Myelination of the rat optic nerve during postnatal undernourishment and recovery: a morphometric analysis.
Myelination of the rat optic nerve during postnatal undernourishment and recovery: a morphometric analysis.
复制标题
出生后营养不良和恢复期间大鼠视神经的髓鞘形成：形态测量分析。
DOI：
10.1016/0006-8993(84)91065-5
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发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Samorajski,T
中科院分区：
文献类型：
--
作者：
Wiggins,RC;Fuller,GN;Brizzee,L;Bissel,AC;Samorajski,T
新生大鼠从出生后第二天到20日龄一直营养不良，断奶后开始自由进食实验室饲料。分别于14日龄、21日龄、35日龄、63日龄用光镜和电子显微镜观察视神经发育情况。营养不良的程度导致身体生长滞后，与我们以前的研究结果相当。虽然少突胶质细胞的细胞密度(每个显微区域的细胞数)没有受到影响，但通过光镜取样，在21日龄时，有髓纤维的总数明显地相对减少。无髓纤维和有髓纤维的比例通过电子显微镜进行了估算，结果表明该比例在早期(14天)有所增加。无论是由于发育滞后的追赶，还是由于康复可能的恢复效果，这些差异在35天龄时都不显著。通过回归分析确定轴突周长与髓鞘板层数之间的关系，结果表明，在14d时，所有大小轴突的板层数均显著减少。21天时，只有周长为1-2μm的纤维有差异，35天时无显著差异。上述结果均表明营养不良大鼠视神经髓鞘明显减少。
Newborn rats were undernourished from the second postnatal day through 20 days of age and weaned to a diet of laboratory chow ad libitum. Optic nerve development was examined by various light and electron microscopic techniques at 14, 21, 35 and 63 days of age. The degree of undernourishment achieved resulted in body growth lag comparable to results obtained in our previous studies. Although cellularity (cells per photomicrograph area) of the oligodendroglia was unaffected, there was an apparent significant relative reduction in the total number of myelinated fibers by 21 days of age, as determined by light micrscopic sampling. Ratios of unmyelinated-to-myelinated fibers were thus estimated by electron microscopy, and results indicated an early increase in the ratio (14 days). Either as the result of catch up in a developmental lag, or as a result of possible restorative effects of rehabilitation, these differences were insignificant by 35 days of age. The relationship between axon circumference and numbers of myelin lamellae was determined by regression analysis, which revealed a significant reduction in numbers of lamellae over axons of all sizes at 14 days. By 21 days, only fibers in the size range of 1–2 μm of circumference showed a difference, and by 35 days there were no significant differences. These results all indicate that there is a significant myelin reduction in optic nerve of the undernourished rat.