Figure 2.

Nocifensive behaviors to heat, cold or mechanical stimulus of the lateral facial skin. A: Mean head-withdrawal latency to heating of the skin, Aa: EMG activity recorded from the splenius capitis muscle during heating of the skin, B: Mean number of face-scratching episodes following topical administration of acetone to the skin, C: Mean head-withdrawal threshold to mechanical stimulus of the skin. *: p < 0.05, **: p < 0.01. Veh: vehicle for capsaicin, Cap: capsaicin.