The firing rates of human motoneurones voluntarily activated in the absence of muscle afferent feedback.
The firing rates of human motoneurones voluntarily activated in the absence of muscle afferent feedback.
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在没有肌肉传入反馈的情况下，人类运动神经元的放电率会自愿激活。
DOI：
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
David Burke
中科院分区：
文献类型：
--
作者：
V. Macefield;S. Gandevia;B. Bigland;R. Gorman;David Burke
1.为了量化肌肉传入反馈对人类运动神经元放电率的净影响，在没有来自目标肌肉的反馈的情况下进行持续的自愿努力期间记录腓总神经中单个运动轴突的放电频率。这些数据进行了比较，在完整的胫骨前肌的单个运动单位的放电率。在5名受试者中，在记录部位远端神经的麻醉阻滞引起的急性传入神经阻滞和背屈肌麻痹期间，对支配胫骨前肌的52个运动轴突进行了记录。2.确定了24个运动神经元的最大可持续放电率，其中12个被归类为相对低阈值（估计募集水平≤ 10%最大值），6个被归类为高阈值。低阈值运动神经元的平均放电率（21.7 +/-2.7 Hz; +/-S.E.M.）显著高于高阈值运动神经元（14.0 +/-4.4 Hz）。在最大努力收缩麻痹肌肉期间，24个去传入运动神经元的平均放电率为18.6 +/-1.9 Hz，显著低于正常神经支配的胫骨前肌记录的单个运动单位的最大放电率（28.2 +/-0.6 Hz）。3.在半最大努力期间，8个去传入运动神经元的平均放电率（10.8 +/-1.1 Hz）显著低于完整运动单位的平均放电率（16.5 +/-0.2 Hz）。在最小的努力中也有类似的发现;在弱的自愿努力中，7个去传入运动神经元的平均放电频率为6.0 +/-0.9 Hz，而完整运动单位的平均放电频率为7.3 +/-0.13 Hz。总体而言，运动神经元放电率的范围（从最小到最大水平的自愿努力）的急性传入神经阻滞的显着影响，但显着转移到较低的利率。4.在持续的最大自愿努力的至少30 s的持续时间的放电率的去传入运动神经元下降，在第一个5 s，但随后被维持，即没有进行性下降，发生与正常神经支配的运动单位在疲劳收缩。这一观察结果支持运动神经元放电正常下降的反射起源。5.可以得出结论，腓总神经中的肌肉传入对胫骨前运动神经元池提供净易化，反射性地增加了约三分之一的自主驱动的所有水平的运动输出。
1. To quantify the net influence of muscle afferent feedback on the firing rates of human motoneurones, the discharge frequencies of single motor axons in the common peroneal nerve were recorded during sustained voluntary efforts performed in the absence of feedback from the target muscle. These data were compared with the firing rates of single motor units in the intact tibialis anterior muscle. In five subjects, recordings were made from fifty‐two motor axons innervating tibialis anterior during acute deafferentation and paralysis of the dorsiflexor muscles produced by anaesthetic block of the nerve distal to the recording site. 2. Maximal sustainable firing rates were determined for twenty‐four motoneurons, twelve of which were classified as relatively low threshold (estimated recruitment level < or = 10% maximal) and six as high threshold. Mean firing rates of the low‐threshold motoneurones (21.7 +/‐ 2.7 Hz; +/‐ S.E.M.) were significantly higher than those of the high‐threshold motoneurones (14.0 +/‐ 4.4 Hz). The mean firing rate of the twenty‐four deafferented motoneurones during maximal efforts to contract the paralysed muscle was 18.6 +/‐ 1.9 Hz, significantly lower than the maximal firing rates of single motor units recorded from the normally innervated tibialis anterior muscle (28.2 +/‐ 0.6 Hz). 3. During half‐maximal efforts, the mean firing rate of eight deafferented motoneurones (10.8 +/‐ 1.1 Hz) was significantly lower than that of intact motor units (16.5 +/‐ 0.2 Hz). A similar finding was apparent during minimal efforts; the mean discharge frequency of seven deafferented motoneurones during weak voluntary efforts was 6.0 +/‐ 0.9 Hz, compared with 7.3 +/‐ 0.13 Hz for intact motor units. Overall, the range of motoneurone firing rates (from minimal to maximal levels of voluntary effort) was significantly affected by the acute deafferentation, but was shifted significantly to lower rates. 4. During sustained maximal voluntary efforts of at least 30 s duration the firing rate of deafferented motoneurones decreased over the first 5 s but was then maintained, i.e. there was no progressive decline as occurs with normally innervated motor units during fatiguing contractions. This observation supports a reflex origin for the normal decline in motoneurone discharge. 5. It is concluded that muscle afferents in the common peroneal nerve provide a net facilitation to the tibialis anterior motoneurone pool, reflexly increasing the motor output at all levels of voluntary drive by approximately one‐third.
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影响因子：
5.5
作者：
BIGLANDRITCHIE, B;JOHANSSON, R;WOODS, JJ
通讯作者：
WOODS, JJ
影响因子：
5.5
作者：
BIGLANDRITCHIE, BR;DAWSON, NJ;LIPPOLD, OCJ
通讯作者：
LIPPOLD, OCJ
疲劳引起的运动神经元放电率反射抑制的证据。
影响因子：
2.5
作者：
Woods,JJ;Furbush,F;Bigland-Ritchie,B
通讯作者：
Bigland-Ritchie,B
影响因子：
2.5
作者：
BIGLANDRITCHIE, B;JOHANSSON, R;WOODS, JJ
通讯作者：
WOODS, JJ