Fig. 6

Neuroprotective effect of Convolamine against Aβ25-35-induced learning impairments in mice: (a), (b) spontaneous alternation in the Y-maze, (c) step-through passive avoidance, and (d)–(h) active avoidance in the rectangular water-maze. Animals received Aβ25-35 peptide (9 nmol ICV) on day 1 and Convolamine (0.3–3 mg/kg IP) o.d. from day 1 to day 12, as shown. Behavioral testing was performed between day 8 and day 15 with the drug being injected 20 min before the Y-maze session or the passive and active avoidance training sessions. Retention was measured 24 h after training for passive avoidance and 72 h after training for active avoidance, without drug injection. (a) Spontaneous alternation percentage and (b) number of arm entries in the Y-maze test. (c) Step-through latency during the passive avoidance retention session. (d), (e) Active avoidance acquisition profiles in the rectangular water-maze, (f) short-term memory (STM) index, (g) latency to reach the platform location and (h) platform location crossings during the retention sesion. Bar graphs show mean ± SEM and individual data in (a), (b), (f)–(h) and box-and-wisker graphs show median and interquartile range and individual data in (C). The numbers of animals per groups were: n = 9–24 in (a), (b), 9–23 in (c), 9–16 in (d)–(h). ANOVA: F(5,105) = 6.061, p < 0.0001, in (a); F(5,105) = 0.9373, p > 0.05, in (b); F(4,54) = 3.342, p = 0.0162, in (g); F(5,54) = 3.434, p = 0.0142, in (h). Kruskal–Wallis ANOVA: H = 26.75, p < 0.0001, in (c). * p < 0.05, ** p < 0.01, *** p < 0.001 versus (V + V)-treated group; # p < 0.05, ## p < 0.01, ### p < 0.001 versus (V + Aβ25-35)-treated group; †† p < 0.01 versus “0″ level; Dunnett's test in (a), (b), (g), (h), Dunn's test in (c), one-column t-test in (f).