Figure 8
Effects of UTP and U0126 on I A and action potentials of small-diameter TG neurons in control rats. (A) 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. Original 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 the presence of U0126 100 μM. (B) Current–voltage relationship for the effect of UTP (30 μM) and co-application with U0126 (100 μM) on IA. The mean peak amplitude of I A was reversed to 0.15 ± 0.03 nA in the U0126 group, which was significantly different from that of the UTP group (Con: 0.14 ± 0.01 nA, n = 20; U0126: 0.15 ± 0.03 nA, n =11, UTP: 0.09 ± 0.01 nA, n = 20, p < 0.05 vs U0126). (C) Original traces of action potentials during intracellular current injection in ION-CCI TG neurons. (D) Mean threshold currents (left panel, n = 8 neurons) and mean number of spikes (right panel, n = 7 neurons) in the presence and absence of U0126 (100 μM) treatment for 16 h. The depolarizing step current amplitude is twice that of the threshold, *, p < 0.05, **, p < 0.01 vs control.