Costello W J, Hill R H, Lang F
J Exp Zool. 1984 Aug;231(2):167-75. doi: 10.1002/jez.1402310202.
The in vivo firing patterns of the fast closer excitor (FCE) and slow closer excitor (SCE) motoneurons to the dimorphic claws of the lobster Homarus americanus were analyzed during reflex closure activity by identifying postsynaptic potentials in muscle fibers with known motor innervation. Three types of claw activity were observed: slow closure, rapid closure, and maintained closure. Slow closure and rapid closure in both claws were mediated by SCE and FCE, respectively. In the cutter, maintained closure was mediated only by SCE; in the crusher, both FCE and SCE could maintain closure. The homologous SCEs displayed no significant differences in activity; in both claws, they fired at medium-to-high frequency. The homologous FCEs did display different spike frequencies during claw closure. The crusher FCE fired at high frequencies; the cutter FCE fired at much lower frequencies. Such in vivo differences in axon activity between homologous FCEs are correlated with claw dimorphism and with the population of muscle fiber types.
通过识别具有已知运动神经支配的肌肉纤维中的突触后电位，分析了美洲螯龙虾快速闭合兴奋神经元（FCE）和慢速闭合兴奋神经元（SCE）运动神经元在反射闭合活动期间对双态螯的体内放电模式。观察到三种类型的螯活动：缓慢闭合、快速闭合和持续闭合。两只螯的缓慢闭合和快速闭合分别由SCE和FCE介导。在切割螯中，持续闭合仅由SCE介导；在粉碎螯中，FCE和SCE都可以维持闭合。同源的SCE在活动中没有显著差异；在两只螯中，它们以中高频放电。同源FCE在螯闭合期间确实表现出不同的峰值频率。粉碎螯的FCE高频放电；切割螯的FCE放电频率低得多。同源FCE之间轴突活动的这种体内差异与螯的双态性以及肌肉纤维类型群体相关。
