A group of scientists from Harvard Medical School found that insulin resistance can cause changes in the behavior of people with diabetes. Also, experts note that people suffering from diabetes are more prone to depression and anxiety, in contrast to people with other chronic diseases.
During the study, scientists used genetically modified mice to make their brain insulin resistant. As a result, it was found that the behavior of rodents changed, for example, increased levels of anxiety and depression, and after that they precisely determined the mechanism that reduces the level of the key dopamine mediator in the parts of the brain that are associated with these symptoms. This study was one of the first to directly show that insulin resistance can actually cause various changes in behavior.
A team of scientists evaluated genetically modified animals using several tests that put mice under stress and are often used to analyze drugs that treat excessive anxiety and depression. The behavior of young individuals did not differ from normal mice, but in rodents over the age of 17 months (age indicating the end of middle age), serious behavioral disorders were observed. Studying the brains of these mice, scientists discovered an altered metabolism in the mitochondria that produce energy for cells. Thus, mitochondria increased the production of two enzymes that destroy dopamine, which is the main controller of brain behavior. These mice produced a normal amount of dopamine, but due to changes in the mitochondria, their dopamine metabolism was faster, which caused changes in behavior.
Despite the fact that behavioral effects were not detected in younger genetically modified individuals, scientists also revealed similar changes in their brain cells.