Fig. 5: Results of NeuriTox hit confirmation testing.

A) Compounds that were classified as hits after the first round of screening were re-ordered independently and re-tested for their effect on neurite outgrowth inhibition (NA, orange) and viability (V, black) in an adjusted concentration range (otherwise same experimental setup as for the screening). EC values and their ratios were calculated from four-parameter log-logistic fit functions. The curves for the compounds that were classified as specific (developmental) neurotoxicants are displayed. B) Comparison of the EC₅₀ values for neurite area and viability of the compounds that went through hit confirmation testing. If the EC₅₀ ratio V/NA was ≥ 4, the compound was classified as a specific (developmental) neurotoxicant (not for captan (Cap) and tebuconazole (Te)). Detailed explanations for calculations and rule sets applied in case of curves not hitting the 50% level (°, ♦) are given in the methods description. All data are means ± SEM from three biological replicates, dotted lines are drawn at 100% and 50%. *: p < 0.05, by one-way ANOVA followed by Dunnett’s post-hoc test.