The seasons have just changed and temperatures have dropped. Everyone feels comfortable at different temperatures, and right now in Wisconsin, it’s not uncommon to see some people wearing winter jackets while others are wearing shorts. During menopause, a woman’s temperature comfort range changes and is the main cause of hot flashes. Hot flashes are commonly blamed on the sudden change in hormone levels, but neurotransmitters also play a major role in hot flashes and temperature regulation.
One of the most significant connections is estradiol and serotonin. Serotonin and estrogen receptors are present together in many of the same tissues throughout the body. Activation of the estradiol receptor E2-β increases the number of the serotonin receptor 5-HT2A. This is important because the 5-HT2A receptor is involved in mood, cognitive function, and temperature regulation.
5-HT2A receptors found in the hypothalamus regulate body temperature and work in conjunction with estradiol to influence the thermoregulatory set point (Figure 1). For example, a pre-menopausal, “healthy” individual should have an abundance of estradiol and serotonin in circulation leading to estrogen binding and an upregulation of 5-HT2A receptors and a wide thermoregulatory set point. As women age estrogen levels decline, resulting in less 5-HT2A receptors and a narrowing of the thermoregulatory set point. This narrowing of the temperature range at which women feel comfortable is thought to be a change that leads to hot flashes.
So when you look to open a window when others reach for a sweater, consider your estrogen and serotonin levels. For more information on the role neurotransmitters can play in hot flashes, please watch the webinar “The Science of Being Hot: Clinical Neuroendocrinology for Hot Flashes and Night Sweats” on the NeuroScience YouTube channel.