Figure 6.
Objective quantification of the ISH signals for five IA-encoding Kv α-subunit mRNAs of individual DRG neurons in the ipsilateral L5 DRG after L5 SNL and GDNF treatment. Left scatterplot diagrams showing the ISH signal densities (× background) for these mRNAs and cell size of the ipsilateral L5 DRG neurons obtained from the indicated groups. At least 350 neuronal profiles pooled from seven rats were plotted. The horizontal lines at 10× background denote the borderline between positively and negatively labeled cells. All cells larger than 1000 μm2, which are designated by a vertical line, are A-fiber neurons.37 Right graphs are box-and-whisker plots showing the distribution of signal densities (× background in log scale) of large (>1000 μm2) neurons. The whiskers indicate the maximum and minimum values, and the box indicates the upper quartile, median, and lower quartile. The dotted lines at 10× background indicate the borderline between positively and negatively labeled cells. n.s. P > 0.05, #P < 0.05, ##P < 0.01, ###P < 0.001 by the Kruskal–Wallis test followed by Dunn’s multiple comparison tests. DRG: dorsal root ganglion; GDNF: glial cell line-derived neurotrophic factor; IA: fast-inactivating transient A-current; ISH: in situ hybridization; Kv: voltage-gated potassium channel; n.s.: not significant; SNL: spinal nerve ligation.