Rapid, excitatory neuronal transmission is primarily mediated through the activation of ionotropic glutamate receptors. Ionotropic glutamate receptors are present in two distinct classes: alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and N-methyl-D-aspartate receptors (NMDARs). AMPARs are typically composed of four subunit proteins (GluA1-A4), which can form hetero or homomeric complexes. Under basal conditions, the tetrameric AMPAR is often composed of GluA2 subunits in complex with either GluA1 or GluA3 (Dingledine, et al., 1999) (Figure 2A).
