Figure 2.

Protocol for testing NGF effects on capsaicin currents on DRG cells recorded in perforated patch clamp. Cells chosen for this analysis were <30 μm in diameter. A microelectrode filled with 1 μM capsaicin was placed close to the patched cell, and the capsaicin was ejected via a brief (400-ms) pressure pulse. The cell was clamped at −60 mV, and the inward capsaicin current lasting ≈10 s is shown at the top. A second pressure pulse was delivered 10 min later. During the interval, the cell was exposed either to control saline solution or to 100 ng/ml of NGF. In controls, the response to the second capsaicin pulse was always smaller than the initial one.