Lumbar dorsal root ganglia neurons co-label with TRPV1 and ATF3 after intraplantar MRS1477 + capsaicin. Double-immunolabeling of TRPV1 (green) and ATF3 (red) is shown in rat DRG neurons from fixed-frozen sections (A-F). Rats were either not treated (A, B with phase), or given an intraplantar injection of 2 μg MRS1477 (C), 30 μg CAP (D), 2 μg MRS1477 + 30 μg CAP (E), or 200 ng RTX (F). ATF3 appears as red fluorescence concentrated in neuronal nuclei. Yellow nuclei result from an overlap of ATF3+ and TRPV1+ staining. ATF3+ nuclei were manually counted and calculated as the ratio of ATF3+/TRPV1+ cells over the total number of TRPV1+ cells in a given field (G). All treatment groups were compared statistically to the untreated controls using an unpaired Student’s t-test (**** = p < 0.0001). Results of cell counts from 10 fields analyzed at 200× magnification are summarized (H). Arrows indicate representative co-labeled cells.
Lebovitz et al. Molecular Pain 2012 8:70 doi:10.1186/1744-8069-8-70