Figure 2. Correlation with nociceptor markers.

A, capsaicin (10 μm) was perfused in a pH 7.4 solution for 5 s. Left panel, a typical current trace; right panel, bar graph showing capsaicin-induced current density for neurones expressing current types 1–3 (n = 14–38). B, action potential shape. Action potentials were induced by short depolarizing current injection in current-clamp mode. The figure shows a representative action potential with (left panel) and without (right panel) inflection in the falling phase and illustrates the different parameters that were measured and are presented in Table 1 of Supplemental data. C, the top panel is a phase contrast image; the bottom panel is a fluorescence image of the same cells after labelling by FITC–IB4. The arrow points to the IB4-positive cell. Scaling bar represents 25 μm. D, bar graph showing the proportion of small IB4-negative (left) and IB4-positive neurones (right) without ASIC current (white), and type 1 (hatched), type 2 (black) and type 3 (cross-hatched).