Figure 2

Fast Blue labeling and immunohistochemistry staining for ASIC3 : (a-b) Naïve- model, (c-d) OA-model, (e-f) APETx2 administration to OA-model in early phase. Photos in each row are the same DRG. In (b),(d),(f), large arrows indicate Fast Blue labeled, ASIC3 immunoreactive (ASIC3-ir) DRG cells, while ASIC3-ir cells that were not labeled by Fast Blue are indicated by small arrowheads. More than 100 FB-labeled neurons were analyzed from 4 rats in each group. The percentage of ASIC3-ir knee joint afferents was 18 ± 3% (mean ± SD) in naïve models, 46 ± 4% in OA-models (p = 0.003), and 20 ± 5% in the early-phase APETx2 group (p = 0.006), respectively. Scale bar: 50 μm.