Quantity or taste? – Or how people’s decision-making process resembles that of flies
Like a true foodie looking for food, flies spend a lot of time looking for sweet nutritious calories and avoiding bitter, potentially toxic food. But what happens in their brains when they make these food choices?
In a study that could also help clarify how people make food choices, researchers at Yale University offered hungry flies the choice between sweet, nutritious, bitter quinine food and a less sweet food, but not bitter, which contains fewer calories. Then, using neuroimaging, they tracked the neural activity in their brains as they made these choices.
So who won? The one with more calories or the best taste?
“It depends on how hungry they are,” said Michael Nitabach, a professor of cellular and molecular physiology, genetics and neuroscience at Yale School of Medicine and lead author of the study. “The hungrier they are, the more they will tolerate the bitter taste to get more calories.” But the real answer to how flies make these decisions is a little more complex, according to a study published July 5 in the journal Nature Communications. Sareen and Li Yan McCurdy, graduate students at Yale School of Medicine, are co-authors of the paper.
According to the research team, led by Preeti Sareen, an associate researcher at Yale, during the flight the fly transmits sensory information to a part of their brain called the “fan-shaped body”, where the signals are integrated, triggering executive decisions. The researchers found that the patterns of neural activity in the body in the form of fans change when new food choices are introduced, which dictates the fly’s decision about what food to eat.
But researchers have taken a step further, and things have become even more interesting. They found that they could change the choice of a fly by manipulating neurons in areas of the brain that feed into the body in the form of fans. For example, when they caused a decrease in activity in the neurons involved in metabolism, it was found that hungry flies choose low-calorie foods.
“It’s a big feedback loop, not just top-down decision making,” Nitabach said. And here there are links to people’s food choices, he said. Neural activity, both in the brain of a fly and in the human brain, is regulated by the secretion of neuropeptides and dopamine, which in humans helps regulate the sensations of reward. Changes in this network can change the way the brain responds to different types of food. In other words, neurochemistry can sometimes dictate food choices that we think we are aware of.
“The study provides a template for understanding how hunger and internal emotional states influence our behavior,” Nitabach said.
You can also test how our brain responds to different types of food using the Dahna app, which is based on the principles of the Mediterranean diet and contains lots of recipes, menus, tips and more. Download it now from the AppStore or Google Play!