title: Complementary mechanisms create direction selectivity in the fly.
abstract: How neurons become sensitive to the direction of visual motion represents a classic example of neural computation. Two alternative mechanisms have been discussed in the literature so far: preferred direction enhancement, by which responses are amplified when stimuli move along the preferred direction of the cell, and null direction suppression, where one signal inhibits the response to the subsequent one when stimuli move along the opposite, i.e. null direction. Along the processing chain in the Drosophila optic lobe, directional responses first appear in T4 and T5 cells. Visually stimulating sequences of individual columns in the optic lobe with a telescope while recording from single T4 neurons, we find both mechanisms at work implemented in different sub-regions of the receptive field. This finding explains the high degree of directional selectivity found already in the fly's primary motion-sensing neurons and marks an important step in our understanding of elementary motion detection.
authors: Max Planck Institute of Neurobiology, Martinsried, Germany.
authors: Juergen
authors: J
authors: Haag
authors: Max Planck Institute of Neurobiology, Martinsried, Germany.
authors: Alexander
authors: A
authors: Arenz
authors: Max Planck Institute of Neurobiology, Martinsried, Germany.
authors: Etienne
authors: E
authors: Serbe
authors: Baylor College of Medicine, Houston, United States.
authors: Fabrizio
authors: F
authors: Gabbiani
authors: Max Planck Institute of Neurobiology, Martinsried, Germany.
authors: Alexander
authors: A
authors: Borst
mesh_terms: D000818:Animals; D004330:Drosophila / Q000502:physiology*; D008124:Locomotion; D009474:Neurons / Q000502:physiology; D009899:Optic Lobe, Nonmammalian / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance; D014795:Visual Pathways / Q000502:physiology
keywords: D. melanogaster; Neurogenetics; computer model; motion vision; neuroscience