Differential Rescue of Light- And Food-Entrainable Circadian Rhythms

Science. 2008 May 23;320(5879):1074-7. doi: 10.1126/science.1153277.

Abstract

When food is plentiful, circadian rhythms of animals are powerfully entrained by the light-dark cycle. However, if animals have access to food only during their normal sleep cycle, they will shift most of their circadian rhythms to match the food availability. We studied the basis for entrainment of circadian rhythms by food and light in mice with targeted disruption of the clock gene Bmal1, which lack circadian rhythmicity. Injection of a viral vector containing the Bmal1 gene into the suprachiasmatic nuclei of the hypothalamus restored light-entrainable, but not food-entrainable, circadian rhythms. In contrast, restoration of the Bmal1 gene only in the dorsomedial hypothalamic nucleus restored the ability of animals to entrain to food but not to light. These results demonstrate that the dorsomedial hypothalamus contains a Bmal1-based oscillator that can drive food entrainment of circadian rhythms.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ARNTL Transcription Factors
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / physiology*
  • Biological Clocks / physiology*
  • Body Temperature
  • Cell Cycle Proteins / genetics
  • Circadian Rhythm / physiology*
  • Dorsomedial Hypothalamic Nucleus / metabolism*
  • Food*
  • Gene Expression
  • Gene Transfer Techniques
  • Light*
  • Mice
  • Motor Activity
  • Nuclear Proteins / genetics
  • Period Circadian Proteins
  • Starvation
  • Suprachiasmatic Nucleus / metabolism
  • Transcription Factors / genetics

Substances

  • ARNTL Transcription Factors
  • Arntl protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Cell Cycle Proteins
  • Nuclear Proteins
  • Per1 protein, mouse
  • Per2 protein, mouse
  • Period Circadian Proteins
  • Transcription Factors