One of three IONOTROPICGLUTAMATE receptor subtypes found in the central nervous system (CNS) that is activated by NMDA (N-methyl-D-aspartate) (though note that NMDA does not occur naturally in the brain). Other ionotropic glutamate receptors are activated by AMPA and KAINIC ACID. NMDA acts only at NMDA receptors, AMPA at AMPA and so on.
NMDA- and AMPA-gated channels mediate the bulk of fast excitatory CNS synaptic transmission and are permeable to SODIUM (Na+), POTASSIUM (K+), and CHLORIDE (Cl−) ions. Inward ionic current through NMDA receptors is voltage-dependent due to MAGNESIUM (Mg2+) block at a negative resting MEMBRANE POTENTIAL. NMDA receptors have been extensively studied in recent decades and it has been found that they play a critical role in many processes, including LONG-TERM POTENTIATION (LTP) for which calcium (Ca2+) entry into neurons via NMDA-gated ion channels is critical. Areas rich in NMDA receptors include limbic regions such as the HIPPOCAMPUS and AMYGDALA, NEOCORTEX, and the BASAL GANGLIA.
