Fig. 3

H3 HCs do not elaborate dendrites to contact more blue cones before ultraviolet-cone regeneration.

(a) Two-photon time-lapse imaging of an H3 HC (grey scale or yellow cell) in the background of Tg(sws1:nfsB-CFP, sws1:nfsB-mCherry, sws2:mCherry) before and during ultraviolet-cone regeneration. d.p.a., days post ablation. Cyan arrowheads point to a dendritic tip invaginating a blue-cone axon pedicle that was maintained throughout the time course of imaging. Magenta arrowheads indicate a dendritic tip that retracted after ultraviolet-cone ablation. New dendritic tips elaborated to contact regenerated ultraviolet cones (white arrowheads). Undefined (orange circle); dendritic tip not apposed to blue or ultraviolet cone. (b) Addition and elimination of cone contacts across time points before ultraviolet-cone regeneration (n=6 cells each for control and regeneration condition (UV Reg.)). Individual cone contacts were followed at 2-day intervals to identify contact appearance or disappearance. (c) Net change in cone contact numbers of the same set of cells in b, after ultraviolet-cone regeneration. Contacts were visualized in fixed tissue at 10 d.p.a. because pigmentation of the larval retina between 4 and 10 d.p.a. (9-15 d.p.f.) prevented in vivo imaging. (b-c) Circles indicate values from individual H3 HCs. Error bars are s.e.m. NS, not significant (P=0.34). P values are from Mann–Whitney rank-sum test. UV, ultraviolet.