Jiménez David, Rivera Rocío, López-Mascaraque Laura, De Carlos Juan A
Instituto Cajal (CSIC), Madrid, Spain.
Dev Neurosci. 2003 Mar-Aug;25(2-4):105-15. doi: 10.1159/000072260.
Using birthdating techniques, we have studied when cells that settle in the marginal zone (future layer 1) of the cortical neuroepithelium are generated in developing rat embryos. The majority of marginal zone cells are generated at embryonic day 12 (E12), E13 and E14, although some cells generated later can incorporate into this stratum after the cortical plate forms. The nature and the origin of the cell populations that colonize the preplate/marginal zone was studied by means of immunohistochemistry using cell markers for gamma-amino butyric acid (GABA), reelin and the calcium binding proteins calretinin and calbindin. At early stages of development, the preplate is formed by Cajal-Retzius cells, subplate cells, subpial granular layer cells, some interneurons and some glial cells. With the arrival of the cortical plate cells, the subplate cells descend to occupy the stratum below. Layer 1 cells are of diverse origin as some of them are generated in the ventricular zone of the cortical neuroepithelium, whereas other cell populations come from extracortical regions such as the olfactory placode or the ganglionic eminences of the basal telencephalon. The predominant cell type in the marginal zone is the Cajal-Retzius cell, which expresses reelin and calretinin, and is probably generated in the cortical neuroepithelium. These cells can be readily distinguished from cells that come from the ganglionic eminences as these later populations mainly express GABA and calbindin. Finally, our results suggest that the cells of the subpial granular layer might be generated in the rostral pole of the lateral ganglionic eminences.
运用出生日期技术，我们研究了在发育中的大鼠胚胎中，定居于皮质神经上皮边缘区（未来的第1层）的细胞是何时产生的。尽管一些较晚产生的细胞在皮质板形成后可并入该层，但大多数边缘区细胞是在胚胎第12天（E12）、E13和E14产生的。通过使用γ-氨基丁酸（GABA）、reelin以及钙结合蛋白钙视网膜蛋白和钙结合蛋白的细胞标记物进行免疫组织化学，研究了定位于前板/边缘区的细胞群体的性质和起源。在发育早期，前板由Cajal-Retzius细胞、亚板细胞、软膜下颗粒层细胞、一些中间神经元和一些神经胶质细胞组成。随着皮质板细胞的到来，亚板细胞下降至占据下方的层。第1层细胞起源多样，其中一些在皮质神经上皮的脑室区产生，而其他细胞群体则来自皮质外区域，如嗅基板或基底前脑的神经节隆起。边缘区的主要细胞类型是Cajal-Retzius细胞，其表达reelin和钙视网膜蛋白，可能在皮质神经上皮中产生。这些细胞很容易与来自神经节隆起的细胞区分开来，因为后者主要表达GABA和钙结合蛋白。最后，我们的结果表明，软膜下颗粒层的细胞可能在外侧神经节隆起的头端产生。
