title: Stimulus-dependent recruitment of lateral inhibition underlies retinal direction selectivity.
abstract: The dendrites of starburst amacrine cells (SACs) in the mammalian retina are preferentially activated by motion in the centrifugal direction, a property that is important for generating direction selectivity in direction selective ganglion cells (DSGCs). A candidate mechanism underlying the centrifugal direction selectivity of SAC dendrites is synaptic inhibition onto SACs. Here we disrupted this inhibition by perturbing distinct sets of GABAergic inputs onto SACs - removing either GABA release or GABA receptors from SACs. We found that lateral inhibition onto Off SACs from non-SAC amacrine cells is required for optimal direction selectivity of the Off pathway. In contrast, lateral inhibition onto On SACs is not necessary for direction selectivity of the On pathway when the moving object is on a homogenous background, but is required when the background is noisy. These results demonstrate that distinct sets of inhibitory mechanisms are recruited to generate direction selectivity under different visual conditions.
authors.affiliation: Department of Neurobiology, The University of Chicago, Chicago, United States.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Neurobiology, The University of Chicago, Chicago, United States.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Pei
authors.affiliation: Department of Neurobiology, The University of Chicago, Chicago, United States.
authors.forename: David
authors.initials: D
authors.lastname: Koren
authors.affiliation: Department of Neurobiology, The University of Chicago, Chicago, United States.
authors.forename: Wei
authors.identifier: 0000-0002-7771-5974
authors.initials: W
authors.lastname: Wei
mesh_terms: D025042:Amacrine Cells / Q000502:physiology*; D000818:Animals; D059330:GABAergic Neurons / Q000502:physiology*; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009039:Motion Perception; D009433:Neural Inhibition; D012160:Retina / Q000502:physiology*
keywords: direction selectivity; inhibition; lateral inhibition; mouse; neuroscience; retinal circuitry; starburst amacrine cell