Differential effects of sex and age on daily and infradian rhythms of mice
First published: 04 February 2026 ; https://doi.org/10.1113/JP289676
Abstract
Intrinsic biological rhythms regulate key physiological and behavioural processes, yet the influence of sex and age on these rhythms is not fully understood. We comprehensively examined 24 h (circadian) and >24 h (infradian; 5 and 10 day) rhythms in wheel-running and ingestive behaviours in single-housed young and middle-aged male and female mice. Circadian analysis revealed that middle-aged mice, particularly females, exhibited more precise daily rhythms and shifted a greater proportion of activity and feeding to the lights-on phase than young female mice. Middle-aged animals also ran for longer durations per day, suggesting age-related changes in activity regulation. Analysis of infradian rhythms further highlighted sex- and age-specific differences. Young female mice displayed robust 5 day rhythms in wheel-running activity, which were absent in middle-aged females. In contrast, few males (young or middle-aged) showed significant 5 day rhythms. Ten-day rhythms were most prominent in male mice, while females rarely expressed this periodicity. Physiologically, middle-aged mice lost more body weight in response to single housing, with middle-aged females being most affected. Interactions among behavioural rhythms in females also showed greater complexity, which increased with age. These findings reveal distinct sex- and age-dependent patterns in circadian and infradian rhythms as well as in physiological responses to isolation. Our work highlights the need to account for sex and age in chronobiological research, with broader implications for understanding vulnerability to age-related metabolic and behavioural disorders.
這項研究探討了性別與年齡對小鼠生物節律（包含 24 小時晝夜節律及超過 24 小時的長周期節律）的影響，發現在 24 小時節律方面，中年小鼠（尤其是雌性）表現出更精確的每日節律，並將更多活動與進食轉移至光照期，且每日跑步時間較長；在長周期節律上，年輕雌性具有顯著的 5 天周期，但中年雌性則消失，而 10 天周期則主要出現在雄性中。此外，中年小鼠（特別是雌性）對單獨居住的生理壓力更敏感，體重下降較多，且雌性的行為節律互動隨年齡增加而更加複雜。總結而言，研究強調了在時辰生物學中納入性別與年齡因素的重要性，這對於理解高齡相關的代謝與行為障礙具有重要意義。
Key points
- Physiological findings:
- –Middle-aged mice lost more body weight after single housing, with females most affected.
- Circadian findings:
- –Older mice show more daytime activity.
- –Precision in daily rhythm differs by sex and age.
- –Middle-aged females showed prolonged daily wheel running.
- Infradian findings:
- –Young females had robust 5 day rhythms, absent in middle-aged females.
- –Some males showed 5 day rhythms, but 10 day rhythms were most prominent in males.
- Complexity of rhythms:
- –Complexity of interactions among behavioural rhythms increases with age, particularly in females.
