Repaired organ of Corti following hair cell loss.

<p><b>A. CBA/Ca mouse; 7 days post-treatment.</b> All OHC lost but all IHC remain. The heads of Deiters' cells and of the outer pillar cells have expanded into the regions where OHC used to be. A regular pattern of cells is created at the epithelial surface. Scale bar: 10 µm. <b>B. C57BL/6; 14 days post-treatment.</b> Phalloidin-FITC labelled whole mount. Wide bands of actin persist at junctions between adjacent supporting cells. Inner hair cells have been lost and the heads of inner border and inner phalangeal cells have expanded to close the lesions. Scale bar: 10 µm. <b>C. CBA/Ca; 24 h post-treatment.</b> OHC lost and Deiters' cell heads have expanded to close the lesions at the luminal surface. There is some widening of the phalangeal processes but extracellular spaces are still open. Arrows indicate dense, microfilament assemblies at the junctions between the adjacent cells that are present in each of the three Deiters' cells. Larger arrowhead denotes microtubule bundle in Deiters' cell. Scale bar: 5 µm. <b>D. CBA/Ca; 14 days post-treatment.</b> Deiters' cells have generally expanded. The outer tunnel is closed but some extracellular spaces in the Deiters' cell region and the tunnel of Corti are still open. The overall architecture is preserved in the repaired epithelium. Scale bar: 10 µm. <b>E. CBA/Ca; 48 h post-treatment.</b> Expansion of the 3^rd row Deiters' cell closes the outer tunnel. Microtubule bundles (large arrowhead) and microfilament assemblies at the intercellular junctions are maintained in Deiters' cells. Scale bar: 5 µm. <b>F. CBA/Ca; 3 months post-treatment.</b> IHC as well as OHC are lost, but the tunnel of Corti is open and the cellular arrangement of the repaired organ of Corti is preserved. Scale bar 10 µm. <b>G. C57BL/6; 4 weeks post-treatment.</b> Both IHC and OHC are missing. The regular pattern of the cells at the surface of the repaired epithelium is maintained. Scale bar: 10 µm.