Norton Jonathan A
Division of Neurosurgery, Department of Surgery, University of Saskatchewan, Saskatoon, SK, Canada.
Front Syst Neurosci. 2021 May 4;15:647430. doi: 10.3389/fnsys.2021.647430. eCollection 2021.
The nervous system uses oscillations to convey information efficiently. Inter-muscular coherence in the 15-35 Hz range is thought to represent common cortical drive to muscles, but is also in the frequency band in which electrical stimulation is applied to restore movement following neurological disease or injury. We wished to determine if, when stimulation is applied at the peak frequency of the coherence spectra it was still possible to determine voluntary effort. Using healthy human subjects we stimulated muscles in the arms and legs, separate experiments, while recording EMG activity from pairs of muscles including the stimulated muscles. Offline coherence analysis was performed. When stimulation is greater than motor threshold, and applied at the peak of the coherence spectra a new peak appears in the spectra, presumably representing a new frequency of oscillation within the nervous system. This does not appear at lower stimulation levels, or with lower frequencies. The nervous system is capable of switching oscillatory frequencies to account for noise in the environment.
神经系统利用振荡来高效地传递信息。15 - 35赫兹范围内的肌间相干性被认为代表了对肌肉的共同皮层驱动，但该频段也是在神经疾病或损伤后通过电刺激来恢复运动时所应用的频段。我们希望确定，当在相干谱的峰值频率施加刺激时，是否仍有可能确定自主努力程度。我们使用健康的人类受试者，在单独的实验中对其手臂和腿部的肌肉进行刺激，同时记录包括受刺激肌肉在内的成对肌肉的肌电图活动。进行离线相干分析。当刺激强度大于运动阈值，并在相干谱的峰值处施加时，谱中会出现一个新的峰值，推测这代表了神经系统内一个新的振荡频率。在较低的刺激水平或较低频率下不会出现这种情况。神经系统能够切换振荡频率以应对环境中的噪声。
