Representative photomicrographs (n ≥6 replicates per condition) from the upper basal turn of cochlear organotypic cultures labeled with myosin VI (red) and SOX2 (green). Representative Z-plane image (A1) and surface view of control cochlear cultured for 48 h. Cytoplasm of three rows of outer hair cells (OHC) and one row of inner hair cells (IHC) labeled with myosin VI. SOX2 expressed in Hensen cells (HC), Deiters cells (DC), pillar cells (PC)) and SC in inner sulcus cells (IS) region. (B1–2) Treatment with 0.25 mM GM for 24 h resulted in loss of most myosin VI expressing OHC and IHC; however, SOX2 labeling was still present in HC, DC, PC and other SC in the IS region. (C1–2) Many myosin VI labeled OHC and IHC and SOX2 labeled SC missing after 48 h treatment with 50 μM CIS. (D1–2) Treatment with 50 μM MEF resulted in significant loss of myosin VI labeled OHC and IHC and SOX2 labeled SC. (E1–2) Many myosin VI labeled OHC and IHC and SOX2 labeled SC missing after treatment with 100 μM Cd.