Gestational and postpartum corticosterone exposure to the dam affects behavioral and endocrine outcome of the offspring in a sexually-dimorphic manner.

Exposure to high levels of glucocorticoids in utero and during the postpartum period has a detrimental effect on brain development. We created an animal model of postpartum stress/depression based on administering high levels of corticosterone (CORT) to the dams during the postpartum period which caused behavioral changes and reduced hippocampal cell proliferation in the offspring. As the consequences of early exposure to glucocorticoids may depend on the dose and the developmental stage of the offspring, the present study was conducted to investigate the effects of low (10 mg/kg) or high levels of CORT (40 mg/kg) given to dams either during gestation, postpartum or across both gestation and postpartum on the outcome of the offspring. Male and female offspring were weighed throughout the experiment, tested in a series of behavioral tests (forced swim test, open field, elevated plus maze) and basal and restraint stress CORT levels were examined in adolescence or young adulthood. Results show that maternal CORT exposure, regardless of when administered, significantly attenuated body weight gain until adulthood in the offspring. Offspring exposed to low maternal CORT, but not high maternal CORT, during the postpartum had higher basal levels of CORT as young adults. Further, male and female offspring of dams exposed to high maternal CORT in utero showed more depressive-like behavior in the forced swim test, while males of dams exposed to high maternal CORT postpartum exhibited more anxiety-like behavior in the elevated plus maze. Taken together, maternal glucocorticoid exposure have long lasting effects on male and female offspring's behavioral and neuroendocrine measures in adolescence and adulthood depending on the time of exposure to glucocorticoids. This article is part of a Special Issue entitled 'Anxiety and Depression'.