title: Comprehensive Characterization of the Major Presynaptic Elements to the Drosophila OFF Motion Detector.
abstract: Estimating motion is a fundamental task for the visual system of sighted animals. In Drosophila, direction-selective T4 and T5 cells respond to moving brightness increments (ON) and decrements (OFF), respectively. Current algorithmic models of the circuit are based on the interaction of two differentially filtered signals. However, electron microscopy studies have shown that T5 cells receive their major input from four classes of neurons: Tm1, Tm2, Tm4, and Tm9. Using two-photon calcium imaging, we demonstrate that T5 is the first direction-selective stage within the OFF pathway. The four cells provide an array of spatiotemporal filters to T5. Silencing their synaptic output in various combinations, we find that all input elements are involved in OFF motion detection to varying degrees. Our comprehensive survey challenges the simplified view of how neural systems compute the direction of motion and suggests that an intricate interplay of many signals results in direction selectivity.
authors: Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany. Electronic address: serbe@neuro.mpg.de.
authors: Etienne
authors: E
authors: Serbe
authors: Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany. Electronic address: mmeier@neuro.mpg.de.
authors: Matthias
authors: M
authors: Meier
authors: Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors: Aljoscha
authors: A
authors: Leonhardt
authors: Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors: Alexander
authors: A
authors: Borst
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000465:Algorithms; D000818:Animals; D030801:Animals, Genetically Modified; D016827:CD8 Antigens / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D004330:Drosophila; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008854:Microscopy, Electron; D009039:Motion Perception / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology* / Q000648:ultrastructure; D011984:Sensory Receptor Cells / Q000502:physiology* / Q000648:ultrastructure; D014794:Visual Fields / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology
chemical_list: D016827:CD8 Antigens; D049452:Green Fluorescent Proteins; D002118:Calcium