Varicosities of intraretinal ganglion cell axons in human and nonhuman primates
Varicosities of intraretinal ganglion cell axons in human and nonhuman primates
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DOI：
10.1167/iovs.02-0333
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发表时间：
2003-01-01
影响因子：
4.4
通讯作者：
Cioffi, GA
中科院分区：
文献类型：
--
作者：
Wang, L;Dong, J;Cioffi, GA
目的。描述人类和非人类灵长类动物视网膜神经纤维层中视网膜内神经节细胞轴突的静脉曲张。方法。使用平装视网膜上的神经丝抗体对七名人类供体（1 - 85 岁）和两只非人类灵长类动物（猕猴，15 岁和 17 岁）的视网膜内神经节细胞轴突进行免疫组织化学染色，并用光学显微镜检查。此外，还用透射电子显微镜检查了一名人类和一名非人类视网膜的视网膜神经纤维层内的轴突。在横向和平行切片上测量单个轴突直径的变化，并统计评估直径的频率分布。结果。在所检查的所有年龄段的非人类灵长类动物和人类眼睛的整个视网膜中都发现了视网膜内神经节细胞轴突的静脉曲张。静脉曲张富含线粒体，并与其他轴突和视网膜神经胶质细胞具有桥粒和半桥粒样连接。在平行切割轴突上测量，静脉曲张的平均直径 (+/-SD) 为 2.7 +/- 0.9 微米，而静脉曲张间区域的平均直径为 0.7 +/- 0.3 微米。横切轴突的直径分布也是双峰的，但两个峰值更接近，因为较大直径组的峰值减少了。结论。结果表明，人类和非人类灵长类动物的视网膜内神经节细胞轴突主要是曲张纤维。单个轴突直径内存在尺寸变化，从而影响横向切割制剂中看到的直径分布模式。富含线粒体的静脉曲张和细胞间连接的存在表明，静脉曲张可能是满足无髓纤维和信号传输局部高能量需求的功能位点。
PURPOSE. To describe varicosities of intraretinal ganglion cell axons in the nerve fiber layer of human and nonhuman primate retinas.METHODS. Intraretinal ganglion cell axons of seven human donors (1 - 85 years old) and two nonhuman primates (Macaca mulatta, 15 and 17 years old) were immunohistochemically stained with an antibody of neurofilament on flatmounted retinas and examined with light microscopy. In addition, the axons within the retinal nerve fiber layer were examined with transmission electron microscopy in one human and one nonhuman retina. The variations of diameters of single axons were measured on transverse- and parallel-cut sections, and the frequency distributions of the diameters were statistically evaluated.RESULTS. Varicosities of the intraretinal ganglion cell axons were found throughout the retinas in both nonhuman primate and human eyes of all ages examined. The varicosities were rich in mitochondria and had desmosome- and hemidesmosome-like junctions with other axons and retinal glial cells. Measured on parallel-cut axons, the mean diameter (+/-SD) of varicosities was 2.7 +/- 0.9 mum, whereas the mean diameter of intervaricosity regions was 0.7 +/- 0.3 mum. The diameter distribution for transverse-cut axons was also bimodal, but the two peaks were much closer because the peak of the larger-diameter group decreased.CONCLUSIONS. The results demonstrated that intraretinal ganglion cell axons are predominantly varicose fibers in both human and nonhuman primates. Size variations exist within a single axon's diameter and thereby affect the patterns of diameter distribution seen in transverse-cut preparations. The mitochondria-rich varicosities and the presence of intercellular junctions suggest that the varicosities may be functional sites that serve local high-energy demands of unmyclinated fibers and signal transmission.