Effects of Photoperiod on Novelty Preference in Preadolescent Siberian Hamster (Phodopus sungorus) Pups

Photoperiod (day length) has been shown to have significant effects on the physical and behavioral development of seasonally breeding mammals and to modulate the timing of their dispersal from the natal burrow or den. Behaviors associated with dispersal, such as novelty preference and exploratory behaviors, have been shown to be modulated by anti-Müllerian hormone (AMH) in mice. Whereas photoperiodic modulation of serum AMH concentrations in female Siberian hamsters (Phodopus sungorus) has been demonstrated, novelty preference and exploratory behaviors have not been previously investigated in this species. Through the manipulation of day length (DL) in Siberian hamsters, this study sought to determine if photoperiod-induced differences in serum AMH concentration correlate with behaviors that are associated with dispersal. Although AMH was significantly different in males and females, and day length had a significant effect on AMH in males, our evaluations of novelty preference and exploratory behaviors revealed no effects of sex or photoperiod when evaluated at 21 days of age. The information acquired from this study will contribute to the understanding and characterization of the associations among DL, AMH, and the behaviors associated with the dispersal of adolescent mammals. Utilizing this study’s results, future research is required to determine the age at which sex differences in novelty preference and exploratory behavior are first apparent in Siberian hamsters and to evaluate variations in AMH associated with age, sex, and photoperiod