PARP1 and Alzheimer disease: In order to investigate whether histone acetylation and/or methylation were deregulated in our AD Aβ42 model and to verify whether PARP-1 inhibition with olaparib and MC2050 may affect histone acetylation and/or methylation levels, we performed Western blotting experiments of epigenetic markers from head tissue of elav-Gal4 > Aβ42 and elav-Gal4/+ control flies.