Cormery B, Marini J F, Gardiner P F
Département de kinésiologie, Université de Montréal, C.P. 6128, Succursale Centre-ville Montréal, H3C 3J7, Québec, Canada.
Neurosci Lett. 2000 Jun 16;287(1):21-4. doi: 10.1016/s0304-3940(00)01110-1.
In this study, we test the hypothesis that 4 weeks tetrodotoxin (TTX) paralysis altered the passive membrane properties of rat tibial motoneurones. Impulse activity along the sciatic nerve was blocked for 4 weeks using TTX delivered by an osmotic minipump to a Silastic cuff placed around the nerve. That portion of the sample exhibiting the 20% slowest After-hyperpolarization (AHP) decay time (AHPd), and which therefore included presumptive type S motoneurons, demonstrated responses (reduced AHPd, increased rheobase and rheobase voltage), which were not evident in the rest of the sample (presumptive fast motoneurons), in which an increased AHPd, in fact, was found. The results thus support the hypothesis that retrograde signals from inactive slow and fast muscle fibers have different effects on their innervating motoneurones.
在本研究中，我们检验了以下假设：4周的河豚毒素（TTX）麻痹改变了大鼠胫运动神经元的被动膜特性。使用渗透微型泵将TTX输送到置于坐骨神经周围的硅橡胶套中，使沿坐骨神经的冲动活动被阻断4周。样本中后超极化（AHP）衰减时间（AHPd）最慢的20%部分，因此包括推测的S型运动神经元，表现出反应（AHPd降低、基强度和基强度电压增加），而在样本的其余部分（推测的快运动神经元）中这些反应并不明显，实际上在其余部分发现AHPd增加。因此，结果支持了以下假设：来自不活动的慢肌纤维和快肌纤维的逆行信号对其支配的运动神经元有不同影响。
