Petit J, Cameron W E, Murthy K S, Barone L A
Exp Brain Res. 1983;51(1):146-52. doi: 10.1007/BF00236812.
The pattern of gamma-efferent innervation of the muscle spindle was investigated in the peroneus tertius muscle of the cat. A number of spindle group Ia afferents were isolated and monitored during tetanic stimulation of isolated gamma-axons. The sample was dominated by efferents producing a static fusimotor effect on the afferent. An individual static axon normally projected to less than five but at times as many as seven muscle spindles. Each spindle normally received innervation from three to five static gamma-efferents but occasionally up to eight. The number of spindles innervated by a static gamma-axon was directly related to the efferent axonal conduction velocity. For each experiment, a probability distribution of the number of fusimotor effects was constructed from all available connections between the muscle spindles and static gamma-efferents considered in matrices of four afferents and four efferents. This distribution was then compared to a random binomial distribution. In each of the ten experiments, statistically significant differences (p less than 0.01) were noted between the experimental and random distributions. In order to interpret such deviations from the random distributions, similar analyses were performed on various combinations of afferents and efferents in simulated sets displaying grouping of effects. It was concluded that the observed differences between experimental and random distributions may be produced by a grouping of fusimotor innervation limited to a small set of spindles.
在猫的第三腓骨肌中研究了肌梭的γ传出神经支配模式。在分离的γ轴突进行强直刺激期间，分离并监测了一些Ia类梭内传入纤维。样本中以对传入纤维产生静态肌梭运动效应的传出纤维为主。单个静态轴突通常支配少于五个，但有时多达七个肌梭。每个肌梭通常接受三到五个静态γ传出纤维的支配，但偶尔多达八个。由静态γ轴突支配的肌梭数量与传出轴突传导速度直接相关。对于每个实验，根据肌梭与静态γ传出纤维之间所有可用的连接，构建了四个传入纤维和四个传出纤维矩阵中考虑的肌梭运动效应数量的概率分布。然后将该分布与随机二项分布进行比较。在十个实验中的每一个中，实验分布和随机分布之间都观察到统计学上的显著差异（p小于0.01）。为了解释与随机分布的这种偏差，对显示效应分组的模拟集中的传入纤维和传出纤维的各种组合进行了类似的分析。得出的结论是，实验分布和随机分布之间观察到的差异可能是由限于一小部分肌梭的肌梭运动神经支配分组产生的。
