Feeding is a complex behavior that is regulated by several internal mechanisms. Neuropeptides are able to survey quantities of stored energy and inform the organism if nutrient intake is required. In addition to this homeostatic regulation, a post-feeding reward system positively reinforces feeding. Slight adjustments to either system can tilt the balance to affect the energy reserves and survivorship in times of nutrient adversity. Neuropeptide F (NPF), a homolog of the mammalian neuropeptide Y, acts to induce feeding within the homeostatic regulation of this behavior.
Amyloid precursor protein (APP) is a key player in Alzheimer’s disease. The proteolytic cleavage of APP results in various short peptide fragments including the toxic amyloid-beta peptide, which is a main component of senile plaques. However, the functions of APP and its processed fragments are not yet well understood.