Ding R, Jansen J K, Laing N G, Tønnesen H
J Neurocytol. 1983 Dec;12(6):887-919. doi: 10.1007/BF01153341.
Chicken embryos were treated with partially paralysing doses of d-tubocurarine (dtc) from embryonic (E) days 6 to 10. The pattern of innervation of the lateral gastrocnemius (GL) muscle was examined both morphologically and physiologically just before hatching on day E20 or E21. There was a 70% increase in number of surviving motor neurons in the lateral motor column and a 50% increase in the number of myelinated axons in the nerve to GL. The GL muscle was significantly atrophic, with an average weight of 40% of normal. The atrophy was largely due to the reduced size of the muscle fibres. The mean size of the motor units was essentially unchanged or perhaps slightly increased. There was a striking increase in the level of polyneuronal innervation of the muscle fibres, both in terms of number of synaptic sites per fibre and number of axons innervating each site. Spontaneous miniature endplate potentials (mepps) indicated focal innervation of the fibres in the normal muscle. Most fibres in the dtc-treated muscles had mepps of widely varying time courses, and there was no simple relation between amplitude and rise time. Many of the slow mepps were not represented in the endplate potentials evoked by nerve stimulation. The quantal content of the endplate potential (epp) was generally increased in the dtc-treated muscles. The findings are discussed in terms of a retrograde signal from muscle to nerve and its dependence on muscle activity.
从胚胎（E）第6天至第10天，用部分麻痹剂量的d - 筒箭毒碱（dtc）处理鸡胚胎。在E20或E21天孵化前，从形态学和生理学角度检查了外侧腓肠肌（GL）的神经支配模式。外侧运动柱中存活的运动神经元数量增加了70%，支配GL的神经中有髓轴突数量增加了50%。GL肌肉明显萎缩，平均重量为正常的40%。萎缩主要是由于肌纤维尺寸减小。运动单位的平均大小基本未变或可能略有增加。就每根纤维的突触位点数量和支配每个位点的轴突数量而言，肌纤维的多神经元支配水平显著增加。自发微小终板电位（mepps）表明正常肌肉中纤维的局部支配。dtc处理的肌肉中的大多数纤维具有时间进程差异很大的mepps，并且幅度与上升时间之间没有简单的关系。许多缓慢的mepps在神经刺激诱发的终板电位中未表现出来。dtc处理的肌肉中终板电位（epp）的量子含量通常增加。根据从肌肉到神经的逆行信号及其对肌肉活动的依赖性对这些发现进行了讨论。
