Fig. 6

Blocking DCC signaling induces changes in dendritic arbor shape without altering total branch number or length. a–c Confocal projections of representative tectal neurons co-expressing tdTomato (red) and PSD95-GFP (green) in tadpoles injected with control vehicle solution (a), netrin-1 (b), or function-blocking antibodies to DCC (c). While control neurons branch, elaborate, and add PSD95-GFP puncta (a), neurons in tadpoles treated with netrin-1 undergo dynamic remodeling of existing branches (b). Short arrows point to dendrites with altered directions of growth. Neurons in tadpoles treated with anti-DCC (c) also appear to change dendritic arbor direction and form small basal projections at 2 and 4 h post-injection (long arrows). Scale bars: 20 μm. d, e Comparison of effects of netrin and anti-DCC on total branch number (d) and dendritic arbor length (e). Note that only netrin-1 treatment decreased arbor length at 24 h (e), but neither netrin nor anti-DCC affects the total number of branches (d). Two-way ANOVA with Bonferroni multiple comparison test; *p < 0.05. Error bars indicate SEM