Fig.5.

A) Chronic incubation of PC12 cells with 10 nM Aβ_1–42 concentration enhances the Ca²⁺ response induced by subsequent 1 μM Aβ_1–42 application. The inactive reverse peptide Aβ_42–1 neither induces a Ca²⁺ response nor modifies the Aβ_1–42 -induced response. B) Proportion of observed responding PC12 cells (Mean ± SD). C) Chronic incubation of cultured cortical neurons with 10 nM Aβ_1–42 concentrations reduces the Ca²⁺ response induced by subsequent 1 μM Aβ_1–42 application. D) Percentage of observed responding neurons (Mean ± SD). As observed for PC12 cells the reverse peptide Aβ_42–1 has no effect on cortical neurons. (Statistics: one way ANOVA and subsequent Bonferroni test;  ^*p <  0.05;  ^**p <  0.01; control: vehicle application).