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

Abstract

BackgroundThe 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.MethodsThe 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.ResultsAn 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.ConclusionThese data provide evidence that a non-pharmacological NM technique facilitates pain relief by endogenous analgesic modulation.

Neural mobilization as a therapeutic option in the treatment of stroke.

“…(5) NM demonstrated efficiency in prevention of hypertrophy, muscular strength gains, improved nerve conduction velocity and reduction of pain in animals. (6,7) Whereas in humans were evidenced gains of flexibility and range of motion, pain relief, increase in the recruitment of muscle fibers, improve in neural conduction velocity, increase in the muscle strength and improve in the functionality. (8)(9)(10)(11)(12)(13) Although the explored studies have shown positive results, researchers still have antagonistic thoughts regarding the clinical applicability of NM.…”

Short‐term swimming exercise attenuates the sensitization of dorsal horn neurons in rats with NGF‐induced low back pain

“…Exercise and other forms of physical therapy are approved therapeutic treatment strategies in the rehabilitation of patients suffering from chronic pain including low back pain (Heneweer et al, 2009;Hooten et al, 2012;Babatunde et al, 2017;Geneen et al, 2017). Physical therapy reduces pain reactions in animals (Cobianchi et al, 2010;Shen et al, 2013;Sluka et al, 2013;Santos et al, 2014;Lima et al, 2017) and pain in humans (Naugle et al, 2012;Babatunde et al, 2017).…”

The neurophysiological response to manual therapy and its analgesic implications: A narrative review

“…Utilizing male Wistar rats and Western blot assays of the PAG, Santos et al (2014) examined the brains of rats following neural mobilization for mu-, delta-, and kappa-opioid receptor expression. Researchers did not find changes in delta-and mu-opioid receptor expression following neural mobilization, but kappa-opioid receptor expression underwent a significant increase, by 17%.…”