Zerlin M, Goldman J E
Department of Pathology and the Center for Neurobiology and Behavior, Columbia University College of Physicians & Surgeons, New York, New York 10032, USA.
J Comp Neurol. 1997 Nov 3;387(4):537-46. doi: 10.1002/(sici)1096-9861(19971103)387:4<537::aid-cne5>3.0.co;2-3.
The post-neurogenic period in the mammalian neocortex is characterized by the growth of astrocyte and oligodendrocyte populations and their incorporation into the network of the developing central nervous system (CNS). Many of these glial cells originate as progenitors in the subventricular zone (SVZ) and then migrate into white and gray matter before differentiating. What determines the specific cellular fate of progenitors in vivo is not known, however. In examining the early stages of gliogenesis from progenitors in the SVZ, we noted that interactions with cortical blood vessels took place at what appeared to be an early stage of glial differentiation. We have examined in more detail the interactions of progenitors with blood vessels in the early postnatal rat neocortex after labeling progenitors in vivo with a LacZ-encoding retrovirus. These early interactions are accompanied by an increase in intermediate filament expression, consistent with astrocytic differentiation. Because astrocytes interact with blood vessels and pia, we suggest that such contact represents an early stage in astrocytic differentiation. Furthermore, since angiogenesis and astrogenesis occur over a similar period, the growth of blood vessels may even play a role in the selection of astrocytic fate by a progenitor. As vessel growth slows, fewer progenitors may be directed toward an astrocyte fate, allowing more to differentiate into oligodendrocytes, perhaps explaining the shift from astrocyte genesis to oligodendrocyte genesis during early postnatal cortical development.
哺乳动物新皮质的神经源性后期以星形胶质细胞和少突胶质细胞群体的生长以及它们融入发育中的中枢神经系统（CNS）网络为特征。这些胶质细胞中的许多起源于脑室下区（SVZ）的祖细胞，然后在分化之前迁移到白质和灰质中。然而，体内祖细胞的特定细胞命运由什么决定尚不清楚。在研究SVZ中祖细胞的胶质细胞生成早期阶段时，我们注意到与皮质血管的相互作用发生在胶质细胞分化的早期阶段。在用编码LacZ的逆转录病毒在体内标记祖细胞后，我们更详细地研究了新生大鼠新皮质中祖细胞与血管的相互作用。这些早期相互作用伴随着中间丝表达的增加，这与星形胶质细胞分化一致。由于星形胶质细胞与血管和软脑膜相互作用，我们认为这种接触代表了星形胶质细胞分化的早期阶段。此外，由于血管生成和星形胶质细胞生成在相似的时期发生，血管的生长甚至可能在祖细胞选择星形胶质细胞命运中起作用。随着血管生长减缓，可能只有较少的祖细胞被导向星形胶质细胞命运，从而使更多祖细胞分化为少突胶质细胞，这或许可以解释出生后早期皮质发育过程中从星形胶质细胞生成向少突胶质细胞生成的转变。
