Boaro S N, Soares J C, König B
Department of Physiotherapy, Faculty of Sciences and Technology, São Paulo State University of Presidente Prudente, Brazil.
Ann Anat. 1998 Apr;180(2):173-9. doi: 10.1016/S0940-9602(98)80020-4.
The authors studied the histochemical and ultrastructural modifications that occur in the neuromuscular junctions (NMJ) of fibularis longus muscles of mice with an age range of 3 to 21 months. Twenty-four male and female animals were killed at 3, 5, 14 and 21 months of age: 7 of them at 3 months, 4 of them at 5 month, 9 at 14 months and 4 at 21 months. The fibularis longus muscles were processed and their NMJ examined with the transmission electron microscope. The most relevant changes were associated with the degeneration and retraction of terminal axons, i.e., axons poor in synaptic vesicles with degenerated mitochondria, and exhibiting multivesicular bodies and vacuoles; exposed and widened junctional folds and cytoplasmic processes of Schwann cells located in the synaptic gutter. The presence of lysosomes or lipofuchsin in the juxtajunctional sarcoplasm was also noted. These observations suggest that the phenomena of retraction and budding occur in the NMJ with advancing age, with a predominance of events associated with degeneration, leading to profound changes in NMJ shape.
作者研究了3至21月龄小鼠腓骨长肌神经肌肉接头（NMJ）中发生的组织化学和超微结构变化。在3、5、14和21月龄时处死24只雄性和雌性动物：其中7只在3月龄，4只在5月龄，9只在14月龄，4只在21月龄。对腓骨长肌进行处理，并用电镜检查其神经肌肉接头。最相关的变化与终末轴突的变性和回缩有关，即突触小泡少、线粒体变性、出现多泡体和空泡的轴突；突触褶皱暴露且变宽，位于突触沟的施万细胞的胞质突起。还注意到在连接旁肌浆中有溶酶体或脂褐素存在。这些观察结果表明，随着年龄的增长，神经肌肉接头会出现回缩和出芽现象，主要是与变性相关的事件，导致神经肌肉接头形状发生深刻变化。
