Mustard oil enhances spinal neuronal responses to noxious heat but not cooling.
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.
Sawyer
Carolyn M
CM
Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA 95616, USA.
Carstens
Mirela Iodi
MI
Carstens
E
E
D000200:Action Potentials; D000498:Allyl Compounds / Q000633:toxicity*; D000818:Animals; D017487:Ankyrins; D002120:Calcium Channel Agonists / Q000633:toxicity*; D015220:Calcium Channels / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects*; D006358:Hot Temperature / Q000009:adverse effects*; D006930:Hyperalgesia / Q000139:chemically induced / Q000503:physiopathology; D017953:Isocyanates / Q000633:toxicity*; D008297:Male; D009149:Mustard Plant / Q000633:toxicity; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology*; D010938:Plant Oils / Q000633:toxicity; D051381:Rats; D012867:Skin / Q000187:drug effects / Q000503:physiopathology; D013116:Spinal Cord / Q000187:drug effects* / Q000503:physiopathology; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels
D000498:Allyl Compounds; D017487:Ankyrins; D002120:Calcium Channel Agonists; D015220:Calcium Channels; D017953:Isocyanates; D010938:Plant Oils; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; C480976:Trpa1 protein, rat; C491149:allyl isocyanate; C027793:mustard oil