Weldon P R, Cohen M W
J Neurocytol. 1979 Apr;8(2):239-59. doi: 10.1007/BF01175564.
Cultures of dissociated myotomal muscle and spinal cord derived from embryos of Xenopus laevis were grown in the presence of curare in order to abolish neuromuscular activity and were examined by electron microscopy. In one-day-old cultures a few of the neuromuscular contacts already displayed several synaptic specializations including 500 A vesicles clustered against the axolemma, increased axolemmal densities, basal lamina in the cleft, an increased sarcolemmal density and subsarcolemmal filamentous material. Contacts with these specializations were observed more frequently in two and three-day-old cultures. Throughout the three-day culture period nerve fibres and neuromuscular contacts were devoid of Schwann cells. Isolated patches of basal lamina were relatively scarce and were usually accompanied by an increase in sarcolemmal density and subsarcolemmal filamentous material even in cultures in which spinal cord cells were not included. These observations indicate that the myotomal neuromuscular synapse differentiates in culture in much the same way as it does in vivo, that muscle contractions are not required for its differentiation, and that apparent postsynaptic specializations can develop in the absence of innervation.
为了消除神经肌肉活动，将源自非洲爪蟾胚胎的解离肌节肌肉和脊髓培养物在箭毒存在的情况下培养，并通过电子显微镜进行检查。在一天大的培养物中，一些神经肌肉接触点已经显示出几种突触特化，包括500埃的小泡聚集在轴膜上、轴膜密度增加、裂隙中有基膜、肌膜密度增加和肌膜下丝状物质。在两天和三天大的培养物中更频繁地观察到具有这些特化的接触点。在整个三天的培养期内，神经纤维和神经肌肉接触点都没有施万细胞。即使在不包括脊髓细胞的培养物中，孤立的基膜斑块也相对稀少，并且通常伴随着肌膜密度和肌膜下丝状物质的增加。这些观察结果表明，肌节神经肌肉突触在培养中的分化方式与在体内大致相同，其分化不需要肌肉收缩，并且在没有神经支配的情况下也可以形成明显的突触后特化。
