Impact of High-Fat Diets on Brain Cells and How Astrocytes Can Reverse Obesity Effects

Recent research highlights the significant influence of fatty diets on the brain's cellular structure, particularly affecting astrocytes—star-shaped glial cells located in the striatum, a brain region involved in processing pleasure from food. These diets and associated obesity lead to morphological changes in astrocytes, causing them to become reactive—a condition indicating cerebral inflammation.

Surprisingly, scientists from CNRS and Université Paris Cité discovered that by manipulating astrocytes within the brain in live mice, they could modify metabolic processes and counteract certain cognitive impairments linked to obesity, such as difficulty in relearning tasks. This was achieved through advanced chemogenetic techniques, which involve using viruses to express proteins that control calcium flow in astrocytes, thereby modulating their activity.

The investigations used both ex vivo and in vivo methods, incorporating brain imaging, behavioral assessments, and energy metabolism measurements. The findings revealed that astrocytes, previously overlooked, play a crucial role in brain function and energy regulation. Particularly, their ability to restore cognitive flexibility in obese models opens promising directions for future therapies targeting metabolic and cognitive disorders.

Published in Nature Communications, this study underscores the importance of astrocytes in understanding obesity's impact on the brain and suggests new avenues for research into treating metabolic and cognitive issues associated with high-fat diets.