APP and Alzheimer disease: To visualize AD pathology at the level of single cholinergic axon arbors, we used APPswe/PS1ΔE9 doubly transgenic mice (Jankowsky et al., 2004; referred to hereafter as APP/PS1) in which Aβ plaque rapidly accumulates with age in the cortex and hippocampus (Figure 5—figure supplement 1).