Study Reveals Brain’s Glycogen-Driven Mechanism for Food Anticipation
A groundbreaking study published in Nature Metabolism has uncovered how the brain’s pro-opiomelanocortin (POMC) neurons use glycogen to prepare the body for food, a discovery with significant implications for understanding and treating metabolic disorders like obesity and diabetes.
How POMC Neurons Use Glycogen to Anticipate Food
Researchers at Yale University and the Institut d’Investigacions Biomèdiques August Pi i Sunyer identified that POMC neurons, which regulate satiety, rely on glycogen stores to activate anticipatory responses to food. This mechanism, observed in mice, involves glycogen synthase—molecular machinery that synthesizes glycogen—being triggered by the sensory perception of food.
“This study identifies a previously unknown molecular mechanism driving food perception, revealing that neuronal glycogen fuels the brain’s anticipatory responses to food,” said Marc Claret, co-principal investigator and head of the Neuronal Control of Metabolism Laboratory at the Institut d’Investigacions Biomèdiques August Pi i Sunyer.
Experimental Evidence and Key Findings
The team conducted experiments where mice were exposed to food through a wire mesh, allowing them to see and smell but not eat it. They found that food exposure activated glycogen synthase in POMC neurons. When mice were genetically modified to lack glycogen synthase in these neurons, they exhibited reduced food-seeking behavior, shorter eating durations, and impaired insulin production before meals.
Additional tests using viral gene suppression in normal mice confirmed these results, demonstrating that glycogen deficiency directly impacted the brain’s ability to respond to food cues. “Obesity is a dysregulation of the feeding circuitry at the level of the brain—it’s more of a disease of the brain than a disease of the body,” noted Marc Schneeberger Pane, assistant professor in cellular and molecular physiology at Yale and co-principal investigator.
Challenging Previous Assumptions About Brain Glycogen
The study challenges long-held beliefs that brain glycogen is primarily stored in astrocytes. Instead, it suggests POMC neurons may play a direct role in energy storage and signaling. The research also highlighted that POMC neurons respond to smell but not visual cues, linking them to olfactory processing centers in the brain.
“This sensory aspect of food prepares the organism for what is coming,” Schneeberger Pane explained. “Dysregulation will compromise the system’s ability to properly respond to food.”
Implications for Obesity and Diabetes Research
Mutant mice lacking glycogen synthase in POMC neurons developed obesity and prediabetic indicators over time, underscoring the link between this mechanism and metabolic health. The findings could inform future therapies targeting brain circuitry involved in appetite regulation.
“These findings suggest that defects in how the brain anticipates food may contribute to obesity and diabetes, opening new therapeutic avenues for these diseases,” Claret said.
Future Directions and Clinical Relevance
The research, funded by the National Institutes of Health and Yale University, builds on existing work with GLP-1 receptor agonists—drugs that target satiety pathways. Understanding this glycogen-driven mechanism could refine drug development for metabolic diseases.
“Studying the neural circuitry driving hunger and satiety can help scientists better understand how to treat metabolic diseases like obesity,” the study concludes.