Fig. 1
CD68+ cells in the rat cochlea 7 days post-intratympanic injection of 0.4 % AgNPs shown by immunofluorescence confocal microscopy or immunohistochemistry. In the cochleae exposed to dH2O, the inner hair cells (IHCs) and pillar cells (PCs) of Corti’s organ (CO) showed moderate staining, while the outer hair cells (OHCs) and Deiters’ cells (DCs) demonstrated extremely weak staining (h). The strial basal cells (SBCs), spiral ligament fibrocytes (SLFs), and spiral ganglion cells (SGCs) exhibited mild staining (d, f). In the cochleae exposed to 0.4 % AgNPs, the SBCs and SLFs (mainly type III) in the first turn (a) and the IHCs and PCs of CO (g) displayed more intensive staining. Sparse ramified cells (c) and mononuclear cells (i) with CD68 staining were identified in the spiral ligament and the modiolus, respectively. However, the SBCs and SLFs in the second and third turns (b, c), SGCs (e), capillary endothelial cells (CaECs) (e), OHCs, and DCs (g) did not show any changes. Comparisons of staining intensity are shown in j and k. Scale bar = 30 μm in a–f, 20 μm in g, h, and the magnified image in i, and 80 μm in i