G-protein coupled receptor for glutamate. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors. Signaling inhibits adenylate cyclase activity. Interacts with PICK1. Strongly expressed in olfactory bulb, accessory olfactory bulb, and mammillary body. Weaker expression in the retina, and in scattered cells in the cortex and hindbrain. Belongs to the G-protein coupled receptor 3 family.