Beyond day and night: The importance of ultradian rhythms in mouse physiology

作者：Vojtěch Škop, Naili Liu, Cuiying Xiao, Emma J. Stinson, Kong Y. Chen, Kevin D. Hall, Paolo Piaggi, Oksana Gavrilova, Marc L. Reitman · 发表于：Molecular Metabolism · 年份：2024 · DOI：10.1016/j.molmet.2024.101946 · 被引用次数：16 · 研究领域：Circadian rhythm and melatonin、Adipose Tissue and Metabolism、Dietary Effects on Health

Our circadian world shapes much of metabolic physiology. In mice ∼40% of the light and ∼80% of the dark phase time is characterized by bouts of increased energy expenditure (EE). These ultradian bouts have a higher body temperature (Tb) and thermal conductance and contain virtually all of the physical activity and awake time. Bout status is a better classifier of mouse physiology than photoperiod, with ultradian bouts superimposed on top of the circadian light/dark cycle. We suggest that the primary driver of ultradian bouts is a brain-initiated transition to a higher defended Tb of the active/awake state. Increased energy expenditure from brown adipose tissue, physical activity, and cardiac work combine to raise Tb from the lower defended Tb of the resting/sleeping state. Thus, unlike humans, much of mouse metabolic physiology is episodic with large ultradian increases in EE and Tb that correlate with the active/awake state and are poorly aligned with circadian cycling.