CFA-induced inflammation increases suprathreshold mechanical responses in C fibers.

<p><i>A</i>, Comparisons of average paw height (<i>left</i>), paw withdrawal threshold for mechanical stimuli (<i>center</i>) and paw withdrawal latency from a noxious heat stimulus (<i>right</i>) in both the injected and uninjected hind paws of saline-injected and CFA-injected mice. <i>B</i>, Force-response curve for C fibers from CFA-injected and saline-injected mice. <i>C</i>, Example C fiber response from a saline-injected mouse (<i>top</i>) and CFA-injected mouse (<i>bottom</i>) to 5, 20 and 100 mN mechanical stimuli. A second fiber with a low-amplitude waveform is noticeable in the bottom trace. <i>D</i>, Action potentials fired during a 20 mN (<i>top</i>) and 150 mN (<i>bottom</i>) mechanical stimulus, displayed in 0.5 sec bins. <i>E</i>, Scatterplot of individual C fiber responses to a 20 mN (<i>left</i>) and 150 mN (<i>right</i>) mechanical stimulus. <i>F</i>, Force-response curve for AM fibers from CFA-injected and saline-injected mice. <i>G</i>, Example AM fiber response from a saline-injected mouse (<i>top</i>) and CFA-injected mouse (<i>bottom</i>) to 5, 20 and 100 mN mechanical stimuli. *, two-way ANOVA followed by a Bonferroni post-hoc test.