Question

In the lithium inhibition of NMDA-elicited currents section of the results section the authors wrote “This could be the case, if NCXs maintain low intracellular free Ca2+ concentration in the close proximity of NMDARs, which prevents the development of Ca2+ -dependent inactivation of NMDARs.” Quote something from the article that explains why low intracellular free Ca2+ concentrations in close proximity of NMDARs would prevent the development of Ca2+ -dependent inactivation of NMDARs.

Link to the article: (https://bmcneurosci.biomedcentral.com/articles/10.1186/s12868-018-0475-3) or (https://bmcneurosci.biomedcentral.com/track/pdf/10.1186/s12868-018-0475-3)

My answer:

“Previously, we demonstrated that the inhibition of NMDA-activated

currents by Li+ is Ca2+-dependent, because it could not be observed in the nominal absence of Ca2+ in the external solution [11].” What this explains is that the inhibition of NMDARs could not be observed because a low concentration of Ca2+ was not present, so no inhibition occurred. This directly coincides with the question, because it has been shown that even low levels of Ca2+ will prevent Ca2+ dependent inactivation of NMDARs.

Is this correct? If not, can you please provide an explanation?

Answer 1

Answer:

NMDA receptors are structurally complex,w with separate binding sites for glutamen glysine MG+2 ,zn+2 and polyamines. NMDA gated channels are most permeable to ca+2 than Na+ions.