AJP - Regu Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 286: R539-R546, 2004. First published November 26, 2003; doi:10.1152/ajpregu.00456.2003
0363-6119/04 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
286/3/R539    most recent
00456.2003v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (4)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Evans, J. A.
Right arrow Articles by Gorman, M. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Evans, J. A.
Right arrow Articles by Gorman, M. R.

COMPLEX FUNCTION OF THE CENTRAL NERVOUS SYSTEM, SLEEP AND LOCOMOTION

Photoperiod differentially modulates photic and nonphotic phase response curves of hamsters

J. A. Evans,1 J. A. Elliott,2 and M. R. Gorman1

Departments of 1Psychology and 2Psychiatry, University of California, San Diego, La Jolla, California 92093

Submitted 12 August 2003 ; accepted in final form 21 November 2003

Circadian pacemakers respond to light pulses with phase adjustments that allow for daily synchronization to 24-h light-dark cycles. In Syrian hamsters, Mesocricetus auratus, light-induced phase shifts are larger after entrainment to short daylengths (e.g., 10 h light:14 h dark) vs. long daylengths (e.g., 14 h light:10 h dark). The present study assessed whether photoperiodic modulation of phase resetting magnitude extends to nonphotic perturbations of the circadian rhythm and, if so, whether the relationship parallels that of photic responses. Male Syrian hamsters, entrained for 31 days to either short or long daylengths, were transferred to novel wheel running cages for 2 h at times spanning the entire circadian cycle. Phase shifts induced by this stimulus varied with the circadian time of exposure, but the amplitude of the resulting phase response curve was not markedly influenced by photoperiod. Previously reported photoperiodic effects on photic phase resetting were verified under the current paradigm using 15-min light pulses. Photoperiodic modulation of phase resetting magnitude is input specific and may reflect alterations in the transmission of photic stimuli.

circadian rhythm; novel wheel running; free running period; tau response curve; pacemaker amplitude


Address for reprint requests and other correspondence: J. A. Evans, Dept. of Psychology, 9500 Gilman Dr., La Jolla, CA 92093 (E-mail: jaevans{at}ucsd.edu).




This article has been cited by other articles:


Home page
 Poult. Sci.Home page
J. B. Zawilska, A. Lorenc, M. Berezinska, B. Vivien-Roels, P. Pevet, and D. J. Skene
Photoperiod-Dependent Changes in Melatonin Synthesis in the Turkey Pineal Gland and Retina
Poult. Sci., July 1, 2007; 86(7): 1397 - 1405.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2004 by the American Physiological Society.