How It’s Made: The Synapse

A model of synapse assembly. A. Before and during synapse formation, groups of synaptic vesicle and active zone proteins are transported along axons in precursor organelles, referred to as STVs (red) and PTVs (grey filled), respectively. STVs pause frequently at future sites of synapse formation. B. Axons and dendrites interact with one another. C. When axo-dendritic interactions occur at STV pause sites and trans-synaptic adhesion is engaged, contacts are stabilized. D. Synaptic proteins are deposited at the site of contact. E. Synaptic structures form, and synaptic proteins are sorted to their appropriate locations as the contact site differentiates into a functional synapse.