Microfluidic System for Recording Fast Ion Channel Kinetics with Electrical Impedance Spectroscopy

Ligand-gated ion channels (LGICs) are involved in many pathophysiological processes and represent a relevant target for drug discovery. In this work, we developed a novel setup based on a microfluidic chip in combination with non-invasive electrical impedance spectroscopy to study ligand-induced changes in Xenopus laevis membrane impedance. As a proof-of-concept, the responses of the human P2X2 receptor hP2X2R as a cation-selective, ligand-gated ion channel, which is gated by adenosine triphosphate, is reported. The impedance measurements show short capacity transients compared with two electrode voltage clamp measurements. In future, the measurement sites can be multiplied and facilitate multiplexed drug screening of ligand-gated ion channels.