S S Bai1,2, S Y Mo1,2, X X Xu1,2, Y Liu1,2, Q F Xie1,2, Y Cao1,2. 1. Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China. 2. Center for Oral and Jaw Functional Diagnosis, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Abstract
OBJECTIVE: To compare the orofacial pain sensitivity with operant test and mechanical hyperalgesia with von Frey filaments of two orofacial pain models (EOI: experimental occlusal interference; pIONX: partial infraorbital nerve transection). To investigate the operant and evoked characteristics of EOI-rats. METHODS: The orofacial operant behaviors were tested by Ugo Basile Orofacial Stimulation Test System. The mechanical thresholds of vibrissal pads were tested by von Frey filaments. Male Sprague-Dawley rats were randomly divided into eight groups: von Frey group: sham-EOI, EOI, sham-pIONX, pIONX (sham: sham-operated group); operant test group: sham-EOI, EOI, sham-pIONX, pIONX (sham: sham-operated group). The mechanical thresholds and orofacial operant behaviors were tested on pre-operation and post-operation days l, 3, 7, 10, 14 and 21. RESULTS: In pIONX of von Frey group, the mechanical withdrawal threshold decreased from days 1 to 21 (P<0.05), peaking from days 7 to 10, and lasted until the end of the experiment. There was no significant difference between the bilateral sides. In pIONX of operant test group, the total contact time decreased from days 10 to 21 (P<0.05), peaking from days 10 to 14, and lasted until the end of the experiment. In EOI of von Frey group, the mechanical withdrawal threshold decreased from days 3 to 21 (P<0.05), peaking on day 7, and lasted until the end of the experiment. There was no significant difference between the bilateral sides. In EOI of operant test group, the total contact time decreased from days 1 to 21 (P<0.05), peaking from days 7 to 10, and lasting until the end of experiment. CONCLUSION: Orofacial operant test is a stable method to evaluate orofacial pain behaviors, which could discriminate the feature of neuropathic and EOI orofacial pain. In these two animal models, both of the operant behaviors and the mechanical hyperalgesia exhibited different time courses. Orofacial operant test provides a novel method for evaluating the orofacial pain sensitivity and studying the orofacial pain mechanism thoroughly.
OBJECTIVE: To compare the orofacial pain sensitivity with operant test and mechanical hyperalgesia with von Frey filaments of two orofacial pain models (EOI: experimental occlusal interference; pIONX: partial infraorbital nerve transection). To investigate the operant and evoked characteristics of EOI-rats. METHODS: The orofacial operant behaviors were tested by Ugo Basile Orofacial Stimulation Test System. The mechanical thresholds of vibrissal pads were tested by von Frey filaments. Male Sprague-Dawley rats were randomly divided into eight groups: von Frey group: sham-EOI, EOI, sham-pIONX, pIONX (sham: sham-operated group); operant test group: sham-EOI, EOI, sham-pIONX, pIONX (sham: sham-operated group). The mechanical thresholds and orofacial operant behaviors were tested on pre-operation and post-operation days l, 3, 7, 10, 14 and 21. RESULTS: In pIONX of von Frey group, the mechanical withdrawal threshold decreased from days 1 to 21 (P<0.05), peaking from days 7 to 10, and lasted until the end of the experiment. There was no significant difference between the bilateral sides. In pIONX of operant test group, the total contact time decreased from days 10 to 21 (P<0.05), peaking from days 10 to 14, and lasted until the end of the experiment. In EOI of von Frey group, the mechanical withdrawal threshold decreased from days 3 to 21 (P<0.05), peaking on day 7, and lasted until the end of the experiment. There was no significant difference between the bilateral sides. In EOI of operant test group, the total contact time decreased from days 1 to 21 (P<0.05), peaking from days 7 to 10, and lasting until the end of experiment. CONCLUSION: Orofacial operant test is a stable method to evaluate orofacial pain behaviors, which could discriminate the feature of neuropathic and EOI orofacial pain. In these two animal models, both of the operant behaviors and the mechanical hyperalgesia exhibited different time courses. Orofacial operant test provides a novel method for evaluating the orofacial pain sensitivity and studying the orofacial pain mechanism thoroughly.
Authors: Elissa J Chesler; Sonya G Wilson; William R Lariviere; Sandra L Rodriguez-Zas; Jeffrey S Mogil Journal: Neurosci Biobehav Rev Date: 2002-12 Impact factor: 8.989