Neuroscience letters
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Neuroscience letters · Apr 1996
Capsaicin blocks tetrodotoxin-resistant sodium potentials and calcium potentials in unmyelinated C fibres of biopsied human sural nerve in vitro.
Topical application of capsaicin has been tested recently for treatment of painful peripheral neuropathy. In the present study, effects of capsaicin were explored on compound action potentials of isolated fascicles from human sural nerve biopsies. Capsaicin reduced the C fibre component by 30-60%; the remaining C fibres were not sensitive to the drug. ⋯ C fibre action potentials recorded in the presence of TTX were completely blocked by capsaicin. Calcium action potentials seen after inhibition of axonal potassium conductances were also completely suppressed. The data indicate that application of capsaicin nearby human peripheral nerves might prevent action potential conduction in specific subtypes of C fibres.