Photoperiodic modulation of GnRH mRNA in the male Syrian hamster

Donald I. Brown, Vasilios T. Garyfallou, Henryk Urbanski

    Research output: Contribution to journalArticle

    21 Scopus citations


    Male Syrian hamsters (Mesocricetus auratus) are seasonal breeders. They show marked testicular regression when exposed to short autumnal photoperiods, and then remain sexually quiescent for several months. By mid-winter, however, they show a loss in responsiveness to the inhibitory influence of short photoperiods and their testes begin to recrudesce. To shed light on the neuroendocrine mechanism responsible for mediating these reproductive changes, we examined the influence of photoperiod on the expression of GnRH mRNA in the hamster forebrain. Adult males were either exposed to short photoperiods (6L:18D) for 16 weeks or were maintained under long photoperiods (14L:10D); additional animals were exposed to short or long photoperiods for 22 weeks. As expected, exposure to short photoperiods for 12 weeks resulted in a marked decrease (P0.05) between the GnRH mRNA levels of the short-photoperiod hamsters and their aged-matched long-photoperiod controls, although an age-related decrease (P

    Original languageEnglish (US)
    Pages (from-to)119-125
    Number of pages7
    JournalMolecular Brain Research
    Issue number1-2
    Publication statusPublished - Apr 18 2001



    • Aging
    • Photoperiodism
    • Seasonality
    • Testes
    • Testosterone

    ASJC Scopus subject areas

    • Molecular Biology
    • Cellular and Molecular Neuroscience

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