New Brain Cell Discovery Provides Insight into Excessive Hunger

In a groundbreaking study published in *Nature Communications* on June 13, 2025, researchers from the University of Southern California (USC) have identified a specific group of brain cells that encode memories associated with eating, a discovery that may explain why individuals with memory impairments frequently overeat. The research focuses on neurons located in the ventral hippocampus, which become activated during meals and form what the researchers term 'meal engrams.' These engrams are specialized memory traces that store crucial information about food consumption, including not only the type of food but also the timing and location of meals.

Scott Kanoski, a professor of biological sciences at USC Dornsife College of Letters, Arts and Sciences and the study's corresponding author, emphasized the significance of these meal engrams: 'An engram is the physical trace that a memory leaves behind in the brain. Meal engrams function like sophisticated biological databases that store multiple types of information such as where you were eating, as well as the time that you ate.' This nuanced understanding of how memories of meals are formed can shed light on overeating behaviors, particularly in individuals with memory challenges, such as those suffering from dementia or brain injuries.

The implications of this research extend beyond academic interest; they could significantly impact clinical approaches to treating eating disorders and obesity. Lea Decarie-Spain, a postdoctoral scholar at USC and the study's first author, noted that distractions during meals, such as watching television or using smartphones, could impair the formation of meal memories, leading to increased food consumption. 'The brain fails to properly catalog the meal experience, leading to weak or incomplete meal engrams,' Decarie-Spain explained.

The methodology employed by the research team involved advanced neuroscience techniques to observe the brain activity of laboratory rats in real-time as they consumed food. The study demonstrated that meal memory neurons differ from other types of memory cells, as evidenced by the impaired memory of food locations in rats when these neurons were selectively destroyed, while their spatial memory for non-food-related tasks remained intact. This specificity suggests a dedicated neural pathway for processing meal-related information.

Furthermore, the research revealed that meal memory neurons communicate with the lateral hypothalamus, a region critical for regulating hunger and eating behaviors. Disruption of this communication pathway resulted in overeating among the rats, indicating that the proper functioning of meal engrams may be essential for maintaining healthy eating patterns.

Kanoski posited that this newfound understanding could inform innovative strategies for obesity management. Traditional approaches often focus solely on dietary restrictions or increased physical activity; however, this research highlights the necessity of improving meal memory formation as a complementary strategy for healthy eating. 'We're finally beginning to understand that remembering what and when you ate is just as crucial for healthy eating as the food choices themselves,' Kanoski stated.

This study was conducted with support from various prestigious grants, including a Quebec Research Funds Postdoctoral Fellowship and a National Institute of Diabetes and Digestive and Kidney Diseases grant. The collaborative research team included authors from USC, the University of Pennsylvania’s Perelman School of Medicine, and the Monell Chemical Senses Center, among others. As the scientific community continues to explore the intricate relationship between memory and eating behaviors, this research paves the way for future inquiries into effective interventions for disordered eating and obesity.