NMDA receptors have a rich and diverse pharmacology reflecting the presence of multiple ligand binding sites at which agonists, antagonists, and modulators interact in an allosteric manner. This chapter describes concentration jump experiments used to characterize the activation of NMDA receptors by agonists and the block of NMDA receptor activity by competitive antagonists. These results were obtained before cDNAs for multiple families of NMDA receptor subunits were identified, and although the experiments illustrate important principles which would be expected to apply to all subtypes of...

NMDA receptors have a rich and diverse pharmacology reflecting the presence of multiple ligand binding sites at which agonists, antagonists, and modulators interact in an allosteric manner. This chapter describes concentration jump experiments used to characterize the activation of NMDA receptors by agonists and the block of NMDA receptor activity by competitive antagonists. These results were obtained before cDNAs for multiple families of NMDA receptor subunits were identified, and although the experiments illustrate important principles which would be expected to apply to all subtypes of NMDA receptor, a challenging task for the future will be to characterize in detail the ligand binding characteristics of native NMDA receptor subtypes in different areas of the brain.