A subpopulation of pain fibers are activated by capsaicin, the ingredient in red peppers that produces a burning sensation when eaten or placed on skin. Previous studies on dorsal root ganglion neurons indicated that capsaicin activates sensory nerves via a single slowly activating and inactivating inward current. In rat trigeminal neurons, we identified a second capsaicin-activated inward curr...

Ionic currents activated by extracellular adenosine 5'-triphosphate (ATP) were studied in voltage-clamped dorsal root ganglion neurons from rats and bullfrogs. Under quasiphysiological ionic conditions, ATP-activated current reversed near 0 mV and showed strong inward rectification. Strong inward rectification was maintained even in symmetric solutions of divalent-free Cs glutamate. Examined wi...

Intracellular recordings were made from neurons in rat dorsal raphe in the slice preparation maintained at 37 degrees C. The single-electrode voltage-clamp method was used to measure membrane currents at potentials more negative than rest (-60 mV). Three types of inward rectification were observed: 2 in the absence of any drugs and the third induced by 5-HT 1 and GABA-B receptor agonists. In th...