Neuroscientists identify a region of the brain that appears to be linked to decisions about food preferences

At holiday buffets and potlucks, people quickly calculate the dishes to try and the quantities to take. Neuroscientists at Johns Hopkins University have discovered a region of the brain that seems to be closely linked to such decisions about food preferences.

Researchers working with rats have discovered robust neuronal activity related to the choice of foods in a previously neglected part of the brain. The discovery suggests that this region of the brain could be the key to developing therapies and treatments to encourage healthy eating. The results are fixed for publication in the journal Nature Communications.

"We found a region in the brain that reflects our perception of food in a remarkably dominant way," said lead author David Ottenheimer, a postgraduate student in neuroscience at the university. Johns Hopkins. "The level of brain activity we saw exceeded our expectations by far."

The research team wanted to know how the brain determines what and how much to eat when you have several good food choices. This is a situation that people face everyday, whether it's in buffets or potlucks, but when they look at restaurant menus or refrigerator contents.

This may seem automatic as you move through a buffet, but when thinking of a cheese macaroni or mashed potatoes, the brain must quickly determine which of these two choices are quite similar. the most rewarding. Even though we can have both, says Ottenheimer, the favorite dish will probably be consumed faster and with bigger bites.

To investigate this issue, the researchers offered rats two similar sugary drinks. Rats preferred the one made with sucrose to that containing maltodextrin and, when they received sucrose, they licked it faster.

Over several days, the rats received one or the other glass. During this time, the team mapped the brain activity of the rats at the precise moment when the animals understood which drink they had been drinking, identifying the neurons that recorded the sucrose excitation and disappointment maltodextrin.

The activated neurons were in an area called the ventral pallidum, a zone long associated with the perception of reward and pleasure, but considered rather a secondary role.

Then, the team presented the rats with a set of different options – either the maltodextrin drink or the pure water. In this scenario, when the rats received maltodextrin, the ventral pallidum neurons were fired as if they had sucrose. This suggests that the brain area makes context-dependent decisions, targeting the best food option at all times.

"Since neural signaling of the ventral pallidum changes immediately when the rat changes its preferred flavor classification, we consider this response as a real-time reading of what you prefer among the currently available options," said Dr. 39, principal author.

The next step is to understand what signage means in this part of the brain. Is it used to reinforce previous foraging actions and make them more likely to reproduce? Or is it used to inform future decisions and refer them to a food reward over the next time a food choice will be presented to someone?

"Our data suggest that further study of the ventral pallidum will be essential to understanding how we make food decisions," Ottenheimer said. "If we want to understand why one food may be exciting in one scenario and disappointing in another, the ventral pallidum might be the key."