Ijkema-Paassen Jos, Meek Marcel F, Gramsbergen Albert
Department of Medical Physiology, University of Groningen, A Deusinglaan 1, Bldg. 3215, 9713 AV Groningen, The Netherlands.
Muscle Nerve. 2002 Jun;25(6):891-7. doi: 10.1002/mus.10130.
Functional recovery after transection of the sciatic nerve in adult rats is poor, probably because of abnormalities in reinnervation. Denervation and reinnervation patterns were studied morphologically in the lateral gastrocnemius (LGC), tibialis anterior (TA), and soleus (SOL) muscles for 21 weeks after nerve transection (motor endplates by acetylcholinesterase staining; nerves by silver impregnation). Motor endplates in the TA showed improving morphology with age, and, at 21 weeks, three-quarters of these were normal. Poorest recovery was observed in the SOL, as, at 21 weeks, only one-third of the motor endplates had a normal morphology. Polyneuronal innervation initially was more pronounced in the SOL, but, at 21 weeks, 10% of the motor endplates in all three muscles were still polyneuronally innervated. Our results indicate important differences in the reinnervation of these three hindleg muscles, and, even at 5 months, abnormalities were still present. These factors may in part explain the abnormal locomotion in rats as well as the limited recovery of function observed clinically in humans after nerve transection.
成年大鼠坐骨神经横断后的功能恢复较差,这可能是由于神经再支配异常所致。在神经横断后的21周内,对大鼠的外侧腓肠肌(LGC)、胫骨前肌(TA)和比目鱼肌(SOL)进行了去神经和再神经支配模式的形态学研究(通过乙酰胆碱酯酶染色观察运动终板;通过银浸染法观察神经)。TA肌中的运动终板形态随年龄增长而改善,在21周时,其中四分之三的运动终板形态正常。在SOL肌中观察到的恢复最差,在21周时,只有三分之一的运动终板形态正常。多神经元支配最初在SOL肌中更为明显,但在21周时,所有三块肌肉中10%的运动终板仍为多神经元支配。我们的结果表明,这三块后肢肌肉的神经再支配存在重要差异,即使在5个月时,异常情况仍然存在。这些因素可能部分解释了大鼠的异常运动以及人类神经横断后临床上观察到的功能恢复有限的现象。