Figure 1.
Normalization of the Dyrk1A copy number reduced Dyrk1A protein expression in the hippocampus of TS mice.
Western blot analysis of Dyrk1A protein levels in the hippocampus of CO +/+, TS +/+/+ and TS +/+/− mice. Differences in the TS +/+/+ and TS +/+/− mice are expressed relative to the values of CO +/+ mice (defined as 100%). ANOVA ‘trisomy’: F(1,17) = 22.79, p<0.001, ‘Dyrk1A’: F(1,17) = 14.40, p<0.001. ***: p<0.001 TS +/+/+ vs. CO +/+; ##: p<0.01 Dyrk1A +/+/+ vs. Dyrk1A +/+/−; Bonferroni tests after significant MANOVAs.
Figure 2.
Normalization of the Dyrk1A protein expression levels in the hippocampus improved spatial working and reference memory and contextual fear conditioning in TS mice.
Data are presented as the mean values ± SEM (a) of the latency to reach the platform during the acquisition sessions (between-session analysis: RM ANOVA: ‘session’ F(7,35) = 48.29, p<0.001; ‘trisomy’: F(1,35) = 44.20, p<0.001; ‘Dyrk1A’: F(1,35) = 7.98, p = 0.006); (b) of the latency to reach the platform in each trial across the 8 acquisition sessions (within-session analysis: ‘trial’ F(7,35) = 14.57, p = 0.001, p<0.001; ‘trisomy’: F(1,35) = 23.65, p<0.001; ‘Dyrk1A’: F(1,35) = 13.47, p = 0.001); (c) of the efficacy of the learning score (‘session’ F(7,35) = 22.31, p<0.001; ‘trisomy’: F(1,35) = 34.40, p<0.001; ‘Dyrk1A’: F(1,35) = 9.70, p = 0.003); (d) of the percentage of time spent in the periphery of the pool during the 8 sessions (‘session’ F(7,35) = 21.94, p<0.001; ‘trisomy’: F(1,35) = 13.92, p<0.001; ‘Dyrk1A’: F(1,35) = 8.52, p<0.001); (e) of the mean swimming speed (ANOVA ‘trisomy’: F(1,35) = 0.03, p = 0.84; ‘Dyrk1A’: F(1,35) = 0.07, p = 0.78); (f) of the mean latency to reach the platform in the 4 averaged cued sessions (ANOVA ‘trisomy’: F(1,35) = 0.01, p = 0.91; ‘Dyrk1A’: F(1,35) = 1.58, p = 0.21) in the MWM test and (g) of the freezing time during the cued and contextual conditioning tests (Cued conditioning: ANOVA ‘trisomy’: F(1,35) = 7.42, p = 0.01; ‘Dyrk1A’: F(1,35) = 0.01, p = 0.97; Contextual conditioning: ANOVA ‘trisomy’: F(1,35) = 18.64, p<0.001; ‘Dyrk1A’: F(1,35) = 5.54, p = 0.11). *: p<0.05, **: p<0.01, ***: p<0.001 TS +/+/+ vs. CO +/+; #: p<0.05, ##: p<0.01 Dyrk1A +/+/+ vs. Dyrk1A +/+/−; Bonferroni tests after significant MANOVAs.
Figure 3.
Normalization of the Dyrk1A copy number did not affect motor coordination in the rotarod test or the levels of general activity and anxiety in the open field test.
Mean values ± SEM of the latency to fall from the rotarod at different constant speeds (a) and during the acceleration cycle (b) or of the activity performed by the three groups of mice in the open field test (c). Rotarod constant speeds: ANOVA ‘trisomy’: F(1,35) = 0.72, p = 0.40; ‘Dyrk1A’: F(1,35) = 1.82, p = 0.18. Acceleration cycle: ANOVA ‘trisomy’: F(1,35) = 0.72, p = 0.40; ‘Dyrk1A’: F(1,35) = 1.69, p = 0.20. Open field periphery: ANOVA ‘trisomy’: F(1,35) = 6.36, p = 0.014; ‘Dyrk1A’: F(1,35) = 0.70, p = 0.17; Center: ANOVA ‘trisomy’: F(1,31) = 2.21, p = 0.14; ‘Dyrk1A’: F(1,31) = 0.17, p = 0.68; Total: ANOVA ‘trisomy’: F(1,35) = 5.39, p = 0.023; ‘Dyrk1A’: F(1,35) = 1.77, p = 0.67. *: p<0.05 TS +/+/+ vs. CO +/+; Bonferroni tests after significant MANOVAs.
Table 1.
Motor test battery (mean scores ± SEM).
Figure 4.
Normalization of the Dyrk1A copy number rescued LTP in TS mice.
(a) Representative fEPSP traces before (gray) and after (black) TBS stimulation (top row). (b) Time courses of the initial slope of fEPSPs recorded from the CA1 region in hippocampal slices following stimulation of the Schaffer collateral-commissural pathway. The data are presented as the mean values ± SEM from 6 slices from 6 different mice in each group (lower row). ANOVA ‘trisomy’: F(1,17) = 9.34, p = 0.009; ‘Dyrk1A’: F(1,17) = 13.62, p = 0.003.
Figure 5.
Normalization of the Dyrk1A copy number reduced the density of GABAergic and increased the density of glutamatergic synapse markers in the hippocampus of TS mice.
(a) Representative images of GAD65/67, VGLUT and GAD6567/VGLUT immunostaining. (b) Mean values ± SEM of the percentage of area occupied by GAD65/67- (top row) and VGLUT-positive boutons (middle row) in the hippocampus of TS +/+/+, TS +/+/− and CO +/+ mice and the ratio of these areas (lower row). GAD65/67: ANOVA ‘trisomy’: F(1,17) = 10.10, p = 0.006; ‘Dyrk1A’: F(1,17) = 3.91, p = 0.066. VGLUT: ANOVA ‘trisomy’: F(1,17) = 10.35, p = 0.006; ‘Dyrk1A’: F(1,17) = 4.49, p = 0.051; Ratio GAD/VGLUT: ANOVA ‘trisomy’: F(1,17) = 37.44, p<0.001; ‘Dyrk1A’: F(1,23) = 9.30, p = 0.009. **: p<0.01, ***: p<0.001 TS +/+/+ vs. CO +/+; #: p<0.05 TS +/+/+ vs. TS +/+/−.
Figure 6.
Normalization of the Dyrk1A gene dosage increased cell proliferation and differentiation in the DG but did not rescue the density of mature granule neurons.
(a) Representative images of Ki67, DCX, CLR and DAPI labeling in the DG. (b) Mean values ± SEM of the density of Ki67-, DCX-, CLR- and DAPI-positive cells of TS mice trisomic (+/+/+) and disomic (+/+/−) for Dyrk1A and euploid (CO +/+) mice. Ki67: ANOVA ‘trisomy’: F(1,17) = 5.60, p = 0.032; ‘Dyrk1A’: F(1,17) = 7.31, p = 0.017. DCX: ANOVA ‘trisomy’: F(1,17) = 7.37, p = 0.016; ‘Dyrk1A’: F(1,17) = 3.79,; p = 0.071. CLR: ANOVA ‘trisomy’: F(1,17) = 0.94 p = 0.34; ‘Dyrk1A’: F(1,17) = 5.56, p = 0.032. DAPI: ANOVA ‘trisomy’: F(1173) = 13.43, p = 0.003; ‘Dyrk1A’: F(1,17) = 1.77, p = 0.20. *: p<0.05 TS +/+/+ vs. CO +/+; #: p<0.05 TS +/+/− vs. TS +/+/+; Bonferroni tests after significant MANOVAs.
Figure 7.
Reduction of the Dyrk1A gene copy number did not rescue the reduced DG volume, SGZ area or body weight in TS mice.
Mean values ± SEM of the DG volume (a), SGZ area (b) and body weight (c) of TS +/+/+ and TS +/+/− mice and of euploid mice. DG volume: ANOVA ‘trisomy’: F(1,17) = 4.94, p = 0.043; ‘Dyrk1A’: F(1,17) = 0.13, p = 0.72. SGZ area: ANOVA ‘trisomy’: F(1,17) = 12.14, p = 0.003; ‘Dyrk1A’: F(1,17) = 0.01, p = 0.89. Body weight: ANOVA ‘trisomy’: F(1,31) = 62.98, p<0.001; ‘Dyrk1A’: F(1,31) = 1.31, p = 0.026. *: p<0.05, **: p<0.01, ***: p<0.001 TS vs. CO; Bonferroni tests after significant MANOVAs.
Table 2.
Summary of the primary effects of the Dyrk1A gene dosage.