Journal
BRAIN RESEARCH
Volume 1205, Issue -, Pages 47-54Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.brainres.2008.02.026
Keywords
orexin; transgenic mice; food anticipatory rhythms; core body temperature; activity; restricted feeding
Categories
Funding
- NINDS NIH HHS [R01 NS030140, NS052287, NS030140, R01 NS030140-15, R01 NS052287-03, R01 NS052287] Funding Source: Medline
Ask authors/readers for more resources
Ablation of the SCN, an established circadian clock, does not abolish food entrainment, suggesting that the food-entrainable oscillator (FEO) must lie outside the SCN. Typically, animals show anticipatory locomotor activity and rise in core body temperature under the influence of the FEO. Signals from the FEO would, therefore, converge onto arousal neurons so that the animal might forage for food. In the present study, we investigate whether the neuropeptide orexin, which has been linked to arousal, might transduce the arousal signal. Orexin-knockout (orexin-KO) and wildtype (WT) mice (both C57BL/6J derived) were implanted with MiniMitter transmitters that recorded core body temperature and activity (12 h LD cycle). After a week of ad-libitum feeding, the mice were given access to food for 4 h (ZT 4-8) for nine days followed by 2-days of fasting. When orexin-KO mice were placed in a restricted feeding schedule, both core body temperature and activity entrained to the feeding schedule. In these mice gross locomotor activity was severely blunted during the nine day period of restricted feeding (-79.4 +/- 6.3%) from the WT, but they showed an increase in core body temperature in anticipation to the meal time similar to the WT mice. There was no difference in the amount of food intake between the genotypes. We conclude that orexin is not required for entrainment of activity and temperature to a restricted feeding schedule, but is required for the robust expression of gross locomotor activity in anticipation of the scheduled feeding. Published by Elsevier B.V.
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