https://www.biorxiv.org/content/10.1101/2025.09.02.673859v1.full.pdf looks like bad news for the “it’s the macrophages, stupid” hypothesis; put aged microglia in young brains and they look like young ones, put young microglia in aged brains and they look like old ones (transcriptionally and morphologically.)
it may be “the NK cells, stupid”? if you deplete NK cells from the cerebellum, cerebellar microglia don’t get the characteristic age-related interferon signaling.
links 11/24/25: https://roamresearch.com/#/app/srcpublic/page/11-24-2025
https://writetobrain.com/olfactory induced smells with transcranial ultrasound
https://www.biorxiv.org/content/10.1101/2025.09.02.673859v1.full.pdf looks like bad news for the “it’s the macrophages, stupid” hypothesis; put aged microglia in young brains and they look like young ones, put young microglia in aged brains and they look like old ones (transcriptionally and morphologically.)
it may be “the NK cells, stupid”? if you deplete NK cells from the cerebellum, cerebellar microglia don’t get the characteristic age-related interferon signaling.
https://www.lesswrong.com/posts/apHWSGDiydv3ivmg6/varieties-of-doom JD Pressman explains what he actually thinks will happen with AI
https://www.lesswrong.com/posts/LaWmoy4s2DLe9u2zq/llm-chatbots-have-half-of-the-kinds-of-consciousness-that Andrew Critch is confident that chatbots introspect, have purposes, have awareness of awareness and perception of perception and memory of memory, have symbol grounding, etc.
i confidently disagree, but it would be hard to prove it.
https://www.untillabs.com/blog/glass-not-ice Until lays out how they intend to improve vitrification for reversible organ preservation (and ultimately preserving whole people).
i’d need a lot more physics/chemistry knowledge to have much sense of how feasible this is.