L6 neurons in mutant explants have decreased neurite elaboration into the MZ. (A) Representation of threshold analysis for the measurement of neurite elaboration into the MZ. Threshold was determined for the flattened, 8-bit grayscale image, and the ratio of GFP + pixels in the MZ (a; ~ 15 x 100 μm ROI) to GFP + pixels in the CP (b; ~ 35 x 100 μm ROI) was determined for each treatment condition. (B) Both r/r Ct-CM and s/s Ct-CM L6 neurons revealed decreased GFP + signal (i.e. neurite elaboration) into the MZ as compared to wt controls and r/r Rln-CM explants. Ratios were compared across images acquired from 18 wt explants, 8 r/r Ct-CM explants, 4 s/s Ct-CM explants, and 8 r/r Rln-CM explants. Error bars denote standard error of the mean. One-way ANOVA with post-hoc Bonferroni t-tests were performed between treatment conditions. *** p < 0.001, as compared to wt controls.