by the axons of other neurons. http://www.lexicon-biology.com/biology/definition_94.html   March 6, 2007 3:02 PM EST [7] NMDA receptor - is an ionotropic receptor for glutamate ( NMDA ( N-methyl d-aspartate ) is a name of its selective specific agonist ). Activation of NMDA receptors results in the opening of an ion channel