Pharmacology of CAP-induced depression of net neuronal excitation. A) Time traces obtained using various agents. The effect of CAP was antagonized by the vanilloid receptor 1 antagonist, CPZ (20 μM), suramin (100 μM), and a Ca++-free medium. It was not affected by BMI (10 μM) and STRY (3 μM), and was potentiated by UTP (30 μM) and at a higher temperature of 33°C. B) Concentration dependencies of CAP effect in normal solution at 27°C (circles) and 33°C (squares), and in UTP at 27°C (diamonds). Points were fitted with IC50 = 1.7 μM, Imax = -30% and N = 1.0 for 27°C, IC50 = 0.3 μM, Imax = -34% and N = 1.2 for 33°C, and IC50 = 0.6 μM, Imax = -33% and N = 1.5 for UTP. C) Averaged percent control response in various agents in 4–6 slices. Statistical significance and insignificance to control change are indicated with signs, * (p < 0.05) and # (p > 0.5), respectively. Although +UTP was not significant, it shifted the dose-response curve reasonably well (diamonds in C).