Hegstrom C D, Breedlove S M
Department of Psychology, University of California, Berkeley 94720-1650, USA.
J Biol Rhythms. 1999 Feb;14(1):54-61. doi: 10.1177/074873099129000443.
Transfer of adult Siberian hamsters (Phodopus sungorus) from long (16 h light and 8 h dark, 16L:8D) to short (8L:16D) daily photoperiods induces an involution of the gonads and a cessation of reproductive behavior 8 to 10 weeks later. However, when male and female long-day hamsters were paired on transfer to short photoperiods, the males' gonads did not undergo the typical short-day response. Similarly, when male long-day hamsters were paired with refractory females (i.e., females housed in short photoperiods for at least 28 weeks so that they became unresponsive to short photoperiods), the response of the males' reproductive system to short photoperiods also was attenuated. Thus, social cues can override or delay the effects of photoperiod on the testes of this species. These results suggest that the inhibitory effects of long durations of melatonin secretion (in response to short photoperiods) on the male hypothalamic-pituitary-gonadal axis may be attenuated by social cues such as contact with the opposite sex.
将成年西伯利亚仓鼠（Phodopus sungorus）从每日长光照周期（16小时光照和8小时黑暗，16L:8D）转移到短光照周期（8L:16D），会导致性腺退化，并在8至10周后停止生殖行为。然而，当长光照周期的雄性和雌性仓鼠在转移到短光照周期时配对，雄性的性腺并未出现典型的短光照周期反应。同样，当长光照周期的雄性仓鼠与不应期雌性（即处于短光照周期至少28周以至于对短光照周期无反应的雌性）配对时，雄性生殖系统对短光照周期的反应也会减弱。因此，社会线索可以超越或延迟光照周期对该物种睾丸的影响。这些结果表明，长时间褪黑素分泌（对短光照周期的反应）对雄性下丘脑 - 垂体 - 性腺轴的抑制作用可能会被诸如与异性接触等社会线索所减弱。
