PSEN1 and Alzheimer disease: Here, we utilized laser ablation–inductively coupled plasma–mass spectrometry and solution nebulization–inductively coupled plasma–mass spectrometry to quantitatively measure Cu, Fe, and Zn concentrations in the retina and hippocampus samples obtained from human donors (i.e. AD and healthy controls), and in the amyloid precursor protein/presenilin 1 (APP/PS1) mouse model of AD and wild-type (WT) controls, aged 9 and 18 months.