Understanding the cellular and molecular mechanisms of neurogenesis is important not only to unravel how the immense neuronal and glial cell diversity is generated during development of the mammalian brain, but also to unravel mechanisms how to reactivate neurogenesis after brain injury. Towards this aim our lab examines the mechanisms of neurogenesis in the developing forebrain and in the niches where neurogenesis persists in the adult brain (www.helmholtz-muenchen.de/isf). These neurogenic sites in the adult brain are wide-spread in many vertebrates, like the zebrafish, but restricted to few sites in most mammalian brains like the mouse. Our work shows that neurogenesis in the adult mammalian brain requires specific molecular mechanisms of fate stabilization as it occurs in an environment that promotes rather the generation of glial cells. Finally we employ our knowledge on the molecular regulators of neuronal fate to directly reprogram different cell types, such as glia or fibroblasts, into functional neurons. To implement this strategy also in a meaningful manner in the injured brain in vivo, we examine the roles of different glial cells reacting to injury to understand which glial cells perform beneficial or adverse functions in different injury conditions (www.genom.physiol.med.uni-muenchen.de/research_gr/goetz_group/index.html).