NBQX

NBQX is a synthetic organic compound that functions as a selective antagonist of AMPA-type ionotropic glutamate receptors, with some activity at kainate receptors and relatively little effect on NMDA receptors. It is widely used in neuroscience research to block AMPA receptor–mediated excitatory neurotransmission in experiments with brain tissue, cultured neurons, and other preparations.

In terms of mechanism, NBQX binds to the ligand-binding site of AMPA receptors and acts as a competitive antagonist, reducing the amplitude of excitatory postsynaptic currents generated by glutamate. Its activity helps researchers dissect the contributions of AMPA receptors to synaptic transmission and plasticity. While NBQX is most closely associated with AMPA receptor blockade, it can also affect kainate receptor signaling at certain concentrations, so interpretation of results often considers potential off-target effects.

NBQX is typically employed in vitro, including brain slice electrophysiology and cultured neuron studies, to isolate NMDA receptor–dependent components by suppressing AMPA receptor activity. The common laboratory form is NBQX disodium salt, used at low micromolar concentrations in many protocols. It is not approved for clinical use and is intended for research purposes under appropriate safety and ethical guidelines.

Safety and handling follow standard laboratory practices for chemical reagents. NBQX remains a standard tool in neuroscience for studying excitatory glutamatergic transmission and the role of AMPA receptors in synaptic function and plasticity. See also related AMPA receptor antagonists such as CNQX.