FIG. 3. Responses of a primate STT cell to graded mechanical stimuli before and after intradermal injection of capsaicin. A: Background discharge of the cell is shown. B: lntradermal injection of capsaicin produced a large increase in the activity of the cell. C-H: Skin was stimulated mechanically at sites 1 to 5 indicated in the drawing. The stimuli included innocuous BRUSH and two intensities of compressive stimuli, PRESS and PINCH. C, E, and G show the responses to these stimuli before and D, F, and H after capsaicin injection. The hatched area in the drawing shows the enlargement of the receptive field following capsaicin. (From ref. 24.) Click here to see the graphic at a different resolution