https://medicalxpress.com/news/2022-08-scientists-eavesdrop-fat-brain.html
sympathetic nervous system—related to the conversion of white fat to brown fat—become overly active in fat cells, resulting in a larger than normal fat pad with especially high levels of brown fat, which breaks down other fat and sugar molecules to produce heat. Indeed, the animals with blocked sensory neurons—and high levels of sympathetic signaling—had increased body temperatures.

The findings suggest that the sensory neurons and sympathetic neurons might have two opposing functions, with sympathetic neurons needed to turn on fat burning and the production of brown fat, and sensory neurons required to turn these programs down.

"This tells us that there's not just a one-size-fits-all instruction that brain sends adipose tissue," says Li. "It's more nuanced than that; these two types of neurons are acting like a gas pedal and a brake for burning fat."

The team doesn't yet know exactly what messages the sensory neurons convey to the brain from adipose tissue, only that the connections and communications are key for keeping fat healthy. They are planning future research into what the neurons are sensing and whether other similar cells exist in additional internal organs.

Other authors of the paper "The role of somatosensory innervation of adipose tissue," were Yu Wang, Verina Leung, Yunxiao Zhang, Victoria S. Nudell, Meaghan Loud, M. Rocio Servin-Vences, Dong Yang and Kristina Wang of Scripps Research; and Maria Dolores Moya-Garzon, Veronica L. Li, and Jonathan Z. Long of Stanford University