Obesity is a global health problem, and research has shown that diets that are high in fats and sugars are a major contributor to this problem. Scientists have now shown that brain cells called astrocytes play a central role in the perception of food intake, and these cells could have an important role in metabolism. This research is one of many recent studies that have demonstrated that astrocytes are much more than supporting players; they have many significant functions in the brain that we are now beginning to appreciate. These latest findings have been reported in Nature Communications.
In this study, the researchers used a mouse model that had been given a high-fat, high-sugar diet for an extended period of time. Compared to mice fed a normal diet, there were major changes in astrocyte function in the mice given diets high in fats and sugars. These changes were accompanied by cognitive and behavioral changes in the mice, and disruption in neuronal activity in a region of the brain that perceives satisfaction after food consumption. This region is known as the striatum.
Previous research has shown that obesity can lead to cognitive changes in the striatum, which appears to promote the creation of bad habits; food cravings; the inability to reduce the amount of food being consumed; and eventually, weight gain.
When the investigators altered the astrocytes of the mice given the high-fat and high-sugar diet, some of the cognitive and behavioral changes were corrected. The scientists altered the astrocytes by changing calcium flow in the cells, as calcium plays a critical role in astrocyte signaling and function.
This research has indicated that astrocytes could play an important role in cognitive changes that are related to obesity. The rodents had disruptions in behvaioral flexibility, which was restored after modulating the astrocytes in the animals’ dorsal striatums. The study suggested that astrocytes are central to a change from habitual to goal-directed behavior.
More work will be needed to confirm these findings and reveal exactly how astrocytes are related to metabolic function and eating behaviors in people.
Sources: CNRS, Nature Communications