Fig. 6.

Cross comparison of test data for the NTP collection. Neurite outgrowth inhibition data using GFP-labeled cortical neurons and motor neurons are shown in parallel with other two published data sets (Delp et al., 2018; Ryan et al., 2016). In our study, the positive compounds were defined by either active in 24- or 48-hour treatment. Selective neurite outgrowth inhibitors are defined as compounds where there is a statistically significant difference between the IC₅₀ values of total neurite length and cell viability (t-test, p<0.05). Selective inhibitors were defined as ones having a high ratio (≥ 3.16) between BMC s (benchmark concentrations) for viability and neurite area (Ryan et al., 2016). Selective inhibitors were defined by an IC₅₀ (viability/neurite area) ratio for NeuriTox test (≥4) and PeriTox test (≥3) (Delp et al., 2018). The effect of the compound is indicated as specific neurotoxicity (green), cytotoxic effect (red) or no effect (white). Compounds with * are known DNT as classified in the previous studies (Aschner et al., 2017; Mundy et al., 2015).