These results lead us to suggest that the in vivo mouse model of AD based on four consecutive intra-dCA1 injections of Aβo(1–42) could constitute a valuable tool to study the Aβo(1–42) impact in the hippocampus which could characterize the very early stage of AD, even though in the general frame of AD, it is focused on a specific brain area which did not reflect the widespread damage occurring during the time-course of the disease. This evidence concerns the gene ABO and Alzheimer disease.