Interval Timer Control of Puberty in Photoinhibited Siberian Hamsters

Authors

Ho Park Jin, University of California, Berkeley
Alexander S. Kauffman, University of Washington
Matthew J. Paul, University of California, Berkeley
Matthew P. Butler, University of California, Berkeley
Annaliese K. Beery, University of California, BerkeleyFollow
Ruth M. Costantini, University of California, Berkeley
Irving Zucker, University of California, Berkeley

Document Type

Article

Publication Date

10-1-2006

Publication Title

Journal of Biological Rhythms

Abstract

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.

Keywords

Development, Hamster, Melatonin, Photoperiodism, Puberty, Testes

Volume

21

Issue

5

First Page

373

Last Page

383

DOI

10.1177/0748730406292315

ISSN

07487304

Rights

© 2006 Sage Publications

Comments

Archived as published. Open access article.

Recommended Citation

Jin, Ho Park; Kauffman, Alexander S.; Paul, Matthew J.; Butler, Matthew P.; Beery, Annaliese K.; Costantini, Ruth M.; and Zucker, Irving, "Interval Timer Control of Puberty in Photoinhibited Siberian Hamsters" (2006). Neuroscience: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/nsc_facpubs/30