Editing NMDA receptor (section)

==== Noncompetitive NMDA receptor antagonists ====
[[File:NMDA receptor antagonist.jpg|thumb|right|200px|'''Figure 4:''' The chemical structures of MK-801, phencyclidine and ketamine, high affinity uncompetitive NMDA receptor antagonists]]
Uncompetitive NMDA receptor antagonists block within the ion channel at the Mg<sup>2+</sup> site (pore region) and prevent excessive influx of Ca<sup>2+</sup>. Noncompetitive antagonism refers to a type of block that an increased concentration of glutamate cannot overcome, and is dependent upon prior activation of the receptor by the agonist, i.e. it only enters the channel when it is opened by agonist.<ref name="Lipton2" /><ref name="Sonkusare">{{cite journal | vauthors = Sonkusare SK, Kaul CL, Ramarao P | title = Dementia of Alzheimer's disease and other neurodegenerative disorders--memantine, a new hope | journal = Pharmacological Research | volume = 51 | issue = 1 | pages = 1–17 | date = January 2005 | pmid = 15519530 | doi = 10.1016/j.phrs.2004.05.005 }}</ref>