A team of US researchers has targeted a gene in the brains of mice. By turning it off, they were able to reduce these animals' appetite for food and make them want to exercise more. This research opens the way to new treatments for obesity in humans.
Modifying the eating and physical behavior of mice was the goal of a team of researchers from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). In their study published on the JCI insight platform on November 3, 2020, the scientists say they have deactivated a gene in the brains of mice . This has led to a reduction in their attraction to food. However, this reduction is accompanied by an increase in motivation to exercise. The authors of the study are now considering adapting this kind of treatment to humans.
It must be said that obesity is a real public health problem . Different factors can come into play such as genetics, environmental factors, etc. Indeed, obesity can cause cardiovascular diseases (heart disease and stroke), type 2 diabetes, musculoskeletal disorders (eg osteoarthritis) or certain cancers (breast, colon). However, for these researchers, genetics could contribute to the development of new treatments.
The habenula is part of the epithalamus, the dorsal portion of the diencephalon . The latter includes the habenula, the epiphysis and the medullary stria. However, this region of the brain is particularly poorly understood. Nevertheless, the habenular neural circuit seems to interest scientists more and more for applications concerning addictions, motivation, depression or even the reward process. The fact is that this neural circuit is influenced by the Prkar2a gene .
In 2012, a French study had already shown that the alteration of the habenular neuronal circuit prevented mice from becoming obese. The researchers then subjected them to a very rich diet during the experience. As for the recent NICHD study, the circuit's alteration aimed to decrease the mice's attraction to reward-producing foods while causing them to exercise more.
Is this really a way to fight obesity in humans? Possible. Nevertheless, therapies targeting this brain circuit will have to be carried out for quite a long time on animals before considering testing them on humans. The goal is obviously to avoid unwanted side effects.
