Figure 1

Separate transduction mechanisms for mechanical and chemical/thermal stimuli in a single polymodal nociceptor terminal. Example of single fiber recordings from polymodal nociceptive endings innervating the cornea of the cat. Responses to acid, heat and mechanical stimuli, before and after topical application of capsaicin at an inactivating concentration (330 μ M). Note the abolition of the response to heat and the marked reduction in the response to local acidic solution (10 mM acetic acid) without affecting the response to mechanical stimulation.