title: The pessimist's and optimist's views of adult neurogenesis.
abstract: The reports by Bonaguidi et al. (in this issue of Cell) and Encinas et al. (in Cell Stem Cell) come to differing conclusions about whether and how the proliferation of radial glia-like stem cells of the adult hippocampus impacts their long-term potential for neurogenesis.
authors.affiliation: CRTD, DFG Center for Regenerative Therapies Dresden, Tatzberg 47-49, 01307 Dresden, Germany. gerd.kempermann@crt-dresden.de
authors.forename: Gerd
authors.initials: G
authors.lastname: Kempermann