Increased neural progenitors in vascular dementia.

Since groundbreaking studies demonstrated the presence of progenitor cells in the adult human brain, there have been intense interests in their potential therapeutic application, but to date only limited data has been obtained in man. An immunohistological study was performed in order to examine neurogenesis in both the subventricular and peri-infarct zones of vascular dementia patients compared to age-matched controls. The results were striking, showing a significant increase of progenitor cells in both the subventricular zone and in peri-infarct area in patients with vascular dementia compared to controls, which was sustained even in patients with infarcts occurring more than three months prior to autopsy. Moreover, the peri-infarct response appeared to be unified with that of the subventricular zone via a stream of cells, with some of them differentiating into immature neurons. We conclude that neurogenesis is stimulated in vascular dementia patients and, specifically, in patients with visible infarcts. Progenitors may migrate from the neurogenic niche to areas of infarction and differentiate into neurons, even three months after cerebrovascular damage, thus implicating the feasibility of enhancing neurogenesis as a novel treatment approach.