Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Exp Neurol. 2019 Jul;317:119-128. doi: 10.1016/j.expneurol.2019.02.005. Epub 2019 Feb 15.
It is well documented that synapses play a significant role in the transmission of information between neurons. However, in the absence of synaptic transmission, neural activity has been observed to continue to propagate. Previous studies have shown that propagation of epileptiform activity takes place in the absence of synaptic transmission and gap junctions and is outside the range of ionic diffusion and axonal conduction. Computer simulations indicate that electric field coupling could be responsible for the propagation of neural activity under pathological conditions such as epilepsy. Electric fields can modulate neuronal membrane voltage, but there is no experimental evidence suggesting that electric field coupling can mediate self-regenerating propagation of neural activity. Here we examine the role of electric field coupling by eliminating all forms of neural communications except electric field coupling with a cut through the neural tissue. We show that 4-AP induced activity generates an electric field capable of recruiting neurons on the distal side of the cut. Experiments also show that applied electric fields with amplitudes similar to endogenous values can induce propagating waves. Finally, we show that canceling the electrical field at a given point can block spontaneous propagation. The results from these in vitro electrophysiology experiments suggest that electric field coupling is a critical mechanism for non-synaptic neural propagation and therefore could contribute to the propagation of epileptic activity in the brain.
有大量文献记载表明，突触在神经元之间的信息传递中起着重要作用。然而，在没有突触传递的情况下，已经观察到神经活动继续传播。先前的研究表明，癫痫样活动的传播发生在没有突触传递和缝隙连接的情况下，并且超出了离子扩散和轴突传导的范围。计算机模拟表明，在癫痫等病理条件下，电场耦合可能是神经活动传播的原因。电场可以调节神经元膜电压，但没有实验证据表明电场耦合可以介导神经活动的自我再生传播。在这里，我们通过在神经组织中进行切割来消除除电场耦合以外的所有形式的神经通讯，从而研究了电场耦合的作用。我们表明，4-AP 诱导的活动产生的电场能够募集切割远端的神经元。实验还表明，施加的电场幅度与内源性值相似，可以诱导传播波。最后，我们表明在给定位置取消电场可以阻止自发传播。这些体外电生理学实验的结果表明，电场耦合是无突触神经传播的关键机制，因此可能有助于大脑中癫痫活动的传播。
