Cortical contributions to anticipatory postural adjustments in the trunk
Cortical contributions to anticipatory postural adjustments in the trunk
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DOI：
10.1113/jp275312
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发表时间：
2018-04-01
影响因子：
5.5
通讯作者：
Strutton, Paul H.
中科院分区：
文献类型：
--
作者：
Chiou, Shin-Yi;Hurry, Madeleine;Strutton, Paul H.
在主动肢体运动之前或同时发生的躯干肌肉活动的增加被称为预期姿势调整（APA）。APA是重要的维持姿势稳定性的扰动，但APA背后的神经机制仍不清楚。我们的研究结果表明，竖脊肌（ES）的皮质脊髓兴奋性增加，在40毫秒前快速屈肩，减少皮质内抑制和脊髓兴奋性没有变化。在ES中观察到皮质脊髓兴奋性的变化，在站立位和卧位之间具有相似的兴奋性特征，但在腹直肌中未观察到。我们认为，神经控制的姿势调整涉及在皮层水平的变化，这部分是由于减少inhibition.Voluntary肢体运动与躯干肌肉活动的增加，其中一些发生在一个时间窗口内被认为是太快的感觉反馈诱导，这些增加被称为预期姿势调整（APA）。虽然它是已知的，APA的功能是保持姿势稳定，以响应扰动，兴奋性的皮质脊髓投射到躯干肌肉在APA期间仍然不清楚。34名健康受试者在站立和躺着的位置进行快速肩部屈曲响应视觉提示。经颅磁刺激（TMS）在躯干运动皮层上传递，以检查前三角肌（AD）肌电图活动（EMG）上升之前的几个时间点的竖脊肌（ES）和腹直肌（RA）的运动诱发电位（MEP）。TMS还用于评估站立位ES的短间期皮质内抑制（SICI）和颈髓MEP（CMEP）。欧洲议会议员在ES是较大的时间点更接近上升AD肌电图在站立和躺的位置，而欧洲议会议员在RA没有不同的时间过程中检查。值得注意的是，SICI在接近AD EMG升高的时间点降低，而CMEP没有变化。我们的研究结果表明，增加兴奋性皮质脊髓预测躯干肌肉之前，自愿肢体运动可能是皮质起源，是肌肉特异性。
Increases in activity of trunk muscles that occur prior to, or concurrent with, a voluntary limb movement are termed anticipatory postural adjustments (APAs). APAs are important for maintaining postural stability in response to perturbations but the neural mechanisms underlying APAs remain unclear. Our results showed that corticospinal excitability of erector spinae (ES) muscle increased at 40ms prior to rapid shoulder flexion, with a reduction in intracortical inhibition and no change in spinal excitability. Changes in corticospinal excitability were observed in ES, with similar excitability profiles between standing and lying positions, but were not observed in rectus abdominis. We suggest that the neural control of postural adjustments involves changes at a cortical level, which in part are due to reduced inhibition.Voluntary limb movements are associated with increases in trunk muscle activity, some of which occur within a time window considered too fast to be induced by sensory feedback; these increases are termed anticipatory postural adjustments (APAs). Although it is known that the function of APAs is to maintain postural stability in response to perturbations, excitability of the corticospinal projections to the trunk muscles during the APAs remains unclear. Thirty-four healthy subjects performed rapid shoulder flexion in response to a visual cue in standing and lying positions. Transcranial magnetic stimulation (TMS) was delivered over the trunk motor cortex to examine motor evoked potentials (MEPs) in erector spinae (ES) and in rectus abdominis (RA) muscles at several time points prior to the rise in electromyographic activity (EMG) of anterior deltoid (AD) muscle. TMS was also used to assess short-interval intracortical inhibition (SICI) and cervicomedullary MEPs (CMEPs) in ES in the standing position. MEPs in ES were larger at time points closer to the rise in AD EMG in both standing and lying positions, whereas MEPs in RA did not differ over the time course examined. Notably, SICI was reduced at time points closer to the rise in AD EMG, with no change in CMEPs. Our results demonstrate that increasing excitability of corticospinal projections to the trunk muscles prior to a voluntary limb movement is likely to be cortical in origin and is muscle specific.