Visual responses in adult cat visual cortex depend on N-methyl-D-aspartate receptors.
We have investigated the role of the N-methyl-D-aspartate (NMDA) receptor, a subtype of glutamate receptor, in the responses of cells in adult cat visual cortex. After intracortical infusion of the NMDA receptor antagonist DL-2-amino-5-phosphonovalerate (DL-APV) for one day, iontophoretic responses to NMDA, to kainate, and to quisqualate revealed a receptor blockade specific to NMDA receptors and extending several millimeters from the cannula. In this region, neuronal responses to visual stimulation were profoundly suppressed, in a manner strongly correlated with the degree of NMDA receptor blockade. Neither NMDA receptor blockade nor activity suppression was caused by the inactive stereoisomer L-APV. Hence, we conclude that NMDA receptors make a major contribution to normal excitatory transmission in adult visual cortex.
Miller
K D
KD
Department of Physiology, University of California, San Francisco 94143-0444.
Chapman
B
B
Stryker
M P
MP
D015763:2-Amino-5-phosphonovalerate; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D002415:Cats; D004553:Electric Conductivity; D007608:Kainic Acid / Q000494:pharmacology; D016202:N-Methylaspartate; D010069:Oxadiazoles / Q000494:pharmacology; D016318:Quisqualic Acid; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000502:physiology*; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D014793:Visual Cortex / Q000187:drug effects / Q000502:physiology*; D014796:Visual Perception
D000927:Anticonvulsants; D010069:Oxadiazoles; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D001224:Aspartic Acid; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D016318:Quisqualic Acid; D014633:Valine; D007608:Kainic Acid