Department of Physical Therapy, Faculty of Health Sciences, Kansai University of Health Sciences, Kumatori, 590-0482, Japan; Graduate School of Health Sciences, Graduate School of Kansai University of Health Sciences, Kumatori, 590-0482, Japan.
Department of Physical Therapy, Faculty of Health Sciences, Kansai University of Health Sciences, Kumatori, 590-0482, Japan.
Neurosci Lett. 2021 May 29;754:135843. doi: 10.1016/j.neulet.2021.135843. Epub 2021 Mar 24.
This study presents a novel approach for identifying neural substrates underlying the beneficial effects of motor imagery. For motor imagery, participants were instructed to imagine contraction of the left thenar muscle at 50 % maximal voluntary contraction (MVC). The participants then performed isometric contractions of the thumb and index finger at 50 % MVC as accurately as possible after motor imagery and without motor imagery. F-waves and oxygen-hemoglobin levels were examined with and without motor imagery relative to the resting condition. These data were analyzed using structural equation modeling. The degree of changes in the excitability of spinal motor neurons using F-waves during motor imagery may be modulated by inputs from the supplementary motor area. F-waves were analyzed with respect to persistence and the F-wave/maximum M-wave amplitude ratio. We found an association between precision pinch force control after motor imagery and spinal motor neuron excitability during motor imagery. The excitability of the supplementary motor area was not directly associated with precision pinch force control. However, spinal motor neuron excitability was adjusted by the supplementary motor area. Thus, the ability to perform precision pinch force control may be influenced by the supplementary motor area through the excitability of spinal motor neurons.
本研究提出了一种新的方法来识别运动想象有益效果的神经基础。在运动想象中，要求参与者想象左鱼际肌以 50%最大自主收缩（MVC）的收缩。然后，参与者在运动想象后和不进行运动想象的情况下，尽可能准确地进行拇指和食指的等长收缩，达到 50%MVC。在运动想象和静息状态下，使用结构方程模型分析 F 波和氧合血红蛋白水平。使用 F 波分析运动想象过程中脊髓运动神经元兴奋性的变化程度，可能受到来自辅助运动区的输入的调节。分析了 F 波的持久性和 F 波/最大 M 波振幅比。我们发现运动想象后精准捏力控制与运动想象过程中脊髓运动神经元兴奋性之间存在关联。辅助运动区的兴奋性与精准捏力控制没有直接关系。然而，脊髓运动神经元的兴奋性是由辅助运动区调节的。因此，通过脊髓运动神经元的兴奋性，执行精准捏力控制的能力可能会受到辅助运动区的影响。
