Brain responses to visual cues varied more in older mice
An experiment recording more than 18,000 nerve cells in 149 mice also found more variable response times in older animals.
Limit: The causal effect of nerve-cell variability on response-time consistency was not measured
Edited by Boris Djordjevic · AgingResearch.News
In an animal experiment, researchers studied 149 C57BL/6 laboratory mice of both sexes, aged 3–20 months, performing a visual decision-making task. The mice turned a wheel to indicate whether an image appeared on the left or right. Researchers analyzed recordings from 18,755 neurons, or nerve cells, across 16 brain regions.
Older mice had more variable response times. Across the recorded cells, activity varied more after images appeared, but not beforehand. The usual drop in activity variability after an image appeared was also smaller in older mice. Firing rates—the frequency of nerve cells’ electrical signals—were higher with age overall. However, cells in the thalamus, a brain region, fired less frequently in older mice.
Why it matters
The work addresses whether less consistent nerve-cell responses may contribute to age-related changes in learning and decision-making.
Caveats
The age comparisons did not establish whether more variable nerve-cell activity caused the less consistent response times. The findings came from mice performing a visual task, not from people.
- Synaptic transmission
- Response time variability
- Neural firing rate
- Fano factor
- Variability quenching
- Mice
The paper
Age-related changes in behavioural and neural variability in a decision-making task
Leiden University
Nature Communications, Jun 30, 2026, Open access
