NERVE REGENERATION AND SCHWANN-CELL BASAL LAMINA - OBSERVATIONS OF THE LONG-TERM REGENERATION
NERVE REGENERATION AND SCHWANN-CELL BASAL LAMINA - OBSERVATIONS OF THE LONG-TERM REGENERATION
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DOI：
10.1679/aohc.46.243
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发表时间：
1983-01-01
期刊：
影响因子：
--
通讯作者：
IDE, C
中科院分区：
文献类型：
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作者：
IDE, C
从预先变性的小鼠坐骨神经切除约6-7 mm长的神经节段，并通过重复冷冻和解冻处理5次以杀死雪旺细胞。将处理后的神经段移植到原位，与坐骨神经近端残端接触。分别于移植后2、3、5、7、10 d和2、3、5、8 wk处死动物。在中间水平检查移植物，即，通过光学显微镜和EM，在移植物近端远端约3-4 mm处。移植后2- 3d内，死亡的雪旺细胞崩解成碎片，并逐渐被巨噬细胞吞噬。雪旺细胞的基底层保持为空管（基底层支架）。再生轴突总是通过这些基底层支架生长。新的雪旺氏细胞似乎从近端残肢沿着这些轴突迁移。随着时间的推移，穿过基底层支架生长的轴突数量逐渐增加。这些轴突被雪旺细胞包裹成一束。移植后约1周，轴突开始被许旺细胞分隔成更小的束。具有相对大直径的轴突（约2 μ m）倾向于被分选出来并被它们自己的许旺细胞包围。髓鞘形成开始。如此大直径的轴突移植后2周。由于再生轴突和雪旺细胞数量和体积的增加，再生轴突生长通过的基底层支架在膨胀力的作用下逐渐崩解成碎片。由同一基底层支架衍生的轴突群被类似神经束膜上皮细胞的细胞包围。这些神经束膜上皮细胞增殖，并进一步将轴突群分离成较小的轴突，甚至分离成单个轴突。有髓轴突的数量随着再生的进展而增加。显然，雪旺细胞的基底层支架作为再生轴突的延伸、维持和成熟的有效管道。
Nerve segments approximately 6-7 mm long were excised from the predegenerated sciatic nerves of mice, and treated 5 times by repetitive freezing and thawing to kill the Schwann cells. Such treated nerve segments were grafted into the original place, being in contact with the proximal stump of the sciatic nerve. The animals were sacrificed 2, 3, 5, 7 and 10 days, and 2, 3, 5 and 8 wk after the grafting. The grafts were examined at the middle level, i.e., about 3-4 mm distal to the proximal end of the graft, by light microscopy and EM. Within 2-3 days after the grafting, the dead Schwann cells were disintegrated into fragments and gradually phagocytized by macrophages. The basal laminae of the Schwann cells remained as empty tubes (basal lamina scaffolds). The regenerating axons always grew through these basal lamina scaffolds. New Schwann cells seemed to migrate along these axons from the proximal stumps. The number of axons growing through the basal lamina scaffolds gradually increased with time. These axons were surrounded in a bundle by Schwann cells. About 1 wk after the grafting, axons began to be segregated into smaller bundles by Schwann cells. Axons with a relatively large diameter (.apprx. 2 .mu.m) tended to be sorted out and surrounded by their own Schwann cells. The myelination began .apprx. 2 wk after the grafting on such large diameter axons. The basal lamina scaffolds, through which the regenerating axons had grown, were gradually disintegrated into fragments by the expansive forces due to the increase in number and volume of the regenerating axons and Schwann cells. Groups of axons, which had been derived from the same basal lamina scaffolds, were enclosed with the cells resembling perineurial epithelial cells. These perineurial epithelial cells proliferated and further separated groups of axons into smaller ones or even into single axons. The number of myelinated axons increased with the advancement of regeneration. Evidently, the basal lamina scaffolds of Schwann cells serve as efficient conduits for the elongation, maintenance and maturation of regenerating axons.