To model the advanced stages of Alzheimer's disease and the impact of long-term isolation, male transgenic 3xTg-AD mice, a triple-transgenic model (3xTg-AD) where mice from a C57BL/6 genetic background harbor PS1(M146V), APP(Swe), and tau(P301L) transgenes, were socially isolated and compared to non-transgenic mice as well as non-isolated transgenic mice (controls). This evidence concerns the gene APP and Alzheimer disease.