Department of Neurosurgery, Brain Tumor Stem Cell Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
J Comp Neurol. 2011 Apr 15;519(6):1165-80. doi: 10.1002/cne.22566.
The fetal development of the anterior subventricular zone (SVZ) involves the transformation of radial glia into neural stem cells, in addition to the migration of neuroblasts from the SVZ towards different regions in the brain. In adult rodents this migration from the anterior SVZ is restricted to the olfactory bulb following a rostral migratory stream (RMS) formed by chains of migratory neuroblasts. Similar to rodents, an RMS has been suggested in the adult human brain, where the SVZ remains as an active proliferative region. Nevertheless, a human fetal RMS has not been described and the presence of migratory neuroblasts in the adult remains controversial. Here we describe the cytoarchitecture of the human SVZ at the lateral ganglionic eminence late in the second trimester of development (23-24 weeks postconception). Cell organization in this region is heterogeneous along the ventricular wall, with GFAP-positive cells aligned to the ventricle. These cells coexpress markers for radial glia like GFAPδ, nestin, and vimentin. We also show the presence of abundant migratory neuroblasts in the anterior horn SVZ forming structures here denominated cell throngs. Interestingly, a ventral extension of the lateral ventricle suggests the presence of a putative RMS. Nevertheless, in the olfactory bulb neuroblast throngs or chain-like structures were not observed. The lack of these structures closer to the olfactory bulb could indicate a destination for the migratory neuroblasts outside the olfactory bulb in the human brain.
胎儿前脑室下区 (SVZ) 的发育涉及放射状胶质细胞向神经干细胞的转化，以及神经母细胞从 SVZ 向大脑不同区域的迁移。在成年啮齿动物中，这种从前 SVZ 的迁移仅限于嗅球，通过由迁移性神经母细胞链形成的嗅球迁移流 (RMS)。与啮齿动物类似，有人提出成人的大脑中存在 RMS，而 SVZ 仍然是一个活跃的增殖区域。然而，尚未描述人类胎儿 RMS，并且成人中是否存在迁移性神经母细胞仍存在争议。在这里，我们描述了在妊娠后第 23-24 周的发育晚期（妊娠后第 23-24 周）侧神经节隆起处的人类 SVZ 的细胞结构。该区域的细胞组织在室壁上是不均匀的，GFAP 阳性细胞与心室对齐。这些细胞共同表达放射状胶质细胞的标志物，如 GFAPδ、巢蛋白和波形蛋白。我们还展示了大量在前 SVZ 中形成此处称为细胞束的迁移性神经母细胞的存在。有趣的是，侧脑室的腹侧延伸表明存在一个假定的 RMS。然而，在嗅球中没有观察到神经母细胞束或链状结构。这些结构在嗅球附近不存在可能表明在人类大脑中，迁移性神经母细胞的目的地在嗅球之外。
