MOSAIC ORGANIZATION OF THE HIPPOCAMPAL NEUROEPITHELIUM AND THE MULTIPLE GERMINAL SOURCES OF DENTATE GRANULE CELLS
MOSAIC ORGANIZATION OF THE HIPPOCAMPAL NEUROEPITHELIUM AND THE MULTIPLE GERMINAL SOURCES OF DENTATE GRANULE CELLS
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DOI：
10.1002/cne.903010302
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发表时间：
1990-11-15
影响因子：
2.5
通讯作者：
BAYER, SA
中科院分区：
文献类型：
--
作者：
ALTMAN, J;BAYER, SA
这项研究涉及胚胎时期大鼠海马主要细胞成分的起源，迁移和定居点。结果表明，海马神经上皮由三个形态学离散的组件组成。SBD。齿状回的较小颗粒神经元，纤维膜的神经胶质细胞。假定的弹药神经上皮在短寿命的胸苷射线图中以高水平的增殖活性和从E16天到E19天的互动核迁移的证据来标记。在E16和E17天，在弹性神经上皮外形成了一个未标记的细胞的扩散带。这些有丝分裂后细胞被认为是辐射层和层层神经元，最早在E15时大量产生。细胞致密的层，即初期的锥体层，在E18天开始形成，并可以从弹药神经上皮细胞中追溯到纺锤形细胞。该迁移带的大小增加了几天，然后下降，最后在E22时消失。可以推断，这种迁移包含Ammon'号角的锥体细胞，这些细胞主要是在E17至E20天生产的。假定的原发性齿状神经上皮与胚胎发育的早期阶段相比，通过其位置，形状和细胞动力学区分开来。它位于心室压痕周围，齿状牙齿牙齿牙齿牙齿牙齿牙齿的牙齿凹口较少，而在心室腔附近的丝裂细胞较少，而不是弹性神经倍义，并且在短寿命和顺序外阳离子胸苷放射线图中显示出不同的标记模式。到第E18天，还原的原代齿状神经上皮被一个增殖细胞的聚集物所包围。这是次级齿状矩阵。在随后的几天，主轴形细胞保留了它们的增殖能力从逐渐退缩的次级齿状基质迁移到齿状回齿状回的本身。后者代表三级生发基质，在围产期期间变得高度活跃。推定的纤维化胶质上皮位于原发性牙齿神经上皮和海马冠状的尖端之间。甲基丙烯酸酯切片和胸苷射线图的观察表明，与典型的神经上皮细胞不同，这种生发基质的细胞不会经历互互核迁移。纤维上的胶质上皮显然是在E16的第2天之前出现的，这是纤维膜变成独特的纤维道的两天。随着纤维膜的出现，推定的神经胶质基质的细胞迁移到其中。
This study deals with the site of origin, migration, and settling of the principal cell constituents of the rat hippocampus during the embryonic period. The results indicate that the hippocampal neuroepithelium consists of three morphogenetically discrete components.sbd.the Ammonic neuroepithelium, th primary dentate neuroepithelium, and the fimbrial glioepithelium.sbd.and that these are discrete sources of the large neurons of Ammon''s horn, the smaller granular neurons of the dentate gyrus, and the glial cells of the fimbria. The putative Ammonic neuroepithelium is marked in short-survival thymidine radiograms by a high level of proliferative activity and evidence of interkinetic nuclear migration from day E16 until day E19. On days E16 and E17 a diffuse band of unlabeled cells forms outside the Ammonic neuroepithelium. These postmitotic cells are considered to be stratum radiatum and stratum oriens neurons, which are produced in large numbers as early as day E15. A cell-dense layer, the incipient stratum pyramidale, begins to form on day E18 and spindle-shaped cells can be traced to it from the Ammonic neuroepithelium. This migratory band increases in size for several days, then declines and finally disappears by day E22. It is inferred that this migration contains the pyramidal cells of Ammon''s horn that are produced mostly on days E17 through E20. The putative primary dentate neuroepithelium is distinguished from the Ammonic neuroepithelium during the early phases of embryonic development by its location, shape, and cellular dynamics. It is located around a ventricular indentation, the dentate notch, contains fewer mitotic cells near the lumen of the ventricle than the Ammonic neuropithelium, and shows a different labeling pattern both in short-survival and sequential-survival thymidine radiograms. By day E18, the reduced primary dentate neuroepithelium is surrounded by an aggregate of proliferative cells; this is the secondary dentate matrix. On the subsequent days spindle-shaped cells that have retained their proliferative capacity migrate from the progressively receding secondary dentate matrix to the dentate gyrus itself. The latter, representing a tertiary germinal matrix, becomes highly active during the perinatal period. The putative fimbrial glioepithelium is situated between the primary dentate neuroepithelium and the tip of the hippocampal rudiment. Observations in methacrylate sections and thymidine radiograms suggest that the cells of this germinal matrix, unlike typical neuroepithelial cells, do not undergo interkinetic nuclear migration. The fimbrial glioepithelium is clearly present by day E16, two days before the fimbria becomes a distinct fiber tract. As the fimbria emerges, cells of the putative glial matrix migrate into it.