Signaling by synaptogenic molecules

Abstract

Multiple signaling pathways initiate and specify the formation of synapses in the central nervous system. General principles that organize nascent synapses have emerged from the studies in multiple model organisms. These include the synapse-organizing roles of dedicated synaptic adhesion molecules, synaptic signaling following receptor-ligand interactions, and the regulation of synapse formation by secreted molecules. Intracellularly, a range of effectors subsequently regulates signaling steps and cytoskeletal changes. Together, a blueprint of synapse formation is emerging into which these distinct signaling steps will need to be integrated temporally and spatially.

Figure 1

A. Structure of neuroligins and neurexins. The neuroligin 1 splice site that regulates its α over β-neurexin binding is highlighted by an asterisk. Pre, presynaptic membrane; post, postsynaptic membrane. B. Key insights recently gained from in vivo studies of neurexins and neuroligins.

Figure 2

Overview of members of the Ig superfamily and proteins containing extracellular leucine-rich-repeats (LRR) that are involved in synapse differentiation.

Figure 3

Roles of signaling receptors in synaptic differentiation.