PMC

Angiogenesis and neurogenesis in the adult songbird brain. Testosterone-induced neuronal addition to the adult songbird vocal control center, HVC, requires the androgenic induction of VEGF, followed by VEGF-stimulated matrix metalloproteinase release and angiogenesis. The expanded vasculature acts as a source of BDNF, which supports the immigration of new neurons from the overlying ventricular zone^,,,. AR, androgen receptor; ER, estrogen receptor; Nucleus RA, the HVC target nucleus robustus archistriatalis.

Perivascular interactions with the adult mammalian subependyma. This cartoon illustrates the architecture of the striatal ventricular wall and shows the relationships of subependymal NSCs (B cells, according to the nomenclature of Alvarez-Buylla^,,) to transit-amplifying progeny (C cells) and their neuronally restricted progeny (A cells). Major molecular interactions, as citevd in the text, include the provision of ATP to vascular NTPDase-2/CD39L1, with generation of ADP that interacts with B and C cell P2YRs, vascular VEGF and PEDF, which interact with cognate B cell receptors, B cell CD15 and C and A cell CD24 with their endothelial P-selectin receptors, endothelial SDF1/CXCL12 with its A cell receptors CXCR4 and CXCR7, endothelial BDNF with both its B and C cell p75 and A cell trkB receptors, endothelial laminin with its C and A cell α6β1 integrin receptor, and both endothelial eNOS and neural precursor-derived nNOS, and their derived NO with cellular targets thereof.

Perivascular interactions within the subgranular zone of the adult mammalian hippocampus. This cartoon illustrates the architecture of the subgranular zone and dentate granule layer of the adult hippocampus and shows the relationships of hippocampal NSCs to transit-amplifying progeny and their neuronally restricted progeny. Only those interactions identified as being specifically between the microvascular bed and hippocampal stem and progenitor cells are noted; many mitogens and differentiation agents of nonvascular origin have otherwise been defined in the hippocampus. The subgranular zone of the dentate gyrus manifests a cellular hierarchy that is similar to that of the ventricular subependyma. Major molecular interactions, as cited in the text, include the provision of ATP to vascular NTPDase-2/CD39L1, with generation of ADP that interacts with P2YRs expressed by the stem cell pool, vascular VEGF, which interacts with both endothelial and neural precursor receptors, CD24 and its endothelial P-selectin receptors, both endothelial NOS (eNOS) and precursor-derived neuronal NOS (nNOS), with their derived NO and targets thereof, and endothelial BDNF and its neuronal receptors. GCL, granule cell layer; ML, molecular layer; SGZ, subgranular zone.