CONCLUSIONS The findings of this study showed a neuroprotective effect of curcumin treatment in an in vitro model of Alzheimer's disease that was associated with the increased expression of the NMDAR subunit, NR2A.
Furthermore, internalisation of synaptic NR2A-NMDAR shows greater damage to the postsynaptic Ca2+ response in comparison with the internalisation of NR2B-NMDARs; thus, the suggested neuroprotective role of the latter is very limited during synaptic transmission in AD.
These results indicate that enhancing synaptic NMDARs and inhibiting extrasynaptic NMDARs concurrently showed protective effects against Aβ-induced neurotoxicity, suggesting that modulation of the balance between GluN2A and GluN2B could be a potential strategy for AD drug development and therapy.
Finally, in the 5XFAD transgenic model of Alzheimer's disease (AD), RNS60 treatment upregulated expression of plasticity-related proteins PSD95 and NR2A and increased AMPA- and NMDA-dependent hippocampal calcium influx.
Significantly lower expression of NR2A and NR2B transcripts was found in susceptible regions of AD brain, whereas expression of NR2C and NR2D transcripts did not differ from that in controls.
Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the messenger RNA (mRNA) levels of the NMDA receptor subunits NR1, NR2A, and NR2B in the hippocampus and entorhinal cortex of postmortem brain samples from nine clinically well-characterized AD patients and nine aged controls.