Filtering of Visual Information in the Tectum by an Identified Neural Circuit

• Published in: Science (American Association for the Advancement of Science) Vol. 330; no. 6004; pp. 669 - 673
• Main Authors: Del Bene, Filippo, Wyart, Claire, Robles, Estuardo, Tran, Amanda, Looger, Loren, Scott, Ethan K, Isacoff, Ehud Y, Baier, Herwig
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 29.10.2010; The American Association for the Advancement of Science
• Subjects: Animals; Animals, Genetically Modified; Apoptosis; Axons; Axons - physiology; Bicuculline - pharmacology; Biological and medical sciences; Conveying; Dendrites; Dendrites - physiology; Dendritic structure; Eye and associated structures. Visual pathways and centers. Vision; Eyes & eyesight; Filtering; Filtration; Freshwater; Fundamental and applied biological sciences. Psychology; GABA Antagonists - pharmacology; gamma-Aminobutyric Acid - metabolism; Genetics; Imaging; Interneurons - physiology; Larvae; Neural conduction; Neural Inhibition; Neurology; Neurons; Neurons - physiology; Neuropil; Neuropil - physiology; Neurotransmitters; Optic Lobe, Nonmammalian - cytology; Optic Lobe, Nonmammalian - physiology; Photic Stimulation; Retina - physiology; Retinal Neurons - physiology; Spatial filtering; Superior colliculus; Synaptic Transmission; Tuning; Vertebrates; Vertebrates: nervous system and sense organs; Visual Pathways - physiology; Visual Perception; Visual stimulation; Visual stimuli; Zebrafish; Calcium; Central nervous system; Axon; Retina; Optic tectum; Encephalon; Dendrite; Interneuron; Neuropile; Eye; Visual system; Vertebrata; Brachydanio rerio; Visual stimulus; Visual pathway; Pisces; Imaging; Behavior; Visual information
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1192949

The optic tectum of zebrafish is involved in behavioral responses that require the detection of small objects. The superficial layers of the tectal neuropil receive input from retinal axons, while its deeper layers convey the processed information to premotor areas. Imaging with a genetically encoded calcium indicator revealed that the deep layers, as well as the dendrites of single tectal neurons, are preferentially activated by small visual stimuli. This spatial filtering relies on GABAergic interneurons (using the neurotransmitter γ-aminobutyric acid) that are located in the superficial input layer and respond only to large visual stimuli. Photo-ablation of these cells with KillerRed, or silencing of their synaptic transmission, eliminates the size tuning of deeper layers and impairs the capture of prey.