AUTORADIOGRAPHIC STUDY OF PROLIFERATION AND DIFFERENTIATION OF GLIAL CELLS IN-VITRO
AUTORADIOGRAPHIC STUDY OF PROLIFERATION AND DIFFERENTIATION OF GLIAL CELLS IN-VITRO
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DOI：
10.1007/bf00685066
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发表时间：
1971-01-01
影响因子：
12.7
通讯作者：
MANUELIDIS, EE
中科院分区：
文献类型：
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作者：
MANUELIDIS, L;MANUELIDIS, EE
用光镜和电子显微镜放射自显影技术研究了用胸腺嘧啶核苷处理的哺乳动物胚胎脊髓-背根神经节的器官型培养。用H3胸腺嘧啶核苷冲击培养长达6小时后，立即固定时，标记神经上皮细胞的比例为0-2%，在体外培养(DIV)中，第二天固定时，标记细胞的数量是固定前的7-15倍。在培养开始时，以及在体外髓鞘形成之前，将暴露在放射性物质中数天的培养物进行比较。累积证据表明，增殖活性的高峰期不是在外植体之后，而是在突触形成后和髓鞘形成之前的DIV7和DIV12之间。另一个较小的增殖高峰出现在DIV 15至DIV 19之间的髓鞘形成后，光镜下的形态观察显示，在第一个增殖高峰，即髓鞘形成之前，有以小暗细胞为主的标记。根据电子显微镜的鉴定标准，这些小的暗细胞是“大的胶质母细胞”、“大的胶质前体细胞”和“年轻的”少突胶质细胞，这些细胞之间可以观察到分化的顺序。与髓鞘紧密相连的少突胶质细胞没有被标记。中等大小的光细胞的标记和增殖不明显地先于少突胶质细胞及其前体细胞，并在髓鞘形成过程中温和地持续，在DIV 15和DIV 19期间达到适度的高峰和优势。超微结构显示这些中等大的光细胞具有星形细胞的特征，并观察到此类细胞的有丝分裂。讨论了部分星形胶质细胞起源于“大胶质母细胞”的可能性。在超微结构上没有观察到符合无丝分裂标准的标记细胞，也没有神经元显示出H3TdR标记。
Organotypic cultures of mammalian embryonic spinal cord-dorsal root ganglia combinations treated with H3thymidine, were studied with light and electron microscopic autoradiography. Cultures pulsed with H3thymidine for up to six hours showed 0–2% of labelled neuroepithelial cells when fixed immediately thereafter, and 7 to 15 times as many labelled cells when fixed on subsequent daysin vitro(DIV). Cultures exposed to radioactive material for days, at the initiation of the culture, and prior to myelinationin vitro, were compared. The cumulative evidence showed that the peak of proliferative activity occurred not after explantation, but between DIV 7 and DIV 12, which is after synapse formation and prior to myelination. Another smaller proliferative peak occurred after myelination between DIV 15 and DIV 19.Morphological observations with the light microscope revealed labelling of predominantly small dark cells during the first proliferative peak, that is, prior to myelination. Using electron microscopic criteria for identification, these small dark cells were “large glioblasts”, “large glial precursors” and “young” oligodendrocytes, and transitions could be observed between these cells in that order of differentiation. Oligodendrocytes when closely connected with myelin sheaths did not become labelled.Labelling and proliferation of medium large light cells inconspicuously preceded that of oligodendrocytes and their precursors, and continued modestly throughout myelination, achieving a modest peak and predominance during DIV 15 and DIV 19. Astrocytic features could be demonstrated ultrastructurally in these medium large light cells and mitotic division in this type of cell was observed. The possibility that part of this astrocytic population arose from “large glioblasts” was discussed.No labelled cells were seen ultrastructurally fulfilling criteria of amitotic division.No neurons showed labelling with H3thymidine.