Abstract
Pregnancy represents a significant challenge to thermal homeostasis, with adaptive changes required to cope with the increased generation of metabolic heat. We have investigated the hypothesis that prolactin action in the preoptic area of the hypothalamus (POA) contributes to adaptive changes in thermoregulation during pregnancy. Prolactin receptors (Prlr) are expressed in warm-responding neurons (WRN) in the POA and chemogenetic activation of this subpopulation induces a profound hypothermia. AAV-Cre-mediated deletion of Prlr in the POA results in significant hyperthermia throughout pregnancy, suggesting that prolactin action in the POA is required for appropriate thermoregulation during pregnancy. Moreover, deletion of Prlr in glutamate neurons (including WRN) results in markedly impaired pup survival when animals were housed at mildly elevated environmental temperatures, demonstrating that prolactin action in the POA provides resilience to thermal challenges in pregnancy. Thus, prolactin has a key role to regulate the thermoregulatory circuits, providing optimal conditions for successful pregnancy.
• Preoptic area prolactin-sensitive neurons show warmth-induced cFos expression•Chemogenetic activation of prolactin-sensitive neurons induces hypothermia
• Loss of prolactin receptors causes hyperthermia during pregnancy
• Prolactin action on glutamate neurons supports thermoregulation in pregnancy