INFLUENCE OF CKAMP39 AND CKAMP59 ON THE AMPA RECEPTORS IN OLFACTORY BULB AND CA1 NEURONS

AMPA receptors (AMPARs) mediate the majority of fast excitatory neurotransmission in the central nervous system. Auxiliary proteins such as CKAMP family members play a crucial role in shaping AMPAR trafficking, gating, and localisation. We analysed the influence of CKAMP39 and CKAMP59 on AMPARs using electrophysiological approaches in two different brain regions. In the olfactory bulb (OB), recordings of AMPAR-mediated currents elicited by fast application of glutamate onto outside-out patches revealed that loss of CKAMP39 leads to reduced steady-state current amplitudes and prolonged deactivation kinetics, indicating it’s crucial role in AMPAR gating. CKAMP59 on the other hand, appears not to affect AMPAR-mediated currents in the OB. In contrast, CKAMP59 influences AMPARs CA1 neurons. Rise time and amplitudes of extrasynaptic AMPAR-mediated currents were increased in CKAMP59 KO mice. Moreover, deletion of CKAMP59 reduced long-term potentiation (LTP), consistent with earlier studies. Additionally, the rectification index of AMPAR-mediated currents was reduced in CKAMP59 KO mice, suggesting altered AMPAR subunit composition and calcium permeability. Together, these results identify distinct, region-specific roles for CKAMP39 and CKAMP59 in shaping AMPAR kinetics, subunit regulation, and synaptic plasticity.