Postpartum female mice exhibit a preference for cooler environments due to changes in brain neurons, according to a recent study by Baylor College of Medicine. This discovery could shed light on similar temperature regulation mechanisms in human mothers.
In an innovative breakthrough, researchers from Baylor College of Medicine and collaborating institutions have unearthed significant findings regarding postpartum females’ temperature preferences, linking them to specific brain changes.
The study, published in the journal Molecular Metabolism, suggests that postpartum female mice prefer cooler environments due to alterations in the neurons of the preoptic area, a brain region pivotal for temperature regulation.
“In both humans and mice, body temperature increases during early pregnancy, drops to normal temperature during late pregnancy and then goes up again during lactation,” corresponding author Chunmei Wang, an assistant professor of pediatrics at USDA/ARS Children’s Nutrition Research Center at Baylor, said in a news release.
Wang and her team embarked on understanding the neural mechanisms behind these intriguing temperature preferences.
Their results highlight that postpartum female mice, similar to their human counterparts, exhibit a penchant for cooler temperatures starting from late pregnancy and lasting well into the postpartum period. Notably, these mice displayed a marked preference for environments cooler than typical preference settings.
“We worked with mice and found that female mice prefer a cooler environment starting from late pregnancy and persisting in long-term postpartum,” Wang added. “For more than four weeks post-weaning female mice had a lower body temperature and preferred cooler environments; they lost their typical preference for warm environments (30°C/86°F) but still avoided cold environments (15°C/59°F).”
The researchers delved deeper to uncover the biological basis of these changes. Their focus was on the preoptic area (POA) of the brain, known for its role in temperature regulation.
They discovered a significant decrease in estrogen receptor alpha (ERα)-expressing neurons within this region. Removing these specific neurons in virgin female mice induced similar cooler temperature preferences as found in postpartum females.
“We discovered that the change in temperature preference in postpartum female mice was associated with a significant decrease in a particular group of neurons, estrogen receptor alpha (ERα)-expressing neurons in the preoptic area of the brain (ERαPOA neurons),” added Wang.
Further investigation revealed differing temperature sensitivities among the ERαPOA neurons. Some neurons specifically responded to warm temperatures, while others responded to the cold. In postpartum females, there was a reduced warmth response and an increased cold response.
“Interestingly, compared to female mice that had not been pregnant, ERαPOA neurons of postpartum females had reduced response to warmth and an enhanced response to cold,” Wang added.
The results of this study emphasize the role of reproductive experience in regulating temperature preferences, unveiling that changes in ERαPOA neurons can lead to significant shifts in behavior regarding temperature seeking.
The researchers are now focused on further exploring the functions of specific neuron groups within the POA related to body temperature and thermal preference.
This groundbreaking research, funded by organizations including the USDA and the National Natural Science Foundation of China, has substantial implications for understanding maternal health and comfort. As the team continues to investigate, their findings could potentially inform new strategies to support postpartum mothers better, emphasizing the crucial role of temperature regulation during this significant life stage.
Contributors to this study include Nan Zhang, Meng Yu, Qianru Zhao, among others, from institutions like Huazhong University of Science and Technology and the University of Illinois.
Source: Baylor College of Medicine