NMDAR complex consists of two NR1 subunits and two NR2 subunits. Each subunit has extensive C terminal tail that is modified by series of protein kinases and protein phosphatases. The NR1 subunits binds co-agonist glycine while the NR2 subunit binds glutamate. Hence the activation of NR1/NR2 containing NMDA receptor complexes are activated upon depolarization of the membrane and binding of both glycine and glutamate. The dual requirement of membrane depolarization and agonist binding facilitate coincidence detection by NMDA receptors that ensures activation of both pre-synaptic and post-synaptic cell. NR1/NR2 containing NMDA receptors are highly Ca2+ permeable and subjected to a voltage dependent Mg2+ block.