Fig. 1.

The Neurotoxicity of MPP⁺ on CATH.a cells and primary cortical neurons. a, b CATH.a cells and cortical neurons were cultured with various concentrations of MPP⁺ for 24 hours. The cell viability of CATH.a cells (opened bars) and cortical neurons (closed bars) were detected by MTT reduction assay (a). Results are means ± S.D. from three independent experiments. Significant differences between the cells treated with vehicle and MPP⁺ were indicated by ***, P < 0.001. The representative phase contrast morphology of the treated cells is shown in panel (b). Scale bar: 50 μm. The representative immunoblots of α-spectrin, spectrin degraded fragments and β-actin are shown in panel (c). In cortical neurons, the activation of calpain cleaved 250-kDa α-spectrin (opened bars) to produce 150- (closed bars) and 145-kDa (dark gray bars) fragments, whereas activation of caspase 3 generated 120- (light gray bars) and 150-kDa fragments of α-spectrin (d). Results are means ± S.D. from three independent experiments. Significant differences between the cells treated with vehicle and MPP⁺ were indicated by ***, P < 0.001