Abstract

EFFECTS OF EARLY, ELEVATED PRENATAL TESTOSTERONE ON THE HPA AXIS AND HORMONE RESPONSIVENESS IN MICE Hayley Ann Wilson University of Guelph, 2019 Advisors: Dr. Neil James MacLusky Dr. Elena Choleris Alterations in developmental testosterone exposure can affect social and anxiety behaviour in male offspring, however, the underlying mechanisms remain unknown. We hypothesized that prenatal testosterone exposure would impact physiological development in a similar way as prenatal glucocorticoid exposure, resulting in altered hypothalamic-pituitary-adrenal axis functioning and hormone profiles in offspring. We treated dams with testosterone propionate, the synthetic glucocorticoid dexamethasone, or sesame oil during mid-late pregnancy. Testosterone was measured in male offspring on the day of birth and in adulthood. Corticosterone was measured in offspring’s hair, and in plasma following restraint stress. Prenatal treatment did not affect offspring testosterone levels. While prenatal testosterone had no effect on corticosterone levels in hair, prenatal testosterone reduced corticosterone responsivity to restraint stress in males, but not females. No effects of prenatal dexamethasone on corticosterone responsivity was observed. This study may have potential implications for conditions in which testosterone or dexamethasone are elevated during pregnancy.