Part 6/14:
When infection occurs, our bodies initiate what is termed sickness behavior—a set of motivated responses including lethargy, loss of appetite, reduced grooming, and social withdrawal. These behaviors serve an adaptive purpose—conserving energy and directing resources toward recovery. Crucially, the vagus nerve mediates this communication between body and brain, signaling via neural pathways to induce these behavioral changes, and promoting a fever through hypothalamic activation to aid pathogen elimination.