This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Park, J. H. Articles by Zucker, I. Search for Related Content PubMed PubMed Citation Articles by Park, J. H. Articles by Zucker, I. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Social Bookmarking                         What's this?

Interval Timer Control of Puberty in Photoinhibited Siberian Hamsters

Departments of Psychology, University of California, Berkeley; Department of Biochemistry & Molecular Genetics, School of Medicine, University of Virginia, 1300 Jefferson Park Avenue, Charlottesville VA 22908 jinhopark{at}virginia.edu

Alexander S. Kauffman

Department of Physiology and Biophysics, University of Washington, Seattle

Matthew J. Paul

Departments of Psychology, University of California, Berkeley

Matthew P. Butler

Departments of Integrative Biology, University of California, Berkeley

Annaliese K. Beery

Departments of Helen Wills Neuroscience Institute, University of California, Berkeley

Ruth M. Costantini

Departments of Integrative Biology, University of California, Berkeley

Irving Zucker

Departments of Psychology, University of California, Berkeley; Departments of Integrative Biology, University of California, Berkeley; Departments of Helen Wills Neuroscience Institute, University of California, Berkeley

Puberty, which is markedly delayed in male Siberian hamsters (Phodopus sungorus) born into short day lengths, is controlled by an interval timer regulated by the duration of nocturnal melatonin secretion. Properties of the interval timer were assessed by perturbing normal patterns of melatonin secretion in males gestated and maintained thereafter in 1 of 2 short day lengths, 10 h light/day (10L) or 12L. Melatonin secretion of short-day hamsters was suppressed by constant light treatment or modified by daily injection of propranolol to mimic nocturnal melatonin durations typical of long-day hamsters. Constant light treatment during weeks 3 to 5 induced early incomplete gonadal growth in 12L but not 10L hamsters but did not affect late onset of gonadal development indicative of puberty in either photoperiod. Propranolol treatment during postnatal weeks 3 to 5 induced transient growth of the testes and ultimately delayed the timing of puberty by 3 weeks. Similar treatments between weeks 5 and 7 or on alternate weeks for 24 weeks did not affect the interval timer. The first 2 weeks after weaning may constitute a critical period during which the interval timer is highly responsive to photoperiod. Alternatively, the hamsters' photoperiodic history rather than age or developmental stage may be the critical variable. The interpolation of long-day melatonin signals at the time of weaning does not appear to reset the interval timer to its zero position but may reduce timer responsiveness to long-day melatonin signals several weeks later.

Key Words: puberty • melatonin • hamster • photoperiodism • development • testes

Journal of Biological Rhythms, Vol. 21, No. 5, 373-383 (2006)
DOI: 10.1177/0748730406292315


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. K. Beery, M. J. Paul, D. M. Routman, and I. Zucker Maternal Photoperiodic History Affects Offspring Development in Syrian Hamsters J Biol Rhythms, October 1, 2008; 23(5): 445 - 455. [Abstract] [PDF]

				M. P. Butler, K. W. Turner, and I. Zucker A Melatonin-Independent Seasonal Timer Induces Neuroendocrine Refractoriness to Short Day Lengths J Biol Rhythms, June 1, 2008; 23(3): 242 - 251. [Abstract] [PDF]

				M. P. Butler, K. W. Turner, J. H. Park, J. P. Butler, J. J. Trumbull, S. P. Dunn, P. Villa, and I. Zucker Simulated natural day lengths synchronize seasonal rhythms of asynchronously born male Siberian hamsters Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R402 - R412. [Abstract] [Full Text] [PDF]

				M. P. Butler, J. J. Trumbull, K. W. Turner, and I. Zucker Timing of puberty and synchronization of seasonal rhythms by simulated natural photoperiods in female Siberian hamsters Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R413 - R420. [Abstract] [Full Text] [PDF]

				D. A. Freeman, B. J. W. Teubner, C. D. Smith, and B. J. Prendergast Exogenous T3 mimics long day lengths in Siberian hamsters Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2368 - R2372. [Abstract] [Full Text] [PDF]