THE ORIGIN AND DEVELOPMENT OF RETINAL ASTROCYTES IN THE MOUSE
THE ORIGIN AND DEVELOPMENT OF RETINAL ASTROCYTES IN THE MOUSE
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DOI：
10.1007/bf01186955
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发表时间：
1992-07-01
期刊：
影响因子：
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通讯作者：
FURBY, JH
中科院分区：
文献类型：
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作者：
HUXLIN, KR;SEFTON, AJ;FURBY, JH
星形胶质细胞是一类出现在哺乳动物视网膜发育后期的胶质细胞，已被认为要么原位起源于Muller细胞，要么起源于视网膜外的视柄上皮，只是随后才侵入眼睛。在小鼠身上研究了视网膜星形胶质细胞的起源和发育特征，这是一个以前没有为此目的进行研究的物种。对不同年龄的正常眼和眼柄进行了切片观察。胶质纤维酸性蛋白(GFAP)阳性细胞于妊娠后第17天在视盘柄的末端首次观察到。从这个部位，GFAP阳性细胞以每天大约290微米的速度迁移到视网膜并穿过视网膜，在怀孕后第28天到达视网膜边缘。在视网膜上迁移时，星形胶质细胞的大小和形态复杂性逐渐增加，通过测量它们的分维来证实这一点。在同一时期，一波分化浪潮席卷了柄向颅骨的方向。当有或没有视柄的胎儿半视网膜移植到雏鸡的绒毛尿囊膜上时，出现了视网膜星形胶质细胞在视网膜外出生的进一步证据。1-12天后检查，无视柄培养的外植体含有GFAP阳性的星形胶质细胞，而有视柄的外植体含有相对正常数量的星形胶质细胞。我们使用荧光共聚焦显微镜观察到，与大鼠一样，小鼠的视网膜星形胶质细胞主要与血管联系，而不是轴突束。人们感兴趣的是确定这类胶质细胞是否对神经视网膜的正常细胞结构发育是必要的。对外植体的形态分析表明，在有或没有星形胶质细胞的情况下，成熟视网膜在细胞结构或发育事件的时间上没有明显的差异。因此，星形胶质细胞可能不是小鼠视网膜正常结构发育所必需的。
Astrocytes, a class of glia which appear in the mammalian retina late in development, have been postulated either to originate in situ from Muller cells or extra-retinally from the optic stalk epithelium, only subsequently invading the eye. The site of origin and the developmental characteristics of retinal astrocytes were examined in the mouse, a species not previously studied for this purpose. Sections of normal eyes and stalks at different ages were examined. Cells positive for glial fibrillary acidic protein (GFAP) were first observed at post-conceptional day 17 at the optic disc end of the stalk. From this site, the GFAP-positive cells migrated into and across the retina at a rate of approximately 290-mu-m per day, reaching its edge by post-conceptional day 28. While migrating across the retina, the astrocytes progressively increased in size and morphological complexity, observations confirmed by measurement of their fractal dimension. Over the same period, a wave of differentiation swept along the stalk in the cranial direction. Further evidence that retinal astrocytes are born outside the retina emerged when foetal hemiretinae with or without optic stalks were explanted to the chorioallantoic membrane of the chick. When examined one to twelve days later, no explant cultured without the optic stalk contained GFAP-positive astrocytes, while explants with the stalk left attached contained relatively normal numbers of astrocytes. We observed, using fluorescence confocal microscopy, that retinal astrocytes in the mouse as in the rat, associate predominantly with blood vessels, not axonal bundles. It was of interest to determine whether this class of glia is essential to the normal cytoarchitectural development of the neural retina. Morphological analysis of the explants revealed no observable differences in cytoarchitecture or in the timing of developmental events between retinae maturing with or without astrocytes. It was therefore concluded that astrocytes may not be essential to the normal structural development of the murine retina.