Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. 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. This receptor binds domoate > kainate >> L-glutamate = quisqualate >> AMPA = NMDA (By similarity). Homotetramer, and heterotetramer with either GRIK4 or GRIK5. Interacts with PRKCABP (By similarity). Interacts with NETO2 (By similarity). Detected in whole brain, cerebellum, brain cortex and hippocampus. Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family. GRIK3 subfamily.