New brain cell discovery may regulate when you should stop eating

Neurons in the mouse brain tell them to stop eating when they have enough food. And since people probably have the same cells, they may one day manipulate them to help treat obesity.

“The main question we were trying to answer was how our brains sense and respond to different signals.” Alexander Nectau At Columbia University in New York.

To learn more, he and his colleagues used a kind of molecular profiling to distinguish between different cell types in the mouse brain. In the dorsal trunk nucleus, part of the brainstem associated with functions such as feeding, mood, and sleep, we encountered cells that produce a hormone called cholecystokinin, which helps regulate appetite.

To study what these cells feel to make them work, researchers measured their activity as mice spent the day. “Every time an animal eats a bite, activity has risen and then it has become corrupted,” says Nectow. “These neurons sense and use information such as food smells and sights, food tastes, food sensations in the intestines, and neurohormones released in response to intestinal foods and so on. You can actually finish your meal.

Next, researchers used a technique called optogenetics. This involves engineering neurons so that they can turn them on and off with light. The mice slowed their diet when they used light to activate them. The more intense the activation, the slower and stopped the animal.

Neurons sit in the brainstem and are similar ancestor characteristics across vertebrates, so Nectow probably thinks we have them too. “We didn’t confirm that, but my guess is that humans have these neurons.”

The team also discovered that mouse neurons can be activated by compounds called glucagon-like peptide-1 (GLP-1) agonists. Brand names such as Ozempic and Wegovy.

If these neurons have the same function in people, theoretically, they can either control the feeding habits of obese people or combine this approach with GLP-1-based drugs to increase greater weight loss. They can be adjusted to achieve, says Nectau.

“Understanding the circuits governing meal halts is particularly important in an environment of near-ubiquitous food availability,” he says. Jeff Davis At Swansea University, UK. “The authors used elegant methods to identify these important cell populations.”