Figure 2. PKC activation enhances the capsaicin-activated current in nociceptive neurones.

A, membrane current activated by a 1 s application of 0.5 μm capsaicin before and 15 s after maximal activation of PKC with PMA (1 μm, 10 s application), in a DRG neurone in 1.8 mm Ca²⁺ (left panel) or in zero Ca²⁺, 5 mm EGTA (right panel). The inset in each case shows that application of PMA itself did not activate detectable membrane current. B, mean current in DRG neurones in response to application of 0.5 μm capsaicin, and the effect of 1 μm PMA, in 1.8 mm Ca²⁺ (left panel) and zero Ca²⁺ (right panel). Error bars show ±s.e.m. (n = 5 in 1.8 mm Ca²⁺ and n = 14 in zero Ca²⁺, where n gives the number of cells on which the experiment was repeated, *** P < 0.0005). Protocol as shown in A. Mean current in this figure is from cells in which stable recordings were obtained for the complete duration of the time course shown; other cells gave stable recordings during and after application of PMA, but not for the entire time course, and these cells were used in addition to those shown here for the data quoted in the text and shown in Fig. 8.