Effects of Ovariectomy on Anxious-Depressive Behavior in Female Rats in Normal Conditions and after Early Proinflammatory Stress

The role of female sex hormones produced by the ovaries in the occurrence of sex-related features in the anxious-depressive behavior of rats was studied. Proinflammatory stress was created in half the cohort of rat pups by administration of bacterial lipopolysaccharide at a dose of 50 μg/kg (LPS group) at ages 3 and 5 days; the other half received saline (PS group, controls). Half of the females underwent bilateral ovariectomy (OE) at age 35 days and the other half underwent sham ovariectomy (SOE) without removing the ovaries. The behavior of two groups of females was compared with the behavior of males at age 75–100 days. OE increased female weight but did not induce any behavioral changes in anxiety tests as compared with SOE females. Ovariectomy produced some smoothing out of differences in anxiety levels compared with males. OE led to depression-like behavior, which was apparent only in animals of the LPS group. OE reduced differences in corticosterone levels between males and females in animals of the LPS group. OE had the greatest impact on animals after early proinflammatory stress. © 2023, Springer Nature Switzerland AG.