Figure 1

Responses to menthol, capsaicin and AIT in dorsal root ganglion neurons of rats. A, B, C ) Images show Fluo-3 fluorescence intensity (ΔF/F₀) before (baseline) and following the sequential applications of menthol (100 μM, 10 s), AIT (100 μM, 10 s), and capsaicin (0.5 μM, 10 s) with a time interval of 10 min between each application. Traces alongside with each set of images are respective time-course of fluorescence intensity (ΔF/F₀) changes. The cell in A was a menthol-sensitive/AIT-insensitive/capsaicin-insensitive neuron and in B was a menthol-sensitive/AIT-sensitive/capsaicin-sensitive neuron. The cell in C was a menthol-insensitive/AIT-sensitive/capsaicin-sensitive neuron. D, E) Pie graphs in each panel show percentage distribution in total menthol-sensitive neurons of menthol-sensitive/capsaicin-insensitive neurons (MS/CI, n = 40) and menthol-sensitive/capsaicin-sensitive (MS/CS, n = 31) neurons (D) as well as in total menthol-sensitive neurons of menthol-sensitive/AIT-insensitive neurons (MS/AI, n = 23) and menthol-sensitive/AIT-sensitive (MS/AS, n = 7) neurons. (E). Traces in D show menthol responsiveness (ΔF/F₀) in MS/CI and MS/CS neurons. Traces in E show menthol responsiveness (ΔF/F₀) in MS/AI and MS/AS neurons. F ) Pie graph shows percentage distribution in total AIT-sensitive neurons of menthol-insensitive/AIT-sensitive neurons (MI/AS, n = 35) and menthol-sensitive/AIT-sensitive (MS/AS) neurons. Two traces show AIT responsiveness (ΔF/F ₀) in MI/AS and MS/AS neurons. Scale bar in each image is 20 μm. The horizontal bar in each trace indicates the 10-sec drug applications. Data are mean ± SEM in C, D, E.