As orexigenic and anorexigenic hormone actions represent neural molecular mechanisms regulating feeding behavior, we also explored the mechanism and expression of different orexigenic (npy, agrp1) and anorexigenic (mc4r, crf, and pomcb) related genes within the hypothalamus of IPNv infected fish, analyzing the relationship between an infection challenge and markers for food intake activity. Here, CRH is linked to infection.