As a neuroscientist, I have been working in the field of neuronal plasticity, neuronal development and neurocircuit adaptation to drugs and environmental factors since my master’s degree. For the last seven years, I have focused my work on how light and shiftwork impact neuroendocrine function and fertility, with an emphasis on women’s health. The neuroendocrine system that relays light information to the reproductive axis is sexually dimorphic, making me particularly interested in understanding how male and female brains respond differently to defined light paradigms. This interest in sex differences has made me aware that pregnancy is, in a sense, similar to a “third sex”, due to the myriad of neurological and physiological adaptations the female body undergoes during this period. I started incorporating late pregnant females into many of my studies, with the goal of understanding how pregnancy impacts neuroendocrine circuits and circadian rhythms in the brain and peripheral tissues. I have now been working for four years on this topic, and, thanks to support from the March of Dimes, I have successfully expanded my projects to include pregnancy, preterm birth, and the study of drugs regulating uterine contractility. Our most recent work (Duong et al., submitted) explores how the circadian molecular clock impacts uterine function during pregnancy. We found that time-of-day of oxytocin administration changes the efficacy of oxytocin to promote contractions in mouse uterine explants and human myometrial cells (chronopharmacology studies). To extend this work to women, I initiated a collaboration with Dr. Zhou, an epidemiologist and bioinformatician at Michigan State University (MSU). This collaboration led to a joint publication in 2021 showing that reduced expression of the clock genes CRY2, CLOCK and PER3 are risk factors for preterm birth in pregnant women. To expand this work, Dr. Zhou and I recently started a new collaboration with Dr. Pertroff (MSU), an expert in pregnancy complications and placental function. This novel collaborative work focuses on how pregnancy complications, such as preeclampsia impacts clock gene expression and function in the placenta, and is currently submitted for publication (Zhou et al. submitted). The research proposed in this R01 project will extend these current collaborations and support our work aimed at identifying the molecular mechanisms by which the clock proteins PER and CRY regulate uterine contractions.