A neurovascular niche for neurogenesis after stroke

Abstract

Stroke causes localized tissue destruction within the infarct. Stroke also induces a limited degree of regeneration in the tissue that borders the infarct, including a process of post‐stroke neurogenesis. In post‐stroke neurogenesis, newly born, immature neurons (neuroblasts) migrate long distances from the subventricular zone to areas of damage. Neuroblasts migrate into these areas of damage in close association with remodeling, angiogenic blood vessels. Inhibiting angiogenesis after stroke blocks neurogenesis. During the time period of neuroblast migration angiogenic blood vessels secrete SDF‐1 and angiogpoietin‐1. Gain and loss of function studies show that these molecules are tropic for migrating neuroblasts in vivo after stroke. This data identifies a neurovascular niche after stroke in which neurogenesis is causally linked to angiogenesis through specific vascular growth factors and chemokines. This data follows from studies of the neural stem cell niche and neuroblast migration in the normal animal to highlight vascular‐neuronal interactions in both normal and regenerative brain function. Supported by NS053957, the Larry L Hillblom Foundation and AHA 0555013Y.