Accordingly, chronic caffeine treatment (0.75 mg/day or 1.5 mg/day for 8 weeks) dose-dependently increased the mBDNF protein levels in the hippocampus of APP/PS1 (Aβ precursor protein/presenelin-1) double transgenic mice, another model of Alzheimer's disease, and reversed the memory impairment observed in the Morris water maze (MWM) test [45]. This evidence concerns the gene APP and Alzheimer disease.