Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland; Laboratory of Neuromuscular System and Rehabilitation Engineering, Department of Electronics and Telecommunications, Politecnico di Torino, Turin, Italy.
Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Neuroscience. 2024 Nov 12;560:314-325. doi: 10.1016/j.neuroscience.2024.09.049. Epub 2024 Sep 30.
Cortical proprioceptive processing of intermittent, passive movements can be assessed by extracting evoked and induced electroencephalographic (EEG) responses to somatosensory stimuli. Although the existent prior research on somatosensory stimulations, it remains unknown to what extent ongoing volitional muscle activation modulates the proprioceptive cortical processing of passive ankle-joint rotations. Twenty-five healthy volunteers (28.8 ± 7 yr, 14 males) underwent a total of 100 right ankle-joint passive rotations (4° dorsiflexions, 4 ± 0.25 s inter-stimulus interval, 30°/s peak angular velocity) evoked by a movement actuator during passive condition with relaxed ankle and active condition with a constant plantarflexion torque of 5 ± 2.5 Nm. Simultaneously, EEG, electromyographic (EMG) and kinematic signals were collected. Spatiotemporal features of evoked and induced EEG responses to the stimuli were extracted to estimate the modulation of the cortical proprioceptive processing between the active and passive conditions. Proprioceptive stimuli during the active condition elicited robustly ∼26 % larger evoked response and ∼38 % larger beta suppression amplitudes, but ∼42 % weaker beta rebound amplitude over the primary sensorimotor cortex than the passive condition, with no differences in terms of response latencies. These findings indicate that the active volitional motor task during naturalistic proprioceptive stimulation of the ankle joint enhances related cortical activation and reduces related cortical inhibition with respect to the passive condition. Possible factors explaining these results include mechanisms occurring at several levels of the proprioceptive processing from the peripheral muscle (i.e. mechanical, muscle spindle status, etc.) to the different central (i.e. spinal, sub-cortical and cortical) levels.
通过提取体感刺激诱发和诱导的脑电图（EEG）响应，可以评估间歇性被动运动的皮质本体感觉处理。尽管已经有关于体感刺激的现有研究，但对于持续的自主肌肉激活在多大程度上调节被动踝关节旋转的本体感受皮质处理仍不清楚。25 名健康志愿者（28.8±7 岁，14 名男性）在被动状态下共接受了 100 次右踝关节被动旋转（4°背屈，4±0.25 s 刺激间隔，30°/s 峰值角速度），由运动执行器在被动状态下引起，踝关节放松，主动状态下恒定的跖屈力矩为 5±2.5 Nm。同时，收集了脑电图（EEG）、肌电图（EMG）和运动学信号。提取诱发和诱导 EEG 响应的时空特征，以估计主动和被动条件之间皮质本体感觉处理的调制。主动状态下的本体感受刺激在初级感觉运动皮层上诱发的诱发电响应和β抑制幅度分别大 26%和 38%，但β回弹幅度小 42%，而潜伏期无差异。这些发现表明，踝关节自然本体感受刺激过程中的主动自主运动任务增强了相关皮质激活，并减少了相关皮质抑制，与被动状态相比。解释这些结果的可能因素包括从外周肌肉（即机械、肌梭状态等）到不同中枢（即脊髓、皮质下和皮质）水平的本体感受处理的几个水平上发生的机制。
