A comparative approach towards the understanding of adult neurogenesis

In all vertebrate species examined thus far the production of new neurons in the central nervous system takes place not only during embryogenesis but also in adult life. However, although in mammals this so-called adult neurogenesis appears to be limited to a very few brain regions, in non-mammalian vertebrates new neurons are generated continuously in many regions of the adult central nervous system. This difference makes it particularly interesting to examine adult neurogenesis from a comparative point of view. Such an approach is likely not only to yield new insights into the evolution and function(s) of this phenomenon, but also to facilitate identification of central sites that, although quiescent in vivo, have retained their intrinsic potential to produce new cells during adulthood in mammals.