Exploring neurogenesis outside the niche: Atypical locations of mammalian neural stem/progenitor cells (Editorial)

摘要

Adult neurogenesis, namely the capacity of generating new nerve and glial cells throughout life, is a phylogenetically highly conserved feature that challenges the dogma of the nervous system as a static, non-renewable tissue (Gage, 2000). Yet, unlike invertebrates and non-mammalian vertebrates, in which neurogenesis persists in wide regions of the central nervous system (CNS), in adult mammals it is mainly restricted to two specific brain sites: the forebrain subventricular zone and the hippocampal dentate gyrus (Gage, 2000; Kriegstein and Alvarez-Buylla, 2009). It is now clear that the persistenceof neurogenesis in these zones depends on stem ells which reside in niches as vestigial remnants of embryonic germinal layers (Kriegstein and Alvarez-Buylla, 2009). This fact leaves the remainder of the CNS as a non-renewable tissue substantially incapable to repair damage coming from neurodegenerative diseases, ischemic/traumatic lesions.