| Autor: |
Rafael Sobrano Fais, A.C. Rossaneis, Q.M. Dias, Wiliam A. Prado, E.A. Del Bel, K. Genaro, L.M. Guethe |
| Rok vydání: |
2014 |
| Předmět: |
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| Zdroj: |
European Journal of Pain. 19:1148-1157 |
| ISSN: |
1090-3801 |
| DOI: |
10.1002/ejp.638 |
| Popis: |
Background: The anterior pretectal nucleus (APtN) activates descendingmechanisms of pain control. This study evaluated whether the APtN alsocontrols neuropathic pain in rats.Methods: The hypersensitivity to mechanical stimulation with anelectronic von Frey apparatus and the number of Fos-immunoreactive(Fos-ir) neurons in the APtN were evaluated in rats before and afterchronic constriction injury of the sciatic nerve.Results: The tactile hypersensitivity was characterized by an initial phase(the 2 days following the injury) and a maintenance phase (thesubsequent 7 days). The injection of 2% lidocaine (0.25 μL) orN-methyl-D-aspartate (2.5 μg/0.25 μL) into the APtN intensified thetactile hypersensitivity observed 2 days after injury but did not alter thetactile hypersensitivity observed 7 and 14 days after injury. The injection ofnaloxone (10 ng/0.25 μL) or methysergide (40 pg/0.25 μL) but notatropine (100 ng/0.25 μL) into the APtN also intensified the tactilehypersensitivity observed 2 days after the injury. A significant increase inthe number of Fos-ir cells was found in the contralateral APtN 2 days butnot 7 or 14 days after the injury. Electrical stimulation of the APtN reducedthe tactile hypersensitivity at 2, 7 and 14 days after the nerve ligation.Conclusion: APtN exerts a tonic inhibitory influence on persistent pain.The results point out to an important role of opioid and serotonergicmediation into the APtN to inhibit hyperalgesia during the initial phase ofneuropathic pain. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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