Protective effects of ent-PREGS against the Aβ25-35-induced memory deficits in mice: (A) spontaneous alternation performances; and (B) step-through passive avoidance. Mice were administered i.c.v. with distilled water (V) or ent-PREGS (0.05-2 nmol) simultaneously with Aβ25-35 peptide (9 nmol). The i.c.v. injection of ScAβ (9 nmol) was used as control. Spontaneous alternation performances in the Y-maze were measured on day 7. Passive avoidance training was carried out on day 8 and retention on day 9. F(5,51) = 7.92, p < 0.0001, n = 6-10 per group, in (A); H = 11.4, p < 0.05, n = 6-10, in (B). * p < 0.05, ** p < 0.01 vs. the (ScAβ+V)-treated group; # p < 0.05 ## p < 0.01 vs. the (Aβ25-35+V)-treated group; Dunnett's test in (A); Dunn's test in (B).