Adult brains keep making neurons, superagers show the most
Feb 27th 2026
A new Nature study using single-cell sequencing of human hippocampal tissue shows ongoing adult neurogenesis, with superagers showing markedly higher neuron production and Alzheimer’s brains showing almost none; the difference appears tied to chromatin accessibility and may point to ways to protect memory as we age.
- Adult human hippocampus produces new neurons, identified as neural stem cells, neuroblasts and immature neurons.
- Superagers had roughly double the neurogenic activity of typical older adults in many measures, while early cognitive decline showed reduced neurogenesis and Alzheimer’s cases showed almost none.
- Reduced chromatin accessibility in hippocampal cells was linked to early shutdown of neuron production, preceding some changes in gene expression.
- Researchers mapped gene expression and chromatin accessibility using single-cell sequencing on post-mortem hippocampi from five donor groups.
- The study is limited by small, variable post-mortem samples and some non-significant comparisons, so larger and longitudinal studies are needed and the team plans to study lifestyle effects on these epigenetic signatures.