Neuropeptide Y is associated with changes in appetite-associated hypothalamic nuclei but not food intake in a hypophagic avian model

While neuropeptide Y (NPY) has been studied extensively per its pronounced role in food intake stimulation as well as its role in central pathways governing eating disorders, it has to our knowledge not been studied in polygenic models of hypo- and hyperphagia. Thus, the present study was designed to measure central NPY-associated food intake in lines of chickens that have undergone long-term genetic selection for low (LWS) or high (HWS) body weight and exhibit hypo- and hyperphagia, respectively. LWS chicks did not respond with any magnitude of altered food intake to any dose of NPY tested, while HWS chicks responded to all doses of NPY at similar magnitudes throughout the duration of observation. Both lines responded with similar increases in c-Fos immunoreactivity in the lateral hypothalamus and both divisions of the paraventricular nucleus; there were no significant line or line by treatment interactions. These data support the hypothesis that differences exist in the central NPY system of chicks from LWS and HWS lines and may provide novel insight for understanding NPY control of appetite.