Supplementary Figure 1: Overview of the Sholl Analysis software.
(a) User interface, version 3.4.1. Sub-modules noted in blue. (b) Maximum intensity projection of a Drosophila class IV dendritic arborization sensory neuron (ddaC) labeled by the ppk1.9-GAL4-driven reporter UAS-mCD8::GFP, a sample image distributed with the plug-in. The annulus formed by Starting radius (the first sampled distance) and Critical radius is indicated. Outer arc depicts Enclosing radius, the distance to the most distal dendritic tip. (c) Semi-log plot of the cell depicted in (b), where the number of intersections was normalized to the area of each sampled shell. Two regression lines are shown to demonstrate that curves can be fitted to all data points, or to a subset restricted to the 10th to 90th percentiles of the data (shaded in gray). R2 is the coefficient of determination, and k the Sholl regression coefficient. (d) Linear Sholl plot of the cell in (b). Key metrics include Critical value (Nm), Critical radius (rc) and Mean value (Nav). Differences between sampled and fitted maxima are shaded in gray. The centroid of the sampled profile is marked (×). Schoenen ramification index (RI) is the ratio between number of branches at the maximum and the number of primary branches, using either sampled data or the fitted Nm. The number of primary branches can be entered manually, or drawn from the number of intersections at Starting radius.
