CHANGES IN MOTONEURON FIRING RATES DURING SUSTAINED MAXIMAL VOLUNTARY CONTRACTIONS
CHANGES IN MOTONEURON FIRING RATES DURING SUSTAINED MAXIMAL VOLUNTARY CONTRACTIONS
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DOI：
10.1113/jphysiol.1983.sp014765
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发表时间：
1983-01-01
影响因子：
5.5
通讯作者：
WOODS, JJ
中科院分区：
文献类型：
--
作者：
BIGLANDRITCHIE, B;JOHANSSON, R;WOODS, JJ
用W型微电极记录人拇收肌单运动单位在最大自主收缩时的电活动。这些电位具有单一肌纤维的特征。在简短的最大收缩中，获得了5名正常人200多个运动单位的放电率。四名受试者有相似的范围(平均26.4.+-)。6.5赫兹)，而第5次稍高(35。+-)。7.4赫兹)。当最大自愿力维持在S 40-120岁时，运动单位放电的幅度和平均比率逐渐下降。在前60名S，平均频率从27赫兹左右下降到15赫兹左右。显然，具有最高初始频率的单元的速率变化最快。显然，运动单位放电率的下降不是力量损失的原因，但它可能使通过速率编码对自愿力量的有效调制在疲劳期间继续下去。
W microelectrodes were used to record the electrical activity of single motor units in the human adductor pollicis during maximal voluntary contractions. The potentials were characteristic of those from single muscle fibers. In brief maximal contractions, the firing rates of over 200 motor units were obtained from 5 normal subjects. Four subjects had a similar range (mean 26.4 .+-. 6.5 Hz), while the 5th was slightly higher (35 .+-. 7.4 Hz). When maximal voluntary force was sustained for 40-120 s, there was a progressive decline in the range and mean rate of motor unit discharge. In the first 60 s, mean rates fell from about 27 Hz-15 Hz. Evidently, those units with the highest initial frequencies changed rate most rapidly. Evidently, this decline in motor unit discharge rates is not responsible for force loss, but it may enable effective modulation of voluntary strength by rate coding to continue during fatigue.