title: A spike-timing mechanism for action selection.
abstract: We discovered a bimodal behavior in the genetically tractable organism Drosophila melanogaster that allowed us to directly probe the neural mechanisms of an action selection process. When confronted by a predator-mimicking looming stimulus, a fly responds with either a long-duration escape behavior sequence that initiates stable flight or a distinct, short-duration sequence that sacrifices flight stability for speed. Intracellular recording of the descending giant fiber (GF) interneuron during head-fixed escape revealed that GF spike timing relative to parallel circuits for escape actions determined which of the two behavioral responses was elicited. The process was well described by a simple model in which the GF circuit has a higher activation threshold than the parallel circuits, but can override ongoing behavior to force a short takeoff. Our findings suggest a neural mechanism for action selection in which relative activation timing of parallel circuits creates the appropriate motor output.
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Catherine R
authors.initials: CR
authors.lastname: von Reyn
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Breads
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Martin Y
authors.initials: MY
authors.lastname: Peek
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Grace Zhiyu
authors.initials: GZ
authors.lastname: Zheng
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: W Ryan
authors.initials: WR
authors.lastname: Williamson
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Alyson L
authors.initials: AL
authors.lastname: Yee
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Leonardo
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
authors.forename: Gwyneth M
authors.initials: GM
authors.lastname: Card
mesh_terms: D000465:Algorithms; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology; D004331:Drosophila melanogaster / Q000502:physiology*; D055724:Electrophysiological Phenomena / Q000502:physiology; D004924:Escape Reaction / Q000502:physiology; D005260:Female; D005426:Flight, Animal / Q000502:physiology; D007150:Immunohistochemistry; D008959:Models, Neurological; D008960:Models, Psychological; D009415:Nerve Net / Q000502:physiology; D063191:Odonata; D010775:Photic Stimulation; D011235:Predatory Behavior; D014741:Video Recording