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Interval Timer Control Of Puberty In Photoinhibited Siberian Hamsters, Ho Park Jin, Alexander S. Kauffman, Matthew J. Paul, Matthew P. Butler, Annaliese K. Beery, Ruth M. Costantini, Irving Zucker

Neuroscience: Faculty Publications

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 …