Excitatory amino acid receptors in the brain: membrane binding and receptor autoradiographic approaches.

In last month's article in this series, Lodge and Johnson discussed the contribution of noncompetitive excitatory amino acid antagonists to understanding of these receptors. In this third article, Anne Young and Graham Fagg describe how radioligand binding experiments have helped to fuel the recent burst of progress in understanding excitatory amino acid receptors in the brain. New and selective radioligands have facilitated mapping the distributions of the major excitatory receptor subtypes in normal and diseased brain, examining allosteric interactions within the NMDA receptor, searching for novel therapeutic agents and determining drug mechanisms, and making first steps along the path to defining receptor structure at the molecular level.