Exposure to extremely low-frequency magnetic field restores spinal cord injury-induced tonic pain and its related neurotransmitter concentration in the brain. (December 2013)

• Record Type: Journal Article
• Authors: Kumar, Suneel; Jain, Suman; Velpandian, Thirumurthy; Petrovich Gerasimenko, Yury; D. Avelev, Valery; Behari, Jitendra; Behari, Madhuri; Mathur, Rashmi
• Is Part Of: Electromagnetic biology and medicine. Volume 32:Number 4(2013:Oct.)
• Page Start: 471
• Page End: 483
• Publication Date: 2013-12
• Subjects: Electrophysiology -- Periodicals; Electromagnetic Fields -- Periodicals; Electrophysiology -- Periodicals; Radiation, Nonionizing -- Periodicals; 574
• DOI: 10.3109/15368378.2012.743907
• Languages: English
• ISSNs: 1536-8378

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <p>Spinal cord injury (SCI) is unequivocally reported to produce hyperalgesia to phasic stimuli, while both hyper- and hypoalgesia to tonic stimuli. The former is spinally mediated and the latter centrally. Besides, its management is unsatisfactory. We report the effect of magnetic field (MF; 17.96 μT, 50 Hz) on tonic pain behavior and related neurotransmitters in the brain of complete thoracic (T13) SCI rats at week 8. Adult male Wistar rats were divided into Sham, SCI and SCI+MF groups. Formalin-pain behavior was compared utilizing 5 min block pain rating (PR), 60 min session-PR, time spent in various categories of increasing pain (T0–T3) and flinch incidences. Serotonin (5-HT), dopamine (DA), norepinepherine (NE), gamma-aminobutyric acid (GABA), glutamate and glycine were estimated in brain tissue by liquid chromatography–mass spectrometry. Session-PR, block-PR and number of flinches were significantly lower, while time spent in categories 0–1 was higher in the SCI <italic>versus</italic> Sham group. These parameters were comparable in the SCI+MF <italic>versus</italic> Sham group. 5-HT concentration in cortex, remaining forebrain areas and brain stem (BS), was lower while GABA and NE were higher in BS of SCI, which were comparable with Sham in the SCI+MF group. The concentration of DA, glutamate and glycine was comparable amongst the groups. The data indicate significant hypoalgesia in formalin pain while increased in GABA, NE and decreased in 5-HT post-SCI, which were restored in the SCI+MF group. We suggest beneficial effect of chronic (2 h/day × 8 weeks) exposure to MF (50 Hz, 17.96 μT) on tonic pain that is mediated by 5-HT, GABA and NE in complete SCI rats.</p> </abstract>