HTT and juvenile Huntington disease: In the present study, this methodology is used to compare three different Drosophila models of neurodegeneration: two cell-specific models of Huntington disease (HD), in which a pathogenic fragment of the human Huntingtin (HTT) protein containing a pathogenic polyglutamine expansion was expressed either in neurons (NHD model)23–29, or in glial cells (GHD model)25,26,30, and a model of excitotoxicity-induced neurodegeneration based on the knock-down of the glutamate transporter Eaat1 in synapse-associated glia (GLU model)31–36.