Increase in flexor but not extensor corticospinal motor outputs following ischemic nerve block.
Increase in flexor but not extensor corticospinal motor outputs following ischemic nerve block.
复制标题
缺血性神经阻滞后，皮质脊髓屈肌运动输出增加，但伸肌运动输出没有增加。
作者：
A. Vallence;G. Hammond;K. Reilly
人类运动皮层能够进行快速而持久的重组，这在全球范围内都很明显，例如身体部位表征的变化，以及个体肌肉水平上皮质脊髓兴奋性的变化。表征转变提供了不同身体部位如何相对于彼此重组的概述，但并没有告诉我们特定身体部位中的所有肌肉是否以相同的方式和相同的程度重组。经颅磁刺激 (TMS) 提供有关个体肌肉的信息，因此可以告诉我们身体部位内塑性变化的均匀性。我们使用 TMS 来研究手腕周围止血带充气后前臂屈肌和伸肌皮质脊髓兴奋性的变化。在阻滞之前和期间同时从腕屈肌和伸肌获得运动诱发电位 (MEP) 幅度和输入/输出 (I/O) 曲线。 TMS 被传送到实验 1 中屈肌、实验 2 中伸肌以及实验 3 中屈肌和伸肌中诱发 MEP 的最佳部位。在所有实验中，屈肌 MEP 幅度在阻滞期间增加，而伸肌 MEP 幅度没有显示系统性变化，并且屈肌 I/O 曲线的斜率增加，但伸肌 I/O 曲线的斜率没有增加。归一化为最大 M 波的屈肌 H 反射幅度在阻滞期间显示出可忽略不计的变化，表明屈肌皮质脊髓兴奋性的增加不能完全用脊髓水平兴奋性的增加来解释。这些发现表明，前臂屈肌和伸肌的可塑性变化潜力不同，强调了研究实验诱导的可塑性如何影响解剖上接近但功能不同的肌肉群的重要性，并表明旨在改变皮质组织的康复干预措施应考虑不同肌肉群对可塑性过程的不同敏感性。
Human motor cortex is capable of rapid and long-lasting reorganization, evident globally, as shifts in body part representations, and at the level of individual muscles as changes in corticospinal excitability. Representational shifts provide an overview of how various body parts reorganize relative to each other but do not tell us whether all muscles in a given body part reorganize in the same manner and to the same extent. Transcranial magnetic stimulation (TMS) provides information about individual muscles and can therefore inform us about the uniformity of plastic changes within a body part. We used TMS to investigate changes in corticospinal excitability of forearm flexors and extensors after inflation of a tourniquet around the wrist. Motor evoked potential (MEP) amplitudes and input/output (I/O) curves were obtained from wrist flexors and extensors simultaneously before and during block. TMS was delivered to the optimal site for eliciting MEPs in flexors in experiment 1, extensors in experiment 2, and both flexors and extensors in experiment 3. In all experiments flexor MEP amplitude increased during block while extensor MEP amplitude showed no systematic change, and the slope of flexor but not extensor I/O curves increased. Flexor H-reflex amplitude normalized to maximal M wave showed negligible changes during block, suggesting that the increase in corticospinal excitability in the flexors cannot be completely explained by increased excitability at the spinal cord level. These findings show that forearm flexors and extensors differ in their potential for plastic changes, highlight the importance of investigating how experimentally induced plasticity affects anatomically close, but functionally distinct, muscle groups, and suggest that rehabilitation interventions aiming to alter cortical organization should consider the differential sensitivity of various muscle groups to plasticity processes.
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影响因子：
2.5
作者：
FETZ, EE;CHENEY, PD
通讯作者：
CHENEY, PD
成对的联想刺激会引起人类腕屈肌 Ia 末端突触前抑制的变化。
影响因子：
2.5
作者：
Lamy,Jean-Charles;Russmann,Heike;Shamim,EjazA;Meunier,Sabine;Hallett,Mark
通讯作者：
Hallett,Mark
影响因子：
2.5
作者：
SCHIEBER, MH
通讯作者：
SCHIEBER, MH
DOI：
10.1073/pnas.97.7.3661
发表时间：
2000-03
影响因子：
11.1
作者：
C. Bütefisch;B. Davis;Steven P. Wise;L. Sawaki;L. Kopylev;Joseph Classen;Leonardo G. Cohen
通讯作者：
C. Bütefisch;B. Davis;Steven P. Wise;L. Sawaki;L. Kopylev;Joseph Classen;Leonardo G. Cohen
小脑红核脊髓系统的运动功能。
影响因子：
33.6
作者：
Keifer,J;Houk,JC
通讯作者：
Houk,JC