The NMDA receptors are members of the glutamate receptor family of ion channels that also include the AMPA and Kainate receptors.

The NMDA receptors are encoded by seven genes: one NMDAR1 (or NR1) subunit, four NR2 (NR2A-NR2D) and two NR3 (NR3A-NR3B) subunits. The functional NMDA receptor appears to be a heterotetramer composed of two NMDAR1 and two NMDAR2 subunits. Whereas the NMDAR2 subunits that assemble with the NMDAR1 subunit can be either of the same kind (i.e. two NMDAR2A subunits) or different (one NMDAR2A with one NMDAR2B). NMDAR3 subunits can substitute the NMDAR2 subunits in their complex with the NMDAR1 subunit.

The NMDAR is unique among ligand-gated ion channels in that it requires the simultaneous binding of two obligatory agonists: glycine and glutamate that bind to the NMDAR1 and NMDAR2 binding sites respectively. Another unique characteristic of the NMDA receptors is their dependence on membrane potential. At resting membrane potentials the channels are blocked by extracellular Mg²⁺. Neuronal depolarization relieves the Mg²⁺ blockage and allows ion influx into the cells. NMDA receptors are strongly selective for Ca²⁺ influx differing from the other glutamate receptor ion channels that are non-selective cation channels.

Ca²⁺ entry through the NMDAR regulates numerous downstream signaling pathways including long term potentiation (a molecular model of memory) and synaptic plasticity that may underlie learning. In addition, the NMDA receptors have been implicated in a variety of neurological disorders including epilepsy, ischemic brain damage, Parkinson’s and Alzheimer’s diseases.

NMDA receptors expression and function are modulated by a variety of factors including receptor trafficking to the synapses and internalization as well as phosphorylation and interaction with other intracellular proteins.

Alomone Labs offers a highly specific antibody directed against a conserved extracellular epitope of the rat NMDAR2B subunit. Anti-NMDA Receptor 2B (NR2B) (extracellular) antibody (#AGC-003) has been tested in Western blot and immunohistochemistry applications and is designed to recognize NMDAR2B from rat, mouse and human samples.

We are pleased to offer a new version of this antibody that is directly labeled with an ATTO-594 fluorescent dye. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. The ATTO-594 fluorescent label belongs to the class of Rhodamine dyes and can be used with fluorescent equipment typically optimized to detect Texas Red and Alexa-594. 

Anti-NMDA Receptor 2B (NR2B) (extracellular)-ATTO-594 antibody (#AGC-003-AR) has been tested in immunohistochemical applications and is specially suited for experiments requiring simultaneous labeling of different markers.