Prevention of rotenone-induced neuronal cell death and oxidative damage by expression of the Ndi1 protein.Rats were treated with the NDI1 gene and rotenone and brain sections were prepared and processed for immunohistochemical staining as described in Figure 2. A: Sections were subjected to Nissl staining and representative images are displayed (upper panel). The number of viable neurons was compared between the left and right SN by counting Nissl-positive cells in a given area of the SN (lower panel). The number of sections used for analysis was; control (2 animals, 3 sections), control+rotenone (5 animals, 12 sections) and NDI1+rotenone (9 animals, 9 sections). In each group, images were collected from the sections with the matching anterior-posterior position and, when multiple sections were used in a given animal, they were separated by at least 30 µm to eliminate possible span of neuron cell bodies over multiple sections. B: Sections were stained for 8-oxo-dG to evaluate oxidative damage to DNA (upper panel). The SN neurons that are positively stained were counted (lower panel). The number of sections used for analysis was; control (2 animals, 3 sections), control+rotenone (3 animals, 5 sections) and NDI1+rotenone (3 animals, 6 sections). Selection of the sections was done as described in A. Statistic analysis was done using student T-test. Error bars represent standard deviation.