Human and mouse brains age similarly—but humans decline faster, study finds

A new study has revealed striking similarities in how human and mouse brains age. Researchers found that both species experience a decline in the brain's ability to keep distinct networks specialised for different tasks. The findings suggest that while greater connectivity in human brains may support higher intelligence, it could also make them more vulnerable to rapid cognitive decline.

The research team used advanced fMRI technology to scan awake mice throughout their lifespans. The scanners, three times more powerful than standard clinical ones, captured fine neural details despite mouse brains being roughly 3,000 times smaller than human brains. This approach allowed scientists to track age-related changes in brain networks with high precision.

Both humans and mice showed a breakdown in 'modular specialisation'—the brain's capacity to maintain separate networks for specific functions. In humans, however, the decline in this specialisation happened faster than in mice. The study suggests that the high level of integration in human brains, while beneficial for complex cognition, may also accelerate age-related deterioration. Previous neuroscience studies on mice have faced criticism for not translating well to human conditions. But this research focused on brain networks rather than isolated regions, offering a more clinically relevant model. The findings open doors to further investigate how genetics, environment, and other factors influence brain aging in mice.

The study highlights a shared pattern of neural decline between humans and mice, though humans appear more susceptible to rapid deterioration. By using high-resolution imaging, researchers can now explore potential interventions for age-related cognitive decline. This work provides a foundation for future studies on brain aging and its underlying mechanisms.