神经退变和再生的构筑变化

将夹伤的大鼠坐骨神经分离成单根纤维,观察98d内轴突和许旺细胞的构筑变化过程发现,损伤既使轴浆转运阻断、积累的细胞器退变,也使髓鞘板层,特别是斯兰氏切迹撕裂、变形或侵入轴突。轴突或髓鞘虽可各呈单一的退变,但以两者并存多见。伤后1d即出现富含微管的再生芽,它被增殖的许旺细胞突起及其基底膜包绕,并逐步发育成熟。根据再生的特征性构筑变化,提出了再生芽、无髓和有髓纤维、斯兰氏切迹、朗氏结与神经小束的初见、发育和成熟高峰期的时间顺序。无髓纤维的发育成熟早于有髓纤维。

ARCHITECTURAL CHANGES OF DEGENERATING AND REGENERATING NERVES

Crushed rat sciatic nerve was teased into single nerve fibers. The architectural changes of degenerating and regenerating nerves were observed for 98 days after crush. The injury blocked axoplasmic transport, caused accumulation of degenerated organelles, and induced the split of myelin lamina, particularly the sub-axolemma sheath and Schmidt-Lanterman incisure. Most profiles showed the combined changes of the degenerating axon and Schwann cell. A diagram of the degenerating course is presented. The regenerating sprout, which was usually full of microtubules, appeared 1 day after crush and was going to be surrounded by the Schwann cell processes and its basal lamina. The nonmyelinated axons matured earlier than the myelinated. According to the architectural characteristics the time course of the development and maturation of nonmyelinated and myelinated axons, Schmidt-Lanterman incisure, node of Ranvier and nerve fasciculus are tabled.