Regulatory cell interactions between retinal ganglion cells and radial glia during axonal and dendritic outgrowth

Neuronal differentiation and the formation of cell polarity are crucial eve nts during the development of the nervous system, Cell polarity is a prereq uisite for directed information flux within neuronal networks. In this arti cle, we focus on neuro-glial cell interactions that influence the establish ment of neural cell polarity and the directed outgrowth of axons versus den drites. The cellular model discussed in detail is the retinal ganglion cell (RGC) of the chick retina, which is investigated by a comprehensive set of in vitro assays. The experiments demonstrate that retinal microenvironment determines axon vs. dendrite formation of RGCs. The instructive difference s in different retinal microenvironments are substantially influenced by ra dial glia. Different glial domains support or inhibit axon vs, dendrite out growth. The data support the notion that neuro-glial interactions are cruci al for directed neurite outgrowth. (C) 2000 Wiley-Liss, Inc.