The neural mobilization technique modulates the expression of endogenous opioids in the periaqueductal gray and improves muscle strength and mobility in rats with neuropathic pain

Author(s)

Santos, Fabio Martinez ^{[1, 2, 3, 4]} ; Grecco, Leandro Henrique ^[2] ; Pereira, Marcelo Gomes ^[3] ; Oliveira, Mara Evany ^[1] ; Rocha, Priscila Abreu ^[1] ; Silva, Joyce Teixeira ^[1] ; Martins, Daniel Oliveira ^[1] ; Miyabara, Elen Haruka ^[3] ; Chacur, Marucia ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Lab Funct Neuroanat Pain, BR-05508000 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Butantan Inst, Special Lab Pain & Signaling, BR-05503900 Butanta, SP - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Lab Skeletal Muscle Plast, BR-05508000 Sao Paulo - Brazil

^[4] Univ Nove Julho, Dept Hlth Sci, Sao Paulo - Brazil

• Document type: Journal article
• Source: Behavioral and Brain Functions; v. 10, MAY 13 2014.
• Web of Science Citations: 10

Abstract

Background: The neural mobilization (NM) technique is a noninvasive method that has been proven to be clinically effective in reducing pain; however, the molecular mechanisms involved remain poorly understood. The aim of this study was to analyze whether NM alters the expression of the mu-opioid receptor (MOR), the delta-opioid receptor (DOR) and the Kappa-opioid receptor (KOR) in the periaqueductal gray (PAG) and improves locomotion and muscle force after chronic constriction injury (CCI) in rats. Methods: The CCI was imposed on adult male rats followed by 10 sessions of NM every other day, starting 14 days after the CCI injury. At the end of the sessions, the PAG was analyzed using Western blot assays for opioid receptors. Locomotion was analyzed by the Sciatic functional index (SFI), and muscle force was analyzed by the BIOPAC system. Results: An improvement in locomotion was observed in animals treated with NM compared with injured animals. Animals treated with NM showed an increase in maximal tetanic force of the tibialis anterior muscle of 172% (p < 0.001) compared with the CCI group. We also observed a decrease of 53% (p < 0.001) and 23% (p < 0.05) in DOR and KOR levels, respectively, after CCI injury compared to those from naive animals and an increase of 17% (p < 0.05) in KOR expression only after NM treatment compared to naive animals. There were no significant changes in MOR expression in the PAG. Conclusion: These data provide evidence that a non-pharmacological NM technique facilitates pain relief by endogenous analgesic modulation. (AU)

• FAPESP's process: 10/20026-6 - Use of low-level laser and mechanisms in molecular and cellular repair process in peripheral nervous system
• Grantee: Daniel de Oliveira Martins
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 12/05840-4 - Neural Mobilization: molecular and behavioral assessment in rats after induction of neuropathic pain
• Grantee: Fabio Martinez dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/24408-6 - Magnetic resonance and supraspinal neuronal activation in chronic neuropathic pain model in rats
• Grantee: Joyce Teixeira da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)