Koehler W, Hamm T M, Enoka R M, Stuart D G, Windhorst U
Brain Res. 1985 Sep 23;343(2):388-93. doi: 10.1016/0006-8993(85)90763-2.
In anesthetized cats, medial gastrocnemius motor units (MUs) were electrically stimulated via their ventral-root axons with independent random patterns. Muscle tension and homonymous alpha-motoneuron (alpha-MN) membrane potential fluctuations in response to these stimuli were recorded simultaneously. Cross-correlating these two signals in temporal relation to the stimuli showed the covariance of the two signals around their respective means. With moderate to strong MU-MN couplings indicated by clear and large average membrane potential changes (PSP trajectories), the correlation coefficients tended to be positive at times when the PSP hyperpolarized, and vice versa. These relations are probably caused by the non-linear behavior of MUs, muscle receptors and afferent pathways. Thus, the signal transfer from motor efferents back to homonymous alpha-MNs depended upon the level of background tension, upon which MU twitches were superimposed.
在麻醉猫中，通过其腹根轴突以独立随机模式电刺激腓肠肌内侧运动单位（MU）。同时记录了肌肉张力和对这些刺激作出反应的同名α运动神经元（α-MN）膜电位波动。将这两个信号与刺激进行时间上的互相关，显示了两个信号围绕各自均值的协方差。当平均膜电位变化明显且较大（PSP轨迹）表明存在中度至强的MU-MN耦合时，在PSP超极化时相关系数往往为正，反之亦然。这些关系可能是由MU、肌肉感受器和传入通路的非线性行为引起的。因此，从运动传出纤维传回同名α-MN的信号传递取决于背景张力水平，MU抽搐叠加在该背景张力之上。
