Can Neural Activity Propagate by Endogenous Electrical Field?
Can Neural Activity Propagate by Endogenous Electrical Field?
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DOI：
10.1523/jneurosci.1045-15.2015
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发表时间：
2015-12-02
影响因子：
5.3
通讯作者：
Durand, Dominique M.
中科院分区：
文献类型：
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作者：
Qiu, Chen;Shivacharan, Rajat S.;Durand, Dominique M.
人们普遍认为，突触传递和缝隙连接是神经系统中信号传递的主要调控机制。然而，一组神经波，无论是生理的还是病理的，都具有与0.1m/S相似的速度，没有突触传递或缝隙连接，这一速度与轴突传导或离子扩散不一致。剩下的唯一解释就是电场效应。我们在硅学和体外实验中验证了内生电场足以解释传播的假设。模拟结果表明，单用场效应确实可以中介神经元的跨层传播，病理动力学的传播速度为0.12+/-0.09m/S，生理动力学的传播速度为0.11+/-0.03m/S，两者产生的弱场幅度都接近2-6 mV/mm。此外，该模型预测传播速度值与细胞到细胞的距离成反比，但不随细胞外电阻率、膜电容或膜电阻的变化而显著变化。在小鼠海马区的体外记录产生相似的速度(0.10+/-0.03m/S)和场幅(2.5-5 mV/mm)，而施加阻断场，传播速度大大降低。最后，渗透压实验证实了该模型的预测，即细胞到细胞的距离与传播速度成反比。综上所述，这些结果表明，尽管其幅度很小，但电场可以单独负责以0.1m/S的速度传播棘波。这一现象可能是解释癫痫活动和其他正常传播速度相似的缓慢传播的重要原因。
It is widely accepted that synaptic transmissions and gap junctions are the major governing mechanisms for signal traveling in the neural system. Yet, a group of neural waves, either physiological or pathological, share the same speed of similar to 0.1 m/s without synaptic transmission or gap junctions, and this speed is not consistent with axonal conduction or ionic diffusion. The only explanation left is an electrical field effect. We tested the hypothesis that endogenous electric fields are sufficient to explain the propagation with in silico and in vitro experiments. Simulation results show that field effects alone can indeed mediate propagation across layers of neurons with speeds of 0.12 +/- 0.09 m/s with pathological kinetics, and 0.11 +/- 0.03 m/s with physiologic kinetics, both generating weak field amplitudes of similar to 2-6 mV/mm. Further, the model predicted that propagation speed values are inversely proportional to the cell-to-cell distances, but do not significantly change with extracellular resistivity, membrane capacitance, or membrane resistance. In vitro recordings in mice hippocampi produced similar speeds (0.10 +/- 0.03 m/s) and field amplitudes (2.5-5 mV/mm), and by applying a blocking field, the propagation speed was greatly reduced. Finally, osmolarity experiments confirmed the model's prediction that cell-to-cell distance inversely affects propagation speed. Together, these results show that despite their weak amplitude, electric fields can be solely responsible for spike propagation at similar to 0.1 m/s. This phenomenon could be important to explain the slow propagation of epileptic activity and other normal propagations at similar speeds.