"Neural stem cells provide throughout life a source of neuronal and glial progenitors in the central nervous system of mammals. In the adult brain, stem cells reside in specialized ‘niches’ which contain molecular and cellular signals capable of regulating their symmetric/asymmetric division, as well as specification and fate of their progeny. In the major neurogenic site, the forebrain subventricular zone (SVZ), the neural stem cells have been identified as a subpopulation of astrocytes originating from the embryonic radial glia. Occasionally, some of these astrocytes divide to give rise to transit amplifying cells that actively proliferate thus generating a neuronal, and to a lesser extent glial, progeny. Yet, the very mode, time, and pattern of cell division, as well as the mechanisms involved in its regulation within the stem cell niche are poorly understood. In this project, several techniques of living cell imaging and tracing, cell proliferation detection, and light, confocal, electron microscopic morphological analyses will be combined with the aim of visualizing and studying in vivo the process of neural stem cell division. Since brain neurogenic niches remarkably change postnatally, neural stem cell division will be analysed at different postnatal stages, through the transformation from radial glia to neurogenic astrocytes. These objectives, other than representing a crucial step in further understanding the neural stem cell biology within their niches, could be of importance in allowing new strategies aimed at modulating in situ the behaviour of mammalian neural stem cells as an innovative approach to brain repair."