Fujita Y, Imagawa T, Uehara M
Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Japan.
Tissue Cell. 2000 Aug;32(4):293-301. doi: 10.1054/tice.2000.0115.
The optic nerve contains the connective tissues, i.e. the lamina cribrosa and pial septa. This report presents a histological comparison of the lamina cribrosa and pial septa in the five classes (mammals, birds, reptiles, amphibians and teleosts) of vertebrates. Furthermore, the distribution of myelinated fibers was observed from the optic nerve through the retina in the same animals. The lamina cribrosa is found in mammals except for mice, and in birds. Structural complexity of the lamina was different in animals but generally dependent of the optic nerve thickness. The pial septa were present in the optic nerve proper of the mammals except for the mice, in birds and in a part of teleosts. Fasciculation of the optic nerve by the pial septa tended to be more prominent as the optic nerve become thicker. The optic nerve consisted of largely myelinated fibers in vertebrates. The retina contained some myelinated fibers in submammals but was thoroughly devoid of myelinated fibers in mammals. The borderline between myelinated and unmyelinated portions in the optic nerve of different species did not related to the lamina cribrosa. Amphibians had exceptionally only a few myelinated fibers in the optic nerve and no myelinated fibers in the retina.
视神经包含结缔组织，即筛板和软脑膜中隔。本报告展示了脊椎动物五个类别（哺乳动物、鸟类、爬行动物、两栖动物和硬骨鱼）中筛板和软脑膜中隔的组织学比较。此外，在相同动物中观察了从视神经到视网膜的有髓纤维分布。除小鼠外，在哺乳动物和鸟类中发现了筛板。筛板的结构复杂性在不同动物中有所不同，但一般取决于视神经的厚度。除小鼠外，在哺乳动物的视神经本部、鸟类以及部分硬骨鱼中存在软脑膜中隔。随着视神经变厚，软脑膜中隔对视神经的束状作用往往更显著。在脊椎动物中，视神经主要由有髓纤维组成。在非哺乳类动物的视网膜中含有一些有髓纤维，但在哺乳动物中视网膜完全没有有髓纤维。不同物种视神经中有髓和无髓部分的边界与筛板无关。两栖动物的视神经中仅有极少数有髓纤维，视网膜中则没有有髓纤维。
