title: Rods in daylight act as relay cells for cone-driven horizontal cell-mediated surround inhibition.
abstract: Vertebrate vision relies on two types of photoreceptors, rods and cones, which signal increments in light intensity with graded hyperpolarizations. Rods operate in the lower range of light intensities while cones operate at brighter intensities. The receptive fields of both photoreceptors exhibit antagonistic center-surround organization. Here we show that at bright light levels, mouse rods act as relay cells for cone-driven horizontal cell-mediated surround inhibition. In response to large, bright stimuli that activate their surrounds, rods depolarize. Rod depolarization increases with stimulus size, and its action spectrum matches that of cones. Rod responses at high light levels are abolished in mice with nonfunctional cones and when horizontal cells are reversibly inactivated. Rod depolarization is conveyed to the inner retina via postsynaptic circuit elements, namely the rod bipolar cells. Our results show that the retinal circuitry repurposes rods, when they are not directly sensing light, to relay cone-driven surround inhibition.
authors.affiliation: Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Tamas
authors.initials: T
authors.lastname: Szikra
authors.affiliation: 1] Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. [2] Department of Biology, University of Victoria, Victoria, British Columbia, Canada.
authors.forename: Stuart
authors.initials: S
authors.lastname: Trenholm
authors.affiliation: 1] Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. [2] University of Basel, Basel, Switzerland.
authors.forename: Antonia
authors.initials: A
authors.lastname: Drinnenberg
authors.affiliation: Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Josephine
authors.initials: J
authors.lastname: Jüttner
authors.affiliation: Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Raics
authors.affiliation: Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Farrow
authors.affiliation: Department of Pharmacy-Center for Drug Research, Center for Integrated Protein Science Munich, Ludwig-Maximilians University, Munich, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Biel
authors.affiliation: Department of Biology, University of Victoria, Victoria, British Columbia, Canada.
authors.forename: Gautam
authors.initials: G
authors.lastname: Awatramani
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA.
authors.forename: Damon A
authors.identifier: 000000018487700X
authors.initials: DA
authors.lastname: Clark
authors.affiliation: 1] Université Pierre et Marie Curie-Sorbonne Universités, Institut de la Vision, Paris, France. [2] Institut national de la santé et de la recherche médicale, Institut de la Vision, Paris, France. [3] Centre national de la recherche scientifique, Institut de la Vision, Paris, France. [4] Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Département Hospitalo-Universitaire ViewMaintain, Paris, France. [5] Fondation Ophtalmologique Adolphe de Rothschild, Paris, France.
authors.forename: José-Alain
authors.initials: JA
authors.lastname: Sahel
authors.affiliation: 1] Department of Physics, École Normale Supérieure, Paris, France. [2] Laboratoire de Physique Statistique, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Denis Diderot, Paris, France.
authors.forename: Rava Azeredo
authors.initials: RA
authors.lastname: da Silveira
authors.affiliation: Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Botond
authors.initials: B
authors.lastname: Roska
mesh_terms: D000818:Animals; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009415:Nerve Net / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D051248:Retinal Horizontal Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*