She helped answer questions about sleep disruptions in children, knowledge that has been helpful to parents

Monique LeBourgeois, associate professor of integrative physiology at the University of Colorado Boulder and an expert on sleep and circadian physiology in children, died on Nov. 28, 2023. She was 54.

LeBourgeois’ colleagues and friends were “devastated by her premature passing,” Marissa Ehringer, CU Boulder chair and professor of integrative physiology, said in a statement. “Monique was an exceptional scientist, teacher, mentor and person who will be greatly missed by many in our department and across campus.” 

In addition to the personal loss, Ehringer noted the loss to science: “Her innovative research pioneered methods for assessing circadian rhythms and sleep measures in toddlers in the home environment.”

In 2018, for example, the LeBourgeois Sleep and Development Lab found that dimming the lights in the hours before bedtime can help children fall asleep. Specifically, the lab found, exposing preschoolers to an hour of bright light before bedtime almost completely shuts down their production of melatonin, a sleep-promoting hormone.

Further, exposure to bright light just before bedtime suppressed the production of melatonin for at least 50 minutes after lights were turned off. The study was the first to assess the hormonal impact nighttime light exposure can have on young children.

“Light is our brain clock's primary timekeeper,” LeBourgeois explained at the time. “We know younger individuals have larger pupils, and their lenses are more transparent. This heightened sensitivity to light may make them even more susceptible to dysregulation of sleep and the circadian clock.”

LeBourgeois and her colleagues also shed new light on the biological, neurological and environmental effects of light and electronic screen time on children. 

In her research, LeBourgeois developed creative, groundbreaking techniques to rigorously conduct circadian and sleep research in the home environment, including performing salivary melatonin and high-density EEG/polysomnography assessments on toddlers.

LeBourgeois earned her BS in psychology in 1995 from the University of Southern Mississippi. Under the mentorship of John Harsh, a scientist who was investigating sleep disturbance in childhood, she later earned her MS in counseling psychology, MS in experimental psychology and PhD in experimental psychology, at the University of Southern Mississippi. 

She did postdoctoral research at Brown Medical School, under the mentorship of Mary Carskadon, professor in the Department of Psychiatry and Human Behavior. There, LeBourgeois’ interest in measurement of sleep homeostasis and circadian rhythms blossomed, and she began to apply these concepts and measures to evaluate the developmental aspects of sleep behavior regulation in young children. 

LeBourgeois had an “outstanding way of working with families and kids and maintaining their engagement throughout longitudinal studies,” Carskadon said.

In 2010, the CU Boulder Department of Integrative Physiology recruited her to join the faculty as a tenure-track professor. She conducted longitudinal studies examining the development of Process C and Process S (two components of a sleep regulation concept) across early childhood, as well as researching the sensitivity of the developing circadian system to light exposure. 

LeBourgeois was successful in securing external research funding and received continuous funding from the National Institutes of Health since 2001. She engaged in collaborative research, where she created opportunities, generously lent her expertise, and shared her passion for developmental sleep and circadian science, colleagues said.

Beyond her scientific accomplishments, LeBourgeois devoted much of her academic life to mentorship, always asking trainees, “What do you want your life to look like?”

She invested time, energy, trust and love into helping trainees to successfully achieve their goals. Recognizing the mentorship she received, she sought to sustain it by creating the Mary A. Carskadon Sleep and Circadian Summer Research Fellowship in 2017. 

This annual fellowship provided enriching and unique opportunities for students to receive hands-on research experiences, form relationships with families in the community and develop basic professional skills. Many of her trainees have gone on to successful careers in professions including biomedical research, health care, science policy and industry. 

She published nearly 80 peer-reviewed journal articles and had another 10 in progress or under review at the time of her death. Among the recognitions she received were the American Academy of Sleep Medicine Young Investigator Award in 2003, the American Academy of Sleep Medicine/Pfizer Scholars Grants in Sleep Medicine Award in 2005, and a College Scholar Award from CU Boulder in 2022.

Last year, she was named a Health Research Accelerator Fellow at the University of Queensland, Brisbane, Australia.