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Food-anticipatory activity and liver per1-luc activity in diabetic transgenic ratsThe mammalian Per1 gene is an important component of the core cellular clock mechanism responsible for circadian rhythms. The rodent liver and other tissues rhythmically express Per1 in vitro but typically damp out within a few cycles. In the liver, the peak of this rhythm occurs in the late subjective night in an ad lib-fed rat, but will show a large phase advance in response to restricted availability of food during the day. The relationship between this shift in the liver clock and food-anticipatory activity (FAA), the circadian behavior entrained by daily feeding, is currently unknown. Insulin is released during feeding in mammals and could serve as an entraining signal to the liver. To test the role of insulin in the shift in liver Per1 expression and the generation of FAA, per-luciferase transgenic rats were made diabetic with a single injection of streptozotocine. Following 1 week of restricted feeding and locomotor activity monitoring, liver was collected for per-luc recording. In two separate experiments, FAA emerged and liver Per1 phase-shifted in response to daytime 8-h food restriction. The results rule out insulin as a necessary component of this system.
Document ID
20040088181
Document Type
Reprint (Version printed in journal)
Authors
Davidson, Alec J. (University of Virginia Charlottesville, VA 22904, United States)
Stokkan, Karl-Arne
Yamazaki, Shin
Menaker, Michael
Date Acquired
August 21, 2013
Publication Date
May 1, 2002
Publication Information
Publication: Physiology & behavior
Volume: 76
Issue: 1
ISSN: 0031-9384
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: T32 DK 07646-10
CONTRACT_GRANT: MH 56647
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Space Human Factors
Non-NASA Center