Development of the posterior neural tube in human embryos
Development of the posterior neural tube in human embryos
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DOI：
10.1007/s00429-004-0421-2
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发表时间：
2004-12-01
期刊：
影响因子：
--
通讯作者：
Shiota, K
中科院分区：
文献类型：
--
作者：
Saitsu, H;Yamada, S;Shiota, K
人类胚胎后神经管（PNT）的发育是一个复杂的过程，涉及初级和次级神经发育。因为PNT的正常发育尚不完全清楚。脊髓神经管缺陷的发病机制尚不清楚。为了阐明PNT的发育机制，我们对20个后神经孔闭合期的人类胚胎进行了组织学检查，发现发育中的PNT可分为三个部分：1)最吻侧区域，对应初级神经管的后部，2)初级神经管和次级神经管的连接区域，3)尾侧区域。它来自于神经索。在交界区，轴向凝聚间质（AM）在后神经孔关闭阶段介入神经板/管与脊索之间，而脊索在最吻侧区直接附着于神经板/管。在AM中发现了一个单一的空腔，因为假定的管腔表面细胞在神经索形成之前在连接区呈放射状排列。单腔与主神经管中心腔连续。相反，在PNT的尾侧区域经常观察到多个或孤立的腔。我们的观察表明，在与脊索的关系和二次神经形成过程中的空化模式方面，PNT的连接区与其他区域不同。
Development of the posterior neural tube (PNT) in human embryos is a complicated process that involves both primary and secondary neurulation. Because normal development of the PNT is not fully understood. pathogenesis of spinal neural tube defects remains elusive. To clarify the mechanism of PNT development, we histologically examined 20 human embryos around the stage of posterior neuropore closure and found that the developing PNT can be divided into three parts: 1) the most rostral region, which corresponds to the posterior part of the primary neural tube, 2) the junctional region of the primary and secondary neural tubes, and 3) the caudal region. which emerges from the neural cord. In the junctional region, the axially-condensed mesenchyme (AM) intervened between the neural plate/tube and the notochord at the stage of posterior neuropore closure, while the notochord was directly attached to the neural plate/tube in the most rostral region. A single cavity was found to be formed in the AM as the presumptive luminal surface cells were radially aligned in the junctional region prior to the formation of the neural cord. The single cavity was continuous with the central cavity of the primary neural tube. In contrast, multiple or isolated cavities were frequently observed in the caudal region of the PNT. Our observation suggests that the junctional region of the PNT is distinct from other regions in terms of the relationship with the notochord and the mode of cavitation during secondary neurulation.