Facilitation of soleus H-reflex amplitude evoked by cutaneous nerve stimulation at the wrist is not suppressed by rhythmic arm movement
Facilitation of soleus H-reflex amplitude evoked by cutaneous nerve stimulation at the wrist is not suppressed by rhythmic arm movement
复制标题
有节奏的手臂运动不会抑制腕部皮神经刺激引起的比目鱼肌 H 反射幅度的促进
DOI：
10.1007/s00221-004-2092-x
复制
发表时间：
2004
影响因子：
2
通讯作者：
D. F. Collins
中科院分区：
文献类型：
--
作者：
E. Zehr;A. Frigon;N. Hoogenboom;D. F. Collins
颈椎和腰骶脊髓之间的神经连接可能有助于运动时手臂和腿部的协调。目前，手臂活动对腿部肌肉反射兴奋性的调节程度尚不完全清楚。我们最近发现，有节奏的手臂运动明显抑制比目鱼h反射振幅，可能是通过改变突触前IA传入通路的抑制。此外，在行走过程中，通过刺激手腕皮神经（桡浅神经；SR）在腿部肌肉中引起的反射依赖于阶段和任务。然而，在行走过程中，手臂和腿都有节奏地活动，因此很难确定这种调节的位点。在这里，我们研究了SR神经刺激对静态收缩和有节奏的手臂运动时腿部比目鱼h反射通路传输的影响。右肩屈曲或伸展时给予神经刺激。h反射被单独（非条件）或通过刺激SR神经（在单独的试验中也没有h反射单独传递）引起皮肤条件反射。SR神经刺激可显著促进手臂伸展静态收缩时的h反射振幅，抵消手臂循环对反射振幅的抑制。结果表明，从手部到腿部比目鱼h反射通路的皮肤反馈在有节奏的手臂运动中没有被抑制。这与观察结果相反，当支配腿部的皮神经受到刺激时，有节奏的手臂运动抑制比目鱼h反射的促进。结合在行走过程中采集的其他数据，这表明SR神经到腰骶脊髓的传导调节部分是由手臂和腿部的节律性活动决定的。
Neural connections between the cervical and lumbosacral spinal cord may assist in arm and leg coordination during locomotion. Currently the extent to which arm activity can modulate reflex excitability of leg muscles is not fully understood. We showed recently that rhythmic arm movement significantly suppresses soleus H-reflex amplitude probably via modification of presynaptic inhibition of the IA afferent pathway. Further, during walking reflexes evoked in leg muscles by stimulation of a cutaneous nerve at the wrist (superficial radial nerve; SR) are phase and task dependent. However, during walking both the arms and legs are rhythmically active thus it is difficult to identify the locus of such modulation. Here we examined the influence of SR nerve stimulation on transmission through the soleus H-reflex pathway in the leg during static contractions and during rhythmic arm movements. Nerve stimulation was delivered with the right shoulder in flexion or extension. H-reflexes were evoked alone (unconditioned) or with cutaneous conditioning via stimulation of the SR nerve (also delivered alone without H-reflex in separate trials). SR nerve stimulation significantly facilitated H-reflex amplitude during static contractions with the arm extended and countered the suppression of reflex amplitude induced by arm cycling. The results demonstrate that cutaneous feedback from the hand on to the soleus H-reflex pathway in the legs is not suppressed during rhythmic arm movement. This contrasts with the observation that rhythmic arm movement suppresses facilitation of soleus H-reflex when cutaneous nerves innervating the leg are stimulated. In conjunction with other data taken during walking, this suggests that the modulation of transmission through pathways from the SR nerve to the lumbosacral spinal cord is partly determined by rhythmic activity of both the arms and legs.