AMPA receptors (AMPAR) are both glutamate receptors and cation channels that are integral to plasticity and synaptic transmission at many postsynaptic membranes. AMPARs are composed of four types of subunits, designated as GluR1-GluR4, which combine to form tetramers. Phosphorylation of AMPARs can regulate channel localization, conductance, and open probability. GluR1 has four known phosphorylation sites at serine 818 (S818), S831, threonine 840, and S845. The first to receive attention was S831, a site phosphorylated by protein kinase C (PKC) and CaMKII, which increases its phosphorylation following LTP. Activity-dependent synaptic trafficking of GluR1 was shown to depend on S845, a protein kinase A (PKA) site, and S818, a PKC site. The phosphorylation of S845 seems to be for targeting GluR1 to the plasma membrane. Dephosphorylation of the S845 site on the GluR1 subunit has been correlated with LTD and down-regulation of cell surface GluR1 by a brief N-methyl-D-aspartate (NMDA) treatment.

This antibody panel investigates the phosphorylated situation of AMPAR. Upon the phosphorylation of AMPAR by PKA or PKC, it triggers the AMPAR trafficking to the plasma membrane. However, dephosphorylation of S845 site on the GluR1 reduces expression level on the plasma through endocytosis. This antibody panel is useful for determining if the neurons undergo LTP or LTD.