Enduring effects of photoperiod on affective behaviors in Siberian hamsters (Phodopus sungorus)

Behav Neurosci. 2006 Feb;120(1):125-34. doi: 10.1037/0735-7044.120.1.125.


The effects of perinatal and postweaning photoperiods on subsequent affective behaviors were examined in adult Siberian hamsters (Phodopus sungorus). Hamsters exposed perinatally to short days (8 hr light/day) exhibited mixed results for adult anxiety-like behaviors and increased some depressive-like behaviors compared with hamsters exposed to long days (16 hr light/day). Postweaning exposure to short days increased depressive- and anxiety-like behaviors compared with long days. Sex differences in affective behaviors were observed. These results suggest that anxiety-like behaviors are organized early in life and endure throughout adulthood, and anxiety- and depressive-like behaviors are modified by postweaning photoperiod. The persistence of photoperiod-induced affective behaviors in rodents supports the hypothesis that symptoms of human affective disorders may reflect ancestral adaptations to seasonal environments.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Affect*
  • Animals
  • Anxiety / psychology
  • Behavior, Animal / physiology*
  • Body Mass Index
  • Cricetinae
  • Depression / psychology
  • Female
  • Male
  • Maze Learning
  • Phenotype
  • Phodopus
  • Photoperiod*
  • Seasons
  • Time Factors