CADHERINS IN THE DEVELOPING CENTRAL-NERVOUS-SYSTEM - AN ADHESIVE CODEFOR SEGMENTAL AND FUNCTIONAL SUBDIVISIONS

In this review, we describe general features of the expression of cadh erins in the developing central nervous system (CNS) of vertebrates. I n the early neuroepithelium, the expression of several cadherins is re stricted to specific regions corresponding to segmental domains. Segme ntal boundaries often coincide with changes in cadherin expression, su bdividing the primordial CNS into different adhesive domains. In the d ifferent neuromeric domains, early neurons are generated which differe ntially express cadherins. In the mantle layer, these early neurons se em to sort out according to which cadherin they express, and they aggr egate into various gray matter regions (brain nuclei and cortical lami na and regions). The gray matter structures expressing a given cadheri n become connected to one another to form parts of particular function al systems or neuronal circuits. Together, these findings show that ca dherins provide a molecular system reflecting both early embryonic and mature nervous system architecture. The possible roles of cadherins i n the formation and maintenance of segmental and functional nervous sy stem structures are discussed. (C) 1996 Academic Press, Inc.