Fig. 3.

QX-314-mediated current activates rapidly and does not require pannexins. A: time course of activation of inward current carried by external 10 mM QX-314 (at −150 mV; blue symbols) compared with outward current carried by internal Cs (at −50 mV; red symbols) when capsaicin is rapidly applied to TRPV1 channels expressed in an N1E-115 cell. A triangular waveform like that in Fig. 1A was applied at 3 Hz, and current at −150 and −50 mV was measured in each sweep (i.e., every 333 ms). B: QX-314-mediated inward current is blocked rapidly by 10 μM ruthenium red (RR). TRPV1 in N1E-115 cell using external 10 mM QX-314 vs. NMDG-based internal solution as in Fig. 1C. Inward current carried by external 10 mM QX-314 (at −64 mV; blue symbols) compared with outward current carried by internal NMDG (at +10 mV; red symbols). A triangular waveform from −64 to +116 mV was applied at 3 Hz. C: QX-314-mediated current carried by TRPV1 channels expressed in C6 glioma cells lacking pannexin expression. Solutions and voltage protocol as in A.