Glutamate is the major excitatory neurotransmitter in the brain, activating NMDA-, AMPA-, and kainate- (KAR) selective families of ionotropic receptors. KARs rapidly desensitize in the continued presence of glutamate, a process thought to be mediated by the separation of subunits at the dimer interface of the ligand binding domain (LBD). Efforts to block desensitization through point mutations along this interface have produced macroscopic responses which are non-decaying. As of yet, the behaviour of these KAR dimer interface mutants has not been studied at the single channel level. Here, we investigated two such mutant subunits, GluK2 D776K, which forms an electrostatic bridge across the dimer interface, and GluK2 Y521C/L783C, which is thought to covalently crosslink dimer subunits. Through electrophysiological experiments performed on outside-out patches excised from transfected tsA201 cells, we found that D776K off-kinetics (2.4 ± 0.2ms, n=11) matched those of wild-type (WT) GluK2 receptors (2.3 ± 0.1ms, n=7) following brief agonist applications. In contrast, the off-kinetics of Y521C/L783C (10.5 ± 0.8ms, n=9) matched those of WT equilibrium responses (11.9 ± 1.3ms, n=8), observed after long agonist applications. Dose-response relationships also revealed glutamate potency was approximately ten-fold lower for D776K (EC50 520 ± 91µM, n=6) and the WT peak response (EC50 652 ± 47µM, n=7), compared to Y521C/L783C (EC50 52 ± 1µM, n=4) and the WT equilibrium response (EC50 40 ± 8µM, n = 4). At saturating agonist concentrations, D776K single channels remained in an open state, except for brief closures, suggesting that this mutant is effectively non-desensitizing. In addition, the amplitude of the D776K unitary conductance was comparable with the main open state of the WT receptor. However, Y521C/L783C single channels accessed much lower conductance levels, and spent long periods in closed states. The difference between the desensitization we observed at the single channel level and the non-decaying macroscopic behaviour of the Y521C/L783C receptor can be explained if its activation process is desynchronized. In conclusion, our data suggests, unexpectedly, that KAR activation states are controlled by the LBD dimer interface, consistent with a sequential model of desensitization.