Researchers have elucidated how odor perception affects food intake. An important step for obese and anorexics. Eventually, a nasal spray could regulate their olfactory system.
By what process does the perception of odors act on our food urges? To this question that many are asking, an Inserm team (1) led by researcher Giovanni Marsicano is partially answering this Monday. These scientists of various nationalities have indeed succeeded in elucidating the mechanism by which the endocannabinoid system controls food intake by acting on the perception of our smells. Unpublished work published in the journal Nature Neuroscience, dated February 9, 2014.
As indicated by Inserm in a press release, these researchers from the NeuroCentre Magendie in Bordeaux started from the following observation: “In animals, as in humans, we know that it is the mechanisms of hunger that encourage food. Hunger triggers a set of mechanisms pushing to eat, such as the increase in sensory perceptions such as olfaction. ”
However, in this work, this international team of scientists has succeeded in demonstrating what links hunger in the brain to an increase in the perception of odor and consequently to the need to eat.
Through research carried out in the laboratory on mice, researchers discovered how this mechanism was triggered at the level of the endocannabinoid system. The latter is indeed very interesting for research since it brings together receptors located in the brain and involved in different sensations such as euphoria, anxiety, or pain.
A mechanism causing increased olfaction during hunger
They found that cannabinoid receptors (CB1) controlled a circuit that connects the olfactory bulb (the first region of the nervous system to process olfactory information, located above the nose) and the olfactory cortex (upper structures of the body). brain). Result, when the sensation of hunger is felt, it triggers the activity of cannabinoid receptors which in turn activate the olfactory circuit which becomes more reactive.
“In the end, it is this biological mechanism that causes an increase in olfaction during hunger. It explains one of the reasons for food intake and the attraction to food ”, explains Edgar Soria-Gómez, 1st author of the study contacted by why actor.
However, the latter adds that we are only at the beginning of the research. “We will now have to explore this avenue, and above all see what happens when we activate these receptors in other structures of the endocannabinoid system. “
Listen to Edgar Soria-Gómez, researcher at Inserm: ” In the future, it will be necessary to identify all the possibilities of action of the endocannabinoid system in the olfactory system. We only worked on part of this system! “
Hope, a nasal spray to help obese or anorexics
Nevertheless, the team of researchers affirms that this mechanism, now “elucidated”, is a “big” step for the future of this research. In particular, to help obese or anorexic patients. In these populations, Inserm scientists assume that “the circuit involving the olfactory system is altered: the sensitivity to odors will be more or less strong compared to normal”, they explain. They add, however, that “elucidating the biological mechanism will allow better management of this type of pathology in the long term. ”
So, even if he confides that, “it is not for tomorrow, and that we will have to be patient”, Edgar-Soria-Gómez is already starting to dream by evoking the possible arrival in the future of a spray nasal as a therapeutic solution for these patients. The goal is to inhibit this endocannabinoid system, for example in obese patients, when it is in the hyperactivation phase. For anorexic patients, the aim of the technique would be to cause the opposite effect, in other words to re-activate this endocannabinoid system, which is broken down in this pathology.
Listen to Edgar Soria-Gómez : ” In the future, it may be thought that a type of spray containing the active components of cannabis could block this endocannabinoid system.. Especially in obese when it is in the hyperactivation phase “
(1) Unit 862 of Inserm (NeuroCentre Magendie de Bordeaux)
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