Your Brain Tells Your Liver to Spike Blood Sugar When You're Stressed
Researchers at Mount Sinai have identified a direct brain-to-liver signaling pathway that explains why blood sugar spikes during stress. When mice encounter a threat, neurons in the medial amygdala activate a chain of signals that reaches the liver and triggers rapid glucose production via gluconeogenesis. Remarkably, this happens independently of cortisol, adrenaline, glucagon, or insulin — the hormones traditionally thought to drive stress hyperglycemia. The circuit also suppresses appetite during stress. Repeated stress exposure disrupts this pathway, producing diabetes-like dysregulation of blood glucose. The findings, published in Nature, reveal a previously unknown amygdala–liver axis that may help explain why chronic psychological stress is a major risk factor for type 2 diabetes.