Figure 4.
Ca2+ transients evoked by capsaicin in corneal nerve terminals. A, Response of an individual nerve terminal to 1 μm capsaicin. B, Response of an individual nerve terminal to 1 μm capsaicin after a 30 min preincubation with 4.1 μm STX. C, Response of an individual nerve terminal to 1 μm capsaicin after a 20 min preincubation with 20 μm nifedipine. D, The response to capsaicin was completely blocked by a 35 min preincubation with 100 μm capsazepine, aVR1 antagonist. The time bar under each trace indicates the duration of capsaicin application. Images were 400 msec exposures acquired at 0.2 Hz (A—C) or 1.0 Hz (D). All traces were smoothed by three-point averaging.