Follmann Rosangela, Rosa Epaminondas, Stein Wolfgang
School of Biological Sciences, Illinois State University, Normal, Illinois 61790, USA.
Department of Physics, Illinois State University, Normal, Illinois 61790, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Sep;92(3):032707. doi: 10.1103/PhysRevE.92.032707. Epub 2015 Sep 14.
Long-range communication in the nervous system is usually carried out with the propagation of action potentials along the axon of nerve cells. While typically thought of as being unidirectional, it is not uncommon for axonal propagation of action potentials to happen in both directions. This is the case because action potentials can be initiated at multiple "ectopic" positions along the axon. Two ectopic action potentials generated at distinct sites, and traveling toward each other, will collide. As neuronal information is encoded in the frequency of action potentials, action potential collision and annihilation may affect the way in which neuronal information is received, processed, and transmitted. We investigate action potential propagation and collision using an axonal multicompartment model based on the Hodgkin-Huxley equations. We characterize propagation speed, refractory period, excitability, and action potential collision for slow (type I) and fast (type II) axons. In addition, our studies include experimental measurements of action potential propagation in axons of two biological systems. Both computational and experimental results unequivocally indicate that colliding action potentials do not pass each other; they are reciprocally annihilated.
神经系统中的远距离通讯通常是通过动作电位沿神经细胞轴突的传播来实现的。虽然通常认为动作电位是单向传播的，但动作电位沿轴突双向传播的情况并不罕见。之所以会出现这种情况，是因为动作电位可以在轴突上的多个“异位”位置产生。在不同位点产生并相向传播的两个异位动作电位会相互碰撞。由于神经元信息是通过动作电位的频率进行编码的，动作电位的碰撞和湮灭可能会影响神经元信息的接收、处理和传递方式。我们使用基于霍奇金-赫胥黎方程的轴突多节段模型来研究动作电位的传播和碰撞。我们对慢速（I型）和快速（II型）轴突的传播速度、不应期、兴奋性和动作电位碰撞进行了表征。此外，我们的研究还包括对两个生物系统轴突中动作电位传播的实验测量。计算和实验结果都明确表明，相互碰撞的动作电位不会相互穿过；它们会相互湮灭。
