NBQX suppresses inhibitory glycine currents in retinal ganglion cells.
The quinoxaline NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo (F) quinoxaline) is a potent non-NMDA receptor antagonist, which appears to be relatively free of antagonistic action at the glycine binding site of the NMDA receptor. However, we report here that at 50 microM, NBQX significantly attenuated the inhibitory currents induced by the exogenous application of 100 microM glycine as observed using whole-cell recordings from ganglion cells in a slice preparation of the tiger salamander retina. In contrast, NBQX had no effect on GABA-mediated inhibition. This observation suggests that care should be taken when attributing the action of NBQX solely to its antagonism of non-NMDA glutamate receptors, particularly when higher concentrations are used.
Yu
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Department of Physiology, University of Minnesota, Minneapolis 55455.
Miller
R F
RF
D000557:Ambystoma; D000818:Animals; D005998:Glycine / Q000378:metabolism*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011810:Quinoxalines / Q000494:pharmacology*; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors*; D018009:Receptors, Glycine / Q000037:antagonists & inhibitors / Q000187:drug effects; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
D007473:Ion Channels; D011810:Quinoxalines; D018091:Receptors, AMPA; D018009:Receptors, Glycine; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D013779:Tetrodotoxin; D005998:Glycine