Our laboratory focuses on neurogenesis during embryonic development and is moving into the field of neural regeneration. During embryonic development neurogenesis requires a perfect balance between mechanisms that support self renewal of undifferentiated progenitors and others that push progenitors towards commitment and post-mitotic differentiation. The mammalian cerebellum is an eloquent example of this: in the mouse, cerebellar neurogenesis starts on embryonic day 11 and is completed only around postnatal day 20, featuring repeated events of self-renewal, cell fate determination, clonal expansion and neuronal migration. Numerous spontaneous and induced mutations are providing precious information on the molecular mechanisms that regulate these phenomena, and on their links with human diseases of cerebellar development and of mature cerebellar neurons. our group is contributing to this knowledge with studies of cerebellar patterning (Masserdotti et al, in press), cerebellar cortical boundary formation (Croci et al., 2006, Chung et al, 2008), cerebellar GABAergic neurogenesis and Purkinje cell specification (Zordan et al., 2008, Leto et al., in preparation), and of Purkinje cells survival (Croci, Barili et al., in press). Furthermore, we have contributed to the characterization of a novel type of neural stem cells (Calabrese et al., in revision, Albieri et al., submitted) to attempt to recapitulate in vitro the regulatory cascade that govern cerebellar neurogenesis in vivo. We are now planning to put our experience to task in order to assess the ability of in vitro implemented neural progenitors to integrate into the postnatal cerebellum of wild type mice and models of cerebellar ataxias.