Adipocyte-targeting neurons (red) within adipocytes (green) in the mouse inguinal fat pad.ANA DOMINGOSThe hormone leptin, produced by fat cells, acts as a satiety signal to the brain, resulting in fat breakdown when levels are high. The hormone, present in proportion to the amount of fat tissue, is known to act on hypothalamic neurons in the brain to tell an animal when it’s full and to kick-start the breakdown of fat. Now, a team led by researchers at the Instituto Gulbenkian de Ciencia (IGC) in Portugal and the Rockefeller University in New York City have, for the first time, provided direct visual evidence that some sympathetic neurons from the brain indeed terminate within fat cells. The researchers also used optogenetics to stimulate these neurons within a fat pad in mice and cause the breakdown of fat. Their results were published today (September 24) in Cell.
“This is a very comprehensive study with quite a beautiful dataset,” said Stephanie Fulton, who studies the neural pathways of food-motivated behavior at the University of Montreal in Canada and was not involved in the work. “[The authors] took advantage of powerful techniques to solidify the strong suggestion that white adipose tissue is directly innervated by the central nervous system and clearly demonstrate that leptin activates this sympathetic input.”
“It’s a real tour de force that combines really modern optogenetic and tissue clearing approaches that are being developed to understand the central nervous system [CNS] and are here applied to understand the neural action outside the CNS and in the body,” said Paul Kenny, director of the Experimental Therapeutics Institute at Mount Sinai Hospital in ...
