Neurons are highly compartmentalized cell-types. In neurodegenerative diseases such as Alzheimer's disease, the protein Tau that serves a distinct function in one cellular compartment (the axon) accumulates in a massively phosphorylated form elsewhere (somatodendritic compartments and their spines) which is believed to impair neuronal functions. We will investigate how Tau is distributed in health and disease, and determine how this distribution is regulated.