A two-process model of Drosophila sleep reveals an inter-dependence between circadian clock speed and the rate of sleep pressure decay
Author:
Abhilash Lakshman1,
Shafer Orie Thomas1ORCID
Affiliation:
1. The Advanced Science Research Center, The City University of New York , New York, NY , USA
Abstract
Abstract
Sleep is controlled by two processes—a circadian clock that regulates its timing and a homeostat that regulates the drive to sleep. Drosophila has been an insightful model for understanding both processes. For four decades, Borbély and Daan’s two-process model has provided a powerful framework for understanding sleep regulation. However, the field of fly sleep has not employed such a model as a framework for the investigation of sleep. To this end, we have adapted the two-process model to the fly and established its utility by showing that it can provide empirically testable predictions regarding the circadian and homeostatic control of fly sleep. We show that the ultradian rhythms previously reported for loss-of-function clock mutants in the fly are robustly detectable and a predictable consequence of a functional sleep homeostat in the absence of a functioning circadian system. We find that a model in which the circadian clock speed and homeostatic rates act without influencing each other provides imprecise predictions regarding how clock speed influences the strength of sleep rhythms and the amount of daily sleep. We also find that quantitatively good fits between empirical values and model predictions were achieved only when clock speeds were positively correlated with rates of decay of sleep pressure. Our results indicate that longer sleep bouts better reflect the homeostatic process than the current definition of sleep as any inactivity lasting 5 minutes or more. This two-process model represents a powerful framework for work on the molecular and physiological regulation of fly sleep.
Funder
National Institute of Neurological Disorders and Stroke
Publisher
Oxford University Press (OUP)
Subject
Physiology (medical),Neurology (clinical)
Reference97 articles.
1. Animal sleep: A review of sleep duration across phylogeny;Campbell;Neurosci Biobehav Rev.,1984
2. A two process model of sleep regulation;Alexander;Hum Neurobiol.,1982
3. Mathematical Models of the Circadian Sleep-Wake Cycle.
4. Circadian gating of human sleep-wake cycles;Daan,1984
5. Timing of human sleep: recovery process gated by a circadian pacemaker;Daan;Am J Physiol.,1984
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献