Texas A&M University

Ashok Shetty's lab at Texas A&M dosed 18-month-old mice twice with extracellular vesicles from human stem cells, sprayed up the nose. Object-recognition memory improved; inflammation markers in the hippocampus dropped and held for months.

The press release says 'reverse brain aging.' The thread says something smaller: it lowered inflammation, in mice, and no human has tried it. A neuroimaging scientist and a skeptic both landed on the same asterisk.

The finding: the regenerative cells are already there, you just have to make them behave. After wound healing, FGF2 redirects cells toward a blastema-like structure, then BMP2 tells them to build new tissue.

A reader with permanent retinal damage noted the same trick in retinas often triggers tumors, the recurring asterisk of the whole field.