Figure 2.

Increase and phenotypic change in BDNF expression in the DRG. BDNF mRNA labeled neuronal profiles increase 2 h after stimulation of the sciatic nerves (B) and 24 h after inflammation (C). The number of labeled profiles/total neuronal profiles per section increased from 11.1 ± 1.7 (naives, A) to 31.4 ± 2.4 (C-fiber stimulation, B) and 35.9 ± 9.2 (inflammation, C) (n = 3, P < 0.05). Scale (A–C): 100 μm. Profile area-frequency histograms constructed from 600 profiles in three animals show an increase in the number of small and medium sized neuronal profiles expressing BDNF mRNA. Cells >600 μm² (shaded) are A fibers (29). (D) Double staining for BDNF mRNA and NF200 immunohistochemistry shows only a small proportion of BDNF mRNA-expressing cells are NF200 positive in naives (arrows), but after inflammation the proportion of double-labeled cells increases 2-fold. Scale (D): 200 μm.