Dab1 deficiency leads to severe morphological alterations of adult-generated neurons. A–D, Representative images of adult-generated neurons infected with GFP- and Cre-expressing retrovirus in Dab1+/+ and Dab1flox/flox mice 2 weeks after surgery. E, F, Tracings of adult-generated neurons at 2 and 8 weeks postsurgery in Dab1+/+ and Dab1flox/flox mice. G–I, Quantification of morphological parameters of adult-generated neurons infected with GFP only (GFP) or Cre and GFP (CreGFP) retroviruses in Dab1+/+ and Dab1flox/flox mice. The number of primary dendrites in Dab1flox/flox-GFP-Cre neurons was higher than in control groups at 2 weeks after surgery (ANOVA: p < 0.05; post hoc: p < 0.05) and in the WT-CreGFP group at 4 weeks (ANOVA: p < 0.05; post hoc: p < 0.05). The number of branches in Dab1flox-flox-GFP-Cre neurons was greater than in control groups at 2 weeks after surgery (ANOVA: p < 0.05; post hoc: p < 0.05) and in the Dab1flox/flox-GFP group at 4 weeks (ANOVA: p < 0.05; post hoc: p < 0.05). The dendritic length of Dab1flox/flox-GFP-Cre neurons was higher than in control groups at 2 and 4 weeks after surgery (ANOVA: p < 0.05; post hoc: p < 0.05), and in the WT-CreGFP group at 8 weeks (ANOVA: p < 0.05; post hoc: p < 0.05). J, K, Sholl analysis. Dab1-deficient neurons have lower numbers of intersections than WT neurons at all the time points studied (ANOVA: p < 0.05; post hoc: p < 0.05).