UW Researchers Discover ‘Love Hormone’ Has Role in Regulating Daily Thermoregulatory Patterns of Rest and Arousal

A University of Wyoming research team found that the neuropeptide oxytocin, often known as the “love hormone,” has a previously unknown role in regulating daily thermoregulatory patterns of rest and arousal. 

 

“Mammals, including humans, are often described as having a body temperature set-point of 37 degrees Celsius. However, we do not have a single set-point but, instead, have at least two set-points: the high set-point is for the active/awake cycle, and the low-set point is for the rest/sleep cycle. There are more possible set-points, including those for fever and hibernation,” says Nicole Bedford, an assistant professor in the UW Department of Zoology and Physiology. “The neural circuits controlling these set-points, and the transitions between them, are not known. Our study sheds light on this by showing that oxytocin neurons trigger the transition from the low set-point to the high set-point.”

 

Bedford was co-author of a paper, titled “Oxytocin neurons signal state-dependent transitions from rest to thermogenesis and behavioral arousal in social and non-social settings,” that appeared online Oct. 3 in eLife. eLife is a nonprofit organization committed to making peer review and publishing better for science.

Morgane Vandendoren, a UW research scientist, was the paper’s lead author. Adam Nelson, an adjunct faculty member in the Department of Zoology and Physiology, was the paper’s senior and corresponding author.

Other contributors were Samantha Killmer, a senior from Portage, Mich., majoring in biology; Celeste Pohlman, a 2023 UW graduate from Cheyenne with a bachelor’s degree in biology; Jason Landen, a spring 2025 graduate from Eaton, Colo., who received his Ph.D. in neuroscience; Joseph Rogers, a 2024 UW graduate from Birmingham, U.K., with a master’s degree in physiology; Baizar Alamiri, a Ph.D. student from Rochester, N.Y., studying neuroscience; and Glenn Tattersall, a professor of biological sciences at Brock University in Saint Catherines, Ontario, Canada.

Using mice, the study revealed that oxytocin neurons in the paraventricular hypothalamus are activated during social thermoregulation. Thermoregulation is orchestrated by the integration of autonomic and behavioral effectors, according to the paper. The research team recorded and manipulated oxytocin neurons in social and non-social settings that involved the mice huddling, nesting and engaging in physical activity over long periods of time.

 

The study also looked at calcium activity in oxytocin neurons of mice and how that was associated with real-time behavior during social thermoregulation in three different thermal conditions. Mice were studied in pairs as well as those that were housed alone.

 

“Using calcium imaging to record the neural activity of oxytocin neurons, we noticed that the neurons became highly active during transitions from a resting state to a thermogenic and aroused state,” Nelson says. 

 

Researchers then conducted optogenetic activation of paraventricular hypothalamus neurons to examine the functional significance of this neural activity. Using light and modified ion channels, researchers were able to precisely activate oxytocin neurons when the mice were at rest. Consistent with the neural recording experiments, this “photoactivation” of oxytocin neurons immediately triggered the mice to enter a thermogenic and more aroused state, Nelson says. 

 

The research may have practical future implications for better understanding diseases associated with disrupted autonomic functions, including thermoregulation, Bedford says. Disruption of central oxytocinergic neural circuits is linked to both neuropsychiatric disorders, such as Phelan-McDermid syndrome, and neurodevelopmental disorders, including Prader-Willi syndrome.

 

“Understanding the timing of how oxytocin neurons coordinate behavior and homeostasis could inform future therapeutic programs,” Bedford says.

 

The study was funded by the National Science Foundation Building Research Capacity of New Faculty in Biology grant awarded to Bedford and Nelson; and UW Sensory Biology Center and  Center of Biomedical Research Excellence Project Leader funds awarded to Nelson.