Terminal SC territories are constrained by neighboring SCs at adult NMJs. (A–C) Two-photon laser–induced ablation (A) of a terminal SC (cyan; asterisk) followed by time-lapse visualization (B) of a neighboring intact terminal SC (white) of the boxed area in A. (C) Post hoc confocal analysis after BTX (red) labeling shows complete coverage of vacated territory by the remaining terminal SC. The axon (labeled by thy1-Membow; green in A) remained intact (not depicted; Video 4). (D–F) Ablation (D) of axonal SC (yellow; asterisk) and time-lapse recording (E) of terminal SC (white). Confocal analysis (F) shows expansion of terminal SC along the axon (labeled by thy1-Membow; green in D; red [BTX] in F). (F, inset) Small postsynaptic area that was vacated during expansion (higher magnification view of boxed area). (G–I). Ablation (G) of terminal SC (cyan; asterisk) and time-lapse recording (H) of adjacent axonal SC. No takeover of territory or phagocytic activity was observed, as confirmed by confocal analysis after fixation (I; axon shown in green in G, labeled by thy1-OFP3; BTX in I). The timers shown represent hours/minutes. Bars, 5 µm.