Research Paper Volume 8, Issue 11 pp 2713—2733

Figure 3. SkQ1 prevents neuronal loss and retards structural neurodegenerative alterations. (A) Representative 100 × histological Cresyl violet images of neurons of the hippocampal CA1 region in 18-month-old Wistar rats, untreated OXYS rats, and SkQ1-treated OXYS rats (n=4). The damaged neurons are indicated by solid arrows, and a dead neuron is indicated by a dashed arrow. (B) Quantification of neuronal populations revealed a significant decrease in neuronal number in the CA1 and CA3 regions and in the dentate gyrus of untreated OXYS rats compared to Wistar rats (p<0.05). Treatment with SkQ1 significantly increased neuronal populations in the hippocampus of OXYS rats (p<0.05). (C) The percentages of normal neurons were smaller in the examined hippocampal regions of OXYS rats compared to Wistar rats. Oral SkQ1 administration improved neuronal health in all the hippocampal regions examined in OXYS rats. (D) The small area of neuronal bodies in the CA3 region and dentate gyrus of the hippocampus in OXYS rats (n=5) is enlarged in response to SkQ1 treatment (p<0.05). (E) The small area of neuronal nuclei in the hippocampal CA1 region of OXYS rats (n=5) is enlarged in response to SkQ1 treatment (p<0.05). (F) SkQ1 improved the ultrastructure of pyramidal neurons in the hippocampal CA1 region in 18-month-old OXYS rats (n=4). The electron micrographs show examples of the normal ultrastructure of pyramidal neurons of Wistar rats and SkQ1-treated OXYS rats, and the substantial changes in the structural organization of cellular organelles in the CA1 region of untreated OXYS rats. The figure shows a pyramidal neuron containing a large cluster of lipofuscin granules (indicated by arrows), and massively swollen mitochondria (m). N: nucleus. The scale bars are 2 µm. DG: dentate gyrus. The data are shown as mean ± SEM. Statistical significance (p<0.05) is denoted by the asterisk.