Effect of environmental lighting on sexual behavior and testosterone levels of female rats.

The effects of exposure to two different lighting regimes, constant light (LL) and cyclic light (LD) on the sexual performance and serum testosterone concentrations of intact, virgin, female rats was investigated. During copulatory pairing there were significant changes in the sexual performance of both LL and LD rats. Sexual receptivity in the LL females increased as a result of copulatory stimulation, whereas the sexual performance of LD females declined. Throughout copulatory testing the level of sexual receptivity displayed by the LL females was significantly less than that of the LD females. Testosterone levels in acyclic virgin LL rats were significantly lower than the levels in cycling, virgin, LD rats. The implications of these findings were discussed.