The effects of prenatal stress and postweaning housing conditions on parental and sexual behavior of male Long-Evans rats

Abstract

Male offspring of stressed and control female rats were housed in pairs with a control male or a female from 22 to 90 days of age, then they were screened for infanticide and tested for parental behavior and sexual behavior. Male rats housed with females were less likely to be infanticidal than males housed with other males, but prenatal stress had no effect on infanticide rate. Control males housed with males showed a longer latency to carry pups than did males in the other three groups, and there was a stress × days interaction in the frequency of parental behavior, with prenatally stressed males showing more parental behavior than control males after 4 days of pup exposure. In the male sexual behavior tests, prenatally stressed males had longer intromission latencies and shorter postejaculatory intervals than did control males, while males housed with females had fewer mounts without intromissions and shorter ejaculation latencies than did males housed with other males. Female sexual behavior was not influenced by stress or housing, but control males showed more aggression toward stud males than did stressed males. Stressed male rats had smaller testes than did control males. Correlations among these measures indicate that prenatal stress results in a general syndrome of behavioral change.