Age-related decreases in the GLUTAMATE NMDA NR2B subunit correlate with memory deficits. Both mice and rats that were engineered to over-express GRIN2B in their brains have increased mental ability, learning faster and remembering better. The "Doogie" mouse had double the learning ability. Glutamate [NMDA] receptor subunit epsilon-2, also known as N-methyl D-aspartate receptor subtype 2B (NMDAR2B or NR2B), is a protein that in humans is encoded by the GRIN2B gene. NR2B interestingly is also linked to depression and neuropathic pain when high.
Sodium Butyrate inhibits IDO1 and here increased NR2B and lowered pro inflammatory cytokines and therefore might be one to consider for some
https://www.sciencedirect.com/science/article/abs/pii/S0009279721000880 and improved memory in Alzheimer's Disease mouse models in later stages (mentioned earlier)
Active B6 appears to as well
https://pubmed.ncbi.nlm.nih.gov/28872356/ The active form of Vitamin B6 (P5P) (but not pyridoxine) prevents IL-1β production by inhibiting NLRP3 inflammasome activation and suggest its potential for preventing inflammatory diseases driven by the NLRP3 inflammasome
https://pubmed.ncbi.nlm.nih.gov/27733681/ (but not pyridoxine form which competitively inhibits the active form.
https://www.sciencedirect.com/science/article/abs/pii/S0887233317301959?via=ihub
It also appears to require balance. Both insufficient and excessive levels of IL-1β (which is increased after NLRP3 activation) impair the formation of memory indicating that IL-1β is important for normal learning and memory formation and would explain all the mixed results. The involvement of IL-1 in hippocampal-dependent memory follows an inverted U-shaped pattern, i.e., a slight increase in brain IL-1 levels can improve memory, whereas any deviation from the physiological range, either by excess elevation in IL-1 levels or by blockade of IL-1 signaling, results in impaired memory.
https://www.ncbi.nlm.nih.gov/pubmed/17976923/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5560336/pdf/12264_2010_Article_6023.pdf
Quinolinic acid (quinolinate) – endogenous glutamate site NMDA agonist (increase). Kynurenic acid – endogenous glycine site NMDA antagonist (decrease). Going in the other direction, Serotonin, by activating 5-HT(1A) 5-hydroxytryptamine receptor 1A receptors, inhibited NMDA receptor-mediated ionic and synaptic currents in PFC pyramidal neurons, and the NR2B subunit-containing NMDA receptor is the primary target of 5-HT(1A) receptors
https://pubmed.ncbi.nlm.nih.gov/15944377/ Activation of 5-HT2A/C receptors counteracts 5-HT1A regulation of n-methyl-D-aspartate receptor channels in pyramidal neurons of prefrontal cortex
https://pubmed.ncbi.nlm.nih.gov/18442977/ Serotonin 5-HT2A receptors (5-HT2ARs) are widely distributed in the central nervous system, especially in brain region essential for learning and cognition
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4594018/ So it appears that this pathway is very involved in the regulation of NMDA NR2B.
https://forums.phoenixrising.me/thr...nfa-itaconate-shunt-part-2.89388/post-2438998
Potential Role of Neuroactive Tryptophan Metabolites in Central Fatigue: Establishment of the Fatigue Circuit Again points to balance as too much Kynurenic acid which lowers or too much Quinolinic acid which raises are both problematic.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325545/
It also appears that the loss of Shank3 via zinc deficiency that is required for its function or lowered from NLRP3 over activation interacts with NMDA receptors. This can also have a downstream effect on Vitamin B6. Since SHANK3 is concentrated in glutamatergic synapses, it interacts with all prominent glutamate receptors, such as NMDA, AMPA, and mGlu receptors. SHANK3 also indirectly interacts with Neuroligins (NLGN), a family of post-synaptic adhesion molecules. Most of these interactions are indirect and mediated by post-synaptic proteins such as GKAP, Homer PSD95 etc. InsG3680 Shank3 mutant mice show disruptions of glutamatergic signaling as compared to WT controls.
https://www.nature.com/articles/s41398-021-01612-3