Figure 1

Cellular changes of Sox10⁺ glial cells in the injured auditory nerve.

(a–d) Acute auditory nerve injury induces an increase in Sox10⁺ glial cells (green) with rounded nuclei. Spiral ganglion neurons were labeled with β Tubulin III (TuJ1, red; (a,b)). Nuclei were counterstained with Dapi (blue; (a,b)) and with propidium iodide (PI, red; (c,d)). Asterisks indicate Sox10⁻ neurons with a spherical nucleus. In the spiral ganglion of a control adult mouse, a large portion of Sox10⁺ glial nuclei (arrows) had a typical elongated spindle shape. Few Sox10⁺ cells had a spherical nucleus (arrowhead). In contrast, in the injured spiral ganglion of mice 3 days after ouabain exposure, most Sox10⁺ glial nuclei (arrowheads) had a spherical shape (b,d). The right panels in (c,d) are the enlarged images of boxed areas in the composite panels. (e) Quantitative analysis of spherical Sox10⁺ cells in control (n = 4) and 3 (n = 10) and 7 (n = 6) days after ouabain exposure. The spherical cells were identified as having nuclei with a long dimension/short dimension ratio of less than 1.5. (f) Injured auditory nerves show a significant increase in Sox10⁺ cells at 3 and 7 days after ouabain exposure. Mean density of Sox10⁺ cells ± S.E.M was obtained from control mice (n = 13) and treated mice at 1 (n = 5), 3 (n = 4) and 7 (n = 5) days after ouabain exposure. Asterisks indicate statistically significant differences between control and treated groups (ANOVA, p < 0.05). (g) Percentages of Sox10⁺ cells in the control and injured auditory nerves. Scale bars, 10 μm in (b) (applies to (a,b)); 10 μm in (d) (applies to the three left panels in (c,d)).