Maternal exposure to the antidepressant fluoxetine impairs sexual motivation in adult male mice

Depressive disorders have a worldwide high prevalence. Fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI) antidepressant, has been widely prescribed for depression during pregnancy and/or lactation. Since serotonin is a neurotrophic factor, the use of FLX by mothers could disrupt brain development resulting in behavioral alterations in their progeny. The aim of the present study was to evaluate the effects of developmental FLX exposure on sexual behavior, as well as on endocrine parameters, of male mice. Swiss dams were treated daily, by gavage, with 7.5 mg/kg of FLX during pregnancy and lactation. Male pups were tested for copulatory behavior and sexual incentive motivation. Male pups also had their anogenital distance, plasmatic testosterone concentration and testis, epididymis, seminal vesicle and pituitary wet weights assessed. Copulatory behavior, anogenital distance, plasmatic testosterone concentration and organs wet weights were not affected by FLX exposure. However, this exposure eliminated preference for a sexual incentive on the sexual incentive motivation test, which indicates reduced sexual motivation, a classic side effect of SSRIs in humans who take these antidepressants.