IVIg treatment improves object recognition memory and anxiety-like behavior in 3xTg-AD mice. (A) NOR test was performed by 12-month-old (3-month-treatment, n = 11 to 12 animals per group) and 16-month-old mice (1- and 3-month-treatments, n = 7 to 8 NonTg and n = 11 to 13 3xTg-AD animals per group. The mean is indicated with a line. One sample t-test. ∞∞
P <0.01, ∞∞∞
P <0.001 versus random chance (50%). (B) Dark-light box emergence test was used to evaluate the anxiety-like behavior (n = 8 NonTg and n = 11 to 13 3xTg-AD mice per group, 12 months of age after a 3-month treatment; mean ± SEM). Kruskal–Wallis test followed by Wilcoxon’s multiple comparison test, *P <0.05 versus NonTg group. (C) Spatial memory deficits were not improved following a 3-month treatment with IVIg as assessed with 16-month-old 3xTg-AD mice exposed to the Barnes maze. Data are presented as mean escape latency ± SEM of 11 to 13 animals per group. Comparisons between groups were performed using a one-way ANOVA followed by Tukey’s multiple comparison test. The area under the curve for the mean escape latency during the training period was also analyzed with a Student’s t-test. Furthermore, the mean escape latency during the probe test was compared using a Student’s t-test with Welch’s correction. P >0.05 in all statistical tests. (D) The locomotor performance was evaluated with open field recording in 16-month-old 3xTg-AD mice after a 3-month treatment. The results are shown as the mean ± SEM of n = 7 NonTg and n = 11 to 12 3xTg-AD animals per group. 1mo, 1-month treatment; 3mo, 3-month treatment; 3xTg-AD, triple-transgenic mouse model of Alzheimer’s disease; ANOVA, analysis of variance; ctrl, control; IVIg, human intravenous immunoglobulin; NonTg, non-transgenic; NOR, novel object recognition.