The research studies the aggregation process of the amyloid (A) beta peptide linked to Alzheimer's disease. Alzheimer's is a dementia disease in which the nerve cells in the brain break down. To combat the disease, it is important to: a) identify which structures of the A-beta peptide are toxic to neurons, b) determine how the toxic structures attack the cells, and c) find molecules that can prevent the formation of toxic A-beta structures. To achieve these goals, fruit flies that can form toxic A-beta structures in the central nervous system are used. In parallel, the aggregation process of the A-beta peptide is also studied in a simpler environment, in test tubes, with different biophysical measurement techniques such as spectroscopy and microscopy, as well as how toxic A-beta structures attack cells from both rats and humans. By combining these studies, it is possible to link the emergence of different structures of the A-beta peptide with their ability to cause neuronal degradation and thus identify the structures that are toxic to the cells. This information is important for finding new treatments for Alzheimer's disease. Banana flies are also used to test different molecules (drug candidates) that can protect cells from being degraded by toxic A-beta structures or counteract the formation of toxic A-beta structures, thus preventing the onset of the disease.