title: Neural Circuits Underlying Visually Evoked Escapes in Larval Zebrafish.
abstract: Escape behaviors deliver organisms away from imminent catastrophe. Here, we characterize behavioral responses of freely swimming larval zebrafish to looming visual stimuli simulating predators. We report that the visual system alone can recruit lateralized, rapid escape motor programs, similar to those elicited by mechanosensory modalities. Two-photon calcium imaging of retino-recipient midbrain regions isolated the optic tectum as an important center processing looming stimuli, with ensemble activity encoding the critical image size determining escape latency. Furthermore, we describe activity in retinal ganglion cell terminals and superficial inhibitory interneurons in the tectum during looming and propose a model for how temporal dynamics in tectal periventricular neurons might arise from computations between these two fundamental constituents. Finally, laser ablations of hindbrain circuitry confirmed that visual and mechanosensory modalities share the same premotor output network. We establish a circuit for the processing of aversive stimuli in the context of an innate visual behavior.
authors.affiliation: Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Program in Neuroscience, Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Dunn
authors.affiliation: Institut Curie, PSL Research University, INSERM, U 934, CNRS UMR3215, 26 rue d'Ulm, 75005 Paris, France.
authors.forename: Christoph
authors.initials: C
authors.lastname: Gebhardt
authors.affiliation: Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: Eva A
authors.initials: EA
authors.lastname: Naumann
authors.affiliation: Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Riegler
authors.affiliation: Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA 20147, USA.
authors.forename: Misha B
authors.initials: MB
authors.lastname: Ahrens
authors.affiliation: Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Program in Neuroscience, Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: florian@mcb.harvard.edu.
authors.forename: Florian
authors.initials: F
authors.lastname: Engert
authors.affiliation: Institut Curie, PSL Research University, INSERM, U 934, CNRS UMR3215, 26 rue d'Ulm, 75005 Paris, France. Electronic address: filippo.del-bene@curie.fr.
authors.forename: Filippo
authors.initials: F
authors.lastname: Del Bene
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D004924:Escape Reaction / Q000502:physiology*; D007395:Interneurons / Q000502:physiology; D007814:Larva / Q000502:physiology; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D012249:Rhombencephalon / Q000166:cytology / Q000502:physiology; D013477:Superior Colliculi / Q000166:cytology / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*