Flies were maintained in standard cornmeal media at 25°C under light–dark cycles of 12:12 hours. To establish the transgenic fly line carrying the human 2N4R tau with or without mutations or deletions, cDNA was subcloned into pUASTattB, and injected to the oocytes carrying into P{CaryP}attP2. UAS-SOD1 (31 (link)) was obtained from Bloomington stock center (Stock #33605). For RU486 feeding, RU486 was mixed into the cornmeal media at the final concentration of 500 μm. Genotypes of the flies used in the experiments are described in Supplementary Material Table S1.