Figure 1.

Effect of nicotine on Aβ (Aβ_25–35, Aβ_1–40 or Aβ_40–1)-induced MTT reduction in hippocampal neuronal cells. Cultures were incubated for 24 h with nicotine or Aβ (Aβ_25–35, Aβ_1–40 or Aβ_40–1) as the indicated concentration. The MTT reduction assay was carried out as described in ‘Method'. Data shown are expressed as percentages of control (no nicotine and no Aβ (Aβ_25–35, Aβ_1–40 or Aβ_40–1) treated) values and each data point (±s.e.m.; bars) is the mean of five independent trials.*P<0.05 significantly different from control cells. A1–40: the concentration of Aβ_1–40; A40–1: the concentration of Aβ_40–1; A25–35: the concentration of Aβ_25–35.