Abstract
Background: The primary motor cortex (M1) stimulation (MCS) is a useful tool for attenuation of the peripheral neuropathic pain in patients with pharmacologically refractory pain. Furthermore, that neurological procedure may also cause antinociception in rodents with neuropathic pain. Cold allodynia is a frequent clinical finding in patients with neuropathic pain, then, we evaluated if an adapted model of neuropathy induced by chronic constriction injury (CCI) of the ischiadicus nervus (sciatic nerve) produces cold allodynia in an animal model of chronic pain. In addition, we also investigated the effect of the electrical stimulation of the M1 on chronic neuropathic pain condition in laboratory animals. Methods: Male Wistar rats were used. An adapted model of peripheral mononeuropathy induced by CCI was carried out by placing a single loose ligature around the right sciatic nerve. The acetone test was used to evaluate the cold allodynia in CCI or Sham (without ligature) rats. The MCS (M1) was performed at low-frequency (20 μA, 100 Hz) during 15 s by deep brain stimulation (DBS-Thomas Recording device) 21 days after CCI or Sham procedures. The cold allodynia was measured before and immediately after the neurostimulation of M1 in the following time-window: 0, 15 and 30 min after MCS. Results: Cold allodynia threshold increased in animals with chronic neuropathic pain submitted to the acetone test 21 days after the CCI surgery. The M1-stimulation by DBS procedure decreased the cold allodynia immediately and until 30 min after M1-stimulation in rats with chronic neuropathic pain. Conclusion: The current proposal for a CCI model by a single loose ligature of the sciatic nerve can be employed as an experimental model of chronic neuropathic pain in rats submitted to peripheral nervous system injury. The M1-stimulation produced antinociception in rats with chronic neuropathic pain. Thus, we reinforced that the MCS decreases cold allodynia in laboratory animals submitted to persistent sciatic nerve constriction and can be a more reasonable procedure for the treatment of chronic intractable neuropathic pain.
Highlights
The most recent definition of pain is given by Williams and Craig [1] in 2016, who say that “pain is a distressing experience associated with actual or potential tissue damage with the sensory, emotional, cognitive and social component”
We evaluated the effect of motor cortex (M1) stimulation (MCS) (M1) in rats with chronic neuropathic pain investigating the modulation of cold allodynia threshold by M1-stimulation in rats with chronic constriction injury (CCI) of the ischiadicus nervus
All protocols were in compliance with the recommendations of the Committee for Ethics in Animal Experimentation (CETEA) of Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP) (Process 015/2005 and 036/2017), which are in accordance with the Animal Research Ethics guidelines adopted by the National Council for Animal Experimentation Control (CONCEA) and with the International Association for the Study of Pain (IASP) guidelines for pain research on laboratory animals [25]
Summary
The most recent definition of pain is given by Williams and Craig [1] in 2016, who say that “pain is a distressing experience associated with actual or potential tissue damage with the sensory, emotional, cognitive and social component”. When such injury or dysfunction is related to the central nervous system activity, the pain is classified as neuropathic pain [2]. Cold allodynia is a frequent clinical finding in patients with neuropathic pain, we roscience, 9, 138-152.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
