Type 2 diabetes linked to weakened brain reward signals

A new study has found a potential link between type 2 diabetes (T2D) and changes in the brain that affect how rewards are processed. The study focuses on the anterior cingulate cortex (ACC), an area of the brain important for emotions and decision-making. Researchers from the University of Nevada, Las Vegas, examined male rats with T2D to see how their brain activity influenced their behavior. The rats were tested in a challenging maze where they had to find rewards. All the rats searched for rewards, but those with T2D showed less interest in the areas where rewards were located. They had weaker signals in the ACC, which made them less likely to stay in rewarding spots. The researchers believe this was due to diminished signals from the hippocampus, a brain region involved in memory and navigation. James Hyman, one of the study's authors, explained that the hippocampus helps the rats understand their location in the maze, while the ACC helps them recognize they are getting a reward. For diabetic rats, these signals did not work together as they should, affecting their memory of rewarding experiences. This research suggests that T2D may disrupt the normal processing of rewards and spatial awareness. The authors think that understanding the connection between the hippocampus and ACC might lead to new treatments for mood disorders linked to the ACC. Hyman also pointed out that T2D could be changing the brain in ways similar to the early stages of Alzheimer's disease, where symptoms may go unnoticed for years. Diabetic rats still sought out rewards, but their experiences were different from those of healthy rats.