Adult dmtn1 flies rescued by expression of wild-type Dementin in glia, i.e. whose neurons expressed only dmtn1, showed pathological features resembling early onset Alzheimer's disease, accumulation of abnormal APPL metabolites, synaptic pathology, mis-localized microtubule-binding proteins, neurodegeneration, and early death. This evidence concerns the gene APPL1 and early-onset autosomal dominant Alzheimer disease.