Preparation and performance of obstacle steps: interaction between brain and spinal neuronal activity
Preparation and performance of obstacle steps: interaction between brain and spinal neuronal activity
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DOI：
10.1111/j.1460-9568.2010.07494.x
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发表时间：
2011-01-01
影响因子：
3.4
通讯作者：
Dietz, Volker
中科院分区：
文献类型：
--
作者：
Haefeli, Jenny;Voegeli, Stefanie;Dietz, Volker
本研究通过记录脑电(EEG)、反射活动和肢体肌肉肌电(EMG)，研究了障碍步态下脊髓上和脊髓神经元环路的相互作用。在跑步机上行走的视力减退的受试者被告知正在接近的障碍物，并收到关于任务表现的反馈。只有在与任务相关的声学信号之后，在站立中期刺激胫神经诱发的脊髓反射反应，在障碍之前的手臂和腿部近侧屈肌中，与正常摆动相比，增强，反映了神经元对任务的准备。在跨越障碍的摆动过程中，肢体肌肉的肌电活动比正常摆动时更大。准备和表演(即越障腿的上升运动斜率)都与增强的脑电信号有关，主要是在右半球的前额叶皮质。重复障碍行走过程中表现、反射活动和肌肉激活的适应性变化没有在脑电活动中反映出来，这可能是由于脑电分辨率不够所致。这些观察表明，来自脊髓上中枢的驱动启动并维持了作为障碍任务准备和执行基础的脊髓神经元的活动。
This study investigated the interactions of supraspinal with spinal neuronal circuits during obstacle steps by recordings of electroencephalography (EEG), reflex activity and limb muscle electromyography (EMG). Subjects walking with reduced vision on a treadmill were acoustically informed about an approaching obstacle and received feedback about task performance. Only following a task-relevant acoustic signal, spinal reflex responses, evoked by tibial nerve stimulation during mid-stance, were enhanced in proximal arm and leg flexor muscles prior to obstacle compared to normal swing, reflecting the neuronal preparation of the task. During swing over the obstacle, limb muscle EMG activity was greater than in normal swing. Both the preparation and the performance (i.e. ascending movement slope of the obstacle-crossing leg) were associated with an enhanced EEG signal mainly in the prefrontal cortex of the right hemisphere. Adaptational changes in performance, reflex activity and muscle activation during repetitive obstacle stepping were not reflected in the EEG activity, probably due to an insufficient resolution of the EEG. The observations suggest that drive from supraspinal centers initiates and maintains spinal neuronal activity underlying obstacle task preparation and performance.