Sex-dependent Differences of Emotional Status in a Rat Model of Prenatal Stress

Abstract

Untoward events during pregnancy negatively affect offspring mental development. We investigated sex-dependent differences of emotional problems in offspring with a history of prenatal stress (PNS). Female rats demonstrated decreased anxiety-like behaviour in comparison to male controls, shown in the light-dark test. Male and female offspring of prenatally stressed mothers were characterized by higher anxiety levels, compared to unstressed controls. PNS induced depression-like behaviour in both sexes without differences among them, indicated with decreased intake of sweet solution in the sucrose consumption tests and increased immobility time spent in the forced swim test. Control females showed higher plasma corticosteroid (CORT) concentrantions after acute stress and decreased recovery (120 min after the stressor) than control males. Both male and female PNS-offspring were with elevated levels of CORT in the plasma, which remained high 120 min after application of the stressogenic procedure. This study evidenced that the unfavourable effect of PNS on emotional state correlated with impaired feedback mechanism of the hypothalamic-pituitary-adrenal (HPA) axis function both in male and female offspring.