Ollivier-Lanvin Karen, Lemay Michel A, Tessler Alan, Burns Anthony S
Department of Neurobiology and Anatomy, Drexel Univ. College of Medicine, 2900 W. Queen Lane, Philadelphia, PA 19129, USA.
J Appl Physiol (1985). 2009 Oct;107(4):1190-4. doi: 10.1152/japplphysiol.00282.2009. Epub 2009 Jul 30.
Current evidence suggests that significant morphological changes occur in nerve-muscle connections caudal to spinal cord injury (SCI). To determine whether neuromuscular junction (NMJ) function is compromised after SCI, we investigated the contribution of NMJ failure to hindlimb muscle fatigue in control and spinalized adult rats. Repetitive supramaximal nerve stimulation was applied to two muscle-nerve preparations: medial gastrocnemius (MG)-tibial and tibialis anterior (TA)-peroneal. NMJ transmission failure was evident in control and SCI animals after repetitive stimulation. At 2 wk post-SCI, NMJ transmission failure was greater in SCI animals compared with controls, but the difference was not significant (P = 0.205 for the MG and P = 0.053 for the TA). At 6 wk post-SCI, there was a significant but small difference in NMJ transmission failure for the TA between control and spinal animals. These results demonstrate that, although there may be a mild decrement in NMJ function, NMJ transmission remains largely intact for supramaximal nerve stimulation.
目前的证据表明，脊髓损伤（SCI）尾侧的神经 - 肌肉连接会发生显著的形态学变化。为了确定脊髓损伤后神经肌肉接头（NMJ）功能是否受损，我们研究了在对照成年大鼠和脊髓损伤成年大鼠中，神经肌肉接头功能障碍对后肢肌肉疲劳的影响。对两种肌肉 - 神经标本施加重复的超强神经刺激：内侧腓肠肌（MG） - 胫神经和胫骨前肌（TA） - 腓总神经。在对照动物和脊髓损伤动物中，重复刺激后神经肌肉接头传递失败明显。脊髓损伤后2周，与对照动物相比，脊髓损伤动物的神经肌肉接头传递失败更严重，但差异不显著（内侧腓肠肌P = 0.205，胫骨前肌P = 0.053）。脊髓损伤后6周，对照动物和脊髓损伤动物之间胫骨前肌的神经肌肉接头传递失败存在显著但较小的差异。这些结果表明，虽然神经肌肉接头功能可能有轻度下降，但对于超强神经刺激，神经肌肉接头传递在很大程度上仍保持完整。
