Drosophila studies based on the direct expression of Aβ peptides from transgenes or on the production of peptides by AβPP processing have shown neurotoxic effects such as reduced longevity and locomotor dysfunction, the rough eye phenotype, learning deficits and the accumulation of extracellular deposits, revealing that AD-like neurodegeneration can be linked to the production of the Aβ1-42 peptide. This evidence concerns the gene APP and Alzheimer disease.