Dupree J L, Coetzee T, Suzuki K, Popko B
Neuroscience Center, University of North Carolina, Chapel Hill 27599, USA.
J Neurocytol. 1998 Sep;27(9):649-59. doi: 10.1023/a:1006908013972.
Myelin sheath formation depends on appropriate axo-glial interactions that are mediated by myelin-specific surface molecules. In this study, we have used quantitative morphological analyses to determine the roles of the prominent myelin lipids galactocerebroside (GalC) and sulfatide in both central and peripheral myelin formation, exploiting mutant mice incapable of synthesizing these lipids. Our results demonstrate a significant increase in uncompacted myelin sheaths, the frequency of multiple cytoplasmic loops, redundant myelin profiles, and Schmidt-Lanterman incisures in the CNS of these mutant mice. In contrast, PNS myelin appeared structurally normal in these animals; however, at post-natal day 10, greater than 10% of the axons withered and pulled away from their myelin sheaths. These results indicate that GalC and sulfatide are critical to the formation of CNS myelin. In contrast, PNS myelin formation is not dependent on these lipids; however, GalC and sulfatide appear to be instrumental in maintaining Schwann cell-axon contact during a specific developmental window.
髓鞘形成依赖于由髓鞘特异性表面分子介导的适当轴突-神经胶质相互作用。在本研究中，我们利用无法合成这些脂质的突变小鼠，通过定量形态学分析来确定主要的髓鞘脂质半乳糖脑苷脂（GalC）和硫脂在中枢和外周髓鞘形成中的作用。我们的结果表明，这些突变小鼠中枢神经系统中未紧密压实的髓鞘、多个细胞质环的频率、多余的髓鞘轮廓以及施密特-兰特尔曼切迹显著增加。相比之下，这些动物的外周神经系统髓鞘在结构上看起来正常；然而，在出生后第10天，超过10%的轴突萎缩并从其髓鞘中脱离。这些结果表明，GalC和硫脂对中枢神经系统髓鞘的形成至关重要。相比之下，外周神经系统髓鞘的形成不依赖于这些脂质；然而，GalC和硫脂似乎在特定的发育窗口期对维持雪旺细胞-轴突接触起作用。
