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Role of Neurotransmitters in Sensitization of Pain Responses
Author(s) -
Willis William D.
Publication year - 2001
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2001.tb05821.x
Subject(s) - hyperalgesia , sensitization , allodynia , nociception , spinothalamic tract , nmda receptor , capsaicin , neuroscience , long term potentiation , chemistry , sensory system , pharmacology , medicine , receptor , psychology
A bstract : Injection of capsaicin into the skin results in pain, primary heat and mechanical hyperalgesia, and secondary mechanical allodynia and hyperalgesia. Sensory receptors in the area of secondary mechanical allodynia and hyperalgesia are unaffected, and so the sensory changes must be due to central actions of the initial intense nociceptive discharge that follows the capsaicin injection. Central sensitization of the responses of spinothalamic tract neurons lasts several hours, but can be prevented by spinal cord administration of non‐NMDA and NMDA glutamate receptor antagonists or NK1 substance P receptor antagonists. The long‐lasting increase in excitability of spinothalamic tract cells depends on the activation of several second messenger cascades (PKC, PKA, and NO/PKG signal transduction pathways). The excitability change also depends on activation of calcium/calmodulin‐dependent kinase II, which is consistent with the proposal that this central sensitization response is a form of long‐term potentiation.