Age-related changes in daily rhythm gene activity in the brain’s timekeeping center, liver, and heart of mice

Circadian clock gene expression is significantly modified in the SCN and peripheral tissues of aged mice.

• Aged mice show preserved circadian profiles of core clock gene expression in the SCN but impaired expression in peripheral tissues.
• Both primary and secondary clock loop components are affected by aging, indicating complex changes in circadian rhythm regulation.
• Specific changes in secondary clock loop components, such as Rev-erbα, are observed in the SCN of older mice.
• The primary clock loop experiences alterations in the liver, while the heart exhibits only minor changes in clock gene expression.
• Findings suggest that aging impacts circadian output through distinct modifications in different tissue types.

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