Das Suman, Kumar Suneel, Jain Suman, Avelev Valery D, Mathur Rashmi
Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
Electromagn Biol Med. 2012 Sep;31(3):180-94. doi: 10.3109/15368378.2012.695706.
Clinically effective modalities of treatment for spinal cord injury (SCI) still remain unsatisfactory and are largely invasive in nature. There are reports of accelerated regeneration in injured peripheral nerves by extremely low-frequency pulsed electromagnetic field (ELF-EMF) in the rat. In the present study, the effect of (50 Hz), low-intensity (17.96 μT) magnetic field (MF) exposure of rats after-hemisection of T13 spinal cord (hSCI) was investigated on sensori-motor and locomotor functions. Rats were divided into hSCI (sham-exposed) and hSCI+MF (MF: 2 h/d X 6 weeks) groups. Besides their general conditions, locomotor function by Basso, Beattie, and Brenahan (BBB) score; motor responses to noxious stimuli by threshold of tail flick (TTF), simple vocalization (TSV), tail flick latency (TFL), and neuronal excitability by H-reflex were noted. It is found that, in the hSCI+MF group, a statistically significant improvement over the hSCI control group was noted in BBB score from post-SCI wk2 and TFL and TTF by post-hSCI wk1 and wk3, respectively. Correspondingly, TSV gradually restored by post-hSCI wk5.The threshold of H-reflex was reduced on ipsilateral side vs. contralateral side in hSCI and hSCI+MF group. A complete bladder control was dramatically restored on post-hSCI day4 (vs. day7 of hSCI group) and the survival rate was 100% in the hSCI+MF group (vs. 90% of hSCI group). The results of our study suggest that extremely low-frequency (50 Hz), low-intensity (17.96 μT) MF exposure for 2 h/d x 6wks promotes recovery of sensori-motor behavior including locomotion and bladder control both in terms of temporal pattern and magnitude in hemisection injury of (T13) spinal cord rats.
脊髓损伤（SCI）的临床有效治疗方式仍不尽人意，且在很大程度上具有侵入性。有报道称，极低频脉冲电磁场（ELF-EMF）可加速大鼠受损外周神经的再生。在本研究中，研究了T13脊髓半横断（hSCI）后大鼠暴露于（50Hz）、低强度（17.96μT）磁场（MF）对感觉运动和运动功能的影响。将大鼠分为hSCI（假暴露）组和hSCI+MF（MF：2小时/天×6周）组。除了观察它们的一般状况外，还通过Basso、Beattie和Brenahan（BBB）评分评估运动功能；通过甩尾阈值（TTF）、简单发声（TSV）、甩尾潜伏期（TFL）评估对有害刺激的运动反应，并通过H反射评估神经元兴奋性。结果发现，在hSCI+MF组中，与hSCI对照组相比，SCI后第2周的BBB评分以及hSCI后第1周和第3周的TFL和TTF均有统计学意义的显著改善。相应地，hSCI后第5周TSV逐渐恢复。hSCI组和hSCI+MF组中，H反射阈值在同侧相对于对侧降低。hSCI后第4天（相对于hSCI组的第7天）膀胱完全控制能力显著恢复，hSCI+MF组的存活率为100%（相对于hSCI组的90%）。我们的研究结果表明，每天暴露于极低频（50Hz）低强度（17.96μT）MF 2小时×6周，可促进T13脊髓半横断损伤大鼠感觉运动行为的恢复，包括运动和膀胱控制，在时间模式和程度方面均有改善。
