Smith A M
Can J Physiol Pharmacol. 1981 Jul;59(7):733-47. doi: 10.1139/y81-110.
Since Sherrington's convincing demonstration of the reciprocal innervation of opposing muscles, it has generally been thought that antagonist muscles are inactive during most voluntary movements. However, more recent evidence suggests that excitation of Renshaw cells may facilitate antagonist coactivation whereas excitation of Ia inhibitory neurons can induce reciprocal inhibition. A body of evidence has accumulated to indicate some of the circumstances which particularly favour the co-contraction of antagonist muscles. Isometric prehension, either in the precision grip or the power grip, can be shown to be one of the most important examples of antagonist coactivation. Studies of the discharge of single Purkinje cells of the intermediate cerebellar cortex in awake monkeys during performance of a maintained grip revealed that the majority of these neurons are deactivated during antagonist co-contraction. In contrast, other, unidentified neurons of the cerebellar cortex were as a group activated during grasping. It is suggested that the Purkinje cells act to inhibit antagonist muscles during reciprocal inhibition but are themselves inhibited during antagonist coactivation. These results support a suggestion made by Tilney and Pike in 1925 that the cerebellum plays an important role in switching between the coactivation and reciprocal inhibition of antagonist muscles.
自从谢灵顿令人信服地证明了拮抗肌的交互神经支配以来，人们普遍认为在大多数随意运动中拮抗肌是不活动的。然而，最近的证据表明，闰绍细胞的兴奋可能促进拮抗肌的共同激活，而Ia抑制性神经元的兴奋可诱导交互抑制。大量证据已经积累起来，表明了一些特别有利于拮抗肌共同收缩的情况。无论是精确抓握还是强力抓握，等长抓握都可被证明是拮抗肌共同激活的最重要例子之一。对清醒猴子在持续抓握过程中小脑中间皮质单个浦肯野细胞放电的研究表明，在拮抗肌共同收缩期间，这些神经元中的大多数被抑制。相反，小脑皮质的其他未明确身份的神经元在抓握过程中作为一个群体被激活。有人提出，浦肯野细胞在交互抑制期间作用于抑制拮抗肌，但在拮抗肌共同激活期间它们自身被抑制。这些结果支持了蒂尔尼和派克在1925年提出的观点，即小脑在拮抗肌的共同激活和交互抑制之间的转换中起重要作用。
