By Abigail Algeier and Emily Landry

Faculty Mentor: Parrish Waters

Abstract

Women report having anxiety and other mood disorders at nearly twice the rate of men. The female menstrual cycle involves fluctuations in pituitary hormones, estrogen, and progesterone. Each of these hormones are psychoactive and can potently affect mood state, both acutely and chronically. In a sample of humans, elevated levels of estrogen were highly correlated with low levels of cortisol, suggesting that the converse is true and indicating that high stress is a potential cause for hormone imbalances in women. This is because stressful situations put the body in a fight or flight response. In animal models, treating ovariectomized mice with progesterone resulted in a decrease in depressive and anxious behaviors through changing gut microbiota, indicating that progesterone acts on mood through mechanisms beyond its intended reproductive function. Given these observations, the hormonal changes that are associated with the female reproductive cycle may be responsible for the increased occurrence of anxiety in women.
The female reproductive cycle may significantly influence the expression of anxiety in females as the hormones fluctuate throughout. This can influence a woman’s motivation to exercise during select stages. We investigated the correlation of anxiety and the female reproductive cycle, as well as the impact of motivation of physical exercise during select reproductive stages using female CD-1 mice as a model for humans due to their similar hormonal cycle. To examine whether estrous cycle affects wheel running, we limited running wheel access of mice to specific estrous stages. Limiting running to specific stages of estrus allowed us to see if the changes in hormones would presumably change anxiety effects in the endocrine and neurocrine ligands.