Mean percent of quadrant entries ± SEM during the 4 days of training in a water maze with the hidden platform (data were averaged to obtain a mean performance for each animal). Six groups (n = 10) were tested: control; Aβ; Aβ+ Tween; Aβ+Zataria multiflora (ZM) essential oil (50, 100, or 200 μL/kg). Error bars indicate ± SEM. *P < 0.05, **P < 0.01 versus control; #P < 0.05, ##P < 0.01, ###P < 0.001 versus Aβ.