Enables NMDA glutamate receptor activity and transmitter-gated ion channel activity involved in regulation of postsynaptic membrane potential. Acts upstream of or within several processes, including excitatory postsynaptic potential; neuromuscular process controlling balance; and protein localization to postsynaptic membrane. Located in glutamatergic synapse. Part of NMDA selective glutamate receptor complex. Is expressed in several structures, including brain; colon; eye; gallbladder; and genitourinary system. Orthologous to human GRIN2C (glutamate ionotropic receptor NMDA type subunit 2C). [provided by Alliance of Genome Resources, Apr 2022]