NMDA receptors are a class of ionotropic glutamate receptors. NMDA receptor channel has been shown to be involved in long term potentiation, an activity dependent increase in the efficiency of synaptic transmission thought to underlie certain kinds of memory and learning. NMDA receptor channels are heteromers composed of the key receptor subunit NMDAR1 (GRIN1) and 1 or more of the 4 NMDAR2 subunits: NMDAR2A (GRIN2A), NMDAR2B (GRIN2B), NMDAR2C (GRIN2C), and NMDAR2D (GRIN2D). GRIN2B may be a candidate gene for the neurodegenerative disorder dentato-rubro-pallidoluysian atrophy (DRPLA).Properties of NMDAR include modulation by glycine, inhibition by Zn2+, voltage dependent Mg2+ blockade and high Ca2+ permeability. The involvement of NMDAR in the CNS has become a focus area for neurodegenerative diseases such as Alzheimer's disease and also epilepsy and ischemic neuronal cell death.