Evidence for stroke-induced neurogenesis in the human brain

The Work of Bhardwaj et. al. mentioned in the Aug. 22 blog posting has made the point that under normal conditions new neurons are not born at detectable levels in the adult human brain. These measurements had a detection limit of ~ 1%, however, and would not have been expected to note small amounts of nerve cell proliferation occurring near areas damaged by stroke. Jin et al. now report in PNAS that in patients with stroke, cells that express markers associated with newborn neurons are present in the ischemic penumbra surrounding cerebral cortical infarcts, where these cells are preferentially localized in the vicinity of blood vessels. These findings suggest that stroke-induced compensatory neurogenesis may occur in the human brain, where it could contribute to postischemic recovery and represent a target for stroke therapy.