Fig. 2.

TEM of the inner hair cells and supporting cells. (A) Overview of the organ of Corti of a CLP mouse with hearing loss, focusing on the supporting cells. The outer hair cells appear normal. A Deiters’ cell has pathological alterations. (B) Close-up view of a Deiters’ cell with reduction in the cellular volume and chromatin condensation (asterix). (C) High magnification of a CLP mouse inner hair cell. The basal membrane of the cell is well preserved. The vacuolization (arrows) is due to a swelling of the afferent nerve fibers, with membrane disruption and loss of cytoplasmic content. (D) Higher magnification of a basal swelling, which is marked with an asterix in C. The vacuole contains a membrane remnant (arrow). Furthermore, on the corresponding inner hair cell side a synaptic ribbon can be seen (bold arrow). (E) Organ of Corti from a sham animal. The basal pole of the inner hair cell does not show any vacuolization. The Deiters’ cell shows a regular configuration with euchromatin-containing nucleus (arrow). (F) Close-up view of the inner hair cell shown in E. At the basal pole, regular afferent nerve fibers with intact membranes and cytoplasmatic content can be seen (asterix). OHC, outer hair cell; IHC, inner hair cell; DC, Deiters’ cells.