近日，美国哈佛大学教授Adam E. Cohen及其研究组实验观测到工程化组织内的拓扑动作电位。2022年12月22日出版的《自然—物理学》杂志发表了这项成果。

研究团队展示了一个不可兴奋组织之间的界面是电可兴奋的，因为缝隙连接（电阻性细胞间连接）电流之间的相互作用，以及界面两侧离子通道的非线性电流-电压依赖性。

他们的理论表明，这种拓扑上强大的电兴奋发生在比支持整体兴奋性大得多的离子通道表达水平范围内。相应的界面动作电位可以引起局部钙离子浓度的升高，可能为界面感应提供了一种生物电机制。观察到的拓扑动作电位指出了在电生理学和其他扩散耦合界面上存在其他类型拓扑效应的可能性。

据介绍，两个组织之间的界面与任何一个组织本身相比具有非常不同的生物电特性。

附：英文原文

Title: Observation of topological action potentials in engineered tissues

Author: Ori, Hillel, Duque, Marc, Frank Hayward, Rebecca, Scheibner, Colin, Tian, He, Ortiz, Gloria, Vitelli, Vincenzo, Cohen, Adam E.

Issue&Volume: 2022-12-22

Abstract: The interface between two tissues can have very different bioelectrical properties compared to either tissue on its own. Here we show that an interface between non-excitable tissues can be electrically excitable because of an interaction between the currents passing through the gap junctions—electrically resistive intercellular connections—and the non-linear current–voltage dependence in the ion channels on either side of the interface. Our theory shows that this topologically robust excitability occurs over a far larger range of ion channel expression levels than can support excitability in the bulk. The corresponding interfacial action potentials can cause local elevations in calcium concentration, possibly providing a bioelectrical mechanism for interface sensing. The observed topological action potentials point to the possibility of other types of topological effect in electrophysiology and at other diffusively coupled interfaces.

DOI: 10.1038/s41567-022-01853-z

Source: https://www.nature.com/articles/s41567-022-01853-z