Fig. 5

Impairment of learning and memory in APP-KI mice by disturbing the intrinsic clock. a The mRNA level of REV-ERBα in in the cortex from APP-KI mice with or without SR9009 injection. The results in represent the mean ± SEM of three independent experiments. The asterisks indicate a statistically significant difference from the controls (***P < 0.001, Student’s t test). b, c The morphological analyses of microglia in APP-KI mice without (b) or with SR9009 (c) injection. Two-dimensional (2D)-stack images of microglia were traced from CLSM images of Iba1-positive microglia. The skeletal images showing the topological staining skeletonized were reconstructed from 2D-stack images. Scale bar, 20 μm. d The length of the microglial process in APP-KI mice without or with SR9009 injection. e The size of microglial cell bodies in APP-KI mice without or with SR9009 injection. The results in d and e represent the mean ± SEM of 60–80 cells from three mice. The asterisks indicate a statistically significant difference from the controls (***P < 0.001, Student’s t test). f Immunoblots showing Iba1, NOS2, and IL-1β in the cortical lysate from APP-KI mice with or without SR9009 injection. g-i The quantitative analyses of Iba1, NOS2, and IL-1β in the immunoblots shown in (f). j Immunoblots showing IκBα and P-IκBα in the cortical lysate from APP-KI mice with or without SR9009 injection. k The quantitative analyses of Iba1, NOS2, and IL-1β in the immunoblots shown in (j). The results in f-k represent the mean ± SEM of three independent experiments. The asterisks indicate a statistically significant difference from the controls (*P < 0.05, **P < 0.01, and ***P < 0.001, Student’s t test). l The mean incidence of line-crossing. m, n The spatial working and reference memory was evaluated by the Y-maze test in APP-KI mice with or without SR9009 injection. The total number of entries of each group was calculated (m), and the spontaneous alternation percentages for each group were also calculated (n). The results are represented as the mean ± SEM (control mice, n = 6; SR9009 mice, n = 6), and the asterisks indicate a statistically significant difference from the control group (***P < 0.001, Student’s t test). o Time spent exploring the familiar and the novel objects in the recognition trial. The results are represented as the mean ± SEM (WT control mice, n = 6; WT SR9009 mice, n = 6; APP-KI control mice, n = 6; APP-KI SR9009 mice, n = 6), and the asterisks indicate a statistically significant difference from the APP-KI control group (***P < 0.001, two-way ANOVA test, interaction between two factors)