Dynamic regulation of cell adhesion molecules during axon outgrowth

✍ Scribed by Long, Kristin E. ;Lemmon, Vance

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 219 KB
• Volume: 44
• Category: Article
• ISSN: 0022-3034
• DOI: 10.1002/1097-4695(200008)44:2<230::aid-neu12>3.0.co;2-w

✦ Synopsis

In the mature nervous system adhesion molecules appear to play a rather static role, maintaining synaptic connections, cell-cell contacts and stabilizing neuron-glial interactions. In contrast, during development and learning, adhesive mechanisms are dynamically regulated both spatially and temporally. It has been clear for many years that the expression of cell adhesion molecules (CAMs) can be regulated at the level of transcription. Now it is apparent that a CAM's functional activity at the cell surface can be regulated by restricting its location on the cell surface and also by its duration of expression on the membrane. Moreover, the expression can be influenced by very local events such as cell contact or neural activity. Perhaps this is not surprising, given the rapidly changing environments encountered by cells and their growing processes. Dynamic regulation of adhesion is critical for proper cell migration, axon guidance, and synapse formation during nervous system development. This review will focus especially on Ig superfamily (IgSF) CAMs such as apCAM, Fas II, L1, and axonin-1/Tag-1 and how their regulated expression participates in both the mechanics of axon outgrowth as well as proper axon guidance, synapse formation, and synaptic plasticity. A variety of model systems have been used to address dynamic regulation of adhesion. Important experiments have been done on integrins and cadherins as well as Ig superfamily CAMs. So we will draw conclusions from invertebrate and vertebrate systems, mixing electrophysiological and cell biolog-ical studies with genetic and biochemical ones to describe a model of how CAM expression and function is regulated spatially and temporally during axon outgrowth.