Document Detail


Increased late night response to light controls the circadian pacemaker in a nocturnal primate.
MedLine Citation:
PMID:  20484690     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mammalian endogenous circadian clock, the suprachiasmatic nuclei, receives environmental inputs, namely the light-dark cycle, through photopigments located in the eye and from melanopsin-expressing retinal ganglion cells. The authors investigated the influence of light wavelength and intensity on the synchronization of the rest-activity rhythm of the gray mouse lemur, a nocturnal Malagasy primate. Animals were tested at different irradiance levels (320, 45, 13, and 6 nmol x m(-2) x s(- 1)) under several light wavelengths (from 400 to 610 nm). Several parameters including circadian period, activity, and body temperature waveforms were used to assess synchronization to a 12:12 light-dark cycle in comparison to control treatments (12:12 white light or continuous darkness). Entrainment of the circadian rest-activity cycle increased with light intensity. It was more efficient for mid wavelengths relative to shorter or longer wavelengths but not coincident with melanopsin maximal sensitivity, suggesting other photoreceptors are likely involved in lemurs' photoentrainment. The authors obtained a novel synchronization pattern characterized by a clear synchronization to lights-on only without phasing to lights-off. Changes in photo-responsiveness at dusk and dawn highlight differential responses of evening and morning oscillators in the circadian clock.
Authors:
Martine Perret; Doris Gomez; Alexandra Barbosa; Fabienne Aujard; Marc Théry
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of biological rhythms     Volume:  25     ISSN:  1552-4531     ISO Abbreviation:  J. Biol. Rhythms     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-05-20     Completed Date:  2010-08-12     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8700115     Medline TA:  J Biol Rhythms     Country:  United States    
Other Details:
Languages:  eng     Pagination:  186-96     Citation Subset:  IM    
Affiliation:
UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Département d'Ecologie et Gestion de la Biodiversité, Brunoy, France. martine.perret@wanadoo.fr
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Activity Cycles / physiology,  radiation effects
Animals
Body Temperature
Cheirogaleidae
Circadian Rhythm / physiology*,  radiation effects*
Female
Light*
Male
Motor Activity / physiology,  radiation effects
Photic Stimulation
Photoperiod*
Photoreceptor Cells, Vertebrate / physiology
Rod Opsins
Chemical
Reg. No./Substance:
0/Rod Opsins; 0/melanopsin

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


Previous Document:  Photoperiod and reproductive condition are associated with changes in RFamide-related peptide (RFRP)...
Next Document:  Two components of nocturnal locomotor suppression by light.