Parkinson’s and Alzheimer’s disease are neurodegenerative diseases, i.e. medical conditions in which nerve cells in the brain (the so called neurons) die over time. Dementia is the most common symptom of these diseases, which affect many millions of people worldwide. Parkinson’s and Alzheimer’s disease damage two different areas in the brain: the first one affects neurons responsible for movement, while the second, neurons responsible for memory. Both diseases are quite difficult to diagnose, but they do present a common feature: certain proteins, the amyloids, which are usually found in the form of insoluble plaques, surround the affected neurons.