Studies on Fast Nach Receptor Kinetics Utilizing a New Approach to Ultra-Fast Compound Applications in Automated Patch Clamp

Abstract

Ligand gated ion channels like nACh Receptors show fast inactivation kinetics in the ms range. Therefore, state of the art investigation of receptor kinetics and drug action requires the combination of patch clamp recording with advanced ultra-fast compound application systems like the piezo-driven “I-Tube”. So far, automated patch clamp systems have not been able to offer this combination. Here, we demonstrate automated ,,Θ-Tube recordings on nACh receptors using the Patchserver, a new device based on automated pipette micro positioning, gigaseal and whole cell formation. Unlike concurrent approaches utilizing “planar” chip designs, the method retains important features of the classical patch clamp methodology, including the possibility to optically select individual cells to be patched. This also enables the use of transiently transfected cells qualified by fluorescent markers. The system offered compound applications to the cell membrane with millisecond exchange- and exposure times, which is crucial to investigate the kinetics of fast inactivating ligand gated ion channels. Thus, the new method offers a cost efficient approach to significantly enhanced throughput and data quality for research on fast inactivating ligand gated ion channels.