Reference
Bing Ren
The account of the hippocampus reorganising itself between roughly 50 and 75, at the level of gene regulation rather than behaviour, comes from work he is corresponding author on.
Ren and colleagues examined gene regulation and the three-dimensional folding of the genome inside individual cells of the human hippocampus, and reported a marked shift between about 50 and 75: resident immune cells decline and are replaced by cells with more inflammatory characteristics, the cells forming the blood-brain barrier weaken, and the organisation of the genome degrades.
What we rely on it for is narrow. It is one structure, examined in tissue, and it says nothing about what any of it felt like to the people whose brains were studied. We cite it because its timetable does not line up with the wiring turning points, which is a useful correction to the idea that the brain has one ageing clock.
Referenced work
- Epigenetic and 3D genome reprogramming during the aging of the human hippocampus (Science, 2026) reference
Elsewhere
Listed here because we name Bing Ren in our writing. We are not affiliated with them and this page is our summary, not theirs.