论文标题
为什么加强间隙连接可能会阻碍动作潜力传播
Why strengthening gap junctions may hinder action potential propagation
论文作者
论文摘要
间隙连接是细胞膜中的通道，使离子可以直接传递在细胞之间。它们连接整个体内的细胞，包括心肌细胞，神经元和星形胶质细胞。间隙连接介导的传播可能是被动的或有效的。在被动传播中，一个细胞的膜电位会影响相邻细胞的膜电位，而不会触发动作电位（AP）。在主动传播中，一个细胞中的AP触发相邻细胞中的AP。这发生在心脏组织和整个神经系统中。在实验上众所周知，AP传播存在理想的间隙连接电导 - 较弱或更强的电导可以阻止传播。我们提出了一种理论来解释这种现象，通过分析一个理想化的模型，该模型仅着眼于间隙连接和尖峰生成电流。我们还发现了一种新型的行为类型，我们称之为半活性传播，其中网络中的细胞在静止时不可激发，但仍会传播动作电位。
Gap junctions are channels in cell membranes allowing ions to pass directly between cells. They connect cells throughout the body, including heart myocytes, neurons, and astrocytes. Propagation mediated by gap junctions can be passive or active. In passive propagation, the membrane potential of one cell influences that of neighboring cells without triggering action potentials (APs). In active propagation, an AP in one cell triggers APs in neighboring cells; this occurs in cardiac tissue and throughout the nervous system. It is known experimentally that there is an ideal gap junction conductance for AP propagation -- weaker or stronger conductance can block propagation. We present a theory explaining this phenomenon by analyzing an idealized model that focuses exclusively on gap junctional and spike-generating currents. We also find a novel type of behavior that we call semi-active propagation, in which cells in the network are not excitable at rest, but still propagate action potentials.
