Fig. 4.

Assessment of degenerative (A–C) and apoptotic (D and E) processes in the organ of Corti of WT, BKβ1^–/–, and BKα^–/– mice at the age of 14 weeks. (A–C) Hematoxylin/eosin staining reveals morphological integrity of the midbasal cochlear turn in WT (A) and BKβ1^–/– (B) mice compared with severe degeneration of OHCs in BKα^–/– animals (C). (D and E) Double labeling of DNA fragmentation (terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining) and caspase-3 immunoreactivity as a marker for apoptosis. Filled arrows depict three rows of OHCs and the IHC; open arrows depict Deiters cells. (Bar = 20 μm.)