Volitional limb motor control involves dynamic and static muscle actions. It remains elusive how such distinct actions are controlled through separated or shared neural circuits. Here we explored the potential separation for dynamic and static controls in primate hand actions, by investigating the neuronal coherence between local field potentials (LFPs) of the spinal cord and the forelimb electromyographic activity (EMGs), and LFPs of the motor cortex and the EMGs during the performance of a precision grip in macaque monkeys. We observed the emergence of beta-range coherence with EMGs at spinal cord and motor cortex in the separated phases; spinal coherence during the grip phase and cortical coherence during the hold phase. Further, both of the coherences were influenced by bidirectional interactions with reasonable latencies as beta oscillatory cycles. These results indicate that dedicated feedback circuits comprising spinal and cortical structures underlie dynamic and static controls of dexterous hand actions.

肢体自主运动控制涉及动态和静态肌肉动作。如何通过分离或共享的神经回路控制这些不同的动作仍然难以捉摸。在这里，我们通过研究脊髓的局部场电位（LFP）和前肢肌​​电图活动（EMG）以及运动皮层和EMG的LFP之间的神经元相干性，探索了灵长类动物手部动作中动态和静态控件的电位分离。在猕猴的精确抓地力过程中。我们观察到在分离相的脊髓和运动皮层中出现了EMG的β范围相干现象。握持阶段的脊椎连贯性和保持阶段的皮质连贯性。进一步，这两个相干性都受到双向交互作用的影响，这些交互作用具有作为β振荡周期的合理延迟。这些结果表明，包括脊柱和皮质结构的专用反馈电路是灵巧手动作的动态和静态控制的基础。