title: Assessing mechanical sensitivity of masseter muscle in lightly anesthetized rats: a model for craniofacial muscle hyperalgesia.
abstract: In this report, we present a simple and reliable way of assessing mechanical sensitivity of masseter muscle as a model for craniofacial muscle hyperalgesia. Mechanical thresholds that evoke nocifensive hindpaw responses following noxious masseter stimulation were assessed. Masseteric injections of widely used sensitizing agents significantly increased mechanical sensitivity of the muscle in a time dependent manner without affecting other muscles and overlying skin. This lightly anesthetized rodent paradigm allows us to provide calibrated and reliable mechanical stimulus, which is not possible in behaving animals. The technique can be applied to study mechanistic bases for craniofacial muscle tenderness.
authors.affiliation: Department of Biomedical Sciences, Program in Neuroscience, University of Maryland Baltimore, School of Dentistry, Baltimore, MD 21201, USA. jro@umaryland.edu
authors.forename: Jin Y
authors.initials: JY
authors.lastname: Ro
authors.forename: Norman F
authors.initials: NF
authors.lastname: Capra
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001519:Behavior / Q000187:drug effects / Q000502:physiology; D001920:Bradykinin / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D005157:Facial Pain; D018698:Glutamic Acid / Q000494:pharmacology; D006801:Humans; D006930:Hyperalgesia; D008297:Male; D008406:Masseter Muscle / Q000187:drug effects*; D008954:Models, Biological; D010147:Pain Measurement; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018712:Analgesics, Non-Narcotic; D018698:Glutamic Acid; D002211:Capsaicin; D001920:Bradykinin