Neural injury, repair, and adaptation in the GI tract. II. The elusive action of capsaicin on the vagus nerve.
Capsaicin is an excitotoxin for primary afferent neurons, and perivagal administration of capsaicin is frequently used to ablate afferent fibers from the vagus nerve in an attempt to elucidate the role of afferent fibers in gastrointestinal (GI) regulation. However, this method has recently been called into question by research demonstrating that the molecular target of capsaicin on spinal and trigeminal afferents, vanilloid receptor subtype 1 (VR1), is absent from vagal afferents. Although some concerns about selectivity exist, the available information suggests that perineural capsaicin defunctionalizes afferent neurons of the vagus nerve by acting on a vanilloid receptor subtype that is structurally different from VR1.
Holzer
P
P
Department of Experimental and Clinical Pharmacology, University of Graz, A-8010 Graz, Austria.
D000344:Afferent Pathways / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D000818:Animals; D002211:Capsaicin / Q000633:toxicity*; D004064:Digestive System / Q000187:drug effects / Q000294:innervation; D004068:Digestive System Physiological Phenomena; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology; D008959:Models, Neurological; D009412:Nerve Fibers / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D011955:Receptors, Drug / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D014276:Trigeminal Nerve / Q000187:drug effects / Q000502:physiology; D014630:Vagus Nerve / Q000187:drug effects / Q000473:pathology / Q000502:physiology*
D011955:Receptors, Drug; D002211:Capsaicin