For comparison, we also examined the effects of expression both of exon 1 of the Htt gene, containing a 128 glutamine residue expansion (Htt-Q128; [40]), and also of mutant (R406W) human tau, which is associated with frontotemporal dementia with parkinsonism-17 (FTDP-17) [41]. This evidence concerns the gene MAPT and semantic dementia.