Faculty Collaboration Database

Individual differences in circadian waveform of Siberian hamsters under multiple lighting conditions. J Biol Rhythms 2012 Oct;27(5):410-9

Date

09/27/2012

Pubmed ID

23010663

Pubmed Central ID

PMC3578227

DOI

10.1177/0748730412455915

Scopus ID

2-s2.0-84866693415 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

Because the circadian clock in the mammalian brain derives from a network of interacting cellular oscillators, characterizing the nature and bases of circadian coupling is fundamental to understanding how the pacemaker operates. Various phenomena involving plasticity in circadian waveform have been theorized to reflect changes in oscillator coupling; however, it remains unclear whether these different behavioral paradigms reference a unitary underlying process. To test whether disparate coupling assays index a common mechanism, we examined whether there is covariation among behavioral responses to various lighting conditions that produce changes in circadian waveform. Siberian hamsters, Phodopus sungorus, were transferred from long to short photoperiods to distinguish short photoperiod responders (SP-R) from nonresponders (SP-NR). Short photoperiod chronotyped hamsters were subsequently transferred, along with unselected controls, to 24-h light:dark:light: dark cycles (LDLD) with dim nighttime illumination, a procedure that induces bifurcated entrainment. Under LDLD, SP-R hamsters were more likely to bifurcate their rhythms than were SP-NR hamsters or unselected controls. After transfer from LDLD to constant dim light, SP-R hamsters were also more likely to become arrhythmic compared to SP-NR hamsters and unselected controls. In contrast, short photoperiod chronotype did not influence more transient changes in circadian waveform. The present data reveal a clear relationship in the plasticity of circadian waveform across 3 distinct lighting conditions, suggesting a common mechanism wherein individual differences reflect variation in circadian coupling.

Author List

Evans JA, Elliott JA, Gorman MR

Author

Jennifer A. Evans PhD Assistant Professor in the Biomedical Sciences department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Circadian Rhythm
Cricetinae
Female
Individuality
Lighting
Male
Motor Activity
Phodopus
Photic Stimulation
Photoperiod