The Alzheimer's Disease Amyloid Precursor Protein and Its Neuritogenic Actions

The Amyloid Precursor Protein (APP) is principally known and studied for its involvement in Alzheimer's disease as the source of the amyloid β peptide; however, its physiological actions within the nervous system are also important as it is involved in a range of neuronal activities, including neurogenesis, synaptic plasticity, neurite outgrowth, and neuroprotection. Of the different neuronal functions that APP can affect, some may be relevant to APP's role in Alzheimer's disease, while others can be primarily related to its physiological roles. This review will focus on APP's neuritogenic actions and surmise the key molecular mechanisms, as well as the structural and signaling requirements, which form the basis for APP's neuritogenic effects. Deciphering the normal function(s) of APP is valuable to properly understanding its role in health as well as Alzheimer's disease.