Researchers at Duke University have discovered why it is extremely difficult for some people to give up unhealthy foods. It turns out that a bad habit changes the nerve circuits in the brain. As a result, a person cannot get rid of cravings. Experts have conducted a study on healthy mice, writes Zee News.
During the experiment, the rodents developed cravings of varying severity for sweets. By pressing the lever, the experimental animals received tiny sweets. Addicted mice continued to push the lever even when there was no reward. The scientists then compared the brains of mice that had developed cravings to those who hadn't developed addictions.
Experts studied electrical activity in the basal ganglia, a complex of neural nodes responsible for motor skills and compulsive behavior, including drug addiction. There are two types of pathways in the basal ganglia. The activating path makes you act, and the inhibitory path, on the contrary, stops. Scientists found that these pathways were more active in sweet-craving mice.
In addition, the activation time of the paths has changed. In rodents with a bad habit, the activating pathway was "turned on" before the inhibitory pathway, while in mice without cravings, everything happened the other way around. The changes in the brain turned out to be persistent and very noticeable. Researchers could pinpoint which of the mice developed cravings by looking at specific areas of their brains in a petri dish.
Moreover, the changes took place in all basal ganglia, and not in individual cells. This is probably why one addiction makes a person prone to other addictions. Scientists have tried to rid the mice of addiction. They rewarded the animals only when they stopped pressing the lever. According to experts, in mice, freed from addiction, the activating cells were weaker.