Journal
JOURNAL OF BIOLOGICAL RHYTHMS
Volume 26, Issue 1, Pages 78-81Publisher
SAGE PUBLICATIONS INC
DOI: 10.1177/0748730410388404
Keywords
suprachiasmatic nucleus; desynchrony; singularity; amplitude suppression; Siberian hamster
Categories
Funding
- NINDS NIH HHS [NS 34950] Funding Source: Medline
Ask authors/readers for more resources
Light can induce arrhythmia in circadian systems by several weeks of constant light or by a brief light stimulus given at the transition point of the phase response curve. In the present study, a novel light treatment consisting of phase advance and phase delay photic stimuli given on 2 successive nights was used to induce circadian arrhythmia in the Siberian hamster (Phodopus sungorus). We therefore investigated whether loss of rhythms in behavior was due to arrhythmia within the suprachiasmatic nucleus (SCN). SCN tissue samples were obtained at 6 time points across 24 h in constant darkness from entrained and arrhythmic hamsters, and per1, per2, bmal1, and cry1 mRNA were measured by quantitative RT-PCR. The light treatment eliminated circadian expression of clock genes within the SCN, and the overall expression of these genes was reduced by 18% to 40% of entrained values. Arrhythmia in per1, per2, and bmal1 was due to reductions in the amplitudes of their oscillations. We suggest that these data are compatible with an amplitude suppression model in which light induces singularity in the molecular circadian pacemaker.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available