Gliogenesis in rat optic nerve: astrocytes are generated in a single wave before oligodendrocytes.
Gliogenesis in rat optic nerve: astrocytes are generated in a single wave before oligodendrocytes.
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DOI：
10.1016/0012-1606(90)90285-q
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发表时间：
1990-05
影响因子：
2.7
通讯作者：
R. Skoff
中科院分区：
文献类型：
--
作者：
R. Skoff
研究大鼠视神经中星形胶质细胞的起源时间，以确定这种细胞类型是否以两个波产生，第一波发生在少突胶质细胞形成之前，第二波发生在少突胶质细胞形成的高峰期之后。为了回答这个问题，在视神经中少突胶质细胞产生的高峰期后，对大鼠多次注射放射性胸苷，并在首次注射后数周处死动物。电镜下可见视神经内胸腺嘧啶标记细胞。在标记的细胞中，>80%是少突胶质细胞，4%是小胶质细胞，2%是星形胶质细胞，其余的是不可分类的。胸腺嘧啶标记的细胞在神经胶质细胞酸性蛋白（GFAP），星形胶质细胞的标志物的特点没有免疫染色。出生后第二周产生的胸腺嘧啶标记的神经胶质细胞的数量是神经胶质细胞总数的一小部分。没有证据表明大鼠视神经中存在星形胶质细胞形成的第二波，如Milleret等人的研究所建议的那样。(1985 Dev. 111，35 -41）;相反，绝大多数星形胶质细胞是在出生后的前2周产生的，这些数据与神经胶质发生的经典研究一致。星形胶质细胞在大鼠视神经是否产生直接从一个未分化的，共同的祖细胞或从一个致力于星形胶质细胞谱系的细胞分裂的问题，解决了结合胸苷放射自显影GFAP免疫细胞化学。注射胸苷后1小时处死大鼠，并对其神经进行GFAP免疫细胞化学和放射自显影。在出生后的第一周，许多胸腺嘧啶标记的细胞免疫染色GFAP。这些观察结果表明，定向为星形胶质细胞谱系的细胞分裂并产生额外的星形胶质细胞。
The time of origin for astrocytes in the rat optic nerve was investigated to determine whether this cell type is generated in two waves, a first wave which occurs before the formation of oligodendrocytes and a second wave which occurs after the peak period of oligodendrocyte formation. To answer this question, multiple injections of radioactive thymidine were administered to rats after the peak period of oligodendrocyte production in the optic nerve and the animals were sacrificed several weeks after the first injection. Thymidine-labeled cells in the optic nerve were identified with the electron microscope. Of the labeled cells, >80% are oligodendrocytes, 4% are microglia, 2% are astrocytes, and the remainder are unclassifiable. The thymidine-labeled cells in the nerve were not immunostained for glial fibrillary acidic protein (GFAP), a marker characteristic of astrocytes. The number of thymidine-labeled glia generated after the second postnatal week is a small fraction of the total number of glia generated neonatally. No evidence exists for a second wave of astrocyte formation in the rat optic nerve as has been suggested in a study by Milleret al.(1985,Dev. Biol.111,35–41); rather, the vast majority of astrocytes are generated during the first 2 postnatal weeks and these data are in keeping with classical studies of gliogenesis. The question of whether astrocytes in the rat optic nerve arise directly from division of an undifferentiated, common progenitor cell or from a cell committed to the astrocyte lineage was addressed by combining thymidine autoradiography with GFAP immunocytochemistry. Rats were sacrificed 1 hr after an injection of thymidine and their nerves were processed for GFAP immunocytochemistry and autoradiography. During the first postnatal week, many thymidine-labeled cells are immunostained for GFAP. These observations demonstrate that cells committed to the astrocyte lineage divide neonatally and give rise to additional astrocytes.