Researchers identify estrogen-regulated brain circuit that helps females control obesity

A group led by researchers at Baylor College of Medicine aims to better understand the important role of the female hormone estrogen in maintaining energy balance and weight management, and is specific in providing these anti-obesity effects. We investigated the interaction of estrogen with the brain region.

Team reveals in journal Science Advances An estrogen-activated neural circuit that stimulates heat generation, or body temperature generation, and physical activity in animal models. The circuit begins with neurons in a region of the hypothalamus called the ventrolateral subdivision of the ventromedial hypothalamus (vlVMH). These neurons interact with estrogen via the estrogen receptor α (ER-α) and connect to and communicate with serotonin-producing neurons in another brain region called the dorsal rape nucleus (DRN). Respond to.

This circuit responds not only to estrogen, but also to changes in ambient temperature and the nutritional status of the animal. Interestingly, this circuit seems to work in men, but its physiological relevance is not clear at this time.

“My lab has long been interested in understanding gender differences in metabolic regulation,” said Dr. Yong Xu, co-author of a professor of nutrition and molecular cell biology at Baylor University. .. “For example, premenopausal women are usually protected from metabolic problems that can lead to weight gain when compared to age-matched men, but after menopause, this benefit seems to disappear. Researchers around the world agree that estrogen is one of the key players. For this benefit. “

In previous studies, researchers showed that one of the estrogen receptors, ER-alpha, is expressed in several brain regions, including v1VMH in the hypothalamus. When v1VMH neurons expressing ER-α respond to estrogen, animals increase heat generation and physical activity. Both reactions are beneficial because they increase energy expenditure that can prevent obesity.

“What we didn’t know at the time was the neural circuits that mediate these reactions,” Xu said. “Using the latest neuroscience and technology, we have identified a neural circuit that connects ER-α-expressing neurons in the vlVMH region to neurons in the DRN region. Estrogen-mediated activation of this circuit actually results in heat generation and physical activity. Confirmed to stimulate. “

Researchers have also discovered that circuits respond to changes in ambient temperature and animal nutritional status.

“For example, circuits are activated when it’s cold, stimulating heat generation and physical activity, and helping keep animals warm,” says Xu. “When an animal is hungry, it can block the circuit, which stops heat generation and physical activity and saves energy to adapt to nutrient deficiencies.”

Xu and his colleagues studied this circuit not only in females but also in men.

“We found that the circuit is conserved in males. It has the same neurons that express ER-α and project to the same downstream brain region. When the circuit is artificially activated in males, The same response occurs. Heat generation and physical activity are stimulated. However, the role this circuit plays in men is still unknown. Further studies will help answer this question. ”