Document Detail

Photoperiodic regulation of the orexigenic effects of ghrelin in Siberian hamsters.
MedLine Citation:
PMID:  20600050     Owner:  NLM     Status:  MEDLINE    
Animals living in temperate climates with predictable seasonal changes in food availability may use seasonal information to engage different metabolic strategies. Siberian hamsters decrease costs of thermoregulation during winter by reducing food intake and body mass in response to decreasing or short-day lengths (SD). These experiments examined whether SD reduction in food intake in hamsters is driven, at least in part, by altered behavioral responses to ghrelin, a gut-derived orexigenic peptide which induces food intake via NPY-dependent mechanisms. Relative to hamsters housed in long-day (LD) photoperiods, SD hamsters consumed less food in response to i.p. treatment with ghrelin across a range of doses from 0.03 to 3 mg/kg. To determine whether changes in photoperiod alter behavioral responses to ghrelin-induced activation of NPY neurons, c-Fos and NPY expression were quantified in the arcuate nucleus (ARC) via double-label fluorescent immunocytochemistry following i.p. treatment with 0.3 mg/kg ghrelin or saline. Ghrelin induced c-Fos immunoreactivity (-ir) in a greater proportion of NPY-ir neurons of LD relative to SD hamsters. In addition, following ghrelin treatment, a greater proportion of ARC c-Fos-ir neurons were identifiable as NPY-ir in LD relative to SD hamsters. Changes in day length markedly alter the behavioral response to ghrelin. The data also identify photoperiod-induced changes in the ability of ghrelin to activate ARC NPY neurons as a possible mechanism by which changes in day length alter food intake.
Sean P Bradley; Lucia M Pattullo; Priyesh N Patel; Brian J Prendergast
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-06-22
Journal Detail:
Title:  Hormones and behavior     Volume:  58     ISSN:  1095-6867     ISO Abbreviation:  Horm Behav     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-09-06     Completed Date:  2011-01-24     Revised Date:  2014-09-10    
Medline Journal Info:
Nlm Unique ID:  0217764     Medline TA:  Horm Behav     Country:  United States    
Other Details:
Languages:  eng     Pagination:  647-52     Citation Subset:  IM    
Copyright Information:
Copyright (c) 2010 Elsevier Inc. All rights reserved.
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MeSH Terms
Arcuate Nucleus / drug effects,  metabolism
Behavior, Animal / drug effects,  physiology
Body Weight / drug effects
Circadian Rhythm
Eating / drug effects*,  physiology
Feeding Behavior / drug effects,  physiology
Ghrelin / pharmacology*
Intracellular Signaling Peptides and Proteins / pharmacology
Neuropeptide Y / metabolism
Neuropeptides / pharmacology
Phodopus / metabolism,  physiology*
Proto-Oncogene Proteins c-fos / metabolism
Grant Support
Reg. No./Substance:
0/Ghrelin; 0/Intracellular Signaling Peptides and Proteins; 0/Neuropeptide Y; 0/Neuropeptides; 0/Proto-Oncogene Proteins c-fos; 0/orexins

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