APP and early-onset autosomal dominant Alzheimer disease: Several neurotoxic Aβ oligomers have thus far been described,12,13 and while it is generally believed that soluble Aβ is the main toxic species in AD,2 insoluble amyloid plaques also induce damage to dendrites and disrupt normal neuronal wiring.14 For these reasons the in-vivo effect of AChE-S and AChE-R was examined in the APPsw mouse model, carrying the amyloid precursor protein (APP) with the “Swedish” mutation leading to early-onset Alzheimer’s disease.