Mean escape latencies in seconds to find the platform in a water maze. On days 1–4, rats learned to reach an invisible platform (data were averaged to obtain a mean performance for each animal; open bars). On day 5, the platform was visible (filled bars). 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 < 0.01, ***P < 0.001 versus control; ##P < 0.01, ###P < 0.001 versus Aβ.