Document Detail

Persistence of a behavioral food-anticipatory circadian rhythm following dorsomedial hypothalamic ablation in rats.
MedLine Citation:
PMID:  16424080     Owner:  NLM     Status:  MEDLINE    
Circadian rhythms of behavior in rodents are regulated by a system of circadian oscillators, including a master light-entrainable pacemaker in the suprachiasmatic nucleus that mediates synchrony to the day-night cycle, and food-entrainable oscillators located elsewhere that generate rhythms of food-anticipatory activity (FAA) synchronized to daily feeding schedules. Despite progress in elucidating neural and molecular mechanisms of circadian oscillators, localization of food-entrainable oscillators driving FAA remains an enduring problem. Recent evidence suggests that the dorsomedial hypothalamic nucleus (DMH) may function as a final common output for behavioral rhythms and may be critical for the expression of FAA (Gooley JJ, Schomer A, and Saper CB. Nat Neurosci 9: 398-407, 2006). To determine whether the reported loss of FAA by DMH lesions is specific to one behavioral measure or generalizes to other measures, rats received large radiofrequency lesions aimed at the DMH and were recorded in cages with movement sensors. Total and partial DMH ablation was associated with a significant attenuation of light-dark-entrained activity rhythms during ad libitum food access, because of a selective reduction in nocturnal activity. When food was restricted to a single 3-h daily meal in the middle of the lights-on period, all DMH and intact rats exhibited significant FAA. The rhythm of FAA persisted during a 48-h food deprivation test and reappeared during a 72-h deprivation test after ad libitum food access. The DMH is not the site of oscillators or entrainment pathways necessary for all manifestations of FAA, but may participate on the output side of this circadian function.
G J Landry; M M Simon; I C Webb; R E Mistlberger
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-01-19
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  290     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2006 Jun 
Date Detail:
Created Date:  2006-05-09     Completed Date:  2006-07-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R1527-34     Citation Subset:  IM    
Department of Psychology, Simon Fraser University, 8888 Univ. Drive, Burnaby, BC, Canada, V5A 1S6.
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MeSH Terms
Appetite Regulation / physiology*
Behavior, Animal / physiology*
Catheter Ablation
Circadian Rhythm / physiology*
Dorsomedial Hypothalamic Nucleus / physiopathology*,  surgery
Eating / physiology,  radiation effects
Food Deprivation / physiology
Hypothalamus / pathology,  physiopathology
Rats, Sprague-Dawley
Comment In:
Am J Physiol Regul Integr Comp Physiol. 2006 Jun;290(6):R1524-6   [PMID:  16455773 ]

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

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