Goemaere-Vanneste J, van den Bosch de Aguilar P
Université Catholique de Louvain, Laboratoire de Biologie Cellulaire.
Cellule. 1987;74:263-79.
An histological study of the peripheral nervous fibres has been performed at various anatomical levels during aging: the spinal ganglion, the dorsal and the ventral nerve roots, the spinal and the sciatic nerves. During aging the various alterations occurring in a peripheral nerve can be summarized as following. In the myelinated fibres, the axoplasm was progressively invaded by several inclusions: glycogen granules, granulo-filamentous bodies and lipofuscins. The crystalloid networks arising from the cytoskeleton were mainly localised in the intraganglionic fibres. Among the axoplasmic organelles, the mitochondria were the most affected. The myelinic sheath split, became dystrophic and then was totally disrupted. The inner schwann cell compartment was invaded by several inclusions like Hirano bodies and dense residual deposits. Further, macrophages phagocytosed the axon and the myelin sheath. In the non-myelinated fibres, the alterations were less important and less precocious. When these results are analysed from a chronological point of view it is established that the alterations appear at the same time in each observed level but their amount differ from each other. In the 24-month-old-rats, the ventral root and the sciatic nerve present many dystrophies whereas in the spinal ganglion and in the dorsal root they are less numerous. From these results, it can be suspected that the motor fibres are more vulnerable during aging. Moreover, the myelinated fibres of large diameter are the first affected. Furthermore, only the ventral root and the sciatic nerve show typical regeneration pictures at 32 months.
在衰老过程中，我们对不同解剖水平的周围神经纤维进行了组织学研究，包括脊髓神经节、背根和腹根、脊髓神经和坐骨神经。在衰老过程中，周围神经发生的各种变化可总结如下。在有髓纤维中，轴浆逐渐被几种内含物侵入：糖原颗粒、颗粒丝状小体和脂褐素。由细胞骨架产生的晶体网络主要位于神经节内纤维中。在轴浆细胞器中，线粒体受影响最大。髓鞘分裂、营养不良，然后完全破坏。雪旺细胞内区被几种内含物侵入，如 Hirano 小体和致密残余沉积物。此外，巨噬细胞吞噬轴突和髓鞘。在无髓纤维中，变化不那么明显，也不那么早熟。从时间顺序的角度分析这些结果时发现，每个观察水平的变化同时出现，但数量彼此不同。在 24 个月大的大鼠中，腹根和坐骨神经出现许多营养不良，而在脊髓神经节和背根中则较少。从这些结果可以推测，运动纤维在衰老过程中更易受损。此外，大直径的有髓纤维首先受到影响。此外，只有腹根和坐骨神经在 32 个月时显示出典型的再生图像。
