Recent studies reveal that pregnancy and lactation significantly influence temperature preferences in female mice. Postpartum females exhibit a long-term preference for cooler environments, driven by specific changes in brain neurons expressing estrogen receptor alpha (ERα) in the preoptic area (POA). This discovery sheds light on how reproductive experience impacts thermal regulation and preference. The findings suggest that deleting ERα in virgin females mimics postpartum behavior, offering new insights into the biological mechanisms behind these changes.
Postpartum Thermal Preference Shifts
Pregnancy and lactation bring about significant physiological adaptations, including altered temperature preferences. Research shows that postpartum female mice develop an enduring preference for cooler environments lasting over four weeks after weaning. This shift is linked to reduced activity of ERα-expressing neurons in the POA, which regulate warmth and cold sensitivity.
During late pregnancy and the postpartum period, female mice demonstrate a marked change in their environmental temperature preferences. Instead of favoring warmer conditions, they increasingly prefer cooler surroundings while still avoiding extremely cold temperatures. This behavioral shift correlates with a decrease in the number of ERα-expressing neurons in the POA. Studies indicate that reproductive experience not only modifies body temperature but also alters the way these neurons respond to thermal stimuli. By examining virgin females with deleted ERα receptors in the POA, researchers observed similar cooler temperature preferences, suggesting that these neurons play a crucial role in mediating postpartum thermal behavior.
Neural Mechanisms Behind Temperature Regulation
Investigations into the POA have uncovered distinct subpopulations of ERα-expressing neurons responsible for sensing warmth and cold. These neurons exhibit varying responses based on reproductive history, influencing how postpartum females perceive and react to different temperatures.
Further exploration reveals that reproductive experience diminishes the excitatory effects of warmth and estrogen signaling in ERα-expressing neurons, enhancing their sensitivity to colder temperatures. Specifically, one group of neurons responds to warmth, while another reacts to cooler conditions. Postpartum females show reduced responsiveness to warmth and heightened reactivity to cold in these neurons. This adaptation aligns with their preference for cooler environments. The study underscores the importance of ERα-expressing neurons in regulating thermal preference and highlights how reproductive experiences shape neural function. Ongoing research aims to understand the precise roles of each neuron subgroup in body temperature regulation and thermal preference, providing deeper insights into the complex interplay between reproduction and thermoregulation.
