Figure 4. Analysis of birthdated immature neurons in young adult mice confirms modulation of dendritic growth and spine formation by canonical Wnt signaling activity.

1. Experimental scheme for birthdating of adult‐born neurons and recombination. For morphology analysis, CAG‐RFP was stereotactically injected into the DG (C–F), for marker expression analysis, BrdU was injected i.p. every 24 h for 3 days (B). Tamoxifen was applied i.p. every 12 h for 5 days from day 10 to day 14. Mice were sacrificed 3 days post‐tamoxifen (dpT) and 13 dpT, which corresponds to 17 and 27 dpi, respectively.
2. Expression of DCX and Calbindin in BrdU⁺ neurons was comparable between experimental groups at 3 and 13 dpT (control: n = 5 animals, β‐cat^ex3 iDCX: n = 5 animals).
3. Representative reconstructions of control and β‐cat^ex3 iDCX neurons expressing RFP at 3 dpT. Scale bar = 20 μm.
4. Quantification of dendritic length (P = 0.0003), branch points (P = 0.0433), and Sholl analysis (P < 0.0001) showed a higher dendritic complexity of β‐cat^ex3 iDCX neurons at 3 dpT (control: n = 22 cells from four animals, β‐cat^ex3 iDCX: n = 19 cells from five animals).
5. Representative reconstructions of control and β‐cat^ex3 iDCX neurons expressing RFP at 13 dpT. Scale bar = 20 μm.
6. Quantification of dendritic length (P < 0.0001), branch points (P = 0.0495), and Sholl analysis (P < 0.0001) showed a lower dendritic complexity of β‐cat^ex3 iDCX neurons at 13 dpT (control: n = 20 cells from four animals, β‐cat^ex3 iDCX: n = 19 cells from five animals).

Data information: Data represented as mean ± SEM, significance was determined using two‐way ANOVA for Sholl analysis and two‐tailed Mann–Whitney U‐test for all other analyses, and significance levels are displayed in GP style (*P < 0.0332, ***P < 0.0002 and ****P < 0.0001).