APP and Alzheimer disease: In this study, we examined the effects of perinatal choline supplementation on AD pathology in the APPswe/PS1deltaE9 (APP.PS1) mice that express murine amyloid precursor protein (APP) with the human Aβ amino acid sequence harboring mutations that cause a familial form of AD (the Swedish mutation APP (K595N/M596L; APPswe) and a mutated form of presenilin 1 (PSEN1 with exon 9 deleted; PS1dE9) [43].