Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man
Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man
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DOI：
10.1152/jn.00143.2015
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发表时间：
2016-02-01
影响因子：
2.5
通讯作者：
Nishimura, Yukio
中科院分区：
文献类型：
--
作者：
Kato, Kenji;Sasada, Syusaku;Nishimura, Yukio
控制神经假体需要学习一种新颖的输入输出转换；然而，受试者如何将其纳入肢体控制仍然不清楚。为了阐明其背后的机制，我们研究了健康人类对从肌肉到周围神经的新型人工循环连接（ARC）的运动适应过程。在这个范例中，尺神经受到与尺侧腕屈肌（FCU）的激活成比例的电刺激，FCU是尺神经支配的，并且由FCU的Ia传入神经单突触支配，定义为“同名肌肉”，或掌长肌（PL），它不受尺神经支配，并产生与FCU类似的运动，定义为“增效肌”。在视觉引导的伸手任务中，ARC 增强了同侧肌肉和腕关节运动的活动。参与者可以控制肌肉活动，利用 ARC 来意志控制腕关节运动，然后重新适应任一输入肌肉的 ARC 缺失。无论输入的肌肉如何，参与者都通过练习减少了同向肌肉的募集。然而，增效肌的适应过程取决于输入肌肉。当输入是同名肌肉时，增效肌的活性降低，而当输入是增效肌时，增效肌的活性增加。这种神经运动图的重组是 ARC 的后遗症，只有当输入是增效肌时才能观察到。这些发现表明 ARC 以有针对性和可持续的方式诱导神经运动图的重组。
Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the "homonymous muscle," or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the "synergist muscle." The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner.