Liu Yujiang, Yue Yuan, Yu Yuguo, Liu Liwei, Yu Lianchun
Institute of Theoretical Physics, Lanzhou University, Lanzhou, 730000, China.
College of Electrical Engineering, Northwest University for Nationalities, Lanzhou, 730070, China.
J Comput Neurosci. 2018 Apr;44(2):219-231. doi: 10.1007/s10827-017-0676-2. Epub 2018 Jan 11.
Action potentials are the information carriers of neural systems. The generation of action potentials involves the cooperative opening and closing of sodium and potassium channels. This process is metabolically expensive because the ions flowing through open channels need to be restored to maintain concentration gradients of these ions. Toxins like tetraethylammonium can block working ion channels, thus affecting the function and energy cost of neurons. In this paper, by computer simulation of the Hodgkin-Huxley neuron model, we studied the effects of channel blocking with toxins on the information transmission and energy efficiency in squid giant axons. We found that gradually blocking sodium channels will sequentially maximize the information transmission and energy efficiency of the axons, whereas moderate blocking of potassium channels will have little impact on the information transmission and will decrease the energy efficiency. Heavy blocking of potassium channels will cause self-sustained oscillation of membrane potentials. Simultaneously blocking sodium and potassium channels with the same ratio increases both information transmission and energy efficiency. Our results are in line with previous studies suggesting that information processing capacity and energy efficiency can be maximized by regulating the number of active ion channels, and this indicates a viable avenue for future experimentation.
动作电位是神经系统的信息载体。动作电位的产生涉及钠通道和钾通道的协同开启和关闭。这个过程在代谢上代价高昂,因为流经开放通道的离子需要被恢复以维持这些离子的浓度梯度。像四乙铵这样的毒素可以阻断工作中的离子通道,从而影响神经元的功能和能量消耗。在本文中,通过对霍奇金 - 赫胥黎神经元模型进行计算机模拟,我们研究了毒素阻断通道对鱿鱼巨轴突中信息传递和能量效率的影响。我们发现,逐渐阻断钠通道会依次使轴突的信息传递和能量效率最大化,而适度阻断钾通道对信息传递影响不大,但会降低能量效率。重度阻断钾通道会导致膜电位的自持振荡。以相同比例同时阻断钠通道和钾通道会提高信息传递和能量效率。我们的结果与之前的研究一致,表明通过调节活性离子通道的数量可以使信息处理能力和能量效率最大化,这为未来的实验指明了一条可行的途径。