Ensemble firing of muscle afferents recorded during normal locomotion in cats
Ensemble firing of muscle afferents recorded during normal locomotion in cats
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DOI：
10.1111/j.1469-7793.1998.293bu.x
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发表时间：
1998-02-15
影响因子：
5.5
通讯作者：
Gorassini, M
中科院分区：
文献类型：
--
作者：
Prochazka, A;Gorassini, M
1.本研究的主要目的是整理猫在正常踏步过程中长期记录的肌肉传入放电特征的群体数据。47个肌梭和腱器官传入的englomerated发射配置文件从存储的数据编译。借助梭形初级、次级传入神经和腱器官的反应特性的数学模型，分析了放电曲线与位移和力信号之间的关系.而发射的腘绳肌梭传入可以预测合理的准确性，从长度和速度信号单独，小腿三头肌梭传入的发射配置文件偏离预测的配置文件，特别是在肌电图（EMG）活动。这表明，与梭外肌活动相关的梭运动动作的组成部分在小腿三头肌中是显著的，可能是因为该肌肉在猫步周期中更强烈地招募。从有限的数据，这是不可能的，以确定“最好的”或最一般的数学函数来预测主轴二次点火。在两个小腿三头肌主轴二级单位的研究，发射蜡以及预测使用最简单的模型，速率成正比的位移，而在腘绳肌主轴二级数据，需要一个更复杂的线性传递函数。对纺锤体次级数据建模的结果与与EMG活动相关的适量阶段性静态纺锤体运动动作一致。肌腱器官传入活动的小腿三头肌的平均合奏给出了整个肌肉的力量，同意与单独的三头肌力测量正常猫运动的预测。这支持了肌腱器官传入信号的整体肌肉力量的想法。6.我们的总体结论是，在第一近似，大肌肉传入在猫后肢信号肌肉速度，肌肉长度和肌肉力量，至少在运动中看到的速度和幅度的运动。
1. The main purpose of this study was to collate population data on the firing characteristics of muscle afferents recorded chronically during normal stepping in cats.2. Ensemble firing profiles of forty-seven muscle spindle and tendon organ afferents were compiled from stored data. The relationships between the firing profiles and the displacement and force signals were analysed with the help of mathematical models of the response characteristics of spindle primary and secondary afferents and tendon organs.3. Whereas the firing of hamstring spindle afferents could be predicted with reasonable accuracy from the length and velocity signals alone, the firing profiles of triceps surae spindle afferents deviated from the predicted profiles, particularly during electromyogram (EMG) activity. This indicated that the components of fusimotor action linked to extrafusal muscle activity were significant in triceps surae, possibly because this muscle is more strongly recruited in the cat step cycle.4. From the limited data available, it was not possible to identify the 'best' or most general mathematical function to predict spindle secondary firing. In the two triceps surae spindle secondary units studied, firing wax well predicted by using the simplest possible model, rate proportional to displacement, whereas in the hamstring spindle secondary data, a more complex linear transfer function was needed. The results of modelling the spindle secondary data were consistent with a modest amount of phasic, static fusimotor action linked to EMG activity.5. The averaged ensemble of tendon organ afferent activity from the triceps surae gave predictions of whole-muscle force that agreed well with separate triceps force measurements in normal cat locomotion. This supports the idea that ensembles of tendon organ afferents signal whole-muscle force.6. Our overall conclusion is that to a first approximation, large muscle afferents in the cat hindlimb signal muscle velocity, muscle length and muscle force, at least in movements of the speed and amplitude seen in locomotion.