Zmysłowski Wojciech, Cabaj Anna M, Sławińska Urszula
Department of Engineering of Nervous and Muscular System, Nałęcz Institute of Biocybernetics and Biomedical Engineering, PAS, Warsaw, Poland.
Department of Neurophysiology, Nencki Institute of Experimental Biology, PAS, Warsaw, Poland.
PLoS One. 2017 Jan 17;12(1):e0170235. doi: 10.1371/journal.pone.0170235. eCollection 2017.
The effects of sciatic nerve crush (SNC) and treatment with Riluzole on muscle activity during unrestrained locomotion were identified in an animal model by analysis of the EMG activity recorded from soleus (Sol) and extensor digitorum longus (EDL) muscles of both hindlimbs; in intact rats (IN) and in groups of rats treated for 14 days with saline (S) or Riluzole (R) after right limb nerve crush at the 1st (1S and 1R) or 2nd (2S and 2R) day after birth. Changes in the locomotor pattern of EMG activity were correlated with the numbers of survived motor units (MUs) identified in investigated muscles. S rats with 2-8 and 10-28 MUs that survived in Sol and EDL muscles respectively showed increases in the duration and duty factor of muscle EMG activity and a loss of correlation between the duty factors of muscle activity, and abnormal flexor-extensor co-activation 3 months after SNC. R rats with 5, 6 (Sol) and 15-29 MUs (EDL) developed almost normal EMG activity of both Sol and control EDL muscles, whereas EDL muscles with SNC showed a lack of recovery. R rats with 8 (Sol) and 23-33 (EDL) MUs developed almost normal EMG activities of all four muscles. A subgroup of S rats with a lack of recovery and R rats with almost complete recovery that had similar number of MUs (8 and 24-28 vs 8 and 23-26), showed that the number of MUs was not the only determinant of treatment effectiveness. The results demonstrated that rats with SNC failed to develop normal muscle activity due to malfunction of neuronal circuits attenuating EDL muscle activity during the stance phase, whereas treatment with Riluzole enabled almost normal EMG activity of Sol and EDL muscles during locomotor movement.
通过分析从双侧后肢比目鱼肌（Sol）和趾长伸肌（EDL）记录的肌电图（EMG）活动，在动物模型中确定了坐骨神经挤压（SNC）和用利鲁唑治疗对自由运动期间肌肉活动的影响；实验对象包括完整大鼠（IN），以及出生后第1天（1S和1R）或第2天（2S和2R）右肢神经挤压后用生理盐水（S）或利鲁唑（R）治疗14天的大鼠组。EMG活动的运动模式变化与在被研究肌肉中识别出的存活运动单位（MUs）数量相关。分别在Sol和EDL肌肉中存活2 - 8个和10 - 28个MUs的S组大鼠，在SNC后3个月，肌肉EMG活动的持续时间和占空因数增加，肌肉活动占空因数之间的相关性丧失，并且出现异常的屈伸共同激活。在Sol肌肉中有5个、6个MUs（Sol）以及在EDL肌肉中有15 - 29个MUs（EDL）的R组大鼠，其Sol和对照EDL肌肉的EMG活动几乎恢复正常，而SNC后的EDL肌肉则未恢复。在Sol肌肉中有8个MUs（Sol）以及在EDL肌肉中有23 - 33个MUs（EDL）的R组大鼠，其所有四块肌肉的EMG活动几乎恢复正常。一组恢复不良的S组大鼠和一组几乎完全恢复的R组大鼠，它们具有相似数量的MUs（8个和24 - 28个与8个和23 - 26个），这表明MUs数量不是治疗效果的唯一决定因素。结果表明，SNC大鼠由于神经元回路功能障碍，在站立期减弱了EDL肌肉活动，从而未能发展出正常的肌肉活动，而用利鲁唑治疗可使运动过程中Sol和EDL肌肉的EMG活动几乎恢复正常。
