Fig. 2.  Acid-sensing ion channel 3 (ASIC3) knockout (KO) mice differed from wild-type (WT) mice in their baseline responses to a stroking mechanical stimulus. Data are shown as mean ± SE in all figures. (A ) In response to punctate von Frey stimulation, ASIC3 KO (n = 20) and WT (n = 19) mice displayed similar stimulus response functions. The average percentage of trials that resulted in paw withdrawal is plotted as a function of force. (B ) ASIC3 KO mice had greater sensitivity to stroking with a 0.74-g von Frey hair than did ASIC3 WT mice (*P < 0.02). The percentage response was calculated and plotted as the average percentage of stroking trials that resulted in a withdrawal response. Values in parentheses indicate sample sizes. (C ) ASIC3 WT and KO mice responded similarly to radiant heat stimuli. The average withdrawal latency was calculated and plotted by averaging baseline left and right paw median responses from five trials. Values in parentheses indicate sample sizes. **P < 0.002 WT male versus  WT female mice. F = female; M = male.