title: Ameroid rings for gradual chronic constriction of the sciatic nerve in rats: contribution of different nerves to neuropathic pain.
abstract: Mononeuropathy was induced by placing an ameroid ring around the sciatic nerve and was compared with chronic constriction injury (CCI) of the sciatic nerve [Pain 33 (1988) 87] in rats. Mechanical allodynia was assessed and the role of sciatic and saphenous afferents (Adelta and C) in thermal hyperalgesia investigated. A shorter duration of mechanical allodynia in ameroid rats as compared to CCI rats was observed. Thermal hyperalgesia was observed in the saphenous innervated skin of the hindpaw for Adelta and C nociceptors in ameroid and for Adelta nociceptors only in CCI rats, respectively. The sciatic innervated skin showed a thermal hypoalgesia with a fast onset for Adelta afferents and a slower onset for C afferents in CCI and ameroid rats. The duration of both thermal hypo- and hyperalgesia was longer in ameroid rats. We conclude that ameroid rings are a useful tool for the investigation of long-duration hyperalgesic effects of nerve injury, as the effects were more stable and seen for a longer time (>8 weeks) as compared to the CCI model. The uninjured saphenous afferents, in particular C fibers, mediate thermal hyperalgesia after chronic constriction of the sciatic nerve using an ameroid ring.
authors.affiliation: Department of Anesthesia, Stanford University School of Medicine, 300 Pasteur Drive, S-276 Stanford, CA 94305, USA.
authors.forename: A
authors.initials: A
authors.lastname: Tzabazis
authors.forename: P H
authors.initials: PH
authors.lastname: Kim
authors.forename: S M
authors.initials: SM
authors.lastname: Sweitzer
authors.forename: D C
authors.initials: DC
authors.lastname: Yeomans
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects*; D002364:Caseins; D003251:Constriction, Pathologic; D020100:Hydrogels / Q000009:adverse effects*; D006930:Hyperalgesia / Q000503:physiopathology; D008297:Male; D020422:Mononeuropathies / Q000150:complications*; D009437:Neuralgia / Q000209:etiology*; D010147:Pain Measurement; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D015203:Reproducibility of Results; D012584:Sciatic Nerve / Q000293:injuries / Q000503:physiopathology*; D012867:Skin / Q000294:innervation / Q000503:physiopathology; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D002364:Caseins; D020100:Hydrogels; C009719:ameroid