CADHERIN EXPRESSION IN THE DEVELOPING VERTEBRATE CNS - FROM NEUROMERES TO BRAIN NUCLEI AND NEURAL CIRCUITS

Cadherins are a family of cell surface glycoproteins which mediate cel l-cell adhesion by a Ca2(+)-dependent mechanism, Results from in vitro studies with cadherin-transfected cell lines show that cadherins pref erentially bind to each other in a hemophilic fashion. In the developi ng vertebrate brain, at least 10 cadherins are found. Some of these ca dherins are expressed in a restricted fashion in particular developing brain nuclei and neural circuits. Based on these results, specific mo rphogenetic roles for cadherins during CNS development have been propo sed. This review focuses on the possible role of cadherin-mediated sor ting and aggregation of early neurons and neurites in the formation of brain nuclei, fiber tracts, and neural circuits. Moreover, at least 1 cadherin is also expressed in a segmental (''neuromeric'') fashion in the early chicken forebrain, suggesting that this cadherin regulates developmental processes involved in the transformation from the neurom eric organization of the early neuroepithelium to the functional organ ization of the mature brain. (C) 1995 Academic Press, Inc.