Reles A, Friede R L
Department of Neuropathology, University of Göttingen, Federal Republic of Germany.
J Neurocytol. 1991 Jun;20(6):450-8. doi: 10.1007/BF01252273.
The relationship between the degree of nodal narrowing and the changes in the structure of the axonal cytoskeleton was studied in 53 fibres of mouse sciatic nerve. Nodal narrowing increased with increasing fibre calibre to reach about 20% of the internodal area in the thicker fibres. The narrowing corresponded quantitatively to a decreased number of nodal neurofilaments. Nodal microtubule numbers varied greatly, and a majority of fibres had considerably (approximately 55%) more microtubules in their nodal profile than in the internode. Nodal profiles of different calibre showed an increase in the number of filaments and of microtubules with nodal calibre, although at rates different from those in the internode. The degree of observed axon non-circularities had no discernible effect on the restructuring of the axonal cytoskeleton at the node. A transnodal transport of the axonal cytoskeleton can occur with: (1) accelerated transnodal transport of filaments, (2) stationary internodal fraction of filaments, (3) depolymerization of filaments proximal to the node and repolymerization distally, or (4) different nodal and internodal polymerization equilibria.
在53根小鼠坐骨神经纤维中研究了结狭窄程度与轴突细胞骨架结构变化之间的关系。结狭窄随着纤维直径的增加而增加，在较粗的纤维中达到节间面积的约20%。这种狭窄在数量上与结处神经丝数量的减少相对应。结处微管数量变化很大，大多数纤维结处的微管数量比节间多得多（约55%）。不同直径的结处轮廓显示，随着结直径的增加，丝和微管的数量增加，尽管其速率与节间不同。观察到的轴突非圆形程度对结处轴突细胞骨架的重组没有明显影响。轴突细胞骨架的跨结运输可能通过以下方式发生：（1）丝的跨结运输加速，（2）丝在节间的比例保持不变，（3）结近端的丝解聚，远端重新聚合，或（4）结处和节间不同的聚合平衡。
