> The researchers found that intermittent exposure to high carbon dioxide levels caused the brain’s blood vessels to pump as they do during deep sleep, driving the glymphatic system.

[...]

> But an around an hour after the intervention ended, the amyloid and tau-clearing benefits had returned to baseline. Further studies need to explore whether this has an impact on Alzheimer’s disease risk or progression in the long-term, and how often you’d need to do it, says Vincent Tay at Changi General Hospital in Singapore.

> Further studies need to explore whether this has an impact on Alzheimer’s disease risk or progression in the long-term, and how often you’d need to do it, says Vincent Tay at Changi General Hospital in Singapore.

I would assume that all sorts of proteins would clear out of the brain in cases of prolonged oxygen depletion.

I can't find it at the moment (edit: found it [2]), but I am sure I read something about Jerome Lettvin [1] doing some experimenting with CO2 but for something like schizophrenia, and that despite having good results he had to stop due to legal liability reasons or the like. I think it came up in an interview with him which I read a transcript of.

[1] https://en.wikipedia.org/wiki/Jerome_Lettvin

[2] https://www.mindstrengthbalance.com/learn/interviews/jeromel... (search for Laszlo to find the bit where they start talking about this)

at least it's not "only in rats" LOLL

“Carbogen” has an interesting history.

https://en.wikipedia.org/wiki/Carbogen

It has some sort of mind altering effect, and in the early days of psychedelic psychotherapy it was used to determine whether someone would freak out under the influence of mind altering substances.

https://www.erowid.org/chemicals/carbogen/carbogen.shtml