Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Light signalling in cryptochrome-deficient mice.

Xavier Bonnefont1, Henk Albus, Johanna H Meijer

  • 1MGC, Department of Cell Biology and Genetics, Erasmus MC, PO Box 1738, 3000 DR Rotterdam, The Netherlands.

Novartis Foundation Symposium
|January 10, 2004
PubMed
Summary

Cryptochrome (CRY) proteins are essential for the mammalian circadian clock

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Physical activity stimulates clock neurons of the day-active rodent <i>Arvicanthis ansorgei</i>.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

The effects of diazepam on sleep depend on the photoperiod.

Acta pharmacologica Sinica·2025
Same author

Incorporating Physical Activity in a New Two-Oscillator Model of Circadian Activity in Nocturnal and Diurnal Mammals.

Journal of biological rhythms·2024
Same author

The effect of sleep and shift work on the primary immune response to messenger RNA-based COVID-19 vaccination.

Journal of sleep research·2024
Same author

Chronotype, sleep quality, depression and pre-sleep rumination: A diary and actigraphy study.

The European journal of neuroscience·2024
Same author

Personalized sleep and nutritional strategies to combat adverse effects of night shift work: a controlled intervention protocol.

BMC public health·2024

Area of Science:

  • Chronobiology
  • Neuroscience
  • Molecular Biology

Background:

  • The mammalian circadian clock, located in the suprachiasmatic nuclei (SCN), regulates daily rhythms.
  • This clock relies on transcription-translation feedback loops, with Cryptochrome (CRY) proteins being crucial for the negative feedback loop.
  • Mice lacking mCry1 and mCry2 genes exhibit arrhythmic behavior and lack molecular clock oscillations.

Purpose of the Study:

  • To investigate the role of CRY proteins in the circadian rhythmicity of SCN neuronal activity.
  • To determine if CRY proteins are necessary for electrical activity oscillations in SCN neurons.

Main Methods:

  • Electrophysiological recordings (multi-unit electrode activity) were performed on hypothalamic slices from mCry-deficient mice.
  • Mice were studied under constant darkness and normal light-dark cycles.

Main Results:

  • In constant darkness, mCry-deficient mice showed a complete absence of circadian oscillations in SCN neuronal firing patterns.
  • Under light-dark cycles, a single, non-circadian peak of neuronal activity was observed in SCN slices from mCry-deficient mice.
  • This suggests CRY proteins are essential for circadian rhythmicity in SCN neuronal excitability.

Conclusions:

  • CRY proteins and an intact circadian clock are prerequisites for circadian rhythmicity in SCN neurons.
  • The absence of CRY proteins transforms the SCN oscillator into an hourglass-like timekeeper, potentially explaining normal behavior in light-dark cycles.

Related Experiment Videos