Fig. 2

Concentration-dependent effects of MeHg, okadaic acid and acrylamide on cell viability and expression of the neuron-specific protein βIII-tubulin in neuronally differentiated P19, PC12 and SH-SY5Y cells. The cells were plated at a density of 500 cells/mm² and cultured for 6 days in the differentiation media, followed by exposure to the test compounds for 48 h. Effects of MeHg (a, b), okadaic acid (c, d) and acrylamide (e, f) on the cell viability were assessed by using the calcein-AM assay (a, c, e), and the immunofluorescence of βIII-tubulin (b, d, f). The data are means ± SEM of n = 6 independent experiments (n = 3 for okadaic acid in the βIII-tubulin assay; panel d). The results are expressed as percentage of non-treated cells or cells treated with 0.1% DMSO (used as vehicle). Wells treated with 2% Triton X-100 for 30 min served as controls for maximal cell death. Statistical analysis was performed using repeated measures one-way ANOVA with post hoc Dunnett’s multiple comparisons test (*p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001) compared to corresponding controls