Fig. 8.

Injured dendrites exhibit calcium-flashing that is suppressed by Wld^S and axed loss. (A) A ddaC neuron in a third instar larva expressing myr-GCaMP6s before (BI) and after (2 s AI, 1 h AI, and 6 h AI) laser injury. Blue arrows, uninjured dendrites or cell body; yellow arrowheads, injured dendrites; and blue asterisk, injury site. (Scale bar, 10 μm) (Movie S5). (B) Labeling of injured ddaC dendrites expressing GCaMP6s by AV-mCard after (2, 4, and 5.5 h) injury. (Scale bar, 10 μm.) (Movie S6). (C) Kymograph of GCaMP6s signal and AV-mCard binding on an injured dendrite shown in B. Yellow dotted lines, timing of AV-mCard binding; blue dotted lines, timing of the final calcium surge. (Scale bars, 3 μm horizontal, 40 min vertical.) (D–F) Kymograph of GCaMP6s signal in wild-type (D), Wld^S-overexpressing (E), and axed KO (F) dendrites AI with 3-min interval (Movies S5, S7, and S11). (Scale bar, 5 μm horizontal, 60 min vertical.) (G–I) Kymograph of GCaMP6s signal in wild-type (G), Wld^S-overexpressing (H), and axed KO (I) dendrites AI with 2-s interval (Movies S8, S9, S10, and S12). (Scale bars, 5 μm horizontal, 45 s vertical.) (J) Plot of GCaMP6s brightness in injured dendrites in D–F over time with 3-m interval. Measurements in injured dendrites start from 0.5 to 1 h AI. (K) Plot of GCaMP6s brightness in injured dendrite in G–I over time with 2-s interval. Measurements start from 0.5 to 1 h AI. (L) Quantification of average flashing amplitude (GCaMP6s brightness difference between maximum peak and neighboring minimum peak) captured in 2-s interval time-lapse images. N = number of dendrite arbors: wild-type 0.5 to 1.5 h AI (n = 19, five animals); Wld^S-overexpressing 2 h AI (n = 8, four animals); and axed KO 0.5 to 1 h AI (n = 7, three animals) (one-way ANOVA and Tukey’s test). For all quantifications, ***P ≤ 0.001 and ns, not significant. The significance level above each genotype is for comparison with the control. Black bar, mean; red bar, SD.