Anti-bulimic neurons have been discovered and are activated by taste

Anti-bulimic neurons have been identified: located in the brainstem, they determine how quickly you eat and when to stop, based on signals sent by the mouth and intestines. This is the same neural circuit that some anti-diabetic drugs such as semaglutide, which are increasingly used for weight loss, act on. This discovery, made in mice, could help study the mechanisms that regulate appetite in humans as well, leading to the development of new treatments against obesity, as researchers from the University of California, San Francisco indicate in their study. published In the journal Nature.

The team, led by physiologist Zachary Knight, genetically modified mice so that neurons, when activated, emit a fluorescent signal that can be detected by a light sensor implanted in the brain. Thanks to this technique, they were able to observe that by placing food directly in the stomach, signals are released from the digestive system that reach the brain to activate neurons and suppress appetite, as previous studies predicted.

However, when the mice were allowed to eat freely, neurons were activated based on input from the mouth, especially the perception of sweet taste, showing that taste buds are the first bulwark against binge eating. In practice, it is a system of checks and balances, which on the one hand recognizes good food and invites you to consume it, and on the other hand prevents you from eating it in excess: the speed with which you eat depends on the balance between these elements. Two forces.

The researchers also identified another family of neurons, called Gcg, which are activated more slowly by signals from the gut that decide when to stop eating, and suppress appetite over a longer period of time. Once activated, Gcg neurons release the hormone Glp-1, the effect of which specifically mimics slimming drugs such as semaglutide.