Within the central nervous system, AMPA-type glutamate receptors mediate fast synaptic transmission and deactivate on the millisecond timescale. In this study, we characterize backbone amide nuclear spin dynamics associated with conformational and hydrogen exchange events in the ligand binding domain of glutamate receptor 2 and obtain a novel view of the backbone motions occurring over five orders of magnitude of timescale, spanning microsecond-to-second timescale motions. Most notably, we find that hydrogen exchange rates of particular residues in the ligand binding site provide important clues about the sequence of events leading to ligand detachment from the ligand binding domain. These results thus provide insights into the mechanism of receptor deactivation.