Beyond affecting the body, obesity reshapes how the brain processes reward, learning, and motivation. Researchers in France have discovered that a type of brain cell long thought to play only a supporting role may hold the key to reversing some of those effects.
A new study from CNRS and Université Paris Cité, published in Nature Communications, shows that manipulating astrocytes—star-shaped brain cells in the striatum—can influence both metabolism and cognition in mice. This work highlights astrocytes as central players in brain function and energy regulation, raising new questions about how these cells could be targeted in future obesity treatments.
What the study reveals
The research focused on astrocytes, glial cells that interact closely with neurons but don’t generate electrical activity themselves. For decades, they were overlooked in neuroscience, but recent advances in brain imaging and chemogenetic techniques have made it possible to study their role more precisely.
Scientists found that diets high in fat altered the structure and activity of astrocytes in the striatum, a region tied to pleasure and reward from eating. These changes not only influenced energy balance but also affected how the brain handled tasks related to learning and flexibility. Mice with obesity showed difficulty relearning tasks, a sign of impaired cognitive adaptability.
By using a viral tool to control calcium flow inside astrocytes—essential for their communication with neurons—the researchers were able to “switch” these cells into a more functional state. The result was striking: metabolic processes improved, and cognitive deficits caused by obesity were partially restored. This is the first time astrocytes have been shown to restore cognitive function in an obesity model.
What this could mean for obesity in the future
These findings suggest that obesity’s effects on the brain may not be permanent. If astrocytes can be tuned to restore lost functions, they could represent an entirely new therapeutic target. Unlike treatments focused only on reducing weight or controlling appetite, approaches aimed at astrocytes might also improve cognition, mood, and motivation—areas often disrupted by obesity.
It also changes the way researchers think about brain health. Neurons have long been the focus of studies on memory, behavior, and metabolic control, but astrocytes appear to be just as important. Their cooperation with neurons may be essential for maintaining both healthy metabolism and mental flexibility.
Still, the work is in its early stages. The experiments were done in mice, not humans. Translating these findings into treatments for people will require years of further research, from identifying safe ways to target astrocytes to testing whether the same mechanisms apply in human brains. Questions about side effects, delivery methods, and long-term impact will also need answers.
Yet the implications are significant. Obesity affects not only physical health but also brain performance, and current therapies don’t address both at once. If astrocytes can be harnessed, they may open the door to treatments that improve metabolism and protect the brain at the same time.
For now, the study offers a glimpse of what may be possible: that the brain’s own support cells could hold the power to reverse some of obesity’s damaging effects.