Overview
- Researchers report in PNAS that large-scale brain networks lose clear boundaries with age in both species.
- Modularization, the brain’s setup of distinct networks for tasks like memory and perception, weakens with age and links to cognitive decline.
- The team scanned 82 mice while awake across ages 3 to 20 months using functional MRI to track changes over the full lifespan.
- Because mouse brains are far smaller, the group used very high‑field scanners more than three times stronger than standard clinical units to resolve fine detail.
- Humans show more integrated networks yet a faster decline than mice, and the authors say the cross‑species match can speed tests of diet, genetic, and drug interventions, with next steps including studies in additional mouse strains.