The effect of prenatal stress on adult sexual behavior in rats depends on the nature of the stressor.

It is well known that prenatal stress induces behavioral demasculinization and/or feminization in male offspring during adulthood. In this study, four different stressors were prenatally applied to rats. Pregnant rats were subjected to immobilization, unavoidable electric foot shocks, rapid eye movement sleep deprivation (REMd), or immersion in cold water. During adulthood, male offspring were tested for masculine and feminine sexual behavior. The results corroborated the fact that immobilization induced an impairment of masculine sexual behavior and a facilitation of feminine sexual behavior. Electric shocks showed only minor differences in masculine behavior when compared to intact controls, and no signs of lordosis behavior were observed. The REMd group displayed a major impairment of masculine behavior, even greater than that observed within the immobilization group. However, lordosis behavior was only induced with estradiol. On the other hand, water immersion seems to have a facilitatory effect on several parameters of masculine behavior and did not show lordosis behavior even with hormonal treatment. These results strongly suggest that changes in sex behavior induced by prenatal stress are linked to the nature of the stressor.