Mustard oil enhances spinal neuronal responses to noxious heat but not cooling

• Published in: Neuroscience letters Vol. 461; no. 3; pp. 271 - 274
• Main Authors: Sawyer, Carolyn M., Carstens, Mirela Iodi, Carstens, E.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 25-09-2009; Elsevier
• Subjects: Action Potentials; Allyl Compounds - toxicity; Animals; Ankyrins; Biological and medical sciences; Calcium Channel Agonists - toxicity; Calcium Channels - physiology; Cold Temperature - adverse effects; Dorsal horn; Fundamental and applied biological sciences. Psychology; Hot Temperature - adverse effects; Hyperalgesia - chemically induced; Hyperalgesia - physiopathology; Isocyanates - toxicity; Male; Mustard oil; Mustard Plant - toxicity; Neurons - drug effects; Neurons - physiology; Nociception; Noxious heat; Pain - chemically induced; Pain - physiopathology; Plant Oils - toxicity; Rat; Rats; Skin - drug effects; Skin - physiopathology; Skin cooling; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Spinal cord; Spinal Cord - drug effects; Spinal Cord - physiopathology; TRPA1; TRPA1 Cation Channel; TRPC Cation Channels; Vertebrates: nervous system and sense organs; Noxious heat; Nociception; Spinal cord; Rat; TRPA1; Mustard oil; Skin cooling; Dorsal horn; Temperature; Rodentia; Central nervous system; Environmental factor; Posterior spinal horn; Vertebrata; Heat; Mammalia; Animal; Skin
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2009.06.036

The TRPA1 agonist mustard oil (allyl isothiocyanate
=
AITC) induces heat hyperalgesia and mechanical allodynia in human skin and sensitizes rat spinal wide dynamic range (WDR) neuronal responses to noxious skin heating. We presently used electrophysiological methods to investigate if AITC affects the responsiveness of individual spinal WDR neurons to intense skin cooling. Recordings were made from cold-sensitive WDR neurons in lamina I and deeper dorsal horn; 21/23 also responded to noxious skin heating. Topical application of AITC excited 8/18 units and significantly enhanced their responses to noxious heat while not significantly affecting responses to the cold stimulus. Vehicle (mineral oil) had no effect on thermal responses. The data confirm a role for the TRPA1 agonist AITC in enhancing heat nociception without significantly affecting cold sensitivity.