Cortical neurons from non-demented control (NDC) and from three different genetic forms of AD—PSEN1 L113_I114insT (referred to here as PS1 Int4) (Moore et al., 2015), APP duplication (APPDp) (Israel et al., 2012), and Ts21 (Park et al., 2008)—were generated from iPSCs according to our previously described methods (Shi et al., 2012b). Here, PSEN1 is linked to Alzheimer disease.