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Northmore DPM. Visual shape discrimination in goldfish, modelled with the neural circuitry of optic tectum and torus longitudinalis. Vision Res 2024; 217:108374. [PMID: 38452566 DOI: 10.1016/j.visres.2024.108374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/08/2024] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
There is no satisfactory neurally-based theory as to how vertebrates that lack a neocortex discriminate even simple geometric shapes. In fishes, an intact optic tectum is necessary for such discriminations, but physiological studies of it have found nothing like the hierarchically arranged feature detecting neurons of mammalian visual cortex. Here, a neural model attempts a solution by basing shape discrimination upon the responses of only those elementary detectors (e.g. of size) that are within a focus of attention, formed by a winner-take-all arrangement of retinotopically mapped units representing tectal pyramidal cells. While this relatively primitive mechanism could recognize an object irrespective of position in space, it fails to distinguish patterns that differ only in their features' spatial relationships. The model's solution - imitating goldfish that naturally attend to the top of shapes - is to shift attention to the edges of a shape by spatially offsetting inputs to the pyramidal neurons, effected by the torus longitudinalis and its prolific synapses on pyramidal dendrites. The model's shape discrimination was compared to an extensive behavioral study using shapes with points and projections. In one test series fish were sensitive to the relative number of points on the tops of shapes. In another, fish were trained to discriminate points on the sides. By using different offset connections and only one elementary feature detector for small dark spots, the model successfully emulated the two sets of goldfish data, as judged by significant correlations between model response and fish discrimination.
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Affiliation(s)
- D P M Northmore
- Department of Psychological and Brain Sciences, University of Delaware, United States of America.
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2
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Wu Q, Zhang Y. Neural Circuit Mechanisms Involved in Animals' Detection of and Response to Visual Threats. Neurosci Bull 2023; 39:994-1008. [PMID: 36694085 PMCID: PMC10264346 DOI: 10.1007/s12264-023-01021-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/30/2022] [Indexed: 01/26/2023] Open
Abstract
Evading or escaping from predators is one of the most crucial issues for survival across the animal kingdom. The timely detection of predators and the initiation of appropriate fight-or-flight responses are innate capabilities of the nervous system. Here we review recent progress in our understanding of innate visually-triggered defensive behaviors and the underlying neural circuit mechanisms, and a comparison among vinegar flies, zebrafish, and mice is included. This overview covers the anatomical and functional aspects of the neural circuits involved in this process, including visual threat processing and identification, the selection of appropriate behavioral responses, and the initiation of these innate defensive behaviors. The emphasis of this review is on the early stages of this pathway, namely, threat identification from complex visual inputs and how behavioral choices are influenced by differences in visual threats. We also briefly cover how the innate defensive response is processed centrally. Based on these summaries, we discuss coding strategies for visual threats and propose a common prototypical pathway for rapid innate defensive responses.
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Affiliation(s)
- Qiwen Wu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yifeng Zhang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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3
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Lloyd E, McDole B, Privat M, Jaggard JB, Duboué ER, Sumbre G, Keene AC. Blind cavefish retain functional connectivity in the tectum despite loss of retinal input. Curr Biol 2022; 32:3720-3730.e3. [PMID: 35926509 DOI: 10.1016/j.cub.2022.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/07/2022] [Accepted: 07/07/2022] [Indexed: 11/26/2022]
Abstract
Sensory systems display remarkable plasticity and are under strong evolutionary selection. The Mexican cavefish, Astyanax mexicanus, consists of eyed river-dwelling surface populations and multiple independent cave populations that have converged on eye loss, providing the opportunity to examine the evolution of sensory circuits in response to environmental perturbation. Functional analysis across multiple transgenic populations expressing GCaMP6s showed that functional connectivity of the optic tectum largely did not differ between populations, except for the selective loss of negatively correlated activity within the cavefish tectum, suggesting positively correlated neural activity is resistant to an evolved loss of input from the retina. Furthermore, analysis of surface-cave hybrid fish reveals that changes in the tectum are genetically distinct from those encoding eye loss. Together, these findings uncover the independent evolution of multiple components of the visual system and establish the use of functional imaging in A. mexicanus to study neural circuit evolution.
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Affiliation(s)
- Evan Lloyd
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Biology, Texas A&M University, College Station, TX 77843, USA; Harriet Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Brittnee McDole
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Martin Privat
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - James B Jaggard
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Erik R Duboué
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - German Sumbre
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France.
| | - Alex C Keene
- Department of Biology, Texas A&M University, College Station, TX 77843, USA.
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Tesmer AL, Fields NP, Robles E. Input from torus longitudinalis drives binocularity and spatial summation in zebrafish optic tectum. BMC Biol 2022; 20:24. [PMID: 35073895 PMCID: PMC8788132 DOI: 10.1186/s12915-021-01222-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/23/2021] [Indexed: 11/29/2022] Open
Abstract
Background A continued effort in neuroscience aims to understand the way brain circuits consisting of diverse neuronal types generate complex behavior following sensory input. A common feature of vertebrate visual systems is that lower-order and higher-order visual areas are reciprocally connected. Feedforward projections confer visual responsiveness to higher-order visual neurons while feedback projections likely serve to modulate responses of lower-order visual neurons in a context-dependent manner. Optic tectum is the largest first-order visual brain area in zebrafish and is reciprocally connected with the torus longitudinalis (TL), a second-order visual brain area that does not receive retinal input. A functional role for feedback projections from TL to tectum has not been identified. Here we aim to understand how this feedback contributes to visual processing. Results In this study, we demonstrate that TL feedback projections to tectum drive binocular integration and spatial summation in a defined tectal circuit. We performed genetically targeted, cell type-specific functional imaging in tectal pyramidal neurons (PyrNs) and their two input neuron populations: retinal ganglion cells (RGCs) and neurons in TL. We find that PyrNs encode gradual changes in scene luminance using a complement of three distinct response classes that encode different light intensity ranges. Functional imaging of RGC inputs to tectum suggest that these response classes originate in the retina and RGC input specifies PyrN functional classes. In contrast, TL input serves to endow PyrNs with large, compound receptive fields that span both retinal hemifields. Conclusions These findings reveal a novel role for the zebrafish TL in driving binocular integration and spatial summation in tectal PyrNs. The neural circuit we describe generates a population of tectal neurons with large receptive fields tailored for detecting changes in the visual scene. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01222-x.
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Mancienne T, Marquez-Legorreta E, Wilde M, Piber M, Favre-Bulle I, Vanwalleghem G, Scott EK. Contributions of Luminance and Motion to Visual Escape and Habituation in Larval Zebrafish. Front Neural Circuits 2021; 15:748535. [PMID: 34744637 PMCID: PMC8568047 DOI: 10.3389/fncir.2021.748535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Animals from insects to humans perform visual escape behavior in response to looming stimuli, and these responses habituate if looms are presented repeatedly without consequence. While the basic visual processing and motor pathways involved in this behavior have been described, many of the nuances of predator perception and sensorimotor gating have not. Here, we have performed both behavioral analyses and brain-wide cellular-resolution calcium imaging in larval zebrafish while presenting them with visual loom stimuli or stimuli that selectively deliver either the movement or the dimming properties of full loom stimuli. Behaviorally, we find that, while responses to repeated loom stimuli habituate, no such habituation occurs when repeated movement stimuli (in the absence of luminance changes) are presented. Dim stimuli seldom elicit escape responses, and therefore cannot habituate. Neither repeated movement stimuli nor repeated dimming stimuli habituate the responses to subsequent full loom stimuli, suggesting that full looms are required for habituation. Our calcium imaging reveals that motion-sensitive neurons are abundant in the brain, that dim-sensitive neurons are present but more rare, and that neurons responsive to both stimuli (and to full loom stimuli) are concentrated in the tectum. Neurons selective to full loom stimuli (but not to movement or dimming) were not evident. Finally, we explored whether movement- or dim-sensitive neurons have characteristic response profiles during habituation to full looms. Such functional links between baseline responsiveness and habituation rate could suggest a specific role in the brain-wide habituation network, but no such relationships were found in our data. Overall, our results suggest that, while both movement- and dim-sensitive neurons contribute to predator escape behavior, neither plays a specific role in brain-wide visual habituation networks or in behavioral habituation.
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Affiliation(s)
- Tessa Mancienne
- The Queensland Brain Institute, The University of Queensland, Saint Lucia, QLD, Australia
| | | | - Maya Wilde
- The Queensland Brain Institute, The University of Queensland, Saint Lucia, QLD, Australia
| | - Marielle Piber
- School of Medicine, Medical Sciences, and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Itia Favre-Bulle
- The Queensland Brain Institute, The University of Queensland, Saint Lucia, QLD, Australia
- School of Mathematics and Physics, The University of Queensland, Saint Lucia, QLD, Australia
| | - Gilles Vanwalleghem
- The Queensland Brain Institute, The University of Queensland, Saint Lucia, QLD, Australia
| | - Ethan K. Scott
- The Queensland Brain Institute, The University of Queensland, Saint Lucia, QLD, Australia
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Connaughton VP, Nelson R. Ganglion cells in larval zebrafish retina integrate inputs from multiple cone types. J Neurophysiol 2021; 126:1440-1454. [PMID: 34550015 DOI: 10.1152/jn.00082.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We recently showed the presence of seven physiological cone opsins-R1 (575 nm), R2 (556 nm), G1 (460 nm), G3 (480 nm), B1 (415 nm), B2 (440 nm), and UV (358 nm)-in electroretinogram (ERG) recordings of larval zebrafish (Danio rerio) retina. Larval ganglion cells (GCs) are generally thought to integrate only four cone opsin signals (red, green, blue, and UV). We address the question as to whether they may integrate seven cone spectral signals. Here we examined the 127 possible combinations of seven cone signals to find the optimal representation, as based on impulse discharge data sets from GC axons in the larval optic nerve. We recorded four varieties of light-response waveform, sustained-ON, transient-ON, ON-OFF, and OFF, based on the time course of mean discharge rates to all stimulus wavelengths combined. Modeling of GC responses revealed that each received 1-6 cone opsin signals, with a mean of 3.8 ± 1.3 cone signals/GC. Most onset or offset responses were opponent (ON, 80%; OFF, 100%). The most common cone signals were UV (93%), R2 (50%), G3 (55%), and G1 (60%). Seventy-three percent of cone opsin signals were excitatory, and 27% were inhibitory. UV signals favored excitation, whereas G3 and B2 signals favored inhibition. R1/R2, G1/G3, and B1/B2 opsin signals were selectively associated along a nonsynergistic/opponent axis. Overall, these results suggest that larval zebrafish GC spectral responses are complex and use inputs from the seven expressed opsins.NEW & NOTEWORTHY Ganglion cells in larval zebrafish retina have complex spectral responses driven by seven different cone opsin types. UV cone inputs are significant and excitatory to ganglion cells, whereas green and blue cone inputs favor inhibition. Most dramatic are the pentachromatic cells. These responses were identified at 5-6 days after fertilization, reflecting an impressive level of color processing not seen in older fish or mammals.
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Affiliation(s)
- V P Connaughton
- Department of Biology, American University, Washington, District of Columbia
| | - R Nelson
- Neural Circuits Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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Isa T, Marquez-Legorreta E, Grillner S, Scott EK. The tectum/superior colliculus as the vertebrate solution for spatial sensory integration and action. Curr Biol 2021; 31:R741-R762. [PMID: 34102128 DOI: 10.1016/j.cub.2021.04.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The superior colliculus, or tectum in the case of non-mammalian vertebrates, is a part of the brain that registers events in the surrounding space, often through vision and hearing, but also through electrosensation, infrared detection, and other sensory modalities in diverse vertebrate lineages. This information is used to form maps of the surrounding space and the positions of different salient stimuli in relation to the individual. The sensory maps are arranged in layers with visual input in the uppermost layer, other senses in deeper positions, and a spatially aligned motor map in the deepest layer. Here, we will review the organization and intrinsic function of the tectum/superior colliculus and the information that is processed within tectal circuits. We will also discuss tectal/superior colliculus outputs that are conveyed directly to downstream motor circuits or via the thalamus to cortical areas to control various aspects of behavior. The tectum/superior colliculus is evolutionarily conserved among all vertebrates, but tailored to the sensory specialties of each lineage, and its roles have shifted with the emergence of the cerebral cortex in mammals. We will illustrate both the conserved and divergent properties of the tectum/superior colliculus through vertebrate evolution by comparing tectal processing in lampreys belonging to the oldest group of extant vertebrates, larval zebrafish, rodents, and other vertebrates including primates.
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Affiliation(s)
- Tadashi Isa
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan; Institute for the Advanced Study of Human Biology, Kyoto University, Kyoto, 606-8501, Japan
| | | | - Sten Grillner
- Department of Neuroscience, Karolinska Institutet, Stockholm SE-17177, Sweden
| | - Ethan K Scott
- The Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia.
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DeMarco E, Tesmer AL, Hech B, Kawakami K, Robles E. Pyramidal Neurons of the Zebrafish Tectum Receive Highly Convergent Input From Torus Longitudinalis. Front Neuroanat 2021; 15:636683. [PMID: 33613200 PMCID: PMC7886788 DOI: 10.3389/fnana.2021.636683] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 01/06/2021] [Indexed: 12/02/2022] Open
Abstract
The torus longitudinalis (TL) is a midbrain structure unique to ray finned fish. Although previously implicated in orienting behaviors elicited by changes in ambient lighting, the role of TL in visual processing is not well-understood. TL is reciprocally connected to tectum and is the only known source of synaptic input to the stratum marginalis (SM) layer of tectal neuropil. Conversely, tectal pyramidal neurons (PyrNs) are the only identified tectal neuron population that forms a dendrite in SM. In this study we describe a zebrafish gal4 transgenic that labels TL neurons that project to SM. We demonstrate that the axonal TL projection to SM in zebrafish is glutamatergic. Consistent with these axons synapsing directly onto PyrNs, SM-targeted dendrites of PyrNs contain punctate enrichments of the glutamatergic post-synaptic marker protein PSD95. Sparse genetic labeling of individual TL axons and PyrN dendrites enabled quantitative morphometric analysis that revealed (1) large, sparsely branched TL axons in SM and (2) small, densely innervated PyrN dendrites in SM. Together this unique combination of morphologies support a wiring diagram in which TL inputs to PyrNs exhibit a high degree of convergence. We propose that this convergence functions to generate large, compound visual receptive fields in PyrNs. This quantitative anatomical data will instruct future functional studies aimed at identifying the precise contribution of TL-PyrN circuitry to visual behavior.
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Affiliation(s)
- Elisabeth DeMarco
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Alexander L Tesmer
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Bruna Hech
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Koichi Kawakami
- Department of Gene Function, National Institute of Genetics, Mishima, Japan
| | - Estuardo Robles
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
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Förster D, Helmbrecht TO, Mearns DS, Jordan L, Mokayes N, Baier H. Retinotectal circuitry of larval zebrafish is adapted to detection and pursuit of prey. eLife 2020; 9:e58596. [PMID: 33044168 PMCID: PMC7550190 DOI: 10.7554/elife.58596] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/07/2020] [Indexed: 12/22/2022] Open
Abstract
Retinal axon projections form a map of the visual environment in the tectum. A zebrafish larva typically detects a prey object in its peripheral visual field. As it turns and swims towards the prey, the stimulus enters the central, binocular area, and seemingly expands in size. By volumetric calcium imaging, we show that posterior tectal neurons, which serve to detect prey at a distance, tend to respond to small objects and intrinsically compute their direction of movement. Neurons in anterior tectum, where the prey image is represented shortly before the capture strike, are tuned to larger object sizes and are frequently not direction-selective, indicating that mainly interocular comparisons serve to compute an object's movement at close range. The tectal feature map originates from a linear combination of diverse, functionally specialized, lamina-specific, and topographically ordered retinal ganglion cell synaptic inputs. We conclude that local cell-type composition and connectivity across the tectum are adapted to the processing of location-dependent, behaviorally relevant object features.
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Affiliation(s)
- Dominique Förster
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
| | - Thomas O Helmbrecht
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU BioCenterMartinsriedGermany
| | - Duncan S Mearns
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU BioCenterMartinsriedGermany
| | - Linda Jordan
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
| | - Nouwar Mokayes
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
| | - Herwig Baier
- Max Planck Institute of Neurobiology, Department Genes – Circuits – BehaviorMartinsriedGermany
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