Standard touchscreen test procedures shift circadian rhythms in mice: a modified protocol to minimize circadian confounds

Touchscreen training in nocturnal mice using standard illuminated chambers induces a ~3.5 h phase delay in daily activity rhythms over 7 consecutive days when started early in the dark period.

• Why it matters: Food reward and touchscreen illumination can entrain or disrupt circadian rhythms, confounding links between sleep/circadian disruption and cognitive performance.
• What they did: The study compared contributions of touchscreen light versus appetitive reward, then tested 10 modified lighting conditions in the test environment and home cage while measuring TUNL acquisition and performance.
• The result: Light from the touchscreen chambers is linked to the observed circadian phase shifting, and the recommended protocol modifications minimize circadian confounds without impairing TUNL task acquisition or performance.

AI summary of the abstract · may contain errors · not medical advice · read the paper.