Researchers in the United States have zeroed in on a specific neuron in the brain which sends the signal to stop eating.
The team at Columbia University found the specialized neurons in the brains of mice and the discovery could lead to new treatments for obesity.
Dr Alexander Nectow said many feeding circuits in the brain were known to play a role in monitoring food intake, but known neurons in those circuits did not make the final decision to cease eating a meal.
Dr Nectow said the newly identified neurons, a new element of these circuits, were located in the brainstem, the oldest part of the vertebrate brain.
“These neurons are unlike any other neuron involved in regulating satiation,” he said.
“Other neurons in the brain are usually restricted to sensing food put into our mouth, or how food fills the gut, or the nutrition obtained from food.
“The neurons we found are special in that they seem to integrate all these different pieces of information and more.”
Dr Nectow said the decision to stop eating was a familiar phenomenon.
“It happens every time we sit down to eat a meal. At a certain point while we’re eating, we start to feel full, and then we get fuller, and then we get to a point where we think, okay, that’s enough.”
He said the question which needed to be answered was how did the brain know when the body had had enough and how did it act on that information to stop eating?
Dr Nectow said the team deployed a new single-cell technique that made it possible to study a region of the brain and discern different types of cells that until now had been difficult to distinguish from one another.
“This technique—spatially resolved molecular profiling—allows you to see cells where they are in the brainstem and what their molecular composition looks like,” he said.
Dr Nectow said using this process they identified the neurons which determined how quickly animals stopped eating.
He said though the specialized neurons were found in mice, their location in the brainstem, a part of the brain that was essentially the same in all vertebrates, suggests that it was highly likely that humans had the same neurons.
“We think it’s a major new entry point to understanding what it means to be full, how that comes about, and how that is leveraged to end a meal. And we hope that it could be used for obesity therapies down the road.”
Read the full study: Brainstem neuropeptidergic neurons link a neurohumoral axis to satiation.
