Schnitzer J, Scherer J
Max-Planck-Institut für Hirnforschung, Abteilung Neuroanatomie, Frankfurt am Main, Germany.
J Comp Neurol. 1990 Dec 22;302(4):779-91. doi: 10.1002/cne.903020410.
The response of retinal microglial cells, which accompanies retrograde degeneration of ganglion cell axons and perikarya (induced by transection of the optic nerve), was studied in whole-mounted rabbit retinae labeled enzyme-histochemically for nucleoside diphosphatase (NDPase), which is a microglial cell marker. A few days after transection, the number of microglial cells/mm2, as well as their staining intensity, began to increase in the inner plexiform layer. The mosaic-like distribution of the star-shaped microglial cells present in the inner plexiform layer of a normal rabbit retina was preserved during ganglion cell degeneration. As in the normal retina, processes of individual cells never overlapped with those of neighboring cells in the inner plexiform layer because individual cells in the "degenerating" retina acquired shorter processes, i.e., the cells occupied a smaller territory compared to the normal retina. In the nerve fiber layer the number and staining intensity of NDPase-labeled microglial cell processes (most of which are aligned in parallel with degenerating ganglion cell axons) transiently increased and returned to normal values by 5 months post-transection. Microglial cells that are not detectably NDPase labeled in the outer plexiform layer of a normal rabbit retina acquire intense staining a few days after the nerve is cut. The functional significance of the increased NDPase activity in the plasma membrane of microglial cells during degeneration remains to be determined.
在经酶组织化学标记核苷二磷酸酶（NDPase，一种小胶质细胞标志物）的兔视网膜全层标本中，研究了伴随视神经切断诱导的神经节细胞轴突和胞体逆行性变性时视网膜小胶质细胞的反应。切断后几天，内丛状层中小胶质细胞的数量/mm²及其染色强度开始增加。在神经节细胞变性过程中，正常兔视网膜内丛状层中星形小胶质细胞的镶嵌样分布得以保留。与正常视网膜一样，内丛状层中单个细胞的突起从不与相邻细胞的突起重叠，因为“变性”视网膜中的单个细胞获得了较短的突起，即与正常视网膜相比，这些细胞占据的区域更小。在神经纤维层，NDPase标记的小胶质细胞突起（其中大多数与变性的神经节细胞轴突平行排列）的数量和染色强度短暂增加，并在切断后5个月恢复到正常值。正常兔视网膜外丛状层中未检测到NDPase标记的小胶质细胞在神经切断后几天获得强烈染色。小胶质细胞质膜在变性过程中NDPase活性增加的功能意义尚待确定。
