[nonce42]

I hesitate to support HN's obsession with random Alzheimer's theories, but there's been a lot of research lately on the glymphatic system, vessels that clean waste protein out of the brain during sleep. This study is in line with that research.

The wikipedia page gives a good background on the glymphatic system: https://en.wikipedia.org/wiki/Glymphatic_system

https://science.sciencemag.org/content/370/6512/50.abstract https://science.sciencemag.org/content/342/6156/373