Cathodal transcranial direct current stimulation suppresses ipsilateral projections to presumed propriospinal neurons of the proximal upper limb
Cathodal transcranial direct current stimulation suppresses ipsilateral projections to presumed propriospinal neurons of the proximal upper limb
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DOI：
10.1152/jn.01084.2010
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发表时间：
2011-05-01
影响因子：
2.5
通讯作者：
Byblow, Winston D.
中科院分区：
文献类型：
--
作者：
Bradnam, Lynley V.;Stinear, Cathy M.;Byblow, Winston D.
首页--期刊主要分类--期刊细介绍--期刊题录与期刊详细文摘内容经颅直流电刺激抑制同侧至上肢近端固有脊髓神经元的投射。神经生理学杂志105：2582-2589,2011。2011年3月9日首次发表；DOI：10.1152/jn.01084.2010。-这项研究调查了对健康人的左侧初级运动皮质(M1)的阴极经颅直流电刺激(c-TDC)是否调节同侧固有脊髓前运动神经元(PN)的兴奋性。通过对右侧运动皮质进行经颅磁刺激(TMS)，在受试者保持左臂二头肌收缩的同时，获得左二头肌的运动诱发电位(MEP)。为了检查推测的PN兴奋性，将左侧BB MEP与左肘正中神经刺激(MNS)条件下的MEP进行比较。TMS和MNS之间的刺激间隔被设置为在脊髓的C3-C4水平产生总和。MNS促进了在接近主动运动阈值的TMS强度下诱发的BB MEP，但在稍高的强度下抑制了BB MEP，这表明可能是PN调制。C-tDCs可抑制MNS的易化和抑制作用。假tdcs不改变任何一种成分。C-tDCs和Sham tDCs对非条件性左BB MEP和同侧BB静默期均无影响。C-tDCs抑制右侧第一背侧骨间MEPs。这些结果表明，M1、c-tDCs可以用来调节同侧投射到可能控制上臂近端肌肉BB的PNS的兴奋性。该技术有望促进卒中后上肢近端功能的运动恢复。
Bradnam LV, Stinear CM, Byblow WD. Cathodal transcranial direct current stimulation suppresses ipsilateral projections to presumed propriospinal neurons of the proximal upper limb. J Neurophysiol 105:2582-2589, 2011. First published March 9, 2011; doi:10.1152/jn.01084.2010.-This study investigated whether cathodal transcranial direct current stimulation (c-tDCS) of left primary motor cortex (M1) modulates excitability of ipsilateral propriospinal premotoneurons (PNs) in healthy humans. Transcranial magnetic stimulation (TMS) of the right motor cortex was used to obtain motor evoked potentials (MEPs) from the left biceps brachii (BB) while participants maintained contraction of the left BB. To examine presumed PN excitability, left BB MEPs were compared with those conditioned by median nerve stimulation (MNS) at the left elbow. Interstimulus intervals between TMS and MNS were set to produce summation at the C3-C4 level of the spinal cord. MNS facilitated BB MEPs elicited at TMS intensities near active motor threshold but inhibited BB MEPs at slightly higher intensities, indicative of putative PN modulation. c-tDCS suppressed the facilitatory and inhibitory effects of MNS. Sham tDCS did not alter either component. There was no effect of c-tDCS and sham tDCS on nonconditioned left BB MEPs or on the ipsilateral silent period of left BB. Right first dorsal interosseous MEPs were suppressed by c-tDCS. These results indicate that M1 c-tDCS can be used to modulate excitability of ipsilateral projections to presumed PNs controlling the proximal arm muscle BB. This technique may hold promise for promoting motor recovery of proximal upper limb function after stroke.