Figure 3

Repeated artemin plantar injections changed the gene expressions of TRPV1 and TRPA1 in DRG neurons. A-C: Artemin was injected into the planter surface once a day for 5 days (20 μg/ml, 100 μl/injection, PBS control, n = 8 each groups) and TRPV1 and TRPA1 mRNA levels in DRG were both increased significantly compared with control (mean ± SEM, *p < 0.05). D-O, ISHH and the scatterplots of TRPV1, TRPA1 and GFRα3 mRNAs in DRG neurons after PBS (D, F, H, J, L, N) or artemin injection (E, G, I, K, M, O). Each DRG neuron was plotted with the signal-to-noise (S/N) ratio and its cross-sectional area. The number of TRPV1/TRPA1 mRNA expressing neurons is quantified (P) and the mean S/N ratio in positive neurons was shown in Q and R. The total number of TRPV1 or TRPA1 mRNA-labeled neurons was not significantly increased (P), while the signal intensity of both mRNAs after artemin injection were clearly increased after repeated artemin injection in small and medium-sized DRG neurons compared to PBS control (Q, R) (mean ± SEM, *p < 0.05). Repeated artemin injection did not change the profiles of GFRα3, which is a receptor of artemin. Bars: 100 μm (D, E, H, I, L, M).