FIGURE 6

Aβ increases the number of dorsal oligodendroglial lineage cells and myelinated axons through PKC. Zebrafish larvae were intracerebroventricularly injected with Aβ (10 μM) or its vehicle at 24 hpf, and some were exposed to Gö6983 (500 nM) at 48 hpf. Larvae were fixed for electron microscopy or immunohistochemistry at 8 dpf. (A) Representative electron micrographs of the dorsal spinal cord of 8 dpf zebrafish larvae, with myelinated axons shaded in pink. (B) Schematic illustration of a cross‐section of the zebrafish spinal cord. The square represents the analyzed area. Histograms showing the (C) number and (D) diameter of myelinated axons in the dorsal area for each condition. Scale bar = 2 μm. n = 6–11 larvae per condition. (E) Representative transverse sections of olig2:EGFP (magenta) larvae spinal cords processed for immunohistochemistry to detect Sox10 expression (cyan; yellow arrowheads). Dashed white line indicates the outer edge of the spinal cord and dorsal and ventral areas. (F) Quantification of Sox10⁺ cells in the ventral and dorsal spinal cord at 8 dpf. Scale bar = 20 μm. n = 8—11larvae per condition. Data indicate means ± SEM, with dots representing individual larvae. *p < 0.05, **p < 0.01, ****p < 0.0001. Statistical significance was determined by two‐way ANOVA followed by Sidak's and Tukey's post hoc tests.