Veldman Menno P, Maurits Natasha M, Zijdewind Inge, Maffiuletti Nicola A, van Middelkoop Stella, Mizelle J Chris, Hortobágyi Tibor
University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences , Groningen , The Netherlands.
Department of Neurology, University of Groningen, University Medical Center Groningen , Groningen , The Netherlands.
J Neurophysiol. 2018 Jul 1;120(1):281-290. doi: 10.1152/jn.00860.2017. Epub 2018 Apr 11.
The interaction between the somatosensory and motor systems is important for normal human motor function and learning. Enhancing somatosensory input using somatosensory electrical stimulation (SES) can increase motor performance, but the neuronal mechanisms underlying these effects are largely unknown. With EEG, we examined whether skill acquisition, consolidation, and interlimb transfer after SES was related to increased activity in sensorimotor regions, as assessed by the N30 somatosensory evoked potential or rather increased connectivity between these regions, as assessed by the phase slope index (PSI). Right- and left-hand motor performance and EEG measures were taken before, immediately after, and 24 h ( day 2) after either SES ( n = 12; 5 men) or Control ( n = 12; 5 men). The results showed skill acquisition and consolidation in the stimulated right hand immediately after SES (6%) and on day 2 (9%) and interlimb transfer to the nonstimulated left hand on day 2 relative to Control (8%, all P < 0.05). Increases in N30 amplitudes correlated with skill acquisition while PSI from electrodes that represent the posterior parietal and primary somatosensory cortex to the electrode representing the primary motor cortex correlated with skill consolidation. In contrast, interlimb transfer did not correlate with the EEG-derived neurophysiological estimates obtained in the present study, which may indicate the involvement of subcortical structures in interlimb transfer after SES. In conclusion, weak peripheral somatosensory inputs in the form of SES improve skill acquisition, consolidation, and interlimb transfer that coincide with different cortical adaptations, including enhanced N30 amplitudes and PSI. NEW & NOTEWORTHY The relationship between adaptations in synaptic plasticity and motor learning following somatosensory electrical stimulation (SES) is incompletely understood. Here, we used for the first time a multifactorial approach that examined skill acquisition, consolidation, and interlimb transfer following 20 min of SES. In addition, we quantified sensorimotor integration and the magnitude and direction of connectivity with EEG. Following artificial electrical stimulation, increases in sensorimotor integration and connectivity were found to correlate with skill acquisition and consolidation, respectively.
体感系统与运动系统之间的相互作用对于人类正常的运动功能和学习至关重要。使用体感电刺激（SES）增强体感输入可以提高运动表现，但其背后的神经元机制在很大程度上尚不清楚。通过脑电图（EEG），我们研究了SES后的技能习得、巩固和肢体间转移是否与感觉运动区域活动增加有关（通过N30体感诱发电位评估），或者是否与这些区域之间增强的连接性有关（通过相位斜率指数（PSI）评估）。在SES组（n = 12；5名男性）或对照组（n = 12；5名男性）中，分别在SES前、SES后即刻以及24小时（第2天）测量右手和左手的运动表现及EEG指标。结果显示，SES后即刻（6%）和第2天（9%），受刺激的右手出现技能习得和巩固，并且在第2天相对于对照组，肢体间转移至未受刺激的左手（8%，所有P < 0.05）。N30波幅增加与技能习得相关，而从代表顶叶后部和初级体感皮层的电极到代表初级运动皮层的电极的PSI与技能巩固相关。相比之下，肢体间转移与本研究中通过EEG得出的神经生理学估计值无关，这可能表明在SES后的肢体间转移中涉及到皮层下结构。总之，以SES形式存在的微弱外周体感输入可改善技能习得、巩固和肢体间转移，这与不同的皮层适应性相吻合，包括增强的N30波幅和PSI。新发现与值得注意之处 体感电刺激（SES）后突触可塑性适应与运动学习之间的关系尚未完全明了。在此，我们首次采用多因素方法，研究了20分钟SES后的技能习得、巩固和肢体间转移。此外，我们用EEG量化了感觉运动整合以及连接性的大小和方向。人工电刺激后，发现感觉运动整合增加和连接性增加分别与技能习得和巩固相关。
