The animals were randomly divided into three groups (n = 6): sham surgery, model, and DNLA (40 mg/kg) treatment group. Mice were anesthetized with 7% chloral hydrate (35–45 mg/kg, i.p.) and fixed on a stereotaxic instrument (RWD Life Science, Guangdong, China). Then Aβ25–35 (2.5 µg/µL, 2 µL) was injected into both lateral cerebral ventricle in the model and DNLA groups via a 5-µl microinjector. The injection site was posterior from the bregma (AP) = −0.4, mediolateral from the midline (MR) = 1.2, and dorsoventral from the skull (DV) = 2.7. Mice in the sham group were treated the same as the model group except for the injection of Aβ25–35 instead of sterile normal saline (Nie et al., 2010). Mice in the DNLA group were administered intragastrically with DNLA (40 mg/kg) on the first day after the injection for 19 consecutive days, while mice in the sham and model groups were administered with distilled water.