The Effects of Perinatal Fluoxetine Exposure on Social and Non-Social Investigation Behaviors in a Novel Environment

Abstract

Selective serotonin reuptake inhibitors (SSRIs) are increasingly prescribed as medication for various affective disorders during pregnancy. SSRIs cross the placenta and affect serotonergic neurotransmission in the fetus, but the neurobehavioral consequences for the offspring remain largely unclear. Recent research has linked perinatal SSRI exposure to alterations in both social and non-social aspects of behavior. However, this research has mainly focused on behavior within simplified environments. The current study investigates the effects of perinatal exposure to SSRIs on social and non-social investigation behaviors when the individual is introduced to a novel seminatural environment with unfamiliar conspecifics. During the perinatal period (gestational day 1 until postnatal day 21), rat dams received daily either SSRI treatment (fluoxetine 10 mg/kg) or vehicle. Four cohorts of offspring, each consisting of four males and four females, were observed in adulthood during the first hour within a seminatural environment. The results showed that perinatal fluoxetine exposure altered aspects of non-social, but not social, investigation behaviors. Both fluoxetine exposed male and female rats spent more time on walking/running than controls, while fluoxetine exposed females also walked/ran more often than control animals. Furthermore, compared to control, fluoxetine exposed female rats spent less time exploring objects and specific elements in the physical environment. We suggest that perinatal exposure to SSRI lead to a quicker, less detailed investigation strategy in novel environments, and that the alteration is most pronounced in females. Whether this effect is disadvantageous or not is yet to be revealed.