Investigating radial glia in vitro.

During mammalian neurogenesis newly born neurons migrate radially along the extended bipolar process of cells termed radial glia. Our views of radial glia as a 'static' support/guide cell have changed over recent years. It is now clear that within the developing cortex, and possibly the entire central nervous system (CNS), radial glia actively divide, producing daughter cells that include both neurons and glia. A subset of forebrain radial glia may serve as the founders of adult forebrain neural stem cells and genetic disruption of normal radial glia function can result in tumorigenesis or congenital neurological disorders. Elucidating the cell intrinsic and environmental cues that regulate radial glia behaviour is therefore essential for a full understanding of mammalian CNS development and physiology. Here, we review those studies in which radial glia have been investigated in vitro following isolation from foetal tissues or differentiation of embryonic stem (ES) cells. We discuss how these approaches, together with an ability to expand radial glia-like neural stem (NS) cell lines, may offer unique opportunities in basic and applied neurobiology.