Agonists and antagonists for group III metabotropic glutamate receptors 6, 7 and 8

Metabotropic glutamate receptors (mGluRs) have been implicated in a variety of neurological and psychiatric disorders. This article describes recent progress in the development of agonists and antagonists for mGluR 6, 7, and 8. All of them are conformationally constrained or substituted amino acids, and they act at N-terminal extracellular glutamate binding site. These ligands serve as valuable tools for studying physiological and pathological roles of mGluRs. However, their therapeutic potential may be restricted by their poor CNS penetration and lack of selectivity for individual receptors.