Figure 1.

Representative firing patterns of C (A), Aδ (B) and Aβ (C) neurons in response to 2000 Hz sine-wave stimulation. In this and subsequent figures 2 and 3, the stimulus intensities were shown above the traces. Action potentials recorded from three types of afferent fibers were shown on the right of the traces. The frequencies of APs were plotted against the stimulus intensity (D). In this and subsequent figures of 2 and 3, ○: C fiber (n = 15), △: Aδ fiber (n = 18), □: Aβ fiber (n = 20).