躯干和四肢肌肉活动之间的关联，但皮层和皮层下对躯干-四肢神经相互作用的贡献的证据仍然不完全清楚。因此，本研究的目的是研究躯干和上肢肌肉之间的相互作用：(i)通过经颅磁刺激引起的运动诱发电位（MEP）来检测皮质脊髓回路；（ii）利用颈髓交界磁刺激引发的颈髓运动诱发电位（CMEP）来观察皮层下回路。在12个健全的个体中，竖脊肌（躯干）和桡腕屈肌（上肢）引起了反应：(1)当参与者放松时；(2)手臂休息时躯干肌肉收缩时；(3)躯干静止时上肢肌肉收缩时。结果表明，躯干肌肉CMEP反应不受上肢肌肉收缩的影响，但MEP反应受到调节。这表明，至少皮质下回路可能与上肢收缩时躯干肌肉的易化无关。另一方面，在上肢肌肉中，CMEP和MEP反应在躯干收缩期间都被调节。这些结果表明，在躯干收缩过程中上肢肌肉的促进是由皮层和皮层下机制引起的。总之，我们的研究证明，躯干-肢体神经相互作用可能归因于皮层和/或皮层下机制，这取决于收缩的肌肉。
Activities of daily living require simultaneous and coordinated activation of trunk and upper-limb segments, which involves complex interlimb interaction within the central nervous system. Although many studies have reported associations between activity of trunk and limb muscles during functional tasks, evidence on cortical and subcortical contributions to trunk-limb neural interactions is still not fully clear. Therefore, the aim of this study was to examine interactions between trunk and upper-limb muscles in the: (i) corticospinal circuits by using motor evoked potential (MEP) elicited through transcranial magnetic stimulation; and (ii) subcortical circuits by using cervicomedullary motor evoked potential (CMEP) elicited through cervicomedullary junction magnetic stimulation. Responses were evoked in the erector spinae (trunk) and flexor carpi radialis (upper-limb) muscles in twelve able-bodied individuals: (1) while participants were relaxed; (2) during trunk muscle contractions while arms were at rest; and (3) during upper-limb muscle contractions while the trunk was at rest. Our results showed that trunk muscle CMEP responses were not affected by upper-limb muscle contractions, while MEP responses were modulated. This indicates that at least the subcortical circuits may not attribute to facilitation of the trunk muscles during upper-limb contractions. On the other hand, in the upper-limb muscles, both CMEP and MEP responses were modulated during trunk contractions. These results indicate that cortical and subcortical mechanisms attributed to facilitation of upper-limb muscles during trunk contractions. In conclusion, our study demonstrated evidence that trunk-limb neural interactions may be attributed to cortical and/or subcortical mechanisms depending on the contracted muscle.