ABSTRACT High-throughput electrophysiology is revolutionizing traditional approaches of manual patch clamp to study ion channel function and accelerating the pace of drug discovery. This proposal requests the purchase of a SyncroPatch 384i workstation capable of simultaneous patch clamp measurements on 384 cells. This high- throughput automated electrophysiology system will enable researchers in the Houston-Galveston area to conduct large-scale analysis of ion channel function and screen channel activity modulators. The initial group of users will share this instrument system for diverse projects, funded by 25 individual NIH grants. Two collaborating user labs will apply the SyncroPatch to identify and characterize new channelrhodopsin variants by screening candidates from sequence databases. Channelrhodopsins are light-gated ion channels from eukaryotic microorganisms widely used by neuroscience researchers to control excitability of neurons and myocytes in animal models (optogenetics), and as optogenetic gene therapy in clinical trials to restore vision to the blind. The SyncroPatch will enable high-throughput selection of mutated populations of known channelrhodopsins to optimize and expand their utility. Ion channelopathies are the cause of myriad human diseases that impair brain, cardiac, the immune system, and other functions. Ten proposed users in this application study ion channels with molecular and cellular methods, as well as animal models, to investigate the role of the channels in human diseases and basic biological mechanisms underlying these pathologies. Accordingly, their labs will apply the requested workstation to: (1) screen for novel modulators of voltage-gated Na+ channels, HCN channels, TRP channels, BK channels, the cochlear anion transporter prestin (SLC26A5) and nAChR channels; (2) map the conformational landscape of ionotropic NMDA receptors; (3) identify structure-function determinants of Ca2+ channels; (4) screen modulators of exocytosis; and (5) analyze mutations and post-translational modifications of TRP, ASIC and TPC channels. The acquisition of the SyncroPatch 384i will answer the urgent need for automated high-throughput patch-clamp electrophysiology in the Houston-Galveston biomedical research community and will enable us to interrogate ion channel function at an unprecedented pace, accelerate discoveries of new optogenetic tools and new therapeutics, and thus broaden the horizon of biomedical research and drug development.