<P> The N - methyl - D - aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel protein found in nerve cells . The NMDA receptor is one of three types of ionotropic glutamate receptors, the others being the AMPA and kainate receptors . It is activated when glutamate and glycine (or D - serine) bind to it, and when activated it allows positively charged ions to flow through the cell membrane . The NMDA receptor is very important for controlling synaptic plasticity and memory function . </P> <P> The NMDAR is a specific type of ionotropic glutamate receptor . The NMDA receptor is so named because the agonist molecule N - methyl - D - aspartate (NMDA) binds selectively to it, and not to other glutamate receptors . Activation of NMDA receptors results in the opening of an ion channel that is nonselective to cations, with a combined reversal potential near 0 mV . While the opening and closing of the ion channel is primarily gated by ligand binding, the current flow through the ion channel is voltage dependent . Extracellular magnesium (Mg) and zinc (Zn) ions can bind to specific sites on the receptor, blocking the passage of other cations through the open ion channel . Depolarization of the cell dislodges and repels the Mg and Zn ions from the pore, thus allowing a voltage - dependent flow of sodium (Na) and small amounts of calcium (Ca) ions into the cell and potassium (K) out of the cell . </P>

Where are nmda receptors located in the brain