Figure 4

Assessment of recognition memory of 6-month-old APP/PS1 mice and wild type age-matched mice injected with saline and with D-Ala2 glucose-dependent insulinotropic polypeptide (GIP) for 32 days and assessment of recognition memory of 12-month-old mice injected for 34 days. Recognition index (RI) for familiar and novel locations during the test task (after a 3-h delay). Data represent mean ± standard error of the mean (SEM) of wild type (WT) mice injected with (A) saline (n = 14) and (B) D-Ala²GIP (n = 14), and APP/PS1 mice injected with (C) saline (n = 12) and (D) D-Ala²GIP (n = 12), (Student's paired t- test, *P < 0.05; **P < 0.01). (E) Difference in score of time spent exploring familiar and novel objects for each group (one-way analysis of variance, ANOVA). At 12 months, WT mice injected with (F) saline (n = 11) and (G) D-Ala²GIP (n = 11), and APP/PS1 mice injected with (H) saline (n = 11) and (I) D-Ala²GIP (n = 11) (Student's paired t- test, *P < 0.05; **P < 0.01). (J) Difference in score for time spent exploring familiar and novel objects for each group (one-way ANOVA).