Document Detail


Time's arrow flies like a bird: two paradoxes for avian circadian biology.
MedLine Citation:
PMID:  19523398     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Biological timekeeping in birds is a fundamental feature of avian physiology, behavior and ecology. The physiological basis for avian circadian rhythmicity has pointed to a multi-oscillator system of mutually coupled pacemakers in the pineal gland, eyes and hypothalamic suprachiasmatic nuclei (SCN). In passerines, the role of the pineal gland and its hormone melatonin is particularly important. More recent molecular biological studies have pointed to a highly conserved mechanism involving rhythmic transcription and translation of "clock genes". However, studies attempting to reconcile the physiological role of pineal melatonin with molecular studies have largely failed. Recent work in our laboratory has suggested that melatonin-sensitive physiological processes are only loosely coupled to transcriptional oscillations. Similarly, although the pineal gland has been shown to be critical for overt circadian behaviors, its role in annual cycles of reproductive function appears to be minimal. Recent work on the seasonal control of birdsong, however, suggests that, although the pineal gland does not directly affect gonadal cycles, it is important for seasonal changes in song. Experimental analyses that address these paradoxes will shed light on the roles the biological clock play in birds and in vertebrates in general.
Authors:
Vincent M Cassone; Jiffin K Paulose; Melissa G Whitfield-Rucker; Jennifer L Peters
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.; Review     Date:  2009-01-23
Journal Detail:
Title:  General and comparative endocrinology     Volume:  163     ISSN:  1095-6840     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  2009 Sep 
Date Detail:
Created Date:  2009-07-14     Completed Date:  2009-09-29     Revised Date:  2010-09-07    
Medline Journal Info:
Nlm Unique ID:  0370735     Medline TA:  Gen Comp Endocrinol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  109-16     Citation Subset:  IM    
Affiliation:
Department of Biology, Thomas Hunt Morgan Building, University of Kentucky, 675 Rose Street, Lexington, KY 40506, USA. Vincent.Cassone@uky.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Biological Clocks / genetics,  physiology*
Birds / physiology*
Circadian Rhythm / genetics,  physiology*
Melatonin / metabolism,  physiology
Photoperiod
Vocalization, Animal / physiology
Grant Support
ID/Acronym/Agency:
P01 NS039546-05/NS/NINDS NIH HHS; P01 NS039546-06A10008/NS/NINDS NIH HHS; P01 NS039546-070008/NS/NINDS NIH HHS; P01 NS039546-080008/NS/NINDS NIH HHS; P01 NS39546/NS/NINDS NIH HHS
Chemical
Reg. No./Substance:
73-31-4/Melatonin

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