CONDUCTION-VELOCITY AND SPIKE CONFIGURATION IN MYELINATED FIBERS - COMPUTED DEPENDENCE ON INTERNODE DISTANCE
CONDUCTION-VELOCITY AND SPIKE CONFIGURATION IN MYELINATED FIBERS - COMPUTED DEPENDENCE ON INTERNODE DISTANCE
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DOI：
10.1136/jnnp.40.8.769
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发表时间：
1977-01-01
影响因子：
11
通讯作者：
JOYNER, RW
中科院分区：
文献类型：
--
作者：
BRILL, MH;WAXMAN, SG;JOYNER, RW
已经从理论上和实验上证实，对于有髓纤维束，如正常的周围神经，传导速度(Theta)应该与神经纤维直径成正比，表现出结构上的相似性。然而，在一些轴突中，兰维尔结节的间距比正常周围神经中的更紧密。分析论证表明，当节点间距离(L)单独改变时，θ对L的曲线图应该有一个相对平坦的最大值。之前的几个有髓轴突的计算机模拟证实了这一点，但没有检查不到正常情况下一半的节间长度。为了深入了解有髓纤维和有髓纤维在短节间长度下的脉冲传播，本研究考察了广泛节间长度范围内的传导速度和棘波形态。当L变大时，theta下降，最终传播受阻；当L变小时，theta下降得越来越厉害。由此预测，对于节间长度很短的纤维，L的局部微小变化将对传导速度产生很大影响。
It has been argued theoretically and confirmed experimentally that conduction velocity (theta) should be proportional to nerve fibre diameter for myelinated fibre tracts, such as normal peripheral nerve, exhibiting 'structural' similarity'. In some axons, however, the nodes of Ranvier are more closely spaced than in normal peripheral nerve. Analytic arguments have suggested that when internodal distance (L) alone is changed, the plot of theta versus L should have a relatively flat maximum. This was confirmed by several previous computer simulations of myelinated axons, but internode lengths of less than half the normal case were not examined. In order to gain insight into impulse propagation in myelinated and remyelinated fibres with short internodal lengths, the present study examines the conduction velocity and spike configuration for a wide range of internodal lengths. As L becomes large, theta falls and finally propagation is blocked; as L becomes small, theta decreases more and more steeply. From this, it is predicted that for fibres with very short internodal lengths, small local changes in L should affect substantially the conduction velocity.