The murine thymocyte antigen promotor (Thy1) drives the expression of the human APP (APP-751) cDNA bearing the Swedish double mutation K670N and M671L and the Indiana mutation V717F primarily in pyramidal neurons of the telencephalon and starting postnatally. Transgene copy number as assessed by Southern blotting is estimated to be about 20. Western blot analysis confirmed overexpression of the transgene in the hippocampus and cortex. Mice express on average 2-fold higher levels of amyloid beta42 than of amyloid beta40 in both cortex and hippocampus.