To analyze how insulin interacts with dopamine, the scientists utilized an innovative measurement method. They combined magnetic resonance imaging (MRI) to assess brain activity and positron emission tomography to measure dopamine production.
Their analysis revealed that administering insulin via the nasal cavity reduced dopamine levels. It also caused changes in the brain’s network structure.
What the Experts Say:
“The study provides direct evidence of how and where in the brain signals triggered after eating — such as insulin release and the reward system — interact,” said Professor Martin Heni, last author of the study. “We were able to show that insulin is able to decrease dopamine levels in the striatum in normal-weight individuals. The insulin-dependent change in dopamine levels was also associated with functional connectivity changes in whole-brain networks. Changes in this system may be an important driver of obesity and related diseases.”
The team wants to study changes in dopamine production and insulin levels in obese and diabetic volunteers in future studies. This population suffers disproportionately from insulin resistance when the body can’t absorb glucose properly. This condition leads to high blood sugar, which may eventually result in diabetes.
The researchers believe this resistance inhibits insulin from regulating dopamine production in the brain’s reward system. So, in further research, they hope to uncover a behavioral or medicinal treatment to balance insulin levels in this population.
Final Thoughts on How Insulin and Dopamine Interact in the Brain
Most people associate dopamine with the euphoric high you get after exercising or eating a chocolate chip cookie, for instance. However, scientists from the German Center for Diabetes Research have found that high insulin levels can inhibit the feel-good hormone. They believe that these changes in the brain may play a significant role in causing diabetes and obesity. In the future, they hope to discover more about possible treatments that may help restore insulin to healthy levels.