Figure 1.

AMPAR trafficking and distribution. AMPARs arrive at the cell surface through exocytosis at dendritic, presynaptic, and synaptic sites. This is both constitutive and triggered by activity. Once on the cell surface, AMPARs are free to laterally diffuse in the plane of the plasma membrane. At synaptic sites, interactions between AMPARs, their accessory proteins, and PSD components act to retain receptors. Within synapses, there is precise alignment between postsynaptic AMPARs and the presynaptic release sites.