EARLY DEVELOPMENT OF AMACRINE CELLS IN MOUSE RETINA - ELECTRON-MICROSCOPIC, SERIAL SECTION ANALYSIS
EARLY DEVELOPMENT OF AMACRINE CELLS IN MOUSE RETINA - ELECTRON-MICROSCOPIC, SERIAL SECTION ANALYSIS
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DOI：
10.1002/cne.901790204
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发表时间：
1978-01-01
影响因子：
2.5
通讯作者：
HINDS, PL
中科院分区：
文献类型：
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作者：
HINDS, JW;HINDS, PL
通过从连续薄切片中重建大量细胞，分析了妊娠第15天（E15）小鼠视网膜无长突细胞的发育。通过重建E13和E17视网膜细胞补充了这一信息。还使用了E15前细胞起源时间的放射自显影研究。E17视网膜细胞的重建证实了外室层中存在双极无长突细胞，E17时出现的较不成熟的双极无长突细胞与E15时的细胞相似;它们与轴突前、迁移阶段的神经节细胞的区别在于它们的扁平而不是圆柱形突起，这些突起的细胞质颜色较深，它们的百分位距细胞核较近。检查大量的重建细胞的整个厚度的E15视网膜显示没有形式直接从心室细胞过渡到双极无长突细胞，相反，双极无长突细胞来自逆行（巩膜定向）迁移的细胞在神经节细胞层，类似于正常的神经节细胞，但缺乏轴突。神经节细胞层的这些轴突细胞的起源尚不确定，但一些发现，包括视神经中轴突变性的证据，表明它们是由神经节细胞原始轴突的丢失引起的。因此，无长突细胞可能是由细胞迁移到神经节细胞层后发生的相对较晚的分化事件形成的。这样的发育起源可能提供了一个合理的解释，在神经节细胞层和IPL [内丛状层]中的位移无长突细胞描述的成人，也许是密切相似的树突树的某些亚型的正常，非位移，神经节和无长突细胞。
Development of retinal amacrine cells in mice at the 15th day of gestation (E15) was analyzed by reconstructing large numbers of cells from serial thin sections. This information was supplemented by reconstructing cells from E13 and E17 retinas. Autoradiographic studies of time of origin of cells arising in the period before E15 was also used. The presence of bipolar amacrine cells in the outer ventricular layer was confirmed by reconstructing cells from the E17 retina when a clearly defined inner plexiform layer (IPL) was 1st found. The less mature bipolar amacrine cells present at E17 resembled similar cells found in the E15 retina; they were distinguished from the pre-axonic, migratory stage of ganglion cells by their flattened rather than cylindrical processes, darker cytoplasm of these processes and the position of their centioles closer to the nucleus. Examination of large numbers of reconstructed cells throughout the thickness of the E15 retina revealed no forms directly transitional from ventricular cells to bipolar amacrine cells; instead, bipolar amacrine cells were derived by retrograde (sclerally directed) migration of cells in the ganglion cell layer that resemble normal ganglion cells but lack axons. The origin of these anaxonic cells of the ganglion cell layer was not certain, but several findings, including evidence of degenerating axons in the optic nerve, suggest that they were derived by loss of the primitive axon of ganglion cells. Thus amacrine cells may be formed by a relatively late differentiating event that occurs after migration of cells to the ganglion cell layer. Such a developmental origin may offer a plausible explanation for displaced amacrine cells in the ganglion cell layer and IPL [inner plexiform layer] described in the adult and perhaps the close similarity of dendritic trees of certain subtypes of normal, nondisplaced, ganglion and amacrine cells.