Glutamate receptor ionotropic, NMDA 2A (NR2A) (NR2A)

The NMDA receptor containing the NR2A subunit (also known as GluN2A) is a heterotetrameric ligand-gated ion channel that serves as a critical mediator of excitatory neurotransmission and synaptic plasticity in the adult central nervous system [1.1.4, 1.3.3]. It is primarily composed of two obligatory GluN1 subunits and two regulatory GluN2A subunits, which confer distinct biophysical properties such as high open probability and fast deactivation kinetics [1.4.4, 1.4.5]. Localized predominantly at the synapse, these receptors act as coincidence detectors, requiring both glutamate binding and postsynaptic depolarization to remove a magnesium block and allow calcium influx [1.2.1, 1.4.3]. This calcium signaling is essential for long-term potentiation (LTP), the cellular basis for learning and memory, and is generally associated with pro-survival pathways in neurons [1.3.5, 1.4.5]. Mutations in the GRIN2A gene, which encodes the NR2A subunit, are linked to a variety of neurological disorders, including focal epilepsy, schizophrenia, and neurodevelopmental delays [1.2.2, 1.2.4]. Pharmacologically, the receptor is a target for non-selective antagonists like memantine and ketamine, as well as emerging subunit-selective positive allosteric modulators (PAMs) designed to treat cognitive deficits [1.3.1, 1.3.5]. However, therapeutic modulation faces challenges, as excessive inhibition can cause psychotomimetic side effects, while over-activation may lead to excitotoxic cell death [1.2.5, 1.3.1].

Other names

GluN2A [1.4.1]GRIN2A [1.4.1]N-methyl-D-aspartate receptor subunit 2A [1.4.1]NMDAR2A [1.4.1]Epsilon-1 [1.4.1]Glutamate [NMDA] receptor subunit epsilon-1 [1.4.1]

Uncompetitive channel blockade [1.3.1], positive allosteric modulation [1.3.4], negative allosteric modulation [1.1.5], and competitive antagonism [1.3.2].