THE APPEARANCE AND DISTRIBUTION OF MICROGLIA IN THE DEVELOPING RETINA OF THE RAT
THE APPEARANCE AND DISTRIBUTION OF MICROGLIA IN THE DEVELOPING RETINA OF THE RAT
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DOI：
10.1017/s0952523800012335
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发表时间：
1989-01-01
影响因子：
1.9
通讯作者：
STONE, J
中科院分区：
文献类型：
--
作者：
ASHWELL, KWS;HOLLANDER, H;STONE, J
我们已经检查了小胶质细胞在大鼠视网膜的发展，使用过氧化物酶结合凝集素衍生的格里菲斯单一。我们研究了从胚胎期12岁（视神经杯内陷之后，视神经裂隙闭合之前）到成年期的动物视网膜。这种凝集素也被证明是发育中的视网膜内皮细胞的敏感标签。我们的结果为小胶质细胞来源于单核-巨噬细胞系列血细胞的观点提供了一些支持。在E12时，大多数标记细胞出现在玻璃体表面，提示它们来自玻璃体循环，而一些细胞进入视网膜，似乎向心室表面迁移。从14岁到出生后早期，大多数标记的细胞都有突起，类似于碳酸银染色研究中描述的变形虫小胶质细胞（Ling, 1982）。标记细胞数从E14时的约700个上升到P（产后）7时的峰值约27,000个，到P12时下降到约19,600个。早在E16时，小胶质细胞在视网膜表面的分布就有明显的规律性，细胞倾向于相互回避。小胶质细胞遍布在非常年轻的视网膜的厚度上，但随着视网膜层的分化，它们越来越局限于视网膜的内半部。我们的研究结果表明，小胶质细胞早在神经元死亡之前就进入视网膜，这使得它们不太可能仅仅是对细胞死亡的反应而侵入视网膜。然而，我们的结果证实，一旦进入视网膜，小胶质细胞就会与神经元死亡期间出现的收缩碎片相关联，并表现出吞噬作用。它们也与视网膜血管系统密切相关。在成人中，小胶质细胞的标记强度大大降低。那些被标记的细胞分化程度更高，类似于早期研究中描述的“静息小胶质细胞”。
We have examined the development of microglia in the rat retina, using a peroxidase-conjugated lectin derived from Griffonia simplicifolia. Retinas were studied from animals aged from E(embryonic day)12, just after the invagination of the optic cup and prior to the closure of the optic fissure, to adulthood. The lectin also proved a sensitive label for the endothelial cells of the developing retina. Our results provide some support for the view that microglia are derived from the monocyte-macrophage series of blood cells. At E12, most labeled cells were found at the vitreal surface, suggesting that they had come from the hyaloid circulation, while some had entered the retina and appeared to be migrating towards its ventricular surface. From E14 to early postnatal ages, most labeled cells had processes and resembled the amoeboid microglial cells described in silver carbonate staining studies (Ling, 1982). The number of labeled cells rose from about 700 to E14 to a peak of about 27,000 at P(postnatal day)7, and fell to about 19,600 by P12. As early as E16, a regularity was apparent in the distribution of microglial cells over the surface of the retina, the cells tending to avoid each other. Microglial cells are found throughout the thickness of the very young retina, but as the layers of the retina differentiate, they are increasingly restricted to the inner half of the retina. Our findings indicate that microglia enter the retina well before the period of neuronal death, making it unlikely that they invade the retina solely in response to cell death. Our results confirm however that, once in the retina, microglia become associated with, and appear to phagocytose, the pyknotic debris which appears during the period of neuronal death. They also become closely associated with the retinal vasculature. In the adult, the intensity of the labeling of microglia was much reduced. Those cells which were labeled appeared more differentiated, resembling the “resting microglia” described in earlier studies.