title: A Role for Synaptic Input Distribution in a Dendritic Computation of Motion Direction in the Retina.
abstract: The starburst amacrine cell in the mouse retina presents an opportunity to examine the precise role of sensory input location on neuronal computations. Using visual receptive field mapping, glutamate uncaging, two-photon Ca(2+) imaging, and genetic labeling of putative synapses, we identify a unique arrangement of excitatory inputs and neurotransmitter release sites on starburst amacrine cell dendrites: the excitatory input distribution is skewed away from the release sites. By comparing computational simulations with Ca(2+) transients recorded near release sites, we show that this anatomical arrangement of inputs and outputs supports a dendritic mechanism for computing motion direction. Direction-selective Ca(2+) transients persist in the presence of a GABA-A receptor antagonist, though the directional tuning is reduced. These results indicate a synergistic interaction between dendritic and circuit mechanisms for generating direction selectivity in the starburst amacrine cell.
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Vlasits
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Morrie
authors.affiliation: Unit of Dynamic Neuronal Imaging, Institut Pasteur, 75724 Paris Cedex 15, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, 75724 Paris Cedex 15, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Tran-Van-Minh
authors.affiliation: Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Bleckert
authors.affiliation: Department of Optometry, University of California, Berkeley, Berkeley, CA 94704, USA.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Gainer
authors.affiliation: Unit of Dynamic Neuronal Imaging, Institut Pasteur, 75724 Paris Cedex 15, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, 75724 Paris Cedex 15, France. Electronic address: david.digregorio@pasteur.fr.
authors.forename: David A
authors.initials: DA
authors.lastname: DiGregorio
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. Electronic address: mfeller@berkeley.edu.
authors.forename: Marla B
authors.initials: MB
authors.lastname: Feller
mesh_terms: D000110:Acetylcholinesterase / Q000235:genetics / Q000378:metabolism; D025042:Amacrine Cells / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D003198:Computer Simulation; D003712:Dendrites / Q000502:physiology*; D000076122:Disks Large Homolog 4 Protein; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018698:Glutamic Acid / Q000494:pharmacology; D051528:Guanylate Kinases / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008959:Models, Neurological; D009039:Motion Perception / Q000187:drug effects / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000166:cytology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D014795:Visual Pathways / Q000502:physiology
chemical_list: D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D008565:Membrane Proteins; D018091:Receptors, AMPA; D018698:Glutamic Acid; D051528:Guanylate Kinases; D000110:Acetylcholinesterase; C104722:glutamate receptor ionotropic, AMPA 2; D002118:Calcium