The role of neurogenesis in stroke recovery

This review investigates the role of neurogenesis after stroke. Neural stem cells reside in the SVZ of the adult mammal, including humans. In response to stroke, proliferation in the SVZ is upregulated, giving rise to neuroblasts that migrate to the ischemic area. Here, some of them differentiate into mature neuronal cell types and survive long-term. Signs of integration have been found, but the capacity of these newborn neurons to replace neurons lost after stroke is not well understood. The mechanisms that govern proliferation, migration, differentiation, integration and survival of newborn neural precursors and neurons are investigated. The role of the vasculature, specialized niches in the SVZ, astrocytes and angiogenesis during the poststroke neurogenic response receive attention. A range of factors that have been shown to influence the neurogenic response are reviewed. It becomes clear that the role of the neurogenic response after stroke in repairing the brain is not well understood. The positive effect on stroke recovery that is associated with neurogenesis may be the result of functional integration, trophic support, neuroprotection, angiogenesis, or a combination. Taking advantage of the neurogenic capacity of the brain in stroke therapy seems promising, but many difficulties remain to be overcome