Document Detail


Food-entrained feeding and locomotor circadian rhythms in rats under different lighting conditions.
MedLine Citation:
PMID:  10373098     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
It has been suggested that two endogenous timekeeping systems, a light-entrainable pacemaker (LEP) and a food-entrainable pacemaker (FEP), control circadian rhythms. To understand the function and interaction between these two mechanisms better, we studied two behavioral circadian rhythmicities, feeding and locomotor activity, in rats exposed to two conflicting zeitgebers, food restriction and light-dark cycles. For this, the food approaches and wheel-running activity of rats kept under light-dark (LD) 12:12, constant darkness (DD), or constant light (LL) conditions and subjected to different scheduled feeding patterns were continuously recorded. To facilitate comparison of the results obtained under the different lighting conditions, the period of the feeding cycles was set in all three cases about 1h less than the light-entrained or free-running circadian rhythms. The results showed that, depending on the lighting conditions, some components of the feeding and wheel-running circadian rhythms could be entrained by food pulses, while others retained their free-running or light-entrained state. Under LD, food pulses had little influence on the light-entrained feeding and locomotor rhythms. Under DD, relative coordination between free-running and food-associated rhythms may appear. In both cases, the feeding activity associated with the food pulses could be divided into a prominent phase-dependent peak of activity within the period of food availability and another afterward. Wheel-running activity mainly followed the food pulses. Under LL conditions, the food-entrained activity consisted mainly of feeding and wheel-running anticipatory activity. The results provide new evidence that lighting conditions influence the establishment and persistence of food-entrained circadian rhythms in rats. The existence of two coupled pacemakers, LEP and FEP, or a multioscillatory LEP may both explain our experimental results.
Authors:
P Lax; S Zamora; J A Madrid
Related Documents :
17750808 - Predaceous feeding in two common gooseneck barnacles.
11033168 - Food choice causes interrupted feeding in the generalist grasshopper schistocerca ameri...
19096078 - Characterization of energetic efficiency in adult broiler breeder hens.
9158888 - Feeding and pecking behaviour in ostrich (struthio camelus) chicks in captivity.
22032748 - Polycyclic aromatic hydrocarbon residues in human milk, placenta and umbilical cord blo...
12475458 - Absence of postprandial surge in coronary blood flow distal to significant stenosis: a ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chronobiology international     Volume:  16     ISSN:  0742-0528     ISO Abbreviation:  Chronobiol. Int.     Publication Date:  1999 May 
Date Detail:
Created Date:  1999-07-23     Completed Date:  1999-07-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8501362     Medline TA:  Chronobiol Int     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  281-91     Citation Subset:  IM    
Affiliation:
Department of Physiology and Pharmacology, Faculty of Biology, University of Murcia, Spain. pelax@fcu.um.es
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Biological Clocks / drug effects,  physiology*
Circadian Rhythm / physiology*
Darkness
Eating
Feeding Behavior / physiology*,  radiation effects
Light
Lighting*
Male
Motor Activity / physiology*,  radiation effects
Rats
Rats, Sprague-Dawley

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Provisional QTL for circadian period of wheel running in laboratory mice: quantitative genetics of p...
Next Document:  Development of inverse circadian blood pressure pattern in transgenic hypertensive TGR(mREN2)27 rats...