|
Sign In to gain access to subscriptions and/or personal tools.
|
Photoperiodism in Hamsters: Abrupt Versus Gradual Changes in Day Length Differentially Entrain Morning and Evening Circadian Oscillators
Michael R. Gorman
Department of Psychology, University of California, Berkeley, CA 94720, Department of Psychology, University of Michigan, Ann Arbor, MI 48109
David A. Freeman
Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269
Irving Zucker
Department of Psychology and Intégrative Biology
In studies of photoperiodism, animals typically are transferred abruptly from a long (e.g., 16 h light per day [16L]) to a short (8L) photoperiod, and circadian oscillators that regulate pineal melatonin secretion are presumed to reentrain rapidly to the new photocycle. Among rats and Siberian hamsters, however, reentrainment rates vary depending on whether additional darkness is added to morning or evening, and a subset of hamsters (nonresponders) fails ever to reentrain normally to short photoperiods. The authors assessed whether several short-day responses occurred at different rates when darkness was extended into morning versus evening hours and the effectiveness of abrupt versus gradual shortening in day lengths (DLs). Entrainment patterns of photoresponsive hamsters also were compared to those of photononresponsive hamsters. Responsive hamsters transferred on a single day from 16L to 8L underwent more rapid gonadal regression, weight loss, decreases in follicle-stimulating hormone titers, and expansion of nocturnal locomotor activity when darkness was added to morning versus evening. When the dark phase was extended gradually by 8 h over 16 weeks, short-day responses occurred at the same rate whether darkness was appended to morning or evening or was added symmetrically. Darkness added to evening promoted more rapid short-day responses when it was added gradually rather than abruptly, despite the fact that average DLs were significantly shorter for the latter group. Among nonresponders, morning extensions of darkness transiently increased activity duration, whereas evening extensions did not. Gradual and abrupt decreases in DL differentially affect entrainment of evening and morning circadian oscillators. The authors argue for the incorporation of simulated natural photoperiods in studies of photoperiodism.
Key Words: testes • circadian rhythms • follicle-stimulating hormone • body weight • melatonin • seasonality
Journal of Biological Rhythms, Vol. 12, No. 2,
122-135 (1997)
DOI: 10.1177/074873049701200204
 CiteULike  Complore  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter What's this?
This article has been cited by other articles:
|
|
|
|
 
B. J. Prendergast and L. M. Pyter
Photoperiod History Differentially Impacts Reproduction and Immune Function in Adult Siberian Hamsters
J Biol Rhythms,
December 1, 2009;
24(6):
509 - 522.
[Abstract]
[PDF]
|
|
|
|
|
|
|
M. P. Butler and R. Silver
Basis of Robustness and Resilience in the Suprachiasmatic Nucleus: Individual Neurons Form Nodes in Circuits that Cycle Daily
J Biol Rhythms,
October 1, 2009;
24(5):
340 - 352.
[Abstract]
[PDF]
|
|
|
|
|
|
|
I. N. Karatsoreos, A. Wang, J. Sasanian, and R. Silver
A Role for Androgens in Regulating Circadian Behavior and the Suprachiasmatic Nucleus
Endocrinology,
November 1, 2007;
148(11):
5487 - 5495.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. H. Park, A. S. Kauffman, M. J. Paul, M. P. Butler, A. K. Beery, R. M. Costantini, and I. Zucker
Interval Timer Control of Puberty in Photoinhibited Siberian Hamsters
J Biol Rhythms,
October 1, 2006;
21(5):
373 - 383.
[Abstract]
[PDF]
|
|
|
|
|
|
|
S. Monecke, A. Malan, and F. Wollnik
Asymmetric Control of Short Day Response in European Hamsters
J Biol Rhythms,
August 1, 2006;
21(4):
290 - 300.
[Abstract]
[PDF]
|
|
|
|
|
|
|
D. A. Freeman, B. J. W. Teubner, and B. D. Goldman
The Thalamic Intergeniculate Leaflet Mediates Locomotor Activity-Induced Reversal of Phenotype in Photoperiod Nonresponsive Siberian Hamsters
J Biol Rhythms,
June 1, 2006;
21(3):
206 - 213.
[Abstract]
[PDF]
|
|
|
|
|
|
|
J. J. Chiesa, M. Angles-Pujolras, A. Diez-Noguera, and T. Cambras
History-Dependent Changes in Entrainment of the Activity Rhythm in the Syrian Hamster (Mesocricetus auratus)
J Biol Rhythms,
February 1, 2006;
21(1):
45 - 57.
[Abstract]
[PDF]
|
|
|
|
|
|
|
H. R. Spieth, F. Xue, and K. Strau
Induction and Inhibition of Diapause by the Same Photoperiod: Experimental Evidence for a "Double Circadian Oscillator Clock"
J Biol Rhythms,
December 1, 2004;
19(6):
483 - 492.
[Abstract]
[PDF]
|
|
|
|
|
|
|
N. F. Ruby, M. T. Barakat, and H. C. Heller
Phenotypic Differences in Reentrainment Behavior and Sensitivity to Nighttime Light Pulses in Siberian Hamsters
J Biol Rhythms,
December 1, 2004;
19(6):
530 - 541.
[Abstract]
[PDF]
|
|
|
|
|
|
|
N. J. Place, C. R. Tuthill, E. E. Schoomer, A. D. Tramontin, and I. Zucker
Short Day Lengths Delay Reproductive Aging
Biol Reprod,
September 1, 2004;
71(3):
987 - 992.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. E. Larkin, T. Yokogawa, H. C. Heller, P. Franken, and N. F. Ruby
Homeostatic regulation of sleep in arrhythmic Siberian hamsters
Am J Physiol Regulatory Integrative Comp Physiol,
July 1, 2004;
287(1):
R104 - R111.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. F. Ruby
Hibernation: When Good Clocks Go Cold
J Biol Rhythms,
August 1, 2003;
18(4):
275 - 286.
[Abstract]
[PDF]
|
|
|
|
|
|
|
N. F. Ruby, N. Joshi, and H. C. Heller
Constant darkness restores entrainment to phase-delayed Siberian hamsters
Am J Physiol Regulatory Integrative Comp Physiol,
December 1, 2002;
283(6):
R1314 - R1320.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. R. Gorman and T. M. Lee
Daily Novel Wheel Running Reorganizes and Splits Hamster Circadian Activity Rhythms
J Biol Rhythms,
December 1, 2001;
16(6):
541 - 551.
[Abstract]
[PDF]
|
|
|
|
|
|
|
M. R. Gorman, S. M. Yellon, and T. M. Lee
Temporal Reorganization of the Suprachiasmatic Nuclei in Hamsters with Split Circadian Rhythms
J Biol Rhythms,
December 1, 2001;
16(6):
552 - 563.
[Abstract]
[PDF]
|
|
|
|
|
|
|
M. R. Gorman
A plastic interval timer synchronizes pubertal development of summer- and fall-born hamsters
Am J Physiol Regulatory Integrative Comp Physiol,
November 1, 2001;
281(5):
R1613 - R1623.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. E. Larkin, D. A. Freeman, and I. Zucker
Low Ambient Temperature Accelerates Short-Day Responses in Siberian Hamsters by Altering Responsiveness to Melatonin
J Biol Rhythms,
February 1, 2001;
16(1):
76 - 86.
[Abstract]
[PDF]
|
|
|
|
|
|
|
M. Jác, A. Sumova, and H. Illnerova
c-Fos rhythm in subdivisions of the rat suprachiasmatic nucleus under artificial and natural photoperiods
Am J Physiol Regulatory Integrative Comp Physiol,
December 1, 2000;
279(6):
R2270 - R2276.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B.-L. Zhang, E. Zannou, and F. Sannajust
Effects of photoperiod reduction on rat circadian rhythms of BP, heart rate, and locomotor activity
Am J Physiol Regulatory Integrative Comp Physiol,
July 1, 2000;
279(1):
R169 - R178.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. J. Prendergast and D. A. Freeman
Pineal-Independent Regulation of Photo-Nonresponsiveness in the Siberian Hamster (Phodopus sungorus)
J Biol Rhythms,
February 1, 1999;
14(1):
62 - 71.
[Abstract]
[PDF]
|
|
|
|
|
|
|
B. J. Prendergast, I. Zucker, S. M. Yellon, D. A. Ringold, and M. R. Gorman
Melatonin Chimeras Alter Reproductive Development and Photorefractoriness in Siberian Hamsters
J Biol Rhythms,
December 1, 1998;
13(6):
518 - 531.
[Abstract]
[PDF]
|
|
|
|
|
|
|
T. A. Wehr
Melatonin and Seasonal Rhythms
J Biol Rhythms,
December 1, 1997;
12(6):
518 - 527.
[Abstract]
[PDF]
|
|
|
|
|
