Receptor for glutamate. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. The postsynaptic actions of Glu are mediated by a variety of receptors that are named according to their selective agonists. Dimer (PubMed:27418511). Interacts (via extracellular N-terminal domain) with CBLN1 (via C1q domain), and more weakly with CBLN2 (PubMed:22220752, PubMed:27418511). Equally in forebrain and cerebellum. Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family. GRID1 subfamily.