Figure 2
Effect of UTP and suramin on I A of small-diameter and FG-labeled TG neurons, with diameters ranging from 18 to 39 μm in control rats. (A) Fluorescence microscopic view of TG neurons from control rats. (a) Retrograde labeling of TG neurons (blue) innervating whisker pad skin. (b) P2Y2 receptor-positive (green) TG neurons were seen in the section of TG. (c) The merged images (purple) of retrograde labeling of TG neurons and P2Y2 receptor-positive TG neurons from the same section, indicating co-localization. (d) Retrograde labeling of TG neurons (blue) innervating whisker pad skin in cultured TG neurons. (B) Electrophysiology recording for small-diameter and FG-labeled TG neurons in control rats. (a) Representative traces showing that the application of 30 μM UTP reduced IA. Suppression of the mean peak amplitudes of I A seen after UTP application was antagonized by suramin 100 μM. (b) Current–voltage relationship for the effects of UTP and suramin on IA. Each value represents the mean ± SEM (con: 0.14 ± 0.01 nA, n = 9; UTP: 0.09 ± 0.01 nA, n = 20, p < 0.05 vs control; suramin: 0.13 ± 0.01 nA, n = 9). IA was initiated via a prepulse (100 ms) of −120 mV and test pulses (400 ms) from −60 to +60 mV in a 10 mV step.