Bottom-Up Midbrain-Subthalamic Control of Feeding

UCLA’s Avishek Adhikari, PhD, presents new research on the role of GABAergic neurons in the brain’s periaqueductal gray (PAG) region. Previously studied for their involvement in fear and defensive behaviors, these neurons were found to promote food-seeking behavior when activated—even in fully fed mice. Using calcium imaging and optogenetics, Adhikari’s team discovered that these neurons are active during food approach but suppressed during eating. The effect is stronger for high-value foods like chocolate or crickets and depends on the mouse’s prior experience with that food. A key finding is that these neurons influence behavior through a specific projection to the zona incerta, a subthalamic region. Rather than signaling hunger, this pathway appears to drive food seeking based on reward value, highlighting a new motivational circuit in the brain. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 40444]