Bohn M C, Friedrich V L
J Neurosci. 1982 Sep;2(9):1292-8. doi: 10.1523/JNEUROSCI.02-09-01292.1982.
Oligodendrocyte formation and myelination in the optic nerve of rats treated with cortisol on postnatal days 7 and 18 were investigated at 21 and 60 days by autoradiographic and morphometric methods. At 21 days, the amount of myelin in the optic nerve of treated rats was reduced by 42%. This reduction was accompanied by a 39% decrease in the number of myelinated axons. In addition, the myelin/axon area ratio was reduced 22% for those axons which were myelinated. At 60 days, the amount of myelin, the number of axons myelinated, the average axonal size, and the average amount of myelin per axon had completely recovered to normal values. Tritiated thymidine-labeling experiments showed that the genesis of oligodendrocytes was enhanced following the cessation of treatment. Since the number of oligodendrocytes in the optic nerve of treated rats was normal at 60 days, it is suggested that the retarding effect of cortisol on myelination in the optic nerve may be mediated, at least in part, by inhibited formation of oligodendrocytes during treatment.
采用放射自显影和形态计量学方法，在出生后第21天和60天研究了出生后第7天和18天用皮质醇处理的大鼠视神经中少突胶质细胞的形成和髓鞘形成情况。在21天时，处理组大鼠视神经中的髓鞘量减少了42%。这种减少伴随着有髓轴突数量减少39%。此外，对于那些有髓鞘的轴突，髓鞘/轴突面积比降低了22%。在60天时，髓鞘量、有髓鞘的轴突数量、平均轴突大小以及每个轴突的平均髓鞘量已完全恢复到正常值。氚标记胸腺嘧啶核苷标记实验表明，停止治疗后少突胶质细胞的生成增强。由于处理组大鼠视神经中少突胶质细胞的数量在60天时正常，因此提示皮质醇对视神经髓鞘形成的抑制作用可能至少部分是由治疗期间少突胶质细胞形成受抑制介导。
