Abraham Hajnalka, Pérez-García Carlos Gustavo, Meyer Gundela
Department of Anatomy, Faculty of Medicine, University La Laguna, Tenerife, Spain.
Cereb Cortex. 2004 May;14(5):484-95. doi: 10.1093/cercor/bhh010. Epub 2004 Mar 28.
In the fetal human hippocampus, Cajal-Retzius (CR) cells coexpress p73, a p53-family member involved in cell survival and apoptosis, and the glycoprotein reelin, crucial for radial migration. We distinguish two populations of putative CR cells. (1). p73/reelin expressing cells appear around 10 gestational weeks (GW) at the cortico-choroid border in the temporal horn of the lateral ventricle (the ventral cortical hem) and occupy the marginal zone (MZ) overlying the ammonic and dentate primordia. (2). Additional p73-positive cells appear from 14 GW onward in the neuroepithelium near the dentate-fimbrial boundary and spread toward the pial surface, flanking the migrating secondary dentate matrix. From 13 to 17 GW, large parts of the dentate gyrus are almost devoid of CR cells. p73/Reelin-positive CR cells appear in the MZ of the suprapyramidal blade at 16 GW and around 21 GW in the infrapyramidal blade. The p73-positive cells of the dentate-fimbrial boundary express reelin when they are close to the pial surface, suggesting that they differentiate into CR cells of the infrapyramidal blade. Reelin-positive, p73-negative interneurons are prominent in the prospective strata lacunosum-moleculare and radiatum of cornu ammonis as early as 14 GW; in the dentate molecular layer and hilus they appear around midgestation. We propose that CR cells of the human hippocampal formation belong to two distinct cell populations: an early one derived from the ventral cortical hem and mainly related to migration of the ammonic and dentate plates and a later appearing one derived from the dentate-fimbrial neuroepithelium, which may be related to the protracted neurogenesis and migration of dentate granule cells, particularly of the infrapyramidal blade.
在人类胎儿海马体中，卡哈尔-雷茨乌斯（CR）细胞共表达p73（一种参与细胞存活和凋亡的p53家族成员）和糖蛋白Reelin（对放射状迁移至关重要）。我们区分出两类假定的CR细胞群体。（1）. 表达p73/Reelin的细胞在妊娠约10周（GW）时出现在侧脑室颞角的皮质-脉络膜边界处（腹侧皮质隆起），并占据覆盖海马和齿状原基的边缘区（MZ）。（2）. 额外的p73阳性细胞从14GW起出现在齿状-伞边界附近的神经上皮中，并向软膜表面扩散，位于迁移的次级齿状基质两侧。从13到17GW，齿状回的大部分区域几乎没有CR细胞。p73/Reelin阳性的CR细胞在16GW时出现在锥体细胞层上叶片的MZ中，在21GW左右出现在下叶片中。当齿状-伞边界的p73阳性细胞靠近软膜表面时表达Reelin，表明它们分化为下叶片的CR细胞。早在14GW时，Reelin阳性、p73阴性的中间神经元就在海马体的预期腔隙分子层和辐射层中很突出；在齿状分子层和门区，它们在妊娠中期左右出现。我们提出，人类海马结构的CR细胞属于两个不同的细胞群体：一个早期群体源自腹侧皮质隆起，主要与海马和齿状板的迁移有关；另一个较晚出现的群体源自齿状-伞神经上皮，可能与齿状颗粒细胞（特别是下叶片的）的长期神经发生和迁移有关。
