APP and major depressive disorder: It has been shown that EphB2 level in the hippocampus of AD patients or APP/PS1 transgenic mice is decreased,22 and increasing EphB2 levels in the dentate gyrus reverse the deficits in memory impairments in APP/PS1 transgenic mice.21 Here we found that increasing EphB2 expression in the dorsal hippocampus of APP transgenic mice with lentiviral vector also reversed the deficits in memory impairment and improved the anxiety- or depression-like behaviors.