Sturrock R R
J Anat. 1975 Feb;119(Pt 1):67-75.
An electron microscopic study of myelination was carried out in the anterior limb of the anterior commissure of the mouse brain. The total number of axons increased from 48 700 at 17 days post-conception to 286 500 at 11 days postnatum. The first evidence of myelination was the presence of a few promyelin fibres at 8 days postnatum. Myelinated axons were first found at 11 days postnatum. The most rapid increase in myelinated fibres occurred between 17 and 21 days postnatum, but myelination continued to increase even after 45 days postnatum. There was no change in mean diameter (0-27 mum) of unmyelinated axons after 18 days post-conception. The mean diameter of myelinated axons (0-53 mum) also showed no variation with age. The modal diameter of myelinated axons lay between 0-4 and 0-6 mum. Small fibres (0-2-0-3 mum) myelinated around 32-35 days postnatum. The greatest increase in large myelinated axons (larger than or equal to 0-8 mum) occurred after 25 days postnatum. At all ages sheaths with outer and inner tongues in the same quadrant predominated and by 240 days postnatum 80% of sheaths showed this configuration.
对小鼠脑前连合前肢的髓鞘形成进行了电子显微镜研究。轴突总数从受孕后17天的48700条增加到出生后11天的286500条。髓鞘形成的首个证据是出生后8天出现了一些前髓鞘纤维。有髓轴突在出生后11天首次被发现。有髓纤维增加最迅速的时期是在出生后17至第21天，但即使在出生后45天之后，髓鞘形成仍在继续增加。受孕后18天之后，无髓轴突的平均直径（0 - 27微米）没有变化。有髓轴突的平均直径（0 - 53微米）也未随年龄而变化。有髓轴突的众数直径在0 - 4至0 - 6微米之间。小纤维（0 - 2 - 0 - 3微米）在出生后约32 - 35天开始髓鞘化。大型有髓轴突（大于或等于0 - 8微米）增加最多的情况出现在出生后25天之后。在所有年龄段，同一象限具有外舌和内舌的髓鞘占主导，到出生后240天，80%的髓鞘呈现这种结构。
