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. Expressed in the neurons of the larval CNS from the beginning of the first until the third instar. Expression in the third-instar larval CNS is restricted to a discrete number of somas and projections in the brain lobes and in the ventral ganglion. In the ventral nerve cord, expression is detected both in somas and projections. Expressed in the antennal lobes, the optic lobes, the central complex and the median bundle in the adult CNS. Expressed in the CNS of the late embryo. Belongs to the G-protein coupled receptor 3 family.