FIGURE 4.
Membrane conductance changes induced by synthetic Aβ1–42 species. a, representative current traces obtained after applying synthetic Aβ1–42 solutions to an artificial lipid bilayer. Synthetic Aβ1–42 (100 μm) was incubated at 25 °C and sampled at different times (t = 0, 5, and 24 h), and then diluted to 100 nm in 144 mm NaCl, 1.8 mm CaCl2, 1.2 mm MgCl2, 10 mm Hepes, pH 5.0, and applied to a lipid bilayer. Current traces were recorded at different potentials (+80, +40 mV, −40 mV, and −80 mV). b, the current/voltage relationship from a complete set of Tip-Dip currents. c, representative histogram comparing the conductance using freshly prepared Aβ1–42 (t = 0, monomers) and after 5 h of incubation (t = 5 h), with the latter preincubated or not with 4G8 (1:500 v/v) or EGCG (equimolar). The values are the means ± S.D. (n = 5). **, p < 0.01 versus all the other groups (Bonferroni's multiple comparison test following one-way ANOVA). 4G8 or EGCG alone had no effect on ionic currents, nor they did induce lipid bilayer ruptures (not shown).