ABSTRACT
Early studies of the development of the nervous system supported the hypothesis that cell adhesion molecules (CAMs) and substrate adhesion molecules (SAMs) play crucial roles in directing cell migration, axon guidance and synapse formation. Studies in invertebrates have provided extensive confirmation of this hypothesis. Furthermore, the identification of specific adhesion molecules in a variety of systems, including the immune system and nervous system, revealed that adhesion molecules not only mediate cell-cell and cell-substrate attachment but they also interact with second messenger systems to regulate cell behavior. The mechanisms and functions of CAM mediated intracellular signaling, however, are largely unknown. Thus, defining how adhesion molecules alter intracellular second messengers and determining what role they play in CAM mediated events is a major challenge at this juncture. Also, it is now clear that events inside cells can alter the functional state of adhesion molecules. This chapter will review recent studies of how Ig superfamily (IgSF) cell adhesion molecules regulate second messengers, have their function altered by both kinases and phosphatases, and how this is likely to influence neural development.
