HTT and Parkinson disease: To test whether this is a common early event in additional types of NDs, we assessed expression of four Tip60 neuroplasticity genes using RNA isolated from the brains of three distinct and well-characterized early-stage Drosophila ND third instar larval models: the HD associated model expressing 128 poly-Q repeats in the human Huntingtin (Htt) gene (Htt(128Q))22, PD associated model expressing mutated form of human α-synuclein (SNCAA30P)23 and ALS associated model overexpressing Vap-33-1, a Drosophila homolog of VAMP-associated protein (Vap-33-1)24.