PDF(Pubmed)
Abstract：
Movement and muscle control are crucial for the survival of all free-living organisms. This study aimed to explore differential patterns of cortical and subcortical activation across different stages of muscle control using functional magnetic resonance imaging (fMRI). An event-related design was employed. In each trial, participants (n = 10) were instructed to gently press a button with their right index finger, hold it naturally for several seconds, and then relax the finger. Neural activation in these temporally separated stages was analyzed using a General Linear Model. Our findings revealed that a widely distributed cortical network, including the supplementary motor area and insula, was implicated not only in the pressing stage, but also in the relaxation stage, while only parts of the network were involved in the steady holding stage. Moreover, supporting the direct/indirect pathway model of the subcortical basal ganglia, their substructures played distinct roles in different stages of muscle control. The caudate nucleus exhibited greater involvement in muscle contraction, whereas the putamen demonstrated a stronger association with muscle relaxation; both structures were implicated in the pressing stage. Furthermore, the subthalamic nucleus was exclusively engaged during the muscle relaxation stage. We conclude that even the control of simple muscle movements involves intricate automatic higher sensory-motor integration at a neural level, particularly when coordinating relative muscle movements, including both muscle contraction and muscle relaxation; the cortical and subcortical regions assume distinct yet coordinated roles across different stages of muscle control.
摘要：
运动和肌肉控制对于所有自由生物的生存至关重要。本研究旨在使用功能磁共振成像（fMRI）探索肌肉控制不同阶段的皮质和皮质下激活的差异模式。采用了与事件相关的设计。在每次审判中,参与者(n=10)被指示用右手食指轻轻按下按钮，自然保持几秒钟，然后放松手指.使用一般线性模型分析这些时间上分离的阶段中的神经激活。我们的发现揭示了一个广泛分布的皮层网络，包括辅助运动区和脑岛，不仅牵涉到紧迫阶段，而且在放松阶段，而只有部分网络参与了稳定的保持阶段。此外，支持皮质下基底神经节的直接/间接途径模型，它们的子结构在肌肉控制的不同阶段发挥着不同的作用。尾状核表现出更大的参与肌肉收缩，而壳核显示出与肌肉松弛的更强关联；这两个结构都与压迫阶段有关。此外，在肌肉松弛阶段，丘脑底核仅参与其中。我们得出的结论是，即使控制简单的肌肉运动也涉及复杂的自动高级感觉-运动整合，特别是在协调相对肌肉运动时，包括肌肉收缩和肌肉松弛;皮质和皮质下区域在肌肉控制的不同阶段承担不同但协调的作用。
