PETERS A
J Biophys Biochem Cytol. 1960 Oct;8(2):431-46. doi: 10.1083/jcb.8.2.431.
The development and structure of myelin sheaths have been studied in the optic nerves of rats and of Xenopus laevis tadpoles. Both potassium permanganate- and osmium-fixed material was examined with the electron microscope. In the first stage of myelinogenesis the nerve fibre is surrounded by a cell process which envelops it and forms a mesaxon. The mesaxon then elongates into a loose spiral from which the cytoplasm is later excluded, so that compact myelin is formed. This process is similar to myelinogenesis in the peripheral nervous system, although in central fibres the cytoplasm on the outside of the myelin is confined in a tongue-like process to a fraction of the circumference, leaving the remainder of the sheath uncovered, so that contacts are possible between adjacent myelin sheaths. The structure of nodes in the central nervous system has been described and it is suggested that the oligodendrocytes may be the myelin-forming cells.
已经在大鼠和非洲爪蟾蝌蚪的视神经中研究了髓鞘的发育和结构。用电子显微镜检查了经高锰酸钾固定和锇固定的材料。在髓鞘形成的第一阶段，神经纤维被一个细胞突起包围，该突起包裹着它并形成轴系膜。然后轴系膜伸长形成一个松散的螺旋，随后细胞质从中被排除，从而形成致密的髓鞘。这个过程类似于周围神经系统中的髓鞘形成，尽管在中枢纤维中，髓鞘外部的细胞质被限制在一个舌状突起中，仅占圆周的一小部分，鞘的其余部分没有覆盖，这样相邻的髓鞘之间就可能发生接触。已经描述了中枢神经系统中结的结构，并提出少突胶质细胞可能是形成髓鞘的细胞。
