A new study, published in the journal Cell Metabolism, shows that humans and other bony vertebrates need a hormone called osteocalcin to develop an acute stress response, a function critical to survival in the wild; when they encounter an immediate danger, a brain-derived signal stimulates the release of osteocalcin from bone. This fight-or-flight pathway is distinct from others mediated by hormones released by the adrenal glands, such as cortisol,...
