(ANSA) ROME – Eating is controlled by an extremely simple brain circuit made up of three types of neurons that connect the hunger hormone to the jaw to stimulate chewing movements.
This was demonstrated in a study conducted on mice by researchers at The Rockefeller University in New York.
The findings, published in the journal Nature, show that the impulse to eat may be more like a reflex than previously thought, and provide new clues about how food initiation is controlled.
The study, led by geneticist Jeffrey M. Friedman, focused on a specific area of the brain associated with the regulation of glucose and appetite: the ventromedial hypothalamus, which has long been known to be damaged when damaged. cause of obesity.
This region contains specific neurons that express the protein BDNF (brain-derived neurotrophic factor): its inhibition causes animals to consume more food (up to 1200% more).
It also causes chewing movements of the jaw, even in the absence of food or other sensory cues indicating it is time to eat.
On the contrary, stimulation of this protein slows down food intake and blocks chewing movements.
By mapping the inputs and outputs of BDNF neurons, the researchers found that they are the center of a tripartite neural circuit that links hormonal signals that regulate appetite with the movements needed to consume food.
At one end of the circuit are neurons in the arcuate nucleus of the hypothalamus that sense hunger signals such as the hormone leptin, produced by fat cells.
These neurons send messages to BDNF neurons in the ventromedial hypothalamus, which in turn communicate with neurons in the center of the brainstem (called Me5), which controls jaw muscle movement.
This Me5 also appears to be associated with stress-related compulsive oral behaviors, such as chewing on pencils or strands of hair.
ALL RIGHTS RESERVED © Copyright ANSA