Fig. 2.

Responses of group IV nociceptors to chemical stimuli. Representative responses of group IV nociceptors to chemical stimulation (arrows) of their natural RFs (A, C, and F) and of their axons passing through the sciatic nerve (B, E, and G). A shows a robust response to inflammatory mediators injected into the RF, but not when applied to the axon of the same neuron (C). C and E (CFA) and F and G (vinblastine) show responses to injections to both RFs and their axons. D shows a response to vehicle injection into the nerve of a mechanically sensitive axon. Note immediate response rather than the delay in E. There were no responses in C–F due to the injections after the time frames of the graphs.