Fig. 3. Current-voltage (I-V) relationships for inward currents in the wild-type and cca-1 pharynxes. (A) Wild type. (B) cca-1.. Voltage protocols for the total current and current in the presence of 10 µmol l^-1 nifedipine were the same as in Fig. 2A: depolarizing pulses were applied in 10 mV increments starting from the holding potential of -80 mV. HVA currents were measured with the same voltage protocol as in Fig. 2B: LVA current was inactivated with the prepulse to -40 mV. For nifedipine experiments, averaged current values at 50-60 ms of the pulse were used (after the LVA current has inactivated); otherwise, peak amplitudes were used for I-V curves.