A study found that diet alters brain communication 2023

The study that was carried out on mice revealed substantial alterations in the manner in which the brain communicates when the mice were on a diet.

Researchers from the Max Planck Institute for Metabolism Research and Harvard Medical School have now shown in mice that communication changes in the brain during a diet. They found that the nerve cells that mediate the feeling of hunger receive stronger signals, which results in the mice eating significantly more after the diet and gaining weight more quickly. These discoveries may, in the long run, contribute to the development of pharmaceuticals that prevent this amplification and assist in maintaining a decreased body weight following dieting.

People have largely looked at the short-term consequences of dieting. We wanted to discover what happens in the brain in the long run,” explains Henning Fenselau, a researcher at the Max Planck Institute for Metabolic Research who conducted the study. “People have looked at the short-term impacts of dieting.”

In order to do this, the researchers gave the mice a special diet and then examined which circuits in the mice’s brains were altered as a result. In particular, scientists focused their attention on the AgRP neurons located in the hypothalamus. These neurons are known to be responsible for regulating the sensation of hunger. They were able to demonstrate that the neural circuits that activate AgRP neurons delivered more signals while the mice were on a diet, which supported their hypothesis. This significant alteration in the brain was observable for a considerable amount of time following the diet.

Avoiding the yo-yo effect as much as possible

In addition to this success, the researchers were able to specifically suppress the neurological circuits in mice that activate AgRP neurons. This resulted in a considerably reduced amount of weight gain following the diet. According to Fenselau, this may present an opportunity for us to lessen the impact of the yo-yo effect. In order to accomplish this long-term objective of ours, we are continuing to investigate ways in which we might be able to block the mechanisms that mediate the strengthening of neural pathways in humans. If we are successful in this endeavor, we will have found therapies for humans that could assist in the maintenance of body weight loss following dieting.

We had previously uncovered a key set of upstream neurons that physically synapse onto and excite AgRP hunger neurons. In the present study, we find that the physical neurotransmitter connection between these two neurons, in a process called synaptic plasticity, greatly increases with dieting and weight loss, and this leads to long-lasting excessive hunger,” comments co-author Bradford Lowel. “This work increases understanding of how neural wiring diagrams control hunger.”