Figure 5.

Complement fB deficiency does not significantly alter macrophage numbers in the adult auditory nerve. (A–F) Electron micrographs of macrophages (black arrows) in the auditory nerve of young adult WTs (A–C), young adult fB^−/− (C) and P16 fB^−/− (B,C) mice. (C) is a magnification of the boxed area in (B) showing a macrophage (ϕ) around a blood vessel with a long and thin cellular process (arrow). An arrow in (D) identifies a macrophage around the axons of the auditory nerve. (F) is a magnification of the boxed area in (E) showing an activated macrophage (ϕ) around a blood vessel. (G) Confocal images of IBA1⁺ macrophages in young adult WT (top panels) and fB^−/− (bottom panels) mice. The images were taken within Rosenthal’s canal (RC) of the middle portions of the mouse cochleas. Nuclei were counterstained with PI. (H–I) Quantification of IBA1⁺ macrophages revealed no significant changes in macrophage numbers in most cochlear areas except in the apical portion within the osseous spiral lamina (OSL) and middle portion within RC in fB^−/− mice. Data bars represent mean; error bars represent SEM. For the auditory nerve in the OSL, n = 7 and 6, n = 6 and 5, and n = 6 and 4 cochleas for WT and fB^−/− mice in the apex, middle and base, respectively; For the auditory nerve within the RC, n = 5 and 4, n = 6 and 5, and n = 7 and 5 cochleas for WT and fB^−/− mice in the apex, middle and base, respectively. Analysis was done with the Mann-Whitney U test; statistical significance was defined as a *p value of ≤0.05.