THE BIOMAGNETIC SIGNATURE OF A CRUSHED AXON - A COMPARISON OF THEORY AND EXPERIMENT
THE BIOMAGNETIC SIGNATURE OF A CRUSHED AXON - A COMPARISON OF THEORY AND EXPERIMENT
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DOI：
10.1016/s0006-3495(93)81496-6
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发表时间：
1993-04-01
影响因子：
3.4
通讯作者：
WIKSWO, JP
中科院分区：
文献类型：
--
作者：
VANEGERAAT, JM;STASASKI, R;WIKSWO, JP
小龙虾内侧巨大轴突对神经挤压的反应是用生物磁电流探针检查的。实验数据用一个理论模型解释，该模型结合了径向和轴向离子传输和膜动力学，类似于霍奇金/赫胥黎模型。我们的实验表明，压碎的影响在静态上表现为静息电位的升高，在动态上表现为动作电流和电位的幅度的降低，并且在距压碎10毫米处都可以观察到。此外，正常的双相作用电流在压溃附近变为单相。该模型准确地反映了这些观测结果，并根据实验数据预测了时间常数为45 s的挤压密封。通过挤压进入轴突的损伤电流密度最初约为0.1 mA/mm2，并可能持续到挤压闭合或细胞内和细胞外空间之间的浓度梯度平衡。
The response of a crayfish medial giant axon to a nerve crush is examined with a biomagnetic current probe. The experimental data is interpreted with a theoretical model that incorporates both radial and axial ionic transport and membrane kinetics similar to those in the Hodgkin/Huxley model. Our experiments show that the effects of the crush are manifested statically as an elevation of the resting potential and dynamically as a reduction in the amplitude of the action current and potential, and are observable up to 10 mm from the crush. In addition, the normally biphasic action current becomes monophasic near the crush. The model reflects these observations accurately, and based on the experimental data, it predicts that the crush seals with a time constant of 45 s. The injury current density entering the axon through the crush is calculated to be initially on the order of 0.1 mA/mm2 and may last until the crush seals or until the concentration gradients between the intra- and extracellular spaces equilibrate.