1
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Schuster S. The archerfish predictive C-start. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:827-837. [PMID: 37481772 PMCID: PMC10465633 DOI: 10.1007/s00359-023-01658-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/25/2023]
Abstract
A very quick decision enables hunting archerfish to secure downed prey even when they are heavily outnumbered by competing other surface-feeding fish. Based exclusively on information that is taken briefly after the onset of prey motion, the fish select a rapid C-start that turns them right towards the later point of catch. Moreover, the C-start, and not later fin strokes, already lends the fish the speed needed to arrive at just the right time. The archerfish predictive C-starts are kinematically not distinguishable from escape C-starts made by the same individual and are among the fastest C-starts known in teleost fish. The start decisions allow the fish-for ballistically falling prey-to respond accurately to any combination of the initial variables of prey movement and for any position and orientation of the responding fish. The start decisions do not show a speed-accuracy tradeoff and their accuracy is buffered against substantial changes of environmental parameters. Here, I introduce key aspects of this high-speed decision that combines speed, complexity, and precision in an unusual way.
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Affiliation(s)
- Stefan Schuster
- Lehrstuhl für Tierphysiologie , University of Bayreuth , 95440, Bayreuth, Germany.
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2
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High Behavioral Variability Mediated by Altered Neuronal Excitability in auts2 Mutant Zebrafish. eNeuro 2021; 8:ENEURO.0493-20.2021. [PMID: 34544758 PMCID: PMC8503961 DOI: 10.1523/eneuro.0493-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 01/28/2023] Open
Abstract
Autism spectrum disorders (ASDs) are characterized by abnormal behavioral traits arising from neural circuit dysfunction. While a number of genes have been implicated in ASDs, in most cases, a clear understanding of how mutations in these genes lead to circuit dysfunction and behavioral abnormality is absent. The autism susceptibility candidate 2 (AUTS2) gene is one such gene, associated with ASDs, intellectual disability and a range of other neurodevelopmental conditions. However, the role of AUTS2 in neural development and circuit function is not at all known. Here, we undertook functional analysis of Auts2a, the main homolog of AUTS2 in zebrafish, in the context of the escape behavior. Escape behavior in wild-type zebrafish is critical for survival and is therefore, reliable, rapid, and has well-defined kinematic properties. auts2a mutant zebrafish are viable, have normal gross morphology and can generate escape behavior with normal kinematics. However, the behavior is unreliable and delayed, with high trial-to-trial variability in the latency. Using calcium imaging we probed the activity of Mauthner neurons during otic vesicle (OV) stimulation and observed lower probability of activation and reduced calcium transients in the mutants. With direct activation of Mauthner by antidromic stimulation, the threshold for activation in mutants was higher than that in wild-type, even when inhibition was blocked. Taken together, these results point to reduced excitability of Mauthner neurons in auts2a mutant larvae leading to unreliable escape responses. Our results show a novel role for Auts2a in regulating neural excitability and reliability of behavior.
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3
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Preclinical methodological approaches investigating of the effects of alcohol on perinatal and adolescent neurodevelopment. Neurosci Biobehav Rev 2020; 116:436-451. [PMID: 32681938 DOI: 10.1016/j.neubiorev.2020.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 06/02/2020] [Accepted: 07/13/2020] [Indexed: 02/08/2023]
Abstract
Despite much evidence of its economic and social costs, alcohol use continues to increase. Much remains to be known as to the effects of alcohol on neurodevelopment across the lifespan and in both sexes. We provide a comprehensive overview of the methodological approaches to ethanol administration when using animal models (primarily rodent models) and their translational relevance, as well as some of the advantages and disadvantages of each approach. Special consideration is given to early developmental periods (prenatal through adolescence), as well as to the types of research questions that are best addressed by specific methodologies. The zebrafish is used increasingly in alcohol research, and how to use this model effectively as a preclinical model is reviewed as well.
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4
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Removing a single neuron in a vertebrate brain forever abolishes an essential behavior. Proc Natl Acad Sci U S A 2020; 117:3254-3260. [PMID: 32001507 PMCID: PMC7022180 DOI: 10.1073/pnas.1918578117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Mauthner cell is the largest neuron known in the vertebrate brain and, in fish, mediates rapid escape behavior. Ablating this neuron has repeatedly failed to eliminate rapid escapes, a survival role of these escapes has not been supported experimentally, and it is unknown which advantage the enormous size and complexity of the cell conveys. By taking care to ensure ablations remove not only the soma but also the giant axon, we find that rapid escapes are lost forever and that this loss directly affects survival in predator–prey assays. The Mauthner cell thus is an example in which a survival-critical function depends on an individual neuron whose axon appears to have unusual capacities to remain functional after severe injury. The giant Mauthner (M) cell is the largest neuron known in the vertebrate brain. It has enabled major breakthroughs in neuroscience but its ultimate function remains surprisingly unclear: An actual survival value of M cell-mediated escapes has never been supported experimentally and ablating the cell repeatedly failed to eliminate all rapid escapes, suggesting that escapes can equally well be driven by smaller neurons. Here we applied techniques to simultaneously measure escape performance and the state of the giant M axon over an extended period following ablation of its soma. We discovered that the axon survives remarkably long and remains still fully capable of driving rapid escape behavior. By unilaterally removing one of the two M axons and comparing escapes in the same individual that could or could not recruit an M axon, we show that the giant M axon is essential for rapid escapes and that its loss means that rapid escapes are also lost forever. This allowed us to directly test the survival value of the M cell-mediated escapes and to show that the absence of this giant neuron directly affects survival in encounters with a natural predator. These findings not only offer a surprising solution to an old puzzle but demonstrate that even complex brains can trust vital functions to individual neurons. Our findings suggest that mechanisms must have evolved in parallel with the unique significance of these neurons to keep their axons alive and connected.
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5
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Abstract
Visual stimuli can evoke complex behavioral responses, but the underlying streams of neural activity in mammalian brains are difficult to follow because of their size. Here, I review the visual system of zebrafish larvae, highlighting where recent experimental evidence has localized the functional steps of visuomotor transformations to specific brain areas. The retina of a larva encodes behaviorally relevant visual information in neural activity distributed across feature-selective ganglion cells such that signals representing distinct stimulus properties arrive in different areas or layers of the brain. Motor centers in the hindbrain encode motor variables that are precisely tuned to behavioral needs within a given stimulus setting. Owing to rapid technological progress, larval zebrafish provide unique opportunities for obtaining a comprehensive understanding of the intermediate processing steps occurring between visual and motor centers, revealing how visuomotor transformations are implemented in a vertebrate brain.
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Affiliation(s)
- Johann H. Bollmann
- Developmental Biology, Institute of Biology I, Faculty of Biology, and Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
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6
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Active behaviour during early development shapes glucocorticoid reactivity. Sci Rep 2019; 9:12796. [PMID: 31488853 PMCID: PMC6728389 DOI: 10.1038/s41598-019-49388-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/22/2019] [Indexed: 01/01/2023] Open
Abstract
Glucocorticoids are the final effectors of the stress axis, with numerous targets in the central nervous system and the periphery. They are essential for adaptation, yet currently it is unclear how early life events program the glucocorticoid response to stress. Here we provide evidence that involuntary swimming at early developmental stages can reconfigure the cortisol response to homotypic and heterotypic stress in larval zebrafish (Danio rerio), also reducing startle reactivity and increasing spontaneous activity as well as energy efficiency during active behaviour. Collectively, these data identify a role of the genetically malleable zebrafish for linking early life stress with glucocorticoid function in later life.
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7
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Dehnert GK, Karasov WH, Wolman MA. 2,4-Dichlorophenoxyacetic acid containing herbicide impairs essential visually guided behaviors of larval fish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 209:1-12. [PMID: 30684730 DOI: 10.1016/j.aquatox.2019.01.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Aquatic herbicides are used worldwide to eradicate nuisance and invasive plants despite limited knowledge of their toxicity to non-target organisms. 2,4-Dichlorophenoxyacetic acid (2,4-D) is a common active ingredient in commercial herbicide formulations, which triggers plant cell death by mimicking the plant-specific hormone auxin. Application practices of 2,4-D commercial herbicides typically coincide with yearly freshwater fish spawning periods. This practice exposes fish to xenobiotics at their vulnerable larval stages. The full impacts of 2,4-D on larval fish remains poorly understood, and hence, whether it may alter larval survival, larval behavior, fish populations, and ecosystem dynamics. In the present study, we exposed embryonic and larval zebrafish (Danio rerio) to the active ingredient 2,4-D (pure 2,4-D) or a 2,4-D containing commercial herbicide DMA4®IVM (DMA4) and evaluated morphology, survival, behavior, and nervous system function. At 2,4-D concentrations producing no overt morphological defects during embryonic or early larval stages, we observed reduced survival throughout a 21-day larval assay (4-8 ppm DMA4 and 0.75-4 ppm pure 2,4-D). Notably, prey capture, a behavior essential to survival, was reduced in 2,4-D-exposed larval zebrafish (4-8 ppm DMA4 and 0.75-4 ppm pure 2,4-D) and yellow perch (Perca flavescens) (4-20 ppm DMA4). In zebrafish, 8 ppm DMA4 exposure reduced prey capture when exposure was restricted to the period of visual system development. Consistent with these results, larval zebrafish exposed to 8 ppm DMA4 showed reduced neural activity within the optic tectum following prey exposure. Together, our results suggest that 2,4-D alters the development and function of neural circuits underlying vision of larval fish, and thereby reduces visually guided behaviors required for survival.
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Affiliation(s)
- Gavin K Dehnert
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, WI, USA
| | - William H Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin - Madison, Madison, WI, USA
| | - Marc A Wolman
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, WI, USA.
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8
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Ferreira-Pinto MJ, Ruder L, Capelli P, Arber S. Connecting Circuits for Supraspinal Control of Locomotion. Neuron 2018; 100:361-374. [DOI: 10.1016/j.neuron.2018.09.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/27/2018] [Accepted: 09/07/2018] [Indexed: 12/21/2022]
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9
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Bhattacharyya K, McLean DL, MacIver MA. Visual Threat Assessment and Reticulospinal Encoding of Calibrated Responses in Larval Zebrafish. Curr Biol 2017; 27:2751-2762.e6. [PMID: 28889979 PMCID: PMC5703209 DOI: 10.1016/j.cub.2017.08.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/11/2017] [Accepted: 08/04/2017] [Indexed: 11/28/2022]
Abstract
All visual animals must decide whether approaching objects are a threat. Our current understanding of this process has identified a proximity-based mechanism where an evasive maneuver is triggered when a looming stimulus passes a subtended visual angle threshold. However, some escape strategies are more costly than others, and so it would be beneficial to additionally encode the level of threat conveyed by the predator's approach rate to select the most appropriate response. Here, using naturalistic rates of looming visual stimuli while simultaneously monitoring escape behavior and the recruitment of multiple reticulospinal neurons, we find that larval zebrafish do indeed perform a calibrated assessment of threat. While all fish generate evasive maneuvers at the same subtended visual angle, lower approach rates evoke slower, more kinematically variable escape responses with relatively long latencies as well as the unilateral recruitment of ventral spinal projecting nuclei (vSPNs) implicated in turning. In contrast, higher approach rates evoke faster, more kinematically stereotyped responses with relatively short latencies, as well as bilateral recruitment of vSPNs and unilateral recruitment of giant fiber neurons in fish and amphibians called Mauthner cells. In addition to the higher proportion of more costly, shorter-latency Mauthner-active responses to greater perceived threats, we observe a higher incidence of freezing behavior at higher approach rates. Our results provide a new framework to understand how behavioral flexibility is grounded in the appropriate balancing of trade-offs between fast and slow movements when deciding to respond to a visually perceived threat.
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Affiliation(s)
- Kiran Bhattacharyya
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - David L McLean
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
| | - Malcolm A MacIver
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA; Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA.
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10
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Performance on innate behaviour during early development as a function of stress level. Sci Rep 2017; 7:7840. [PMID: 28798473 PMCID: PMC5552790 DOI: 10.1038/s41598-017-08400-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/07/2017] [Indexed: 12/28/2022] Open
Abstract
What is the relationship between the level of acute stress and performance on innate behaviour? The diversity of innate behaviours and lack of sufficient data gathered under the same experimental conditions leave this question unresolved. While evidence points to an inverted-U shaped relationship between the level of acute stress and various measures of learning and memory function, it is unknown the extent to which such a non-linear function applies to performance on innate behaviour, which develops without example or practice under natural circumstances. The fundamental prediction of this view is that moderate stress levels will improve performance, while higher levels will not. Testing this proposition has been difficult because it entails an overall effect that must be invariant to the nature of the stressor, the behaviour under scrutiny and the stimulus that drives it. Here, we report new experimental results showing that developing zebrafish (Danio rerio) under moderate but not higher levels of stress improved their performance on instinctive activities driven by visual, hydrodynamic and thermal inputs. Our findings reveal, for the first time, the existence of an inverted-U shaped performance function according to stress level during early development in a series of innate behaviours.
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11
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Nishimura Y, Murakami S, Ashikawa Y, Sasagawa S, Umemoto N, Shimada Y, Tanaka T. Zebrafish as a systems toxicology model for developmental neurotoxicity testing. Congenit Anom (Kyoto) 2015; 55:1-16. [PMID: 25109898 DOI: 10.1111/cga.12079] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 07/29/2014] [Indexed: 12/18/2022]
Abstract
The developing brain is extremely sensitive to many chemicals. Exposure to neurotoxicants during development has been implicated in various neuropsychiatric and neurological disorders, including autism spectrum disorder, attention deficit hyperactive disorder, schizophrenia, Parkinson's disease, and Alzheimer's disease. Although rodents have been widely used for developmental neurotoxicity testing, experiments using large numbers of rodents are time-consuming, expensive, and raise ethical concerns. Using alternative non-mammalian animal models may relieve some of these pressures by allowing testing of large numbers of subjects while reducing expenses and minimizing the use of mammalian subjects. In this review, we discuss some of the advantages of using zebrafish in developmental neurotoxicity testing, focusing on central nervous system development, neurobehavior, toxicokinetics, and toxicodynamics in this species. We also describe some important examples of developmental neurotoxicity testing using zebrafish combined with gene expression profiling, neuroimaging, or neurobehavioral assessment. Zebrafish may be a systems toxicology model that has the potential to reveal the pathways of developmental neurotoxicity and to provide a sound basis for human risk assessments.
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Affiliation(s)
- Yuhei Nishimura
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Tsu, Japan; Mie University Medical Zebrafish Research Center, Tsu, Japan; Depertment of Systems Pharmacology, Mie University Graduate School of Medicine, Tsu, Japan; Department of Omics Medicine, Mie University Industrial Technology Innovation Institute, Tsu, Japan; Department of Bioinformatics, Mie University Life Science Research Center, Tsu, Japan
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12
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De Marco RJ, Groneberg AH, Yeh CM, Treviño M, Ryu S. The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development. Front Behav Neurosci 2014; 8:367. [PMID: 25368561 PMCID: PMC4202704 DOI: 10.3389/fnbeh.2014.00367] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/05/2014] [Indexed: 01/09/2023] Open
Abstract
The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging.
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Affiliation(s)
- Rodrigo J De Marco
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research Heidelberg, Germany
| | - Antonia H Groneberg
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research Heidelberg, Germany
| | - Chen-Min Yeh
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research Heidelberg, Germany
| | - Mario Treviño
- Laboratorio de Plasticidad Cortical y Aprendizaje Perceptual, Instituto de Neurociencias, Universidad de Guadalajara Guadalajara, México
| | - Soojin Ryu
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research Heidelberg, Germany
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13
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Abstract
Genetic means to visualize and manipulate neuronal circuits in the intact animal have revolutionized neurobiology. "Dynamic neuroanatomy" defines a range of approaches aimed at quantifying the architecture or subcellular organization of neurons over time during their development, regeneration, or degeneration. A general feature of these approaches is their reliance on the optical isolation of defined neurons in toto by genetically expressing markers in one or few cells. Here we use the afferent neurons of the lateral line as an example to describe a simple method for the dynamic neuroanatomical study of axon terminals in the zebrafish by laser-scanning confocal microscopy.
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Affiliation(s)
- Adèle Faucherre
- Département de Physiologie, Institut de Génomique Fonctionnelle, CNRS UMR 5203, INSERM U661, Universtités Montpellier 1 & 2, Montpellier, France
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14
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De Marco RJ, Groneberg AH, Yeh CM, Castillo Ramírez LA, Ryu S. Optogenetic elevation of endogenous glucocorticoid level in larval zebrafish. Front Neural Circuits 2013; 7:82. [PMID: 23653595 PMCID: PMC3644639 DOI: 10.3389/fncir.2013.00082] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/11/2013] [Indexed: 11/28/2022] Open
Abstract
The stress response is a suite of physiological and behavioral processes that help to maintain or reestablish homeostasis. Central to the stress response is the hypothalamic-pituitary-adrenal (HPA) axis, as it releases crucial hormones in response to stress. Glucocorticoids (GCs) are the final effector hormones of the HPA axis, and exert a variety of actions under both basal and stress conditions. Despite their far-reaching importance for health, specific GC effects have been difficult to pin-down due to a lack of methods for selectively manipulating endogenous GC levels. Hence, in order to study stress-induced GC effects, we developed a novel optogenetic approach to selectively manipulate the rise of GCs triggered by stress. Using this approach, we could induce both transient hypercortisolic states and persistent forms of hypercortisolaemia in freely behaving larval zebrafish. Our results also established that transient hypercortisolism leads to enhanced locomotion shortly after stressor exposure. Altogether, we present a highly specific method for manipulating the gain of the stress axis with high temporal accuracy, altering endocrine and behavioral responses to stress as well as basal GC levels. Our study offers a powerful tool for the analysis of rapid (non-genomic) and delayed (genomic) GC effects on brain function and behavior, feedbacks within the stress axis and developmental programming by GCs.
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Affiliation(s)
- Rodrigo J De Marco
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research Heidelberg, Germany
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15
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Arrenberg AB, Driever W. Integrating anatomy and function for zebrafish circuit analysis. Front Neural Circuits 2013; 7:74. [PMID: 23630469 PMCID: PMC3632786 DOI: 10.3389/fncir.2013.00074] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/03/2013] [Indexed: 01/31/2023] Open
Abstract
Due to its transparency, virtually every brain structure of the larval zebrafish is accessible to light-based interrogation of circuit function. Advanced stimulation techniques allow the activation of optogenetic actuators at different resolution levels, and genetically encoded calcium indicators report the activity of a large proportion of neurons in the CNS. Large datasets result and need to be analyzed to identify cells that have specific properties—e.g., activity correlation to sensory stimulation or behavior. Advances in three-dimensional (3D) functional mapping in zebrafish are promising; however, the mere coordinates of implicated neurons are not sufficient. To comprehensively understand circuit function, these functional maps need to be placed into the proper context of morphological features and projection patterns, neurotransmitter phenotypes, and key anatomical landmarks. We discuss the prospect of merging functional and anatomical data in an integrated atlas from the perspective of our work on long-range dopaminergic neuromodulation and the oculomotor system. We propose that such a resource would help researchers to surpass current hurdles in circuit analysis to achieve an integrated understanding of anatomy and function.
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Affiliation(s)
- Aristides B Arrenberg
- Developmental Biology, Institute of Biology I, Faculty of Biology, BIOSS - Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg Freiburg, Germany
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16
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Pujol-Martí J, López-Schier H. Developmental and architectural principles of the lateral-line neural map. Front Neural Circuits 2013; 7:47. [PMID: 23532704 PMCID: PMC3607791 DOI: 10.3389/fncir.2013.00047] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/06/2013] [Indexed: 11/13/2022] Open
Abstract
The transmission and central representation of sensory cues through the accurate construction of neural maps is essential for animals to react to environmental stimuli. Structural diversity of sensorineural maps along a continuum between discrete- and continuous-map architectures can influence behavior. The mechanosensory lateral line of fishes and amphibians, for example, detects complex hydrodynamics occurring around the animal body. It triggers innate fast escape reactions but also modulates complex navigation behaviors that require constant knowledge about the environment. The aim of this article is to summarize recent work in the zebrafish that has shed light on the development and structure of the lateralis neural map, which is helping to understand how individual sensory modalities generate appropriate behavioral responses to the sensory context.
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Affiliation(s)
- Jesús Pujol-Martí
- Research Unit of Sensory Biology and Organogenesis, Helmholtz Zentrum München Neuherberg, Munich, Germany
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17
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Cheng YC, Scotting PJ, Hsu LS, Lin SJ, Shih HY, Hsieh FY, Wu HL, Tsao CL, Shen CJ. Zebrafish rgs4 is essential for motility and axonogenesis mediated by Akt signaling. Cell Mol Life Sci 2013; 70:935-50. [PMID: 23052218 PMCID: PMC11113239 DOI: 10.1007/s00018-012-1178-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 12/21/2022]
Abstract
The schizophrenia susceptibility gene, Rgs4, is one of the most intensively studied regulators of G-protein signaling members, well known to be fundamental in regulating neurotransmission. However, little is known about its role in the developing nervous system. We have isolated zebrafish rgs4 and shown that it is transcribed in the developing nervous system. Rgs4 knockdown did not affect neuron number and patterning but resulted in locomotion defects and aberrant development of axons. This was confirmed using a selective Rgs4 inhibitor, CCG-4986. Rgs4 knockdown also attenuated the level of phosphorylated-Akt1, and injection of constitutively-activated AKT1 rescued the motility defects and axonal phenotypes in the spinal cord but not in the hindbrain and trigeminal neurons. Our in vivo analysis reveals a novel role for Rgs4 in regulating axonogenesis during embryogenesis, which is mediated by another schizophrenia-associated gene, Akt1, in a region-specific manner.
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Affiliation(s)
- Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, Taoyuan, 33383, Taiwan.
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18
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Souza BR, Tropepe V. The role of dopaminergic signalling during larval zebrafish brain development: a tool for investigating the developmental basis of neuropsychiatric disorders. Rev Neurosci 2011; 22:107-19. [PMID: 21615265 DOI: 10.1515/rns.2011.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neurodevelopment depends on intrinsic and extrinsic factors that influence the overall pattern of neurogenesis and neural circuit formation, which has a direct impact on behaviour. Defects in dopamine signalling and brain morphology at a relatively early age, and mutations in neurodevelopmental genes are strongly correlated with several neuropsychiatric disorders. This evidence supports the hypothesis of a neurodevelopmental origin of at least some forms of mental illness. Zebrafish (Danio rerio) has emerged as an important vertebrate model system in biomedical research. The ease with which intrinsic and extrinsic factors can be altered during early development, the relatively conserved dopaminergic circuit organisation in the larval brain, and the emergence of simple sensorimotor behaviours very early in development are some of the appealing features that make this organism advantageous for developmental brain and behaviour research. Thus, examining the impact of altered dopamine signalling and disease related genetic aberrations during zebrafish development presents a unique opportunity to holistically analyse the in vivo biochemical, morphological and behavioural significance of altered dopamine signalling during a crucial period of development using a highly tractable vertebrate model organism. Ultimately, this information will shed new light on potential therapeutic targets for the treatment of schizophrenia and perhaps serve as a paradigm for investigating the neurodevelopmental origin of other psychiatric disorders.
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Affiliation(s)
- Bruno Rezende Souza
- Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto M5S 3G5, ON, Canada
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19
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Korzh V, Teh C, Kondrychyn I, Chudakov DM, Lukyanov S. Visualizing Compound Transgenic Zebrafish in Development: A Tale of Green Fluorescent Protein and KillerRed. Zebrafish 2011; 8:23-9. [DOI: 10.1089/zeb.2011.0689] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Vladimir Korzh
- Genomics and Development Division, Institute of Molecular and Cell Biology, A-STAR, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Cathleen Teh
- Genomics and Development Division, Institute of Molecular and Cell Biology, A-STAR, Singapore, Singapore
| | - Igor Kondrychyn
- Genomics and Development Division, Institute of Molecular and Cell Biology, A-STAR, Singapore, Singapore
| | - Dmitry M. Chudakov
- Shemiakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Sergey Lukyanov
- Shemiakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
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20
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Teh C, Chudakov DM, Poon KL, Mamedov IZ, Sek JY, Shidlovsky K, Lukyanov S, Korzh V. Optogenetic in vivo cell manipulation in KillerRed-expressing zebrafish transgenics. BMC DEVELOPMENTAL BIOLOGY 2010; 10:110. [PMID: 21040591 PMCID: PMC2989954 DOI: 10.1186/1471-213x-10-110] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 11/02/2010] [Indexed: 11/10/2022]
Abstract
Background KillerRed (KR) is a novel photosensitizer that efficiently generates reactive oxygen species (ROS) in KR-expressing cells upon intense green or white light illumination in vitro, resulting in damage to their plasma membrane and cell death. Results We report an in vivo modification of this technique using a fluorescent microscope and membrane-tagged KR (mem-KR)-expressing transgenic zebrafish. We generated several stable zebrafish Tol2 transposon-mediated enhancer-trap (ET) transgenic lines expressing mem-KR (SqKR series), and mapped the transposon insertion sites. As mem-KR accumulates on the cell membrane and/or Golgi, it highlights cell bodies and extensions, and reveals details of cellular morphology. The photodynamic property of KR made it possible to damage cells expressing this protein in a dose-dependent manner. As a proof-of-principle, two zebrafish transgenic lines were used to affect cell viability and function: SqKR2 expresses mem-KR in the hindbrain rhombomeres 3 and 5, and elsewhere; SqKR15 expresses mem-KR in the heart and elsewhere. Photobleaching of KR by intense light in the heart of SqKR15 embryos at lower levels caused a reduction in pumping efficiency of the heart and pericardial edema and at higher levels - in cell death in the hindbrain of SqKR2 and in the heart of SqKR15 embryos. Conclusions An intense illumination of tissues expressing mem-KR affects cell viability and function in living zebrafish embryos. Hence, the zebrafish transgenics expressing mem-KR in a tissue-specific manner are useful tools for studying the biological effects of ROS.
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Affiliation(s)
- Cathleen Teh
- Institute of Molecular and Cell Biology, A-STAR, Singapore
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21
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Nevin LM, Robles E, Baier H, Scott EK. Focusing on optic tectum circuitry through the lens of genetics. BMC Biol 2010; 8:126. [PMID: 20920150 PMCID: PMC2949621 DOI: 10.1186/1741-7007-8-126] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/24/2010] [Indexed: 11/10/2022] Open
Abstract
The visual pathway is tasked with processing incoming signals from the retina and converting this information into adaptive behavior. Recent studies of the larval zebrafish tectum have begun to clarify how the 'micro-circuitry' of this highly organized midbrain structure filters visual input, which arrives in the superficial layers and directs motor output through efferent projections from its deep layers. The new emphasis has been on the specific function of neuronal cell types, which can now be reproducibly labeled, imaged and manipulated using genetic and optical techniques. Here, we discuss recent advances and emerging experimental approaches for studying tectal circuits as models for visual processing and sensorimotor transformation by the vertebrate brain.
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Affiliation(s)
- Linda M Nevin
- Department of Physiology, University of California, San Francisco, 1550 4th Street, San Francisco, CA 94158-23241, USA.
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22
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Mann KD, Hoyt C, Feldman S, Blunt L, Raymond A, Page-McCaw PS. Cardiac response to startle stimuli in larval zebrafish: sympathetic and parasympathetic components. Am J Physiol Regul Integr Comp Physiol 2010; 298:R1288-97. [PMID: 20130228 DOI: 10.1152/ajpregu.00302.2009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Central regulation of cardiac output via the sympathetic and parasympathetic branches of the autonomic nervous system allows the organism to respond to environmental changes. Sudden onset stimuli, startle stimuli, are useful probes to study central regulatory responses to the environment. In mammals, startle stimuli induce a transient bradycardia that habituates with repeated stimulation. Repeated presentation of the stimulus results in tachycardia. In this study, we investigate the behavioral regulation of heart rate in response to sudden stimuli in the zebrafish. Larval zebrafish show a stereotyped heart rate response to mild electrical shock. Naïve fish show a significant increase in interbeat interval that resolves in the 2 s following stimulation. This transient bradycardia decreases on repeated exposure to the stimulus. Following repeated stimulation, the fish become tachycardic within 1 min of stimulation. Both the transient bradycardia and following tachycardia responses are blocked with administration of the ganglionic blocker hexamethonium, demonstrating that these responses are mediated centrally. The transient bradycardia is blocked by the muscarinic antagonist atropine, suggesting that this response is mediated by the parasympathetic system, while the following tachycardia is specifically blocked by the beta-adrenergic antagonist propranolol, suggesting that this response is mediated by the sympathetic nervous system. Together, these results demonstrate that at the larval stage, zebrafish actively regulate cardiac output to changes in their environment using both the parasympathetic and sympathetic branches of the autonomic nervous system, a behavioral response that is markedly similar to that observed in mammals to similar sudden onset stimuli.
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Affiliation(s)
- Kara D Mann
- New York Neural Stem Cell Institute, One Discovery Place, Rensselaer, NY 12144, USA
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23
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Abstract
For more than a decade, the zebrafish has proven to be an excellent model organism to investigate the mechanisms of neurogenesis during development. The often cited advantages, namely external development, genetic, and optical accessibility, have permitted direct examination and experimental manipulations of neurogenesis during development. Recent studies have begun to investigate adult neurogenesis, taking advantage of its widespread occurrence in the mature zebrafish brain to investigate the mechanisms underlying neural stem cell maintenance and recruitment. Here we provide a comprehensive overview of the tools and techniques available to study neurogenesis in zebrafish both during development and in adulthood. As useful resources, we provide tables of available molecular markers, transgenic, and mutant lines. We further provide optimized protocols for studying neurogenesis in the adult zebrafish brain, including in situ hybridization, immunohistochemistry, in vivo lipofection and electroporation methods to deliver expression constructs, administration of bromodeoxyuridine (BrdU), and finally slice cultures. These currently available tools have put zebrafish on par with other model organisms used to investigate neurogenesis.
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Affiliation(s)
- Prisca Chapouton
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
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24
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Ganser LR, Dallman JE. Glycinergic synapse development, plasticity, and homeostasis in zebrafish. Front Mol Neurosci 2009; 2:30. [PMID: 20126315 PMCID: PMC2815536 DOI: 10.3389/neuro.02.030.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Accepted: 11/26/2009] [Indexed: 11/13/2022] Open
Abstract
The zebrafish glial glycine transporter 1 (GlyT1) mutant provides an animal model in which homeostatic plasticity at glycinergic synapses restores rhythmic motor behaviors. GlyT1 mutants, initially paralyzed by the build-up of the inhibitory neurotransmitter glycine, stage a gradual recovery that is associated with reductions in the strength of evoked glycinergic responses. Gradual motor recovery suggests sequential compensatory mechanisms that culminate in the down-regulation of the neuronal glycine receptor. However, how motor recovery is initiated and how other forms of plasticity contribute to behavioral recovery are still outstanding questions that we discuss in the context of (1) glycinergic synapses as they function in spinal circuits that produce rhythmic motor behaviors, (2) the proteins involved in regulating glycinergic synaptic strength, (3) current models of glycinergic synaptogenesis, and (4) plasticity mechanisms that modulate the strength of glycinergic synapses. Concluding remarks (5) explore the potential for distinct plasticity mechanisms to act in concert at different spatial and temporal scales to achieve a dynamic stability that results in balanced motor behaviors.
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Affiliation(s)
- Lisa R Ganser
- Department of Biology, University of Miami Coral Gables, FL, USA
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25
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Dreosti E, Odermatt B, Dorostkar MM, Lagnado L. A genetically encoded reporter of synaptic activity in vivo. Nat Methods 2009; 6:883-9. [PMID: 19898484 PMCID: PMC2859341 DOI: 10.1038/nmeth.1399] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 10/07/2009] [Indexed: 12/04/2022]
Abstract
To image synaptic activity within neural circuits, we tethered the genetically encoded calcium indicator (GECI) GCaMP2 to synaptic vesicles by fusion to synaptophysin. The resulting reporter, SyGCaMP2, detected the electrical activity of neurons with two advantages over existing cytoplasmic GECIs: it identified the locations of synapses and had a linear response over a wider range of spike frequencies. Simulations and experimental measurements indicated that linearity arises because SyGCaMP2 samples the brief calcium transient passing through the presynaptic compartment close to voltage-sensitive calcium channels rather than changes in bulk calcium concentration. In vivo imaging in zebrafish demonstrated that SyGCaMP2 can assess electrical activity in conventional synapses of spiking neurons in the optic tectum and graded voltage signals transmitted by ribbon synapses of retinal bipolar cells. Localizing a GECI to synaptic terminals provides a strategy for monitoring activity across large groups of neurons at the level of individual synapses.
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Affiliation(s)
- Elena Dreosti
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
| | - Benjamin Odermatt
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
| | | | - Leon Lagnado
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK
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26
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Abstract
Expression of halorhodopsin (NpHR), a light-driven microbial chloride pump, enables optical control of membrane potential and reversible silencing of targeted neurons. We generated transgenic zebrafish expressing enhanced NpHR under control of the Gal4/UAS system. Electrophysiological recordings showed that eNpHR stimulation effectively suppressed spiking of single neurons in vivo. Applying light through thin optic fibers positioned above the head of a semi-restrained zebrafish larva enabled us to target groups of neurons and to simultaneously test the effect of their silencing on behavior. The photostimulated volume of the zebrafish brain could be marked by subsequent photoconversion of co-expressed Kaede or Dendra. These techniques were used to localize swim command circuitry to a small hindbrain region, just rostral to the commissura infima Halleri. The kinetics of the hindbrain-generated swim command was investigated by combined and separate photo-activation of NpHR and Channelrhodopsin-2 (ChR2), a light-gated cation channel, in the same neurons. Together this "optogenetic toolkit" allows loss-of-function and gain-of-function analyses of neural circuitry at high spatial and temporal resolution in a behaving vertebrate.
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27
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McKeown KA, Downes GB, Hutson LD. Modular laboratory exercises to analyze the development of zebrafish motor behavior. Zebrafish 2009; 6:179-85. [PMID: 19537944 DOI: 10.1089/zeb.2008.0564] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The embryonic zebrafish is an excellent research model to examine the neural networks that coordinate locomotive behavior. It demonstrates robust locomotive behavior early in development, its nervous system is relatively simple and accessible compared to mammalian systems, and there are mutants available with specific molecular and motor deficits. We have developed a series of four exercises that provide students with a basic understanding of locomotive behavior development, nervous system organization, development of neurotransmitter responsiveness, and genetics. The first two exercises can be performed in one 3-h laboratory period, and the third and fourth exercises, which build on the first two, can be completed in one or two subsequent periods. In the first exercise, students observe and quantify two distinct behaviors that characterize different developmental stages, spontaneous movement, and touch-evoked tail coiling. In the second, the students use a pharmacological approach to determine if the neurotransmitter glycine is required for the embryo to perform each behavior. In the third, they use simple lesions to assess whether the brain is required for each type of behavior. In the fourth, the students examine bandoneon, a zebrafish motility mutant that has a glycine receptor defect, by observing its behavior during spontaneous movement and touch-evoked tail coiling, performing lesions, and applying pharmacological drugs. These exercises are readily adaptable, such that portions can be omitted or expanded to examine other neurotransmitter systems or later stages of locomotive behavior development.
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Affiliation(s)
- Kelly Anne McKeown
- Molecular and Cellular Biology Program, Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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28
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Abstract
Over recent years, several groundbreaking techniques have been developed that allow for the anatomical description of neurons, and the observation and manipulation of their activity. Combined, these approaches should provide a great leap forward in our understanding of the structure and connectivity of the nervous system and how, as a network of individual neurons, it generates behavior. Zebrafish, given their external development and optical transparency, are an appealing system in which to employ these methods. These traits allow for direct observation of fluorescence in describing anatomy and observing neural activity, and for the manipulation of neurons using a host of light-triggered proteins. Gal4/Upstream Activating Sequence techniques, as they are based on a binary system, allow for the flexible deployment of a range of transgenes in expression patterns of interest. As such, they provide a promising approach for viewing neurons in a variety of ways, each of which can reveal something different about their structure, connectivity, or function. In this study, the author will review recent progress in the development of the Gal4/Upstream Activating Sequence system in zebrafish, feature examples of promising studies to date, and examine how various new technologies can be used in the future to untangle the complex mechanisms by which behavior is generated.
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Affiliation(s)
- Ethan K Scott
- The University of Queensland, The Queensland Brain Institute, Brisbane, Australia.
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29
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Orger MB, Kampff AR, Severi KE, Bollmann JH, Engert F. Control of visually guided behavior by distinct populations of spinal projection neurons. Nat Neurosci 2008; 11:327-33. [PMID: 18264094 DOI: 10.1038/nn2048] [Citation(s) in RCA: 181] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 01/01/2008] [Indexed: 11/09/2022]
Abstract
A basic question in the field of motor control is how different actions are represented by activity in spinal projection neurons. We used a new behavioral assay to identify visual stimuli that specifically drive basic motor patterns in zebrafish. These stimuli evoked consistent patterns of neural activity in the neurons projecting to the spinal cord, which we could map throughout the entire population using in vivo two-photon calcium imaging. We found that stimuli that drive distinct behaviors activated distinct subsets of projection neurons, consisting, in some cases, of just a few cells. This stands in contrast to the distributed activation seen for more complex behaviors. Furthermore, targeted cell by cell ablations of the neurons associated with evoked turns abolished the corresponding behavioral response. This description of the functional organization of the zebrafish motor system provides a framework for identifying the complete circuit underlying a vertebrate behavior.
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Affiliation(s)
- Michael B Orger
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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30
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Selected papers on zebrafish and other aquarium fish models. Zebrafish 2008; 1:165-72. [PMID: 18248227 DOI: 10.1089/zeb.2004.1.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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31
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Abstract
One enduring challenge of biological imaging is achieving depth of penetration-into cells, tissues, and animals. How deeply can we probe and with what resolution and efficacy? These are critical issues as microscopists seek to push ever deeper, while resolving structural details and observing specific molecular events. In this guide to depth-appropriate modalities, standard optical platforms such as confocal and two-photon microscopes are considered along with complementary imaging modalities that range in depth of penetration. After an introduction to basic techniques, the trade-offs and limitations that distinguish competing technologies are considered, with emphasis on the visualization of subcellular structures and dynamic events. Not surprisingly, there are differences of opinion regarding imaging technologies, as highlighted in a section on point-scanning and Nipkow-disk style confocal microscopes. Confocal microscopy is then contrasted with deconvolution and multi-photon imaging modalities. It is also important to consider the detectors used by current instruments (such as PMTs and CCD cameras). Ultimately specimen properties, in conjunction with instrumentation, determine the depth at which subcellular operations and larger-scale biological processes can be visualized. Relative advantages are mentioned in the context of experiment planning and instrument-purchase decisions. Given the rate at which new optical techniques are being invented, this report should be viewed as a snapshot of current capabilities, with the goal of providing a framework for thinking about new developments.
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32
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Curado S, Anderson RM, Jungblut B, Mumm J, Schroeter E, Stainier DYR. Conditional targeted cell ablation in zebrafish: a new tool for regeneration studies. Dev Dyn 2007; 236:1025-35. [PMID: 17326133 DOI: 10.1002/dvdy.21100] [Citation(s) in RCA: 381] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Conditional targeted cell ablation in zebrafish would greatly expand the utility of this genetic model system in developmental and regeneration studies, given its extensive regenerative capabilities. Here, we show that, by combining chemical and genetic tools, one can ablate cells in a temporal- and spatial-specific manner in zebrafish larvae. For this purpose, we used the bacterial Nitroreductase (NTR) enzyme to convert the prodrug Metronidazole (Mtz) into a cytotoxic DNA cross-linking agent. To investigate the efficiency of this system, we targeted three different cell lineages in the heart, pancreas, and liver. Expression of the fusion protein Cyan Fluorescent Protein-NTR (CFP-NTR) under control of tissue-specific promoters allowed us to induce the death of cardiomyocytes, pancreatic beta-cells, and hepatocytes at specific times. Moreover, we have observed that Mtz can be efficiently washed away and that, upon Mtz withdrawal, the profoundly affected tissue can quickly recover. These findings show that the NTR/Mtz system is effective for temporally and spatially controlled cell ablation in zebrafish, thereby constituting a most promising genetic tool to analyze tissue interactions as well as the mechanisms underlying regeneration.
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Affiliation(s)
- Silvia Curado
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158-2324, USA
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33
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Prober DA, Rihel J, Onah AA, Sung RJ, Schier AF. Hypocretin/orexin overexpression induces an insomnia-like phenotype in zebrafish. J Neurosci 2007; 26:13400-10. [PMID: 17182791 PMCID: PMC6675014 DOI: 10.1523/jneurosci.4332-06.2006] [Citation(s) in RCA: 337] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
As many as 10% of humans suffer chronic sleep disturbances, yet the genetic mechanisms that regulate sleep remain essentially unknown. It is therefore crucial to develop simple and cost-effective vertebrate models to study the genetic regulation of sleep. The best characterized mammalian sleep/wake regulator is hypocretin/orexin (Hcrt), whose loss results in the sleep disorder narcolepsy and that has also been implicated in feeding behavior, energy homeostasis, thermoregulation, reward seeking, addiction, and maternal behavior. Here we report that the expression pattern and axonal projections of embryonic and larval zebrafish Hcrt neurons are strikingly similar to those in mammals. We show that zebrafish larvae exhibit robust locomotive sleep/wake behaviors as early as the fifth day of development and that Hcrt overexpression promotes and consolidates wakefulness and inhibits rest. Similar to humans with insomnia, Hcrt-overexpressing larvae are hyperaroused and have dramatically reduced abilities to initiate and maintain rest at night. Remarkably, Hcrt function is modulated by but does not require normal circadian oscillations in locomotor activity. Our zebrafish model of Hcrt overexpression indicates that the ancestral function of Hcrt is to promote locomotion and inhibit rest and will facilitate the discovery of neural circuits, genes, and drugs that regulate Hcrt function and sleep.
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Affiliation(s)
| | - Jason Rihel
- Department of Molecular and Cellular Biology
| | | | | | - Alexander F. Schier
- Department of Molecular and Cellular Biology
- Division of Sleep Medicine
- Center for Brain Science
- Harvard Stem Cell Institute, and
- Broad Institute, Harvard University, Cambridge, Massachusetts 02138
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34
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Uematsu K, Baba Y, Kake Y, Ikenaga T, Moon SJ, Miyai Y, Yoshida M. Central Mechanisms Underlying Fish Swimming. BRAIN, BEHAVIOR AND EVOLUTION 2007; 69:142-50. [PMID: 17230022 DOI: 10.1159/000095203] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although the basic swimming rhythm is created by central pattern generators (CPGs) located in each spinal segment, command signals from the brain should be indispensable for the activation of CPGs to initiate swimming. We hypothesized that the nucleus of medial longitudinal fascicles (Nflm) is the midbrain locomotor region driving swimming rhythms in teleosts. To test this hypothesis, we recorded neuronal activities from Nflm neurons in swimming carp and analyzed the cytoarchitecture of the nucleus. We identified two types of Nflm neurons exhibiting electric activities closely related to swimming rhythms. Remarkably, tonic neurons that continued firing during swimming were found. The Nflm and neighboring oculomotor nucleus contain about 600 neurons in total, and among them as many as 500 were labeled retrogradely by an intraspinal tracer implantation and 400 neurons showed glutamatergic immunoreactivity. They are the most likely candidates for the descending neurons as the origin of driving signals that initiate swimming. Double-labeling experiments demonstrated direct connections of Nflm neurons to spinal neurons consisting of the CPG. These data imply that most Nflm neurons possibly exert an excitatory drive to the spinal CPGs through the descending axons with excitatory transmitter(s), probably glutamate. Furthermore, we confirmed that the caudal part of Nflm and the rostral part of the oculomotor nucleus overlap rostrocaudally by approximately 200 mum. In connection with the control of swimming by the brain, we carried out experiments to clarify the efferent system of the cerebellum of the goldfish. Cerebellar efferent fibers terminated in most brain regions except for the telencephalon. Importantly, the cerebellum projected also to the Nflm, suggesting the involvement of this brain region in the control of swimming. We have also determined that in the carp so-called eurydendroid cells are cerebellar efferent neurons.
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Affiliation(s)
- Kazumasa Uematsu
- Laboratory of Fish Physiology, Graduate School of Biosphere Sciences, Hiroshima University, Hiroshima, Japan.
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35
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Ramdya P, Reiter B, Engert F. Reverse correlation of rapid calcium signals in the zebrafish optic tectum in vivo. J Neurosci Methods 2006; 157:230-7. [PMID: 16765450 DOI: 10.1016/j.jneumeth.2006.04.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 04/18/2006] [Accepted: 04/25/2006] [Indexed: 11/17/2022]
Abstract
Reverse correlation techniques provide a quantitative means of computing neuronal input/output relationships. Until now these methods have been limited to electrically recorded responses since unprocessed optical signals generally lack necessary temporal characteristics. We sought to overcome this barrier since combining reverse correlation with calcium imaging would afford a powerful alternative to current methods of measuring response properties of neurons non-invasively in vivo. We labeled zebrafish optic tecta with a calcium indicator and measured responses to a whole-field random flicker light stimulus. Although calcium signals exhibited slow decay kinetics, we could use computational modeling to show that the positive differential of these traces extracts high frequency information. Experimentally, we found that calcium signals processed in this way were synchronous with simultaneously measured synaptic responses and could be used with reverse correlation to determine temporal filters of neurons in the zebrafish optic tectum. These findings demonstrate that calcium responses to physiological stimulation can be processed to obtain rapid signal information and consequently to determine linear filter properties in vivo.
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Affiliation(s)
- Pavan Ramdya
- Program in Neuroscience, Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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36
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Abstract
The zebrafish is an excellent model system for studying the molecular basis of inner ear development and function. The eggs develop ex utero and the ear is transparent for the first few weeks of life. Forward genetic screens and antisense technology have helped to elucidate the signaling pathways and molecules required for inner ear development and function. This review addresses the most recent advances in our understanding of how the ear forms and discusses the molecules in hair cells that are essential for sensing sound and movement in the zebrafish.
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Affiliation(s)
- Teresa Nicolson
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239, USA.
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37
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Muto A, Orger MB, Wehman AM, Smear MC, Kay JN, Page-McCaw PS, Gahtan E, Xiao T, Nevin LM, Gosse NJ, Staub W, Finger-Baier K, Baier H. Forward genetic analysis of visual behavior in zebrafish. PLoS Genet 2005; 1:e66. [PMID: 16311625 PMCID: PMC1287954 DOI: 10.1371/journal.pgen.0010066] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Accepted: 10/19/2005] [Indexed: 11/19/2022] Open
Abstract
The visual system converts the distribution and wavelengths of photons entering the eye into patterns of neuronal activity, which then drive motor and endocrine behavioral responses. The gene products important for visual processing by a living and behaving vertebrate animal have not been identified in an unbiased fashion. Likewise, the genes that affect development of the nervous system to shape visual function later in life are largely unknown. Here we have set out to close this gap in our understanding by using a forward genetic approach in zebrafish. Moving stimuli evoke two innate reflexes in zebrafish larvae, the optomotor and the optokinetic response, providing two rapid and quantitative tests to assess visual function in wild-type (WT) and mutant animals. These behavioral assays were used in a high-throughput screen, encompassing over half a million fish. In almost 2,000 F2 families mutagenized with ethylnitrosourea, we discovered 53 recessive mutations in 41 genes. These new mutations have generated a broad spectrum of phenotypes, which vary in specificity and severity, but can be placed into only a handful of classes. Developmental phenotypes include complete absence or abnormal morphogenesis of photoreceptors, and deficits in ganglion cell differentiation or axon targeting. Other mutations evidently leave neuronal circuits intact, but disrupt phototransduction, light adaptation, or behavior-specific responses. Almost all of the mutants are morphologically indistinguishable from WT, and many survive to adulthood. Genetic linkage mapping and initial molecular analyses show that our approach was effective in identifying genes with functions specific to the visual system. This collection of zebrafish behavioral mutants provides a novel resource for the study of normal vision and its genetic disorders.
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Affiliation(s)
- Akira Muto
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Michael B Orger
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Ann M Wehman
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Matthew C Smear
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Jeremy N Kay
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Patrick S Page-McCaw
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Ethan Gahtan
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Tong Xiao
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Linda M Nevin
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Nathan J Gosse
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Wendy Staub
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Karin Finger-Baier
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
| | - Herwig Baier
- Department of Physiology, Programs in Neuroscience, Genetics, and Developmental Biology, Center for Human Genetics, University of California, San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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Gahtan E, Tanger P, Baier H. Visual prey capture in larval zebrafish is controlled by identified reticulospinal neurons downstream of the tectum. J Neurosci 2005; 25:9294-303. [PMID: 16207889 PMCID: PMC6725764 DOI: 10.1523/jneurosci.2678-05.2005] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many vertebrates are efficient hunters and recognize their prey by innate neural mechanisms. During prey capture, the internal representation of the prey's location must be constantly updated and made available to premotor neurons that convey the information to spinal motor circuits. We studied the neural substrate of this specialized visuomotor system using high-speed video recordings of larval zebrafish and laser ablations of candidate brain structures. Seven-day-old zebrafish oriented toward, chased, and consumed paramecia with high accuracy. Lesions of the retinotectal neuropil primarily abolished orienting movements toward the prey. Wild-type fish tested in darkness, as well as blind mutants, were impaired similarly to tectum-ablated animals, suggesting that prey capture is mainly visually mediated. To trace the pathway further, we examined the role of two pairs of identified reticulospinal neurons, MeLc and MeLr, located in the nucleus of the medial longitudinal fasciculus of the tegmentum. These two neurons extend dendrites into the ipsilateral tectum and project axons into the spinal cord. Ablating MeLc and MeLr bilaterally impaired prey capture but spared several other behaviors. Ablating different sets of reticulospinal neurons did not impair prey capture, suggesting a selective function of MeLr and MeLc in this behavior. Ablating MeLc and MeLr neurons unilaterally in conjunction with the contralateral tectum also mostly abolished prey capture, but ablating them together with the ipsilateral tectum had a much smaller effect. These results suggest that MeLc and MeLr function in series with the tectum, as part of a circuit that coordinates prey capture movements.
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Affiliation(s)
- Ethan Gahtan
- Department of Psychology, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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Orger MB, Baier H. Channeling of red and green cone inputs to the zebrafish optomotor response. Vis Neurosci 2005; 22:275-81. [PMID: 16079003 DOI: 10.1017/s0952523805223039] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Accepted: 02/16/2005] [Indexed: 11/07/2022]
Abstract
Visual systems break scenes down into individual features, processed in distinct channels, and then selectively recombine those features according to the demands of particular behavioral tasks. In primates, for example, there are distinct pathways for motion and form processing. While form vision utilizes color information, motion pathways receive input from only a subset of cone photoreceptors and are generally colorblind. To explore the link between early channeling of visual information and behavioral output across vertebrate species, we measured the chromatic inputs to the optomotor response of larval zebrafish. Using cone-isolating gratings, we found that there is a strong input from both red and green cones but not short-wavelength cones, which nevertheless do contribute to another behavior, phototaxis. Using a motion-nulling method, we measured precisely the input strength of gratings that stimulated cones in combination. The fish do not respond to gratings that stimulate different cone types out of phase, but have an enhanced response when the cones are stimulated together. This shows that red and green cone signals are pooled at a stage before motion detection. Since the two cone inputs are combined into a single ‘luminance’ channel, the response to sinusoidal gratings is colorblind. However, we also find that the relative contributions of the two cones at isoluminance varies with spatial frequency. Therefore, natural stimuli, which contain a mixture of spatial frequencies, are likely to be visible regardless of their chromatic composition.
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Affiliation(s)
- Michael B Orger
- Department of Physiology, Program in Neuroscience, University of California--San Francisco, 94143, USA
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McElligott MB, O'malley DM. Prey tracking by larval zebrafish: axial kinematics and visual control. BRAIN, BEHAVIOR AND EVOLUTION 2005; 66:177-96. [PMID: 16088102 DOI: 10.1159/000087158] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 12/13/2004] [Indexed: 11/19/2022]
Abstract
High-speed imaging was used to record the prey-tracking behavior of larval zebrafish as they fed upon paramecium. Prey tracking is comprised of a variable set of discrete locomotor movements that together align the larva with the paramecium and bring it into close proximity, usually within one body length. These tracking behaviors are followed by a brief capture swim bout that was previously described [Borla et al., 2002]. Tracking movements were classified as either swimming or turning bouts. The swimming bouts were similar to a previously characterized larval slow swim [Budick and O'Malley, 2000], but the turning movements consisted of unique J-shaped bends which appear to minimize forward hydrodynamic disturbance when approaching the paramecium. Such J-turn tracking bouts consisted of multiple unilateral contractions to one side of the body. J-turns slowly and moderately alter the orientation of the larva - this is in contrast to previously described escape and routine turns. Tracking behaviors appear to be entirely visually guided. Infra-red (IR) imaging of locomotor behaviors in a dark environment revealed a complete absence of tracking behaviors, even though the normal repertoire of other locomotive behaviors was recorded. Concomitantly, such larvae were greatly impaired in consuming paramecia. The tracking behavior is of interest because it indicates the presence of sophisticated locomotor control circuitry in this relatively simple model organism. Such locomotor strategies may be conserved and elaborated upon by other larval and adult fishes.
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Love DR, Pichler FB, Dodd A, Copp BR, Greenwood DR. Technology for high-throughput screens: the present and future using zebrafish. Curr Opin Biotechnol 2004; 15:564-71. [PMID: 15560983 DOI: 10.1016/j.copbio.2004.09.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The zebrafish is a popular vertebrate model organism with similar organ systems and gene sequences to humans. Zebrafish embryos are optically transparent enabling organ visualisation, which can be complemented with gene expression analysis at the transcript and protein levels. Furthermore, zebrafish can be treated with small molecules and drugs in a microtitre plate format for high-throughput analysis and for the identification and validation of drugs. High-throughput methodologies for use in zebrafish include phenotype-based visualisation, transcript studies using low-density DNA microarrays and proteomic analysis. These technologies offer significant whole-organism biological value in the drug discovery and drug development pipeline.
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Affiliation(s)
- Donald R Love
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1001, New Zealand.
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Orger MB, Gahtan E, Muto A, Page-McCaw P, Smear MC, Baier H. Behavioral screening assays in zebrafish. Methods Cell Biol 2004; 77:53-68. [PMID: 15602905 DOI: 10.1016/s0091-679x(04)77003-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Michael B Orger
- Program in Neuroscience, Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
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O'Malley DM, Sankrithi NS, Borla MA, Parker S, Banden S, Gahtan E, Detrich HW. Optical physiology and locomotor behaviors of wild-type and nacre zebrafish. Methods Cell Biol 2004; 76:261-84. [PMID: 15602880 DOI: 10.1016/s0091-679x(04)76013-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Donald M O'Malley
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
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