NMDA receptor
This term refers to a specific protein complex in the central nervous system. In scientific literature, it is almost exclusively used in a technical, biological context to discuss neuroplasticity, long-term potentiation, and the pathophysiology of conditions like Alzheimer's disease or stroke.
Because it is a specific biological entity, it is treated as a countable noun. Researchers typically refer to "the NMDA receptor" when discussing the general mechanism or "NMDA receptors" when referring to the population of these proteins across a set of synapses.
Meanings
An ionotropic glutamate receptor in the brain that is activated by the neurotransmitter glutamate and the co-agonist glycine, requiring the binding of both and the removal of a magnesium block to allow the influx of calcium and sodium ions.
The NMDA receptor plays a critical role in synaptic plasticity and memory formation.