The presence of adult neurogenesis in the mammalian brain has been a theme of intense controversy for a long time since the origi-nal report by Altman and Das (1965). The scientific community, for about 30 years, has difficulties to accept that progenitor cells give rise to new neurons in some specific regions of the mammalian adult brain, the neurogenic niches (Kuhn et al., 1996; Doetsch et al., 1997, 1999).