Fig. 5. Aβ-induced neurotoxicity measured by the MTT and LDH assays.

Rat primary cortical or hippocampal neurons were treated with Aβ40, Aβ42, or their Nle³⁵- or Val³⁵-substituted analogues for 48 h. Cell viability was assayed by measuring MTT reduction by active cells or by LDH release. A) Dose–response analysis of Aβ42 analogues by the MTT assay in cortical neuron. B) Dose–response analysis of Aβ42 analogues by the LDH assay in cortical neuron. C) Cell viability following treatment with 10 µM of each peptide measured by the MTT assay in cortical neurons. D) Cell viability following treatment with 10 µM of each peptide measured by the LDH assay in cortical neurons. E) Cell viability following treatment with 10 µM of each peptide measured by the MTT assay in hippocampal neurons. F) Cell viability following treatment with 10 µM of each peptide measured by the LDH assay in hippocampal neurons. The data are average of three independent experiments with 6 data points per condition (n=18). *p<0.05, **p<0.01, and ***p<0.001 vs the corresponding Aβ40 analogue.