Strict, healthy diets often sound great and manageable on paper. But, once that midnight craving for some cookies and chips inevitably comes one random Thursday night it’s very difficult for many people to stick to the goals they set for themselves in the cold light of day.
If only there were a way to manipulate or control our food choices while they’re still being formulated in the mind. It sounds more like a sci-fi novel than reality, but researchers at Johns Hopkins University just made some incredible neurological findings in mice that may pave the way toward artificial manipulation of one’s food choices and preferences (and potentially other substances as well like drugs).
On a more technical level, the study’s authors identified a certain part of the mind that monitors and updates changes in food and drink desires/preferences as a person shifts from being hungry to satisfied or vice versa.
For example, if you hadn’t eaten in two days and were then asked to choose between chocolate ice cream or grilled chicken and vegetables, you’ll almost assuredly go for the more balanced meal.
Using a group of lab rats, the research team was able to manipulate the neurons operating in this brain region (known as the ventral pallidum) to influence what type of water the rodents wanted to drink.
“Your brain has to weigh different possible outcomes or options in order to make good decisions that are necessary for survival,” says senior study author Patricia Janak, Bloomberg Distinguished Professor of Psychological and Brain Sciences and Neuroscience at Johns Hopkins, in a release. “We knew the ventral pallidum is involved in that process. Exactly how the neurons there do that was still a bit of a mystery, especially in real time when the best decision for you to make right now can change based on your state.”
Back in 2018, scientists at JHU originally discovered that the ventral pallidum is related to food choices, desires, and preferences. Fast forward to today, however, and lead study author David Ottenheimer (a former Johns Hopkins doctoral student) wanted to investigate the matter in more detail. More specifically, what role are the neurons in the ventral pallidum playing in all of this, especially in response to different physiological states (hungry, satisfied)?
To that end, a group of initially thirsty lab rats was given two options on what to drink: plain old water, or a more sugary version of water that would taste a bit sweeter. The rats were able to choose between one of two levers to make their choices.
“At the beginning they picked the water when they were thirsty,” Ottenheimer explains. “At the end of the test when they were no longer thirsty they picked the sugar water, which tastes sweeter.”
While all of that was going on the research team kept close track of the rodents’ neural activity. Sure enough, neurons located within the ventral pallidum followed a pattern according to each rat’s decision.
“We saw that the neural activity when tasting the sucrose gradually increased over time while the neural activity when tasting the water decreased, which gave us evidence that the brain signal is closely related to the change in preference as the subjects became less thirsty and were less interested in the water,” Ottenheimer says.
So, the neurons fired more often when the rats chose to drink the sugary water and less often if they just went with regular H2O. With this information in mind, the study’s authors set out to see if they could artificially change the rodents’ preferences by manipulating their neural activity.
In short, their experiment was a success. The team was able to shift the rats’ preferences toward regular water instead of the sugary alternative.
“We hypothesize that the ventral pallidum neurons that are tracking our preferences may actually be involved in forming the choices we make when faced with food decisions,” Ottenheimer notes. “In the future, ventral pallidum may be a good therapeutic target to change our decision-making processes.”
These findings are an incredible first step, but there is of course still a long way to go before modern science can stop you from reaching for the Cheetos at 10:30 at night. Still, these initial results open the door toward a myriad of potential possibilities for helping people make healthier choices – and not just with food either.
“These same circuits are responsible for choices made in addiction,” Janak concludes. “So the knowledge we gain here can help in understanding how we prioritize drugs over other rewards.”
The full study can be found here, published in Science Advances.