Departamento de Neurobiología Molecular y Celular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001 Juriquilla, Querétaro CP 76230, México.
Biol Res. 2013;46(1):27-32. doi: 10.4067/S0716-97602013000100004.
Axons and glial cells are the main components of white matter. The corpus callosum (CC) is the largest white matter tract in mammals; in rodents, 99% of the cells correspond to glia after postnatal day 5 (P5). The area of the CC varies through life and regional differences related to the number of axons have been previously described. Whether glial cell density varies accordingly is unknown; thus the aim of this study was to estimate glial cell density for the genu, body and splenium -the three main regions of CC-, of P6 and P30 rats. Here we report that the density of CC glial cells reduced by ~10% from P6 to P30. Even so, the density of astrocytes showed a slight increase (+6%), probably due to differentiation of glioblasts. Interestingly, glial cell density decreased for the genu (-21%) and the body (-13%), while for the splenium a minor increase (+5%) was observed. The astrocyte/glia ratio increased (from P6 to P30) for the genu (+27%), body (+17%) and splenium (+4%). Together, our results showed regional differences in glial cell density of the CC. Whether this pattern is modified in some neuropathologies remains to be explored.
轴突和神经胶质细胞是白质的主要组成部分。胼胝体（CC）是哺乳动物中最大的白质束；在啮齿动物中，出生后第 5 天（P5）后 99%的细胞对应于神经胶质细胞。CC 的面积在一生中发生变化，并且之前已经描述了与轴突数量相关的区域差异。神经胶质细胞密度是否相应变化尚不清楚；因此，本研究的目的是估计 P6 和 P30 大鼠 CC 的三个主要区域（膝部、体部和压部）的神经胶质细胞密度。在这里，我们报告说，从 P6 到 P30，CC 神经胶质细胞的密度降低了约 10%。即便如此，星形胶质细胞的密度显示出轻微的增加（+6%），可能是由于成神经胶质细胞的分化。有趣的是，膝部和体部的神经胶质细胞密度下降（分别为-21%和-13%），而压部则观察到轻微增加（+5%）。星形胶质细胞/神经胶质细胞比率增加（从 P6 到 P30），膝部（+27%）、体部（+17%）和压部（+4%）。总之，我们的结果显示 CC 神经胶质细胞密度存在区域差异。这种模式在某些神经病理学中是否会发生改变还有待探索。
