Evidence of Altered Trigeminal Nociception in an Animal Model of Fibromyalgia

• Published in: Pain medicine (Malden, Mass.) Vol. 19; no. 2; pp. 328 - 335
• Main Authors: Nazeri, Masoud, Zarei, Mohammad-Reza, Pourzare, Amin-Reza, Ghahreh-Chahi, Hamid-Reza, Abareghi, Fatemeh, Shabani, Mohammad
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.02.2018
• Subjects: Analysis; Animals; Anxiety; Chronic illnesses; Chronic pain; Clinical trials; Disease Models, Animal; Facial Pain - physiopathology; Fibromyalgia; Fibromyalgia - physiopathology; Formaldehyde; Hyperalgesia - physiopathology; Male; Medical research; Milnacipran; Neurology; Nociception - physiology; Pain perception; Quality of life; Rats; Rats, Wistar; Rodents; Stress, Psychological; Fibromyalgia; Animal Model; Trigeminal Nociception; Anxiety-Like Behavior
• ISSN: 1526-2375; 1526-4637
• DOI: 10.1093/pm/pnx114

Abstract Objective Fibromyalgia (FM) is a debilitating chronic condition that significantly affects quality of life. A strong association has been demonstrated between FM and chronic pain in the trigeminal region in clinical studies. This study was performed to evaluate the response to acute and chronic noxious stimuli applied to the facial region. Methods Adult male Wistar rats (250–270 g, N = 10 for each group) were used in the current study. A subchronic swim stress model was used as the animal model of FM. Anxiety-like behaviors and response to acute and chronic noxious stimuli were assayed using the elevated plus maze, eye wiping test, and orofacial formalin test, respectively. Balance and motor function were evaluated using rotarod and wire grip tests. Results An increased anxiety-like behavior was observed in swim stress rats in comparison with control and sham subjects. Response to acute and chronic noxious stimuli in the trigeminal region was increased in the stressed rats. Motor and balance function were not altered following stress. Conclusions Results of the current study demonstrated a hyperalgesic state in the trigeminal region in a possible animal model of FM. This study provides a reliable animal model for further research on the possible mechanisms of orofacial pain in FM.