Modelling the effects of electric fields on nerve fibres: influence of the myelin sheath
Modelling the effects of electric fields on nerve fibres: influence of the myelin sheath
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DOI：
10.1007/bf02345014
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发表时间：
2000-07-01
影响因子：
3.2
通讯作者：
Grill, WM
中科院分区：
文献类型：
--
作者：
Richardson, AG;McIntyre, CC;Grill, WM
哺乳动物运动神经纤维，将三种不同的髓鞘表示，基于计算机的电缆模型的兴奋和传导性能进行了比较。三种髓磷脂表示是完全绝缘的单电缆（模型A）、有限阻抗单电缆（模型B）和有限阻抗双电缆（模型C）。采用细胞外刺激方法，研究了三种模型的强度-持续时间和电流-距离（I-X）关系、传导速度（CV）和动作电位形状。所有三个模型的时值时间都在实验范围内。与模型A相比，模型B和C的阈值电流有所增加，但每个模型的I-X关系的斜率与实验结果相匹配。模型B具有与实验数据匹配的CV，而模型A和C的CV分别高于和低于实验范围，模型C能够产生去极化后电位（DAP），而模型A和B表现出超极化后电位。当使用低频刺激（<类似于25 Hz）时，由于其效率和精确的激励和传导特性，模型A和B被确定为优选模型。对于高频刺激（类似于25 Hz或更高），模型C具有产生DAP的能力，需要准确模拟激励行为。
The excitation and conduction properties of computer-based cable models of mammalian motor nerve fibres, incorporating three different myelin representations, are compared. The three myelin representations are a perfectly insulating single cable (model A), a finite impedance single cable (model B) and a finite impedance double cable (model C). Extracellular stimulation of the three models is used to study their strength-duration and current-distance (I-X) relationships, conduction velocity (CV) and action potential shape. AII three models have a chronaxie time that is within the experimental range. Models B and C have increased threshold currents compared with model A, but each model has a slope to the I-X relationship that matches experimental results. Model B has a CV that matches experimental data, whereas the CV of models A and C are above and below the experimental range, respectively Model C is able to produce a depolarising afterpotential (DAP), whereas models A and B exhibit hyperpolarising afterpotentials. Models A and B are determined to be the preferred models when low-frequency stimulation (< similar to 25 Hz) is used, owing to their efficiency and accurate excitation and conduction properties. For high frequency stimulation (similar to 25 Hz and greater), model C, with its ability to produce a DAP, is necessary accurately to simulate excitation behaviour.