Phase modulation of the short-latency crossed spinal response in the human soleus muscle.
Phase modulation of the short-latency crossed spinal response in the human soleus muscle.
复制标题
人类比目鱼肌中短延迟交叉脊柱反应的相位调制。
DOI：
10.1152/jn.00786.2010
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发表时间：
2011
影响因子：
2.5
通讯作者：
N. Mrachacz‐Kersting
中科院分区：
文献类型：
--
作者：
P. Stubbs;J. Nielsen;T. Sinkjær;N. Mrachacz‐Kersting
最近报道了人类下肢坐着时左右比目鱼肌之间的短潜伏期脊柱介导的肢间反射通路。当前研究的目的是确定这些通路是否在功能性运动任务（如人类步态）中被观察到，并受到步态周期阶段和/或电刺激强度的调节。第二个目的是阐明所涉及的事件。研究了两种干预措施。首先是对同侧胫骨神经（iTN）进行运动阈值（MT）、最大峰对峰m波（M-Max）的35%和85% M-Max （85M-Max）的刺激，并在同侧腿的60%、70%、80%、90%和100%的步态周期进行刺激。第二种是对同侧腓肠神经（SuN）和内侧足底神经（MpN）进行1、2和3倍的知觉阈值刺激，在步态周期的90%[校正]。对侧比目鱼肌（cSOL）反应的均方根（RMS）在iTN刺激后40-55 ms（或bb0 - 50 y/o受试者45-60 ms）的时间窗内进行分析。在较高的刺激强度下，最一致的反应发生在步态周期的90%和100%。在85M-Max时，60对80% （P = 0.03）、90% （P = 0.006）和100% （P = 0.002）以及70对90% （P = 0.02）和100% （P = 0.009）的步态周期均有显著的抑制反应（P = 0.006）。在步态周期的80% （P = 0.01）、90% （P = 0.001）和100% （P = 0.004）时，随着刺激强度的增加，反应的抑制性增强。在所有刺激强度下刺激MpN和SuN均无短潜伏期反应。因此，这些神经内的传入神经不太可能参与反应。这是第一个显示行走过程中iTN刺激后cSOL短潜伏期脊髓介导反应的研究。它提供了新的脊髓通路有助于运动控制的证据，并证明反应可能具有功能相关性。
Short-latency spinally mediated interlimb reflex pathways were recently reported between the left and right soleus muscles in the human lower-limb during sitting. The aim of the current study was to establish if these pathways were observed during a functional motor task such as human gait and modulated by the gait cycle phase and/or electrical stimulation intensity. The second aim was to elucidate on the afferents involved. Two interventions were investigated. First was ipsilateral tibial nerve (iTN) stimulation at motor threshold (MT), 35% of the maximal peak-to-peak M-wave(M-Max) and 85% M-Max (85M-Max) with stimuli applied at 60%, 70%, 80%, 90%, and 100%of the gait cycle of the ipsilateral leg. Second was ipsilateral sural nerve (SuN) and medial plantar nerve (MpN) stimulation at 1, 2, and 3X perceptual threshold at 90% of the gait cycle [corrected]. The root mean squared (RMS) of the contralateral soleus (cSOL) responses were analyzed in a time window, 40-55 ms (or 45-60 ms for subjects >50 y/o) following iTN stimulation. The most consistent responses occurred at 90 and 100% of the gait cycle at higher stimulation intensities of the iTN. Significantly inhibitory responses (P = 0.006) were reported at 60 versus 80% (P = 0.03), 90% (P = 0.006), and 100% (P = 0.002) and 70 versus 90% (P = 0.02) and 100% (P = 0.009) of the gait cycle at 85M-Max. The responses became more inhibitory with increasing stimulation intensities at 80% (P = 0.01), 90% (P = 0.001), and 100% (P = 0.004) of the gait cycle. Stimulation of the MpN and SuN at all stimulation intensities demonstrated no short-latency responses. Therefore, it is unlikely that afferents within these nerves contribute to the response. This is the first study to show short-latency spinally mediated responses in the cSOL following iTN stimulation, during walking. It provides evidence for a new spinal pathway contributing to motor control and demonstrates that the response likely has functional relevance.