title: Internal structure of the fly elementary motion detector.
abstract: Recent experiments have shown that motion detection in Drosophila starts with splitting the visual input into two parallel channels encoding brightness increments (ON) or decrements (OFF). This suggests the existence of either two (ON-ON, OFF-OFF) or four (for all pairwise interactions) separate motion detectors. To decide between these possibilities, we stimulated flies using sequences of ON and OFF brightness pulses while recording from motion-sensitive tangential cells. We found direction-selective responses to sequences of same sign (ON-ON, OFF-OFF), but not of opposite sign (ON-OFF, OFF-ON), refuting the existence of four separate detectors. Based on further measurements, we propose a model that reproduces a variety of additional experimental data sets, including ones that were previously interpreted as support for four separate detectors. Our experiments and the derived model mark an important step in guiding further dissection of the fly motion detection circuit.
authors.affiliation: Department of Systems and Computational Neurobiology, Max-Planck-Institute of Neurobiology, 82152 Martinsried, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Eichner
authors.forename: Maximilian
authors.initials: M
authors.lastname: Joesch
authors.forename: Bettina
authors.initials: B
authors.lastname: Schnell
authors.forename: Dierk F
authors.initials: DF
authors.lastname: Reiff
authors.forename: Alexander
authors.initials: A
authors.lastname: Borst
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D004175:Diptera; D004594:Electrophysiology; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D014795:Visual Pathways / Q000166:cytology / Q000502:physiology*