WIKIMEDIA, TAKEAWAYCapsaicin—a substance in chili pepper plants that makes them spicy hot—exerts its pain-attenuating effects by triggering a signaling cascade that results in the inactivation of mechano-sensitive transmembrane channels in neurons, according to a study published this week (February 10) in Science Signaling.
Initially causing a burning hot sensation, the compound is used as a topical pain medication because, when applied regularly, results in numbness to local tissue. Despite being widely used, researchers have previously not known how capsaicin exerts its pain-killing effects.
The initial pain-dulling sensation occurs when capsaicin activates heat-sensing transient receptor potential vanilloid 1 (TRPV1) ion channels on sensory neurons. Prolonged stimulation with the compound results in desensitization of these neurons. “This is one of the underlying mechanisms of capsaicin’s numbing effect, but TRPV1 is a heat sensor, so how it affects mechanical pain was not known,” said Tibor Rohacs, an associate professor of pharmacology and physiology at Rutgers New Jersey Medical School, who led the study.
Rohacs and his colleagues uncovered a link between ...
