Figure 2.

Postsynaptic Dendrites Have Significantly Broader Exploration Range Than Presynaptic Axons

(A) Me and Bs neurons were imaged in developing live embryos.

(B) Time lapse of Me (red) and Bs (green) neurons. Images are confocal Z-projections of a representative embryonic VNC. Time points are relative to the start of the imaging session (13 h AEL, time point + 0 h), when GFP in Bss is first detected. First row, entire field of view; subsequent rows, subregions marked with white square. Dashed line, midline (M).

(C and D) Temporal projection of Me axons (C) and Bs neurons (D) in one hemisegment.

(C) Cumulative Me exploration area (white) slightly exceeds the mature axon area (red).

(D) Bs dendritic filopodia explore most of their hemisegment, eventually adopting a final morphology (green) much more compact than the cumulative exploration area (white). Bs axons explore much less compared with their dendrites. CB, cell body; De, dendrites; Ax, axon.

(E) Bs dendrites and Me axons covered a wider cumulative area (mediolateral and anteroposterior axes) during developmental exploration than the area occupied by their respective mature arbor (stars above each bar; one-sample t test with default value of 100%). However, the relative exploration range of Bs dendrites is significantly larger than that of Me axons (Wilcoxon test). ^∗∗∗p < 0.001. n = 10 hemisegments each.

See also Video S1.