Electrophysiological Studies of GABAA Receptors Using QPatch II, the Next Generation of Automated Patch-Clamp Instruments

Abstract

Ligand-gated ion channels (LGICs) are a group of diverse ion channels that are gated by ligands and play important roles in normal physiological and pathological conditions. Many of them are drug targets that have been pursued, are being pursued, and will likely be pursued in the future by pharmaceutical companies and academic groups for a variety of diseases. One of those LGICs is the GABA_A receptor, a heterooligomeric chloride channel that can be blocked and modulated at various sites. In order to study the receptor's functional response to compounds, the manual patch-clamp method provides a detailed but low-throughput electrophysiological characterization. QPatch II, a next-generation automated patch clamp machine that was recently developed by Sophion Bioscience, provides an automated electrophysiological study of ion channels. In this article, we use the GABA_A receptor as an example for studying LGICs and describe two detailed protocols for using QPatch II to carry out pharmacological studies on the receptor. © 2020 by John Wiley & Sons, Inc.

Basic Protocol 1: Ligand concentration-response experiment (GABA_A receptor) on QPatch II

Alternate Protocol: Non-cumulative ligand concentration-response experiment (GABA_A receptor) on QPatch II

Support Protocol 1: Cell culture of HEK293-hGABA_A (α5β3γ2)

Support Protocol 2: Data analysis for Basic Protocol 1

Support Protocol 3: Data analysis for Alternate Protocol

Basic Protocol 2: Antagonist dose-response experiment (GABA_A receptor) on QPatch II

Support Protocol 3: Data analysis for Basic Protocol 2