Aβ42 accumulation induces stem cell proliferaton and neurogenesis in old adult zebrafish brain. S100β (neural stem/progenitor cells, red) and PCNA (proliferation marker, green) immunostaining in control (A) and TR-Aβ42-injected brains (B) at 1 day after injection. Insets on the right of the panels are individual channels from the boxes in corresponding panels. Immunostaining for Acetylated tubulin (green, neurons) in control (C) and TR-Aβ42-injected brains (D) at 2 weeks after injection. Insets below the panels (C’, C,“ D’, D”) are individual fluorescent channels. Quantification graphs for S100-PCNA (E) and Acetylated-tubulin-BrdU (F). Data shown as mean ± s.e.m. Red dots are individual data points as an overlaid scatter plot. Scale bars equal 50 μm. n = 5 fish, and 18 sections in total for every staining.