H2 treatment reduced the ouabain-induced cochlear SGN apoptosis evidenced by TUNEL staining. H2 treatment was given as Figure 2. The SGN apoptosis was detected by TUNEL staining (A–C, A′–C′) 24 h after ouabain or saline administration. For quantitative measurement, the number of SGN that was positive for TUNEL staining (green) was recorded in each specimen in a blind fashion (D). The values are expressed as mean±SEM (n=6 per group). bP<0.05 vs Saline group. eP<0.05 vs Ouabain group. ND=not detected. SGN, spiral ganglion neuron; SM, scala media; ST, scala tympani; SV, scala vestibuli. Scale bar for A, B, and C is 100 μm; Scale bar for A′, B′, and C′ is 50 μm.