Mol Med Rep 12: [Related article:] 7883–7890, 2015; DOI: 10.3892/mmr.2015.4430 Following the publication of this article, an interested reader drew to our attention an anomaly associated with the presentation of Fig. 2. Fig. 2D presented an alternative view of the same mitochondria shown in Fig. 2B. On re-examining our data, we realized that Figs. 2B and C showed the results from the D-gal(H) group, and 'D-gal(H) group' was incorrectly written as 'D-gal(L) group' in the Fig. 2B legend. Since changes in the mitochondrial ultrastructure were not readily discernible for the D-gal(L) group, our intention was only to show microscopic images from the control and the D-gal(H) groups in Fig. 2. Therefore, Fig. 2D, as originally presented, similarly to Fig. 2B, showed mitochondria with reduced electron density or severe degeneration in the spiral ganglion cell of the D-gal(H) group, and its inclusion with the Figure was redundant. A corrected version of Fig. 2 is presented below, which includes only the three relevant panels, and a corrected version of the Figure legend. This error did not affect the overall conclusions reported in the present study. We sincerely apologize for this mistake, and thank the reader of our article who drew this matter to our attention. Furthermore, we regret any inconvenience this mistake has caused.