Transformation of radial glia into postnatal neural stem cells depends on birth.

A common feature of various postnatal stem cells is their close association with blood vessels. Postnatal neural stem cells (NSCs) in the ventricular-subventricular zone originate from fetal radial glia (RG), which possess NSC properties. Here, using live imaging and three-dimensional (3D) electron microscopy, we investigated how RG convert into postnatal NSCs and characterized the fine 3D morphology of the ventricular-subventricular zone. We found that preterm birth disrupts RG-endothelial cell interactions during this transformation, impairing both the structure and stemness of adult NSCs. These findings underscore the importance of a birth-dependent transformation. Our results indicate that RG fiber transection, which depends on the birth process, and endfoot formation on blood vessels, which depends on birth timing, are both critical steps in the conversion of RG into adult NSCs.