Assay Development for Ligand Gated Ion Channel Pharmacology

Steve Smith, Ali Yehia, Andrew Baxter, Qin Chen, Juliette Johnson, Cristian Ionescu-Zanetti
Fluxion Biosciences, South San Francisco, CA 94080 


Modulators of ligand gated ion channel (LGIC) activity are being actively developed by a number of leading pharmaceutical companies. Electro- physiology assays remain the gold standard for determining functional compound effects on these targets, and pose unique challenges due to the need for accurate temporal control of agonist and compound application. In this study we present results from complex assays enabled by a novel microfluidic automated patch clamp platform. The data includes case studies from NMDA receptors, nicotinic receptors and GABA receptors and trade-offs between the different available measurement modalities developed. For targets where cell byproducts activate the channel (such as NMDA) continuous perfusion is required for removing such products from the extracellular space in order to obtain a robust assay. Continuous perfusion is also essential for accurate measurements of channel recovery times are important (nicotinic receptors).