The amyloid precursor protein gene (APP) has important functions in the vertebrate nervous system. APP and its derivative peptides possess properties that fulfil criteria as neuractive peptides: presence, release and identity of action. APP is involved in synaptic action, neurogenesis and the brain’s response to injury. Aβ is a peptide of 1-43 amino acids in length and derived from APP and is the major protein component of the core of neuritic plaques found in Alzheimer’s disease. The neuropharmacological regulation of APP and Aβ is of considerable interest in terms of the understanding of the physiological properties of APP and providing insights that might lead to new treatments