Systemic increase of AMPA receptors associated with cognitive impairment of long COVID, 2025, Fujimoto et al.

[mariovitali]

And regarding excitotoxicity risk (also discussed in the study):

 

[Creekside]

In one of my algorithmic runs, glutamate has been identified as a key factor for MECFS symptoms.

Would that theory require the patient to show sensitivity to MSG?

 

[forestglip]

A cursory look at info around AMPA receptors seems to suggest that learning increases the density of them on the surface of neurons. If the density of these receptors on neurons are a marker of how well a brain works i.e. ongoing learning and connection making, perhaps the people with Long covid who made it to the trial are more likely to be well educated (versus those who didn't find out about the trial or couldn't marshal the resources to take part). I don't know yet how the controls were recruited, but if, for example, they were paid, perhaps they were less likely to be well educated?

I would think upregulating receptors related to learning would happen in specific locations in the brain relevant to learning, but figure 2B seems to show that AMPAR density was increased pretty much everywhere in this study. Would be good to know in what regions learning increases AMPAR.

Also, we have seen papers before underlining how important it is in scan studies that controls are included in the same runs as the disease participants. If the controls were scanned in a separate study, that means that there is an additional source of variation.

True, but they seem to say they also found correlations between AMPAR density and brain fog measures in similar regions within the patient cohort as they did between the patients and the controls, which makes artifacts related to different runs less likely as the reason for the findings:

In addition, we noted brain regions where SUVRWM and the scores of the Picture naming and Figure Recall, which are RBANS subcategories, were negatively correlated (Fig. 2C and E), most of which were identified as areas where AMPAR density was elevated in patients with Cog-LC compared with those in HCs (Fig. 2D and F).

Edit: Though maybe the within-patient cognitive score correlations are not great evidence because they only mention correlations in 2 out of 17 total cognitive scores.

Still, 'figure recall' is one of the most significant scales in terms of difference from controls (table 1), and it's also one of the two within group correlations.