Cell adhesion molecules in synapse formation

Abstract

Neuronal transmission relies on signals transmitted through a vast array of excitatory and inhibitory neuronal synaptic connections. How do axons communicate with dendrites to build synapses, and what molecules regulate this interaction? There is a wealth of evidence suggesting that cell adhesion molecules (CAMs) provide much of the information required for synapse formation. This review highlights the molecular mechanisms used by CAMs to regulate presynaptic and postsynaptic differentiation.

Figure 1.

Diagram depicting the morphological transformation of an axodendritic contact to a mature synapse. Contact between an axonal growth cone filopodia and a dendrite via the homophilic adhesion molecule SynCAM 1 (blue-pink) develops to form a stereotypical excitatory synapse. SynCAM, an example of one of several synaptically localized adhesion molecules, remains at the synapse to hold the presynaptic and postsynaptic terminals together. The presynaptic terminal is filled with synaptic vesicles (white spheres), and neurotransmitter receptors (green) are recruited to the postsynaptic membrane.