title: Engineering a light-regulated GABAA receptor for optical control of neural inhibition.
abstract: Optogenetics has become an emerging technique for neuroscience investigations owing to the great spatiotemporal precision and the target selectivity it provides. Here we extend the optogenetic strategy to GABAA receptors (GABAARs), the major mediators of inhibitory neurotransmission in the brain. We generated a light-regulated GABAA receptor (LiGABAR) by conjugating a photoswitchable tethered ligand (PTL) onto a mutant receptor containing the cysteine-substituted α1-subunit. The installed PTL can be advanced to or retracted from the GABA-binding pocket with 500 and 380 nm light, respectively, resulting in photoswitchable receptor antagonism. In hippocampal neurons, this LiGABAR enabled a robust photoregulation of inhibitory postsynaptic currents. Moreover, it allowed reversible photocontrol over neuron excitation in response to presynaptic stimulation. LiGABAR thus provides a powerful means for functional and mechanistic investigations of GABAAR-mediated neural inhibition.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley , Berkeley, California 94720, United States.
authors.forename: Wan-Chen
authors.initials: WC
authors.lastname: Lin
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Davenport
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mourot
authors.forename: Devaiah
authors.initials: D
authors.lastname: Vytla
authors.forename: Caleb M
authors.initials: CM
authors.lastname: Smith
authors.forename: Kathryne A
authors.initials: KA
authors.lastname: Medeiros
authors.forename: James J
authors.initials: JJ
authors.lastname: Chambers
authors.forename: Richard H
authors.initials: RH
authors.lastname: Kramer
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D057809:HEK293 Cells; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008024:Ligands; D008027:Light; D008958:Models, Molecular; D009433:Neural Inhibition; D009474:Neurons / Q000166:cytology / Q000502:physiology; D062308:Optogenetics / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014981:Xenopus
chemical_list: D008024:Ligands; D011963:Receptors, GABA-A