Siegel A, Reichenbach A, Hanke S, Senitz D, Brauer K, Smith T G
Carl Ludwig Institute of Physiology, Leipzig University, Federal Republic of Germany.
Anat Embryol (Berl). 1991;183(6):605-12. doi: 10.1007/BF00187909.
Bergmann glial (Golgi epithelial) cells were Golgi-impregnated in the cerebella of species with great differences in the thickness of the molecular layer, in small African native mouse, rat, rhesus monkey, and man. The thickness of the molecular layer determines the length of the radial Bergmann cell processes. Whereas the overall morphology of the cells was found to be strikingly similar in all species studied, there were great quantitative differences in length and diameter of the stem processes. Species with thick molecular layers (man, monkey) have thicker stem processes than species with short distances between Bergmann glial cell soma and pial surface (rat, mouse). This could mean that larger animals with longer gestation periods allow for prolonged growth of cell volumes. On the other hand, an increase in the diameter of long processes should reduce the cytoplasmic resistance against ionic currents; this would be important when Bergmann glial cells--like retinal Müller cells--would act as "cables" for spatial buffering of potassium ions released by electrically active neurons. By contrast, the fractal dimension--i.e., a quantitative measure of the complexity of the cell's border--of the cell processes was lower in species with long processes. In an age series of rat cells, the fractal dimension is shown to increase slightly up to a very old age.
在分子层厚度差异很大的物种（小型非洲本地小鼠、大鼠、恒河猴和人类）的小脑中，对伯格曼神经胶质细胞（高尔基上皮细胞）进行了高尔基染色。分子层的厚度决定了放射状伯格曼细胞突起的长度。尽管在所研究的所有物种中，细胞的整体形态都惊人地相似，但主干突起的长度和直径存在很大的数量差异。分子层厚的物种（人类、猴子）的主干突起比伯格曼神经胶质细胞胞体与软脑膜表面距离短的物种（大鼠、小鼠）的主干突起更厚。这可能意味着妊娠期较长的较大动物允许细胞体积有更长的生长时间。另一方面，长突起直径的增加应会降低细胞质对离子电流的阻力；当伯格曼神经胶质细胞——像视网膜穆勒细胞一样——充当电活动神经元释放的钾离子空间缓冲的“电缆”时，这将很重要。相比之下，长突起物种的细胞突起的分形维数——即细胞边界复杂性的定量测量——较低。在大鼠细胞的年龄系列中，分形维数在非常老龄之前会略有增加。
