Entrainment (chronobiology)

In the study of chronobiology, entrainment refers to the synchronization of a biological clock to an environmental cycle. An example is the interaction between circadian rhythms and environmental cues, such as light and temperature. Entrainment helps organisms adapt their bodily processes with the timing of a changing environment.[1] For example, entrainment is manifested during travel between time zones, hence why humans experience jet lag.

Biological rhythms are endogenous; they persist even in the absence of environmental cues as they are driven by an internal mechanism, the circadian clock being the best characterized. Of the several possible cues, known as zeitgebers (German for 'time-givers'), which can contribute to entrainment of the circadian clock, light has the greatest impact.[2][3] Units of circadian time (CT) are used to describe entrainment to refer to the relationship between the rhythm and the light signal/pulse.[4]

  1. ^ Olds, William (2015). Sleep, Circadian Rhythms, and Metabolism: The Rhythm of Life. Apple Academic Press. ISBN 978-1771880626.[page needed]
  2. ^ Edgar, DM; Dement, WC (1991). "Regularly scheduled voluntary exercise synchronizes the mouse circadian clock". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 261 (4): R928–R933. doi:10.1152/ajpregu.1991.261.4.R928. PMID 1928438.
  3. ^ Van Reeth, O; Sturis, J; Byrne, MM. "Nocturnal exercise phase delays circadian rhythms of melatonin and thyrotropin secretion in normal men". American Journal of Physiology-Endocrinology and Metabolism. 266 (6): E964–E974.
  4. ^ Pittendrigh, CS (1981). "Circadian Systems: Entrainment". Handbook Behavioral Neurobiology. 4: 239–268.