| First Author | Škop V | Year | 2024 |
| Journal | Mol Metab | Volume | 84 |
| Pages | 101946 | PubMed ID | 38657735 |
| Mgi Jnum | J:348091 | Mgi Id | MGI:7639010 |
| Doi | 10.1016/j.molmet.2024.101946 | Citation | Skop V, et al. (2024) Beyond day and night: The importance of ultradian rhythms in mouse physiology. Mol Metab 84:101946 |
| abstractText | Our circadian world shapes much of metabolic physiology. In mice approximately 40% of the light and approximately 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. |
