L1-type cell adhesion molecules: Distinct roles in synaptic targeting, organization, and function

Abstract

L1-type cell adhesion molecules are known to be involved in several early developmental processes such as neurite outgrowth, axon guidance, fasciculation, and cell migration. In this chapter, we review their less well-studied roles in synaptogenesis. Despite the limited number of studies that has been conducted to assay the cellular mechanisms involving L1-type CAMs at the synapse, the breadth and scope of their synaptic functions described so far are astonishing. The functions for the various L1-type members range from synaptic targeting and synapse formation to synaptic transmission in GABAergic (gamma-aminobutyric acid), glutamatergic, and cholinergic synapses in the CNS or the NMJ. Some of these functions are conserved and shared between all L1-type family members while others are distinct to a particular member. Exciting discoveries will continue to be made in elucidating the roles L1-type cell adhesion molecules play at the synapse.