1
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Lin A, Álvarez-Salvado E, Milicic N, Pujara N, Ehrlich DE. Multisensory navigational strategies of hatchling fish for dispersal. Curr Biol 2023; 33:4917-4925.e4. [PMID: 37865093 PMCID: PMC10842570 DOI: 10.1016/j.cub.2023.09.070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/23/2023]
Abstract
Animals influence how they disperse in the environment by sensing local cues and adapting how they move. However, controlling dispersal can present a particular challenge early in life when animals tend to be more limited in their capacities to sense and move. To what extent and by what mechanisms can newly hatched fish control how they disperse? Here, we reveal hatchling sensorimotor mechanisms for controlling dispersal by combining swim tracking and precise sensory manipulations of a model species, zebrafish. In controlled laboratory experiments, if we physically constrained hatchlings or blocked sensations of motion through vision and the lateral line, hatchlings responded by elevating their buoyancy and passively moving with faster surface currents. Complementarily, in stagnant water, hatchlings covered more ground using hyperstable swimming, strongly orienting based on graviception. Using experimentally calibrated hydrodynamic simulations, we show that these hatchling behaviors nearly tripled diffusivity and made dispersal robust to local conditions, suggesting this multisensory strategy may provide important advantages for early life in a variable environment.
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Affiliation(s)
- Allia Lin
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Efrén Álvarez-Salvado
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nikola Milicic
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA; Integrative Biology Graduate Program, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nimish Pujara
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - David E Ehrlich
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA; Integrative Biology Graduate Program, University of Wisconsin-Madison, Madison, WI 53706, USA.
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2
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Gao Y, Khan YA, Mo W, White KI, Perkins M, Pfuetzner RA, Trapani JG, Brunger AT, Nicolson T. Sensory deficit screen identifies nsf mutation that differentially affects SNARE recycling and quality control. Cell Rep 2023; 42:112345. [PMID: 37027300 PMCID: PMC10524599 DOI: 10.1016/j.celrep.2023.112345] [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: 11/15/2022] [Revised: 02/24/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
The AAA+ NSF complex is responsible for SNARE complex disassembly both before and after membrane fusion. Loss of NSF function results in pronounced developmental and degenerative defects. In a genetic screen for sensory deficits in zebrafish, we identified a mutation in nsf, I209N, that impairs hearing and balance in a dosage-dependent manner without accompanying defects in motility, myelination, and innervation. In vitro experiments demonstrate that while the I209N NSF protein recognizes SNARE complexes, the effects on disassembly are dependent upon the type of SNARE complex and I209N concentration. Higher levels of I209N protein produce a modest decrease in binary (syntaxin-SNAP-25) SNARE complex disassembly and residual ternary (syntaxin-1A-SNAP-25-synaptobrevin-2) disassembly, whereas at lower concentrations binary disassembly activity is strongly reduced and ternary disassembly activity is absent. Our study suggests that the differential effect on disassembly of SNARE complexes leads to selective effects on NSF-mediated membrane trafficking and auditory/vestibular function.
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Affiliation(s)
- Yan Gao
- Department of Otolaryngology, Head and Neck Surgery, Stanford Medical School, 300 Pasteur Drive, Stanford, CA 94303, USA
| | - Yousuf A Khan
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Center for Biomedical Informatics Research, Stanford University, Stanford, CA, USA
| | - Weike Mo
- Graduate Program Biomedical Sciences, Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - K Ian White
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Matthew Perkins
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA 01002, USA
| | - Richard A Pfuetzner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Josef G Trapani
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA 01002, USA
| | - Axel T Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Teresa Nicolson
- Department of Otolaryngology, Head and Neck Surgery, Stanford Medical School, 300 Pasteur Drive, Stanford, CA 94303, USA.
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3
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Kindig K, Stepanyan R, Kindt KS, McDermott BM. Asymmetric mechanotransduction by hair cells of the zebrafish lateral line. Curr Biol 2023; 33:1295-1307.e3. [PMID: 36905930 DOI: 10.1016/j.cub.2023.02.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 11/22/2022] [Accepted: 02/09/2023] [Indexed: 03/12/2023]
Abstract
In the lateral line system, water motion is detected by neuromast organs, fundamental units that are arrayed on a fish's surface. Each neuromast contains hair cells, specialized mechanoreceptors that convert mechanical stimuli, in the form of water movement, into electrical signals. The orientation of hair cells' mechanosensitive structures ensures that the opening of mechanically gated channels is maximal when deflected in a single direction. In each neuromast organ, hair cells have two opposing orientations, enabling bi-directional detection of water movement. Interestingly, Tmc2b and Tmc2a proteins, which constitute the mechanotransduction channels in neuromasts, distribute asymmetrically so that Tmc2a is expressed in hair cells of only one orientation. Here, using both in vivo recording of extracellular potentials and calcium imaging of neuromasts, we demonstrate that hair cells of one orientation have larger mechanosensitive responses. The associated afferent neuron processes that innervate neuromast hair cells faithfully preserve this functional difference. Moreover, Emx2, a transcription factor required for the formation of hair cells with opposing orientations, is necessary to establish this functional asymmetry within neuromasts. Remarkably, loss of Tmc2a does not impact hair cell orientation but abolishes the functional asymmetry as measured by recording extracellular potentials and calcium imaging. Overall, our work indicates that oppositely oriented hair cells within a neuromast employ different proteins to alter mechanotransduction to sense the direction of water motion.
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Affiliation(s)
- Kayla Kindig
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ruben Stepanyan
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| | - Katie S Kindt
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA.
| | - Brian M McDermott
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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4
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Holmgren M, Ravicz ME, Hancock KE, Strelkova O, Kallogjeri D, Indzhykulian AA, Warchol ME, Sheets L. Mechanical overstimulation causes acute injury and synapse loss followed by fast recovery in lateral-line neuromasts of larval zebrafish. eLife 2021; 10:69264. [PMID: 34665127 PMCID: PMC8555980 DOI: 10.7554/elife.69264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022] Open
Abstract
Excess noise damages sensory hair cells, resulting in loss of synaptic connections with auditory nerves and, in some cases, hair-cell death. The cellular mechanisms underlying mechanically induced hair-cell damage and subsequent repair are not completely understood. Hair cells in neuromasts of larval zebrafish are structurally and functionally comparable to mammalian hair cells but undergo robust regeneration following ototoxic damage. We therefore developed a model for mechanically induced hair-cell damage in this highly tractable system. Free swimming larvae exposed to strong water wave stimulus for 2 hr displayed mechanical injury to neuromasts, including afferent neurite retraction, damaged hair bundles, and reduced mechanotransduction. Synapse loss was observed in apparently intact exposed neuromasts, and this loss was exacerbated by inhibiting glutamate uptake. Mechanical damage also elicited an inflammatory response and macrophage recruitment. Remarkably, neuromast hair-cell morphology and mechanotransduction recovered within hours following exposure, suggesting severely damaged neuromasts undergo repair. Our results indicate functional changes and synapse loss in mechanically damaged lateral-line neuromasts that share key features of damage observed in noise-exposed mammalian ear. Yet, unlike the mammalian ear, mechanical damage to neuromasts is rapidly reversible.
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Affiliation(s)
- Melanie Holmgren
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Michael E Ravicz
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Kenneth E Hancock
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Olga Strelkova
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Dorina Kallogjeri
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Artur A Indzhykulian
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St Louis, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States
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5
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Wang J, Wang D, Hu G, Yang L, Liu Z, Yan D, Serikuly N, Alpyshov E, Demin KA, Strekalova T, Gil Barcellos LJ, Barcellos HHA, Amstislavskaya TG, de Abreu MS, Kalueff AV. The role of auditory and vibration stimuli in zebrafish neurobehavioral models. Behav Processes 2021; 193:104505. [PMID: 34547376 DOI: 10.1016/j.beproc.2021.104505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022]
Abstract
Strongly affecting human and animal physiology, sounds and vibration are critical environmental factors whose complex role in behavioral and brain functions necessitates further clinical and experimental studies. Zebrafish are a promising model organism for neuroscience research, including probing the contribution of auditory and vibration stimuli to neurobehavioral processes. Here, we summarize mounting evidence on the role of sound and vibration in zebrafish behavior and brain function, and outline future directions of translational research in this field. With the growing environmental exposure to noise and vibration, we call for more active use of zebrafish models for probing neurobehavioral and bioenvironmental consequences of acute and long-term exposure to sounds and vibration in complex biological systems.
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Affiliation(s)
- Jingtao Wang
- School of Pharmacy, Southwest University, Chongqing, China
| | - Dongmei Wang
- School of Pharmacy, Southwest University, Chongqing, China
| | - Guojun Hu
- School of Pharmacy, Southwest University, Chongqing, China
| | - LongEn Yang
- School of Pharmacy, Southwest University, Chongqing, China
| | - ZiYuan Liu
- School of Pharmacy, Southwest University, Chongqing, China
| | - Dongni Yan
- School of Pharmacy, Southwest University, Chongqing, China
| | - Nazar Serikuly
- School of Pharmacy, Southwest University, Chongqing, China
| | - Erik Alpyshov
- School of Pharmacy, Southwest University, Chongqing, China
| | - Konstantin A Demin
- St. Petersburg State University, St. Petersburg, Russia; Neurobiology Program, Sirius University, Sochi, Russia
| | - Tatiana Strekalova
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia; Maastricht University, Maastricht, The Netherlands; Research Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Leonardo J Gil Barcellos
- Graduate Programs in Bio-experimentation and Environmental Sciences, University of Passo Fundo, Passo Fundo, Brazil; Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | | | | | - Murilo S de Abreu
- Bioscience Institute, University of Passo Fundo, Passo Fundo, Brazil; Laboratory of Cell and Molecular Biology and Neurobiology, Moscow Institute of Physics and Technology, Moscow, Russia.
| | - Allan V Kalueff
- School of Pharmacy, Southwest University, Chongqing, China; Ural Federal University, Ekaterinburg, Russia.
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6
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Hardy K, Amariutei AE, De Faveri F, Hendry A, Marcotti W, Ceriani F. Functional development and regeneration of hair cells in the zebrafish lateral line. J Physiol 2021; 599:3913-3936. [PMID: 34143497 PMCID: PMC7612129 DOI: 10.1113/jp281522] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/03/2021] [Indexed: 12/22/2022] Open
Abstract
Hair cells are mechanosensory receptors responsible for transducing auditory and vestibular information into electrical signals, which are then transmitted with remarkable precision to afferent neurons. Different from mammals, the hair cells of lower vertebrates, including those present in the neuromasts of the zebrafish lateral line, regenerate following environmental or chemical insults. Here we investigate the time-course of regeneration of hair cells in vivo using electrophysiology, 2-photon imaging and immunostaining applied to wild-type and genetically-encoded fluorescent indicator zebrafish lines. Functional hair cells drive spontaneous action potentials in the posterior lateral line afferent fibres, the frequency of which progressively increases over the first 10-days post-fertilization (dpf). Higher firing-rate fibres are only observed from ~6 dpf. Following copper treatment, newly formed hair cells become functional and are able to drive APs in the afferent fibres within 48 hours in both early-larval (≤8 dpf) and late-larval (12-17 dpf) zebrafish. However, the complete functional regeneration of the entire neuromast is delayed in late-larval compared to early-larval zebrafish. We propose that while individual regenerating hair cells can rapidly become active, the acquisition of fully functional neuromasts progresses faster at early-larval stages, a time when hair cells are still under development. At both ages, the afferent terminals in the regenerating neuromast appear to make initial contact with supporting cells. The ablation of the lateral line afferent neurons prevents the timely regeneration of supporting cells and hair cells. These findings indicate that the afferent system is likely to facilitate or promote the neuromast regeneration process.
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Affiliation(s)
- Katherine Hardy
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Ana E Amariutei
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | | | - Aenea Hendry
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, UK.,Sheffield Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Federico Ceriani
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
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7
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Colón-Cruz L, Rodriguez-Morales R, Santana-Cruz A, Cantres-Velez J, Torrado-Tapias A, Lin SJ, Yudowski G, Kensler R, Marie B, Burgess SM, Renaud O, Varshney GK, Behra M. Cnr2 Is Important for Ribbon Synapse Maturation and Function in Hair Cells and Photoreceptors. Front Mol Neurosci 2021; 14:624265. [PMID: 33958989 PMCID: PMC8093779 DOI: 10.3389/fnmol.2021.624265] [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: 10/31/2020] [Accepted: 02/24/2021] [Indexed: 02/04/2023] Open
Abstract
The role of the cannabinoid receptor 2 (CNR2) is still poorly described in sensory epithelia. We found strong cnr2 expression in hair cells (HCs) of the inner ear and the lateral line (LL), a superficial sensory structure in fish. Next, we demonstrated that sensory synapses in HCs were severely perturbed in larvae lacking cnr2. Appearance and distribution of presynaptic ribbons and calcium channels (Cav1.3) were profoundly altered in mutant animals. Clustering of membrane-associated guanylate kinase (MAGUK) in post-synaptic densities (PSDs) was also heavily affected, suggesting a role for cnr2 for maintaining the sensory synapse. Furthermore, vesicular trafficking in HCs was strongly perturbed suggesting a retrograde action of the endocannabinoid system (ECs) via cnr2 that was modulating HC mechanotransduction. We found similar perturbations in retinal ribbon synapses. Finally, we showed that larval swimming behaviors after sound and light stimulations were significantly different in mutant animals. Thus, we propose that cnr2 is critical for the processing of sensory information in the developing larva.
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Affiliation(s)
- Luis Colón-Cruz
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Roberto Rodriguez-Morales
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Alexis Santana-Cruz
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Juan Cantres-Velez
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Aranza Torrado-Tapias
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Sheng-Jia Lin
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Guillermo Yudowski
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico.,School of Medicine, Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico
| | - Robert Kensler
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Bruno Marie
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico.,School of Medicine, Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico
| | - Shawn M Burgess
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Olivier Renaud
- Cell and Tissue Imaging Facility (PICT-IBiSA, FranceBioImaging), Institut Curie, PSL Research University, U934/UMR3215, Paris, France
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Martine Behra
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
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8
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Valera G, Markov DA, Bijari K, Randlett O, Asgharsharghi A, Baudoin JP, Ascoli GA, Portugues R, López-Schier H. A neuronal blueprint for directional mechanosensation in larval zebrafish. Curr Biol 2021; 31:1463-1475.e6. [PMID: 33545047 DOI: 10.1016/j.cub.2021.01.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/30/2020] [Accepted: 01/13/2021] [Indexed: 01/02/2023]
Abstract
Animals have a remarkable ability to use local cues to orient in space in the absence of a panoramic fixed reference frame. Here we use the mechanosensory lateral line in larval zebrafish to understand rheotaxis, an innate oriented swimming evoked by water currents. We generated a comprehensive light-microscopy cell-resolution projectome of lateralis afferent neurons (LANs) and used clustering techniques for morphological classification. We find surprising structural constancy among LANs. Laser-mediated microlesions indicate that precise topographic mapping of lateral-line receptors is not essential for rheotaxis. Recording neuronal-activity during controlled mechanical stimulation of neuromasts reveals unequal representation of water-flow direction in the hindbrain. We explored potential circuit architectures constrained by anatomical and functional data to suggest a parsimonious model under which the integration of lateralized signals transmitted by direction-selective LANs underlies the encoding of water-flow direction in the brain. These data provide a new framework to understand how animals use local mechanical cues to orient in space.
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Affiliation(s)
- Gema Valera
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany
| | | | - Kayvan Bijari
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | - Owen Randlett
- Department of Molecular and Cellular Biology, Harvard University, MA, USA
| | | | | | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | | | - Hernán López-Schier
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany; Centre for Genomic Regulation, Barcelona, Spain.
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9
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Recording Channelrhodopsin-Evoked Field Potentials and Startle Responses from Larval Zebrafish. Methods Mol Biol 2021; 2191:201-220. [PMID: 32865747 DOI: 10.1007/978-1-0716-0830-2_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Zebrafish are an excellent model organism to study many aspects of vertebrate sensory encoding and behavior. Their escape responses begin with a C-shaped body bend followed by several swimming bouts away from the potentially threatening stimulus. This highly stereotyped motor behavior provides a model for studying startle reflexes and the neural circuitry underlying multisensory encoding and locomotion. Channelrhodopsin (ChR2) can be expressed in the lateral line and ear hair cells of zebrafish and can be excited in vivo to elicit these rapid forms of escape. Here we review our methods for studying transgenic ChR2-expressing zebrafish larvae, including screening for positive expression of ChR2 and recording field potentials and high-speed videos of optically evoked escape responses. We also highlight important features of the acquired data and provide a brief review of other zebrafish research that utilizes or has the potential to benefit from ChR2 and optogenetics.
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10
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Unraveling the Molecular Players at the Cholinergic Efferent Synapse of the Zebrafish Lateral Line. J Neurosci 2020; 41:47-60. [PMID: 33203744 DOI: 10.1523/jneurosci.1772-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/25/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
The lateral line (LL) is a sensory system that allows fish and amphibians to detect water currents. LL responsiveness is modulated by efferent neurons that aid in distinguishing between external and self-generated stimuli, maintaining sensitivity to relevant cues. One component of the efferent system is cholinergic, the activation of which inhibits afferent activity. LL hair cells (HCs) share structural, functional, and molecular similarities with those of the cochlea, making them a popular model for studying human hearing and balance disorders. Because of these commonalities, one could propose that the receptor at the LL efferent synapse is a α9α10 nicotinic acetylcholine receptor (nAChR). However, the identities of the molecular players underlying ACh-mediated inhibition in the LL remain unknown. Surprisingly, through the analysis of single-cell expression studies and in situ hybridization, we describe that α9, but not the α10, subunits are enriched in zebrafish HCs. Moreover, the heterologous expression of zebrafish α9 subunits indicates that homomeric receptors are functional and exhibit robust ACh-gated currents blocked by α-bungarotoxin and strychnine. In addition, in vivo Ca2+ imaging on mechanically stimulated zebrafish LL HCs show that ACh elicits a decrease in evoked Ca2+ signals, regardless of HC polarity. This effect is blocked by both α-bungarotoxin and apamin, indicating coupling of ACh-mediated effects to small-conductance Ca2+-activated potassium (SKs) channels. Our results indicate that an α9-containing (α9*) nAChR operates at the zebrafish LL efferent synapse. Moreover, the activation of α9* nAChRs most likely leads to LL HC hyperpolarization served by SK channels.SIGNIFICANCE STATEMENT The fish lateral line (LL) mechanosensory system shares structural, functional, and molecular similarities with those of the mammalian cochlea. Thus, it has become an accessible model for studying human hearing and balance disorders. However, the molecular players serving efferent control of LL hair cell (HC) activity have not been identified. Here we demonstrate that, different from the hearing organ of vertebrate species, a nicotinic acetylcholine receptor composed only of α9 subunits operates at the LL efferent synapse. Activation of α9-containing receptors leads to LL HC hyperpolarization because of the opening of small-conductance Ca2+-activated potassium channels. These results will further aid in the interpretation of data obtained from LL HCs as a model for cochlear HCs.
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11
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A new method for vibration-based neurophenotyping of zebrafish. J Neurosci Methods 2020; 333:108563. [DOI: 10.1016/j.jneumeth.2019.108563] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/12/2019] [Accepted: 12/17/2019] [Indexed: 02/08/2023]
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12
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Manchanda A, Chatterjee P, Bonventre JA, Haggard DE, Kindt KS, Tanguay RL, Johnson CP. Otoferlin Depletion Results in Abnormal Synaptic Ribbons and Altered Intracellular Calcium Levels in Zebrafish. Sci Rep 2019; 9:14273. [PMID: 31582816 PMCID: PMC6776657 DOI: 10.1038/s41598-019-50710-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 09/13/2019] [Indexed: 01/10/2023] Open
Abstract
The protein otoferlin plays an essential role at the sensory hair cell synapse. Mutations in otoferlin result in deafness and depending on the species, mild to strong vestibular deficits. While studies in mouse models suggest a role for otoferlin in synaptic vesicle exocytosis and endocytosis, it is unclear whether these functions are conserved across species. To address this question, we characterized the impact of otoferlin depletion in zebrafish larvae and found defects in synaptic vesicle recycling, abnormal synaptic ribbons, and higher resting calcium concentrations in hair cells. We also observed abnormal expression of the calcium binding hair cell genes s100s and parvalbumin, as well as the nogo related proteins rtn4rl2a and rtn4rl2b. Exogenous otoferlin partially restored expression of genes affected by endogenous otoferlin depletion. Our results suggest that in addition to vesicle recycling, depletion of otoferlin disrupts resting calcium levels, alters synaptic ribbon architecture, and perturbs transcription of hair cells specific genes during zebrafish development.
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Affiliation(s)
- Aayushi Manchanda
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, USA
| | - Paroma Chatterjee
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, USA
| | - Josephine A Bonventre
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, USA
| | - Derik E Haggard
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA
| | - Katie S Kindt
- National Institute of Deafness and Other Communication Disorders (NIDCD), NIH, Maryland, USA
| | - Robert L Tanguay
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, USA
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA
| | - Colin P Johnson
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, USA.
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, USA.
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13
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Genomic non-redundancy of the mir-183/96/182 cluster and its requirement for hair cell maintenance. Sci Rep 2019; 9:10302. [PMID: 31311951 PMCID: PMC6635406 DOI: 10.1038/s41598-019-46593-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 07/02/2019] [Indexed: 01/02/2023] Open
Abstract
microRNAs are important regulators of gene expression. In the retina, the mir-183/96/182 cluster is of particular interest due to its robust expression and studies in which loss of the cluster caused photoreceptor degeneration. However, it is unclear which of the three miRNAs in the cluster are ultimately required in photoreceptors, whether each may have independent, contributory roles, or whether a single miRNA from the cluster compensates for the loss of another. These are important questions that will not only help us to understand the role of these particular miRNAs in the retina, but will deepen our understanding of how clustered microRNAs evolve and operate. To that end, we have developed a complete panel of single, double, and triple mir-183/96/182 mutant zebrafish. While the retinas of all mutant animals were normal, the triple mutants exhibited acute hair cell degeneration which corresponded with impaired swimming and death at a young age. By measuring the penetrance of this phenotype in each mutant line, we determine which of the three miRNAs in the cluster are necessary and/or sufficient to ensure normal hair cell development and function.
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14
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Unconventional secretory pathway activation restores hair cell mechanotransduction in an USH3A model. Proc Natl Acad Sci U S A 2019; 116:11000-11009. [PMID: 31097578 DOI: 10.1073/pnas.1817500116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The pathogenic variant c.144T>G (p.N48K) in the clarin1 gene (CLRN1) results in progressive loss of vision and hearing in Usher syndrome IIIA (USH3A) patients. CLRN1 is predicted to be an essential protein in hair bundles, the mechanosensory structure of hair cells critical for hearing and balance. When expressed in animal models, CLRN1 localizes to the hair bundle, whereas glycosylation-deficient CLRN1N48K aggregates in the endoplasmic reticulum, with only a fraction reaching the bundle. We hypothesized that the small amount of CLRN1N48K that reaches the hair bundle does so via an unconventional secretory pathway and that activation of this pathway could be therapeutic. Using genetic and pharmacological approaches, we find that clarin1 knockout (clrn1 KO/KO ) zebrafish that express the CLRN1 c.144T>G pathogenic variant display progressive hair cell dysfunction, and that CLRN1N48K is trafficked to the hair bundle via the GRASP55 cargo-dependent unconventional secretory pathway (GCUSP). On expression of GRASP55 mRNA, or on exposure to the drug artemisinin (which activates GCUSP), the localization of CLRN1N48K to the hair bundles was enhanced. Artemisinin treatment also effectively restored hair cell mechanotransduction and attenuated progressive hair cell dysfunction in clrn1 KO/KO larvae that express CLRN1 c.144T>G , highlighting the potential of artemisinin to prevent sensory loss in CLRN1 c.144T>G patients.
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15
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O’Connor MJ, Beebe LL, Deodato D, Ball RE, Page AT, VanLeuven AJ, Harris KT, Park S, Hariharan V, Lauderdale JD, Dore TM. Bypassing Glutamic Acid Decarboxylase 1 (Gad1) Induced Craniofacial Defects with a Photoactivatable Translation Blocker Morpholino. ACS Chem Neurosci 2019; 10:266-278. [PMID: 30200754 PMCID: PMC6337688 DOI: 10.1021/acschemneuro.8b00231] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
![]()
γ-Amino
butyric acid (GABA) mediated signaling is critical
in the central and enteric nervous systems, pancreas, lungs, and other
tissues. It is associated with many neurological disorders and craniofacial
development. Glutamic acid decarboxylase (GAD) synthesizes GABA from
glutamate, and knockdown of the gad1 gene results
in craniofacial defects that are lethal in zebrafish. To bypass this
and enable observation of the neurological defects resulting from
knocking down gad1 expression, a photoactivatable
morpholino oligonucleotide (MO) against gad1 was
prepared by cyclization with a photocleavable linker rendering the
MO inactive. The cyclized MO was stable in the dark and toward degradative
enzymes and was completely linearized upon brief exposure to 405 nm
light. In the course of investigating the function of the ccMOs in
zebrafish, we discovered that zebrafish possess paralogous gad1 genes, gad1a and gad1b. A gad1b MO injected at the 1–4 cell stage
caused severe morphological defects in head development, which could
be bypassed, enabling the fish to develop normally, if the fish were
injected with a photoactivatable, cyclized gad1b MO
and grown in the dark. At 1 day post fertilization (dpf), light activation
of the gad1b MO followed by observation at 3 and
7 dpf led to increased and abnormal electrophysiological brain activity
compared to wild type animals. The photocleavable linker can be used
to cyclize and inactivate any MO, and represents a general strategy
to parse the function of developmentally important genes in a spatiotemporal
manner.
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Affiliation(s)
- Matthew J. O’Connor
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
| | - Lindsey L. Beebe
- Department of Genetics, University of Georgia, Athens, Georgia 30602, United States
| | - Davide Deodato
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
| | - Rebecca E. Ball
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - A. Tyler Page
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Ariel J. VanLeuven
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Kyle T. Harris
- Department of Chemistry, University of Georgia, Athens, Georgia 30602 United States
| | - Sungdae Park
- Department of Genetics, University of Georgia, Athens, Georgia 30602, United States
| | - Vani Hariharan
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - James D. Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, United States
- Neuroscience
Division
of the Biomedical and Health Sciences Institute, Athens, Georgia 30602, United States
| | - Timothy M. Dore
- New York University Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
- Department of Chemistry, University of Georgia, Athens, Georgia 30602 United States
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16
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Pickett SB, Thomas ED, Sebe JY, Linbo T, Esterberg R, Hailey DW, Raible DW. Cumulative mitochondrial activity correlates with ototoxin susceptibility in zebrafish mechanosensory hair cells. eLife 2018; 7:38062. [PMID: 30596476 PMCID: PMC6345563 DOI: 10.7554/elife.38062] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 12/31/2018] [Indexed: 12/11/2022] Open
Abstract
Mitochondria play a prominent role in mechanosensory hair cell damage and death. Although hair cells are thought to be energetically demanding cells, how mitochondria respond to these demands and how this might relate to cell death is largely unexplored. Using genetically encoded indicators, we found that mitochondrial calcium flux and oxidation are regulated by mechanotransduction and demonstrate that hair cell activity has both acute and long-term consequences on mitochondrial function. We tested whether variation in mitochondrial activity reflected differences in the vulnerability of hair cells to the toxic drug neomycin. We observed that susceptibility did not correspond to the acute level of mitochondrial activity but rather to the cumulative history of that activity.
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Affiliation(s)
- Sarah B Pickett
- Department of Biological Structure, University of Washington, Seattle, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, United States
| | - Eric D Thomas
- Department of Biological Structure, University of Washington, Seattle, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, United States
| | - Joy Y Sebe
- Department of Biological Structure, University of Washington, Seattle, United States
| | - Tor Linbo
- Department of Biological Structure, University of Washington, Seattle, United States
| | - Robert Esterberg
- Department of Biological Structure, University of Washington, Seattle, United States.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - Dale W Hailey
- Department of Biological Structure, University of Washington, Seattle, United States.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - David W Raible
- Department of Biological Structure, University of Washington, Seattle, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, United States.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
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17
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Lukasz D, Kindt KS. In Vivo Calcium Imaging of Lateral-line Hair Cells in Larval Zebrafish. J Vis Exp 2018. [PMID: 30582593 DOI: 10.3791/58794] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Sensory hair cells are mechanoreceptors found in the inner ear that are required for hearing and balance. Hair cells are activated in response to sensory stimuli that mechanically deflect apical protrusions called hair bundles. Deflection opens mechanotransduction (MET) channels in hair bundles, leading to an influx of cations, including calcium. This cation influx depolarizes the cell and opens voltage-gated calcium channels located basally at the hair-cell presynapse. In mammals, hair cells are encased in bone, and it is challenging to functionally assess these activities in vivo. In contrast, larval zebrafish are transparent and possess an externally located lateral-line organ that contains hair cells. These hair cells are functionally and structurally similar to mammalian hair cells and can be functionally assessed in vivo. This article outlines a technique that utilizes a genetically encoded calcium indicator (GECI), GCaMP6s, to measure stimulus-evoked calcium signals in zebrafish lateral-line hair cells. GCaMP6s can be used, along with confocal imaging, to measure in vivo calcium signals at the apex and base of lateral-line hair cells. These signals provide a real-time, quantifiable readout of both mechanosensation- and presynapse-dependent calcium activities within these hair cells. These calcium signals also provide important functional information regarding how hair cells detect and transmit sensory stimuli. Overall, this technique generates useful data about relative changes in calcium activity in vivo. It is less well-suited for quantification of the absolute magnitude of calcium changes. This in vivo technique is sensitive to motion artifacts. A reasonable amount of practice and skill are required for proper positioning, immobilization, and stimulation of larvae. Ultimately, when properly executed, the protocol outlined in this article provides a powerful way to collect valuable information about the activity of hair-cells in their natural, fully integrated states within a live animal.
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Affiliation(s)
- Daria Lukasz
- Section on Sensory Cell Development and Function, NIDCD/National Institutes of Health; National Institutes of Health-Johns Hopkins University Graduate Partnerships Program
| | - Katie S Kindt
- Section on Sensory Cell Development and Function, NIDCD/National Institutes of Health;
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18
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Song S, Lee JA, Kiselev I, Iyengar V, Trapani JG, Tania N. Mathematical Modeling and Analyses of Interspike-Intervals of Spontaneous Activity in Afferent Neurons of the Zebrafish Lateral Line. Sci Rep 2018; 8:14851. [PMID: 30291277 PMCID: PMC6173758 DOI: 10.1038/s41598-018-33064-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/21/2018] [Indexed: 12/25/2022] Open
Abstract
Without stimuli, hair cells spontaneously release neurotransmitter leading to spontaneous generation of action potentials (spikes) in innervating afferent neurons. We analyzed spontaneous spike patterns recorded from the lateral line of zebrafish and found that distributions of interspike intervals (ISIs) either have an exponential shape or an "L" shape that is characterized by a sharp decay but wide tail. ISI data were fitted to renewal-process models that accounted for the neuron refractory periods and hair-cell synaptic release. Modeling the timing of synaptic release using a mixture of two exponential distributions yielded the best fit for our ISI data. Additionally, lateral line ISIs displayed positive serial correlation and appeared to exhibit switching between faster and slower modes of spike generation. This pattern contrasts with previous findings from the auditory system where ISIs tended to have negative serial correlation due to synaptic depletion. We propose that afferent neuron innervation with multiple and heterogenous hair-cells synapses, each influenced by changes in calcium domains, can serve as a mechanism for the random switching behavior. Overall, our analyses provide evidence of how physiological similarities and differences between synapses and innervation patterns in the auditory, vestibular, and lateral line systems can lead to variations in spontaneous activity.
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Affiliation(s)
- Sangmin Song
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA, 01002, USA
| | - Ji Ah Lee
- Department of Mathematics and Statistics, Smith College, Northampton, MA, 01063, USA
| | - Ilya Kiselev
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA, 01002, USA
| | - Varun Iyengar
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA, 01002, USA
| | - Josef G Trapani
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA, 01002, USA
| | - Nessy Tania
- Department of Mathematics and Statistics, Smith College, Northampton, MA, 01063, USA.
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19
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Kindt KS, Sheets L. Transmission Disrupted: Modeling Auditory Synaptopathy in Zebrafish. Front Cell Dev Biol 2018; 6:114. [PMID: 30258843 PMCID: PMC6143809 DOI: 10.3389/fcell.2018.00114] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/23/2018] [Indexed: 01/04/2023] Open
Abstract
Sensorineural hearing loss is the most common form of hearing loss in humans, and results from either dysfunction in hair cells, the sensory receptors of sound, or the neurons that innervate hair cells. A specific type of sensorineural hearing loss, referred to as auditory synaptopathy, occurs when hair cells are able to detect sound but fail to transmit sound stimuli at the hair-cell synapse. Auditory synaptopathy can originate from genetic alterations that specifically disrupt hair-cell synapse function. Additionally, environmental factors such as noise exposure can leave hair cells intact but result in loss of hair-cell synapses, and represent an acquired form of auditory synaptopathy. The zebrafish model has emerged as a valuable system for studies of hair-cell function, and specifically hair-cell synaptopathy. In this review, we describe the experimental tools that have been developed to study hair-cell synapses in zebrafish. We discuss how zebrafish genetics has helped identify and define the roles of hair-cell synaptic proteins crucial for hearing in humans, and highlight how studies in zebrafish have contributed to our understanding of hair-cell synapse formation and function. In addition, we also discuss work that has used noise exposure or pharmacological mimic of noise-induced excitotoxicity in zebrafish to define cellular mechanisms underlying noise-induced hair-cell damage and synapse loss. Lastly, we highlight how future studies in zebrafish could enhance our understanding of the pathological processes underlying synapse loss in both genetic and acquired auditory synaptopathy. This knowledge is critical in order to develop therapies that protect or repair auditory synaptic contacts.
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Affiliation(s)
- Katie S. Kindt
- Section on Sensory Cell Development and Function, NIDCD/National Institutes of Health, Bethesda, MD, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
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20
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Sun P, Zhang Y, Zhao F, Wu JP, Pun SH, Peng C, Du M, Vai MI, Liu D, Chen F. An Assay for Systematically Quantifying the Vestibulo-Ocular Reflex to Assess Vestibular Function in Zebrafish Larvae. Front Cell Neurosci 2018; 12:257. [PMID: 30186115 PMCID: PMC6113563 DOI: 10.3389/fncel.2018.00257] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 07/27/2018] [Indexed: 12/25/2022] Open
Abstract
Zebrafish (Danio rerio) larvae are widely used to study otic functions because they possess all five typical vertebrate senses including hearing and balance. Powerful genetic tools and the transparent body of the embryo and larva also make zebrafish a unique vertebrate model to study otic development. Due to its small larval size and moisture requirement during experiments, accurately acquiring the vestibulo-ocular reflex (VOR) of zebrafish larva is challenging. In this report, a new VOR testing device has been developed for quantifying linear VOR (LVOR) in zebrafish larva, evoked by the head motion about the earth horizontal axis. The system has a newly designed larva-shaped chamber, by which live fish can be steadily held without anesthesia, and the system is more compact and easier to use than its predecessors. To demonstrate the efficacy of the system, the LVORs in wild-type (WT), dlx3b and dlx4b morphant zebrafish larvae were measured and the results showed that LVOR amplitudes were consistent with the morphological changes of otoliths induced by morpholino oligonucleotides (MO). Our study represents an important advance to obtain VOR and predict the vestibular conditions in zebrafish.
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Affiliation(s)
- Peng Sun
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Taipa, China.,Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, China.,Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Yingla Zhang
- School of Life Sciences, Peking University, Beijing, China
| | - Feng Zhao
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jian-Ping Wu
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China.,SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Taipa, China
| | - Cheng Peng
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Meide Du
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Mang I Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Taipa, China.,Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, China
| | - Dong Liu
- School of Life Sciences, Peking University, Beijing, China.,Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
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21
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Chou SW, Chen Z, Zhu S, Davis RW, Hu J, Liu L, Fernando CA, Kindig K, Brown WC, Stepanyan R, McDermott BM. A molecular basis for water motion detection by the mechanosensory lateral line of zebrafish. Nat Commun 2017; 8:2234. [PMID: 29269857 PMCID: PMC5740173 DOI: 10.1038/s41467-017-01604-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 09/29/2017] [Indexed: 11/16/2022] Open
Abstract
Detection of water motion by the lateral line relies on mechanotransduction complexes at stereocilia tips. This sensory system is comprised of neuromasts, patches of hair cells with stereociliary bundles arranged with morphological mirror symmetry that are mechanically responsive to two opposing directions. Here, we find that transmembrane channel-like 2b (Tmc2b) is differentially required for mechanotransduction in the zebrafish lateral line. Despite similarities in neuromast hair cell morphology, three classes of these cells can be distinguished by their Tmc2b reliance. We map mechanosensitivity along the lateral line using imaging and electrophysiology to determine that a hair cell's Tmc2b dependence is governed by neuromast topological position and hair bundle orientation. Overall, water flow is detected by molecular machinery that can vary between hair cells of different neuromasts. Moreover, hair cells within the same neuromast can break morphologic symmetry of the sensory organ at the stereocilia tips.
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Affiliation(s)
- Shih-Wei Chou
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Zongwei Chen
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Shaoyuan Zhu
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Robin W Davis
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jiaqi Hu
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Li Liu
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Carol A Fernando
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Kayla Kindig
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - William C Brown
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Ruben Stepanyan
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Brian M McDermott
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA.
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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22
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Vargo JW, Walker SN, Gopal SR, Deshmukh AR, McDermott BM, Alagramam KN, Stepanyan R. Inhibition of Mitochondrial Division Attenuates Cisplatin-Induced Toxicity in the Neuromast Hair Cells. Front Cell Neurosci 2017; 11:393. [PMID: 29311828 PMCID: PMC5732985 DOI: 10.3389/fncel.2017.00393] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/28/2017] [Indexed: 12/31/2022] Open
Abstract
Cisplatin and other related platinum antineoplastic drugs are commonly used in the treatment of a variety of cancers in both adults and children but are often associated with severe side effects, including hearing loss. Cisplatin’s ototoxic effects are multifaceted, culminating in irreversible damage to the mechanosensory hair cells in the inner ear. Platinum drugs act on cancerous cells by forming nuclear DNA adducts, which may initiate signaling leading to cell cycle arrest or apoptosis. Moreover, it was reported that cisplatin may induce mitochondrial DNA damage in non-cancerous cells. Therefore, protecting mitochondria may alleviate cisplatin-induced insult to non-proliferating cells. Thus, it is important to identify agents that shield the mitochondria from cisplatin-induced insult without compromising the anti-tumor actions of the platinum-based drugs. In this study we tested the protective properties of mitochondrial division inhibitor, mdivi-1, a derivative of quinazolinone and a regulator of mitochondrial fission. Interestingly, it has been reported that mdivi-1 increases the apoptosis of cells that are resistant to cisplatin. The ability of mdivi-1 to protect hair cells against cisplatin-induced toxicity was evaluated in a fish model. Wild-type (Tübingen strain), cdh23 mutant, and transgenic pvalb3b::GFP zebrafish stably expressing GFP in the hair cells were used in this study. Larvae at 5–6 days post fertilization were placed in varying concentrations of cisplatin (50–200 μM) and/or mdivi-1 (1–10 μM) for 16 h. To evaluate hair cell’s viability the number of hair bundles per neuromast were counted. To assess hair cell function, we used the FM1-43 uptake assay and recordings of neuromast microphonic potentials. The results showed that mdivi-1 protected hair cells of lateral line neuromasts when they were challenged by 50 μM of cisplatin: viability of hair cells increased almost twice from 19% ± 1.8% to 36% ± 2.0% (p < 0.001). No protection was observed when higher concentrations of cisplatin were used. In addition, our data were in accord with previously reported results that functional mechanotransduction strongly potentiates cisplatin-induced hair cell toxicity. Together, our results suggest that mitochondrial protection may prevent cisplatin-induced damage to hair cells.
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Affiliation(s)
- Jonathon W Vargo
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Steven N Walker
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Suhasini R Gopal
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Aditi R Deshmukh
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Brian M McDermott
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.,Department of Biology, Case Western Reserve University, Cleveland, OH, United States.,Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States.,Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Kumar N Alagramam
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.,Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States.,Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Ruben Stepanyan
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.,Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
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23
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Abstract
Our ears are remarkable sensory organs, providing the important senses of balance and hearing. The complex structure of the inner ear, or 'labyrinth', along with the assorted neuroepithelia, have evolved to detect head movements and sounds with impressive sensitivity. The rub is that the inner ear is highly vulnerable to genetic lesions and environmental insults. According to National Institute of Health estimates, hearing loss is one of the most commonly inherited or acquired sensorineural diseases. To understand the causes of deafness and balance disorders, it is imperative to understand the underlying biology of the inner ear, especially the inner workings of the sensory receptors. These receptors, which are termed hair cells, are particularly susceptible to genetic mutations - more than two dozen genes are associated with defects in this cell type in humans. Over the past decade, a substantial amount of progress has been made in working out the molecular basis of hair-cell function using vertebrate animal models. Given the transparency of the inner ear and the genetic tools that are available, zebrafish have become an increasingly popular animal model for the study of deafness and vestibular dysfunction. Mutagenesis screens for larval defects in hearing and balance have been fruitful in finding key components, many of which have been implicated in human deafness. This review will focus on the genes that are required for hair-cell function in zebrafish, with a particular emphasis on mechanotransduction. In addition, the generation of new tools available for the characterization of zebrafish hair-cell mutants will be discussed.
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Affiliation(s)
- Teresa Nicolson
- Oregon Hearing Research Center and the Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, Tel: 503-494-3693,
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24
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Brown DJ, Pastras CJ, Curthoys IS. Electrophysiological Measurements of Peripheral Vestibular Function-A Review of Electrovestibulography. Front Syst Neurosci 2017; 11:34. [PMID: 28620284 PMCID: PMC5450778 DOI: 10.3389/fnsys.2017.00034] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/05/2017] [Indexed: 12/19/2022] Open
Abstract
Electrocochleography (EcochG), incorporating the Cochlear Microphonic (CM), the Summating Potential (SP), and the cochlear Compound Action Potential (CAP), has been used to study cochlear function in humans and experimental animals since the 1930s, providing a simple objective tool to assess both hair cell (HC) and nerve sensitivity. The vestibular equivalent of ECochG, termed here Electrovestibulography (EVestG), incorporates responses of the vestibular HCs and nerve. Few research groups have utilized EVestG to study vestibular function. Arguably, this is because stimulating the cochlea in isolation with sound is a trivial matter, whereas stimulating the vestibular system in isolation requires significantly more technical effort. That is, the vestibular system is sensitive to both high-level sound and bone-conducted vibrations, but so is the cochlea, and gross electrical responses of the inner ear to such stimuli can be difficult to interpret. Fortunately, several simple techniques can be employed to isolate vestibular electrical responses. Here, we review the literature underpinning gross vestibular nerve and HC responses, and we discuss the nomenclature used in this field. We also discuss techniques for recording EVestG in experimental animals and humans and highlight how EVestG is furthering our understanding of the vestibular system.
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Affiliation(s)
- Daniel J Brown
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Christopher J Pastras
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Ian S Curthoys
- Department of Psychology, The University of SydneySydney, NSW, Australia
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Enlargement of Ribbons in Zebrafish Hair Cells Increases Calcium Currents But Disrupts Afferent Spontaneous Activity and Timing of Stimulus Onset. J Neurosci 2017; 37:6299-6313. [PMID: 28546313 PMCID: PMC5490065 DOI: 10.1523/jneurosci.2878-16.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 12/26/2022] Open
Abstract
In sensory hair cells of auditory and vestibular organs, the ribbon synapse is required for the precise encoding of a wide range of complex stimuli. Hair cells have a unique presynaptic structure, the synaptic ribbon, which organizes both synaptic vesicles and calcium channels at the active zone. Previous work has shown that hair-cell ribbon size is correlated with differences in postsynaptic activity. However, additional variability in postsynapse size presents a challenge to determining the specific role of ribbon size in sensory encoding. To selectively assess the impact of ribbon size on synapse function, we examined hair cells in transgenic zebrafish that have enlarged ribbons, without postsynaptic alterations. Morphologically, we found that enlarged ribbons had more associated vesicles and reduced presynaptic calcium-channel clustering. Functionally, hair cells with enlarged ribbons had larger global and ribbon-localized calcium currents. Afferent neuron recordings revealed that hair cells with enlarged ribbons resulted in reduced spontaneous spike rates. Additionally, despite larger presynaptic calcium signals, we observed fewer evoked spikes with longer latencies from stimulus onset. Together, our work indicates that hair-cell ribbon size influences the spontaneous spiking and the precise encoding of stimulus onset in afferent neurons. SIGNIFICANCE STATEMENT Numerous studies support that hair-cell ribbon size corresponds with functional sensitivity differences in afferent neurons and, in the case of inner hair cells of the cochlea, vulnerability to damage from noise trauma. Yet it is unclear whether ribbon size directly influences sensory encoding. Our study reveals that ribbon enlargement results in increased ribbon-localized calcium signals, yet reduces afferent spontaneous activity and disrupts the timing of stimulus onset, a distinct aspect of auditory and vestibular encoding. These observations suggest that varying ribbon size alone can influence sensory encoding, and give further insight into how hair cells transduce signals that cover a wide dynamic range of stimuli.
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Ca 2+-Permeable AMPARs Mediate Glutamatergic Transmission and Excitotoxic Damage at the Hair Cell Ribbon Synapse. J Neurosci 2017; 37:6162-6175. [PMID: 28539424 DOI: 10.1523/jneurosci.3644-16.2017] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 01/21/2023] Open
Abstract
We report functional and structural evidence for GluA2-lacking Ca2+-permeable AMPARs (CP-AMPARs) at the mature hair cell ribbon synapse. By using the methodological advantages of three species (of either sex), we demonstrate that CP-AMPARs are present at the hair cell synapse in an evolutionarily conserved manner. Via a combination of in vivo electrophysiological and Ca2+ imaging approaches in the larval zebrafish, we show that hair cell stimulation leads to robust Ca2+ influx into afferent terminals. Prolonged application of AMPA caused loss of afferent terminal responsiveness, whereas blocking CP-AMPARs protects terminals from excitotoxic swelling. Immunohistochemical analysis of AMPAR subunits in mature rat cochlea show regions within synapses lacking the GluA2 subunit. Paired recordings from adult bullfrog auditory synapses demonstrate that CP-AMPARs mediate a major component of glutamatergic transmission. Together, our results support the importance of CP-AMPARs in mediating transmission at the hair cell ribbon synapse. Further, excess Ca2+ entry via CP-AMPARs may underlie afferent terminal damage following excitotoxic challenge, suggesting that limiting Ca2+ levels in the afferent terminal may protect against cochlear synaptopathy associated with hearing loss.SIGNIFICANCE STATEMENT A single incidence of noise overexposure causes damage at the hair cell synapse that later leads to neurodegeneration and exacerbates age-related hearing loss. A first step toward understanding cochlear neurodegeneration is to identify the cause of initial excitotoxic damage to the postsynaptic neuron. Using a combination of immunohistochemical, electrophysiological, and Ca2+ imaging approaches in evolutionarily divergent species, we demonstrate that Ca2+-permeable AMPARs (CP-AMPARs) mediate glutamatergic transmission at the adult auditory hair cell synapse. Overexcitation of the terminal causes Ca2+ accumulation and swelling that can be prevented by blocking CP-AMPARs. We demonstrate that CP-AMPARs mediate transmission at this first-order sensory synapse and that limiting Ca2+ accumulation in the terminal may protect against hearing loss.
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27
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Behavioral methods for the functional assessment of hair cells in zebrafish. Front Med 2017; 11:178-190. [PMID: 28349300 DOI: 10.1007/s11684-017-0507-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/24/2016] [Indexed: 10/19/2022]
Abstract
Zebrafish is an emerging animal model for studies on auditory system. This model presents high comparability with humans, good accessibility to the hearing organ, and high throughput capacity. To better utilize this animal model, methodologies need to be used to quantify the hearing function of the zebrafish. Zebrafish displays a series of innate and robust behavior related to its auditory function. Here, we reviewed the advantage of using zebrafish in auditory research and then introduced three behavioral tests, as follows: the startle response, the vestibular-ocular reflex, and rheotaxis. These tests are discussed in terms of their physiological characteristics, up-to-date technical development, and apparatus description. Test limitation and areas to improve are also introduced. Finally, we revealed the feasibility of these applications in zebrafish behavioral assessment and their potential in the high-throughput screening on hearing-related genes and drugs.
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28
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Excessive activation of ionotropic glutamate receptors induces apoptotic hair-cell death independent of afferent and efferent innervation. Sci Rep 2017; 7:41102. [PMID: 28112265 PMCID: PMC5255535 DOI: 10.1038/srep41102] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/15/2016] [Indexed: 02/07/2023] Open
Abstract
Accumulation of excess glutamate plays a central role in eliciting the pathological events that follow intensely loud noise exposures and ischemia-reperfusion injury. Glutamate excitotoxicity has been characterized in cochlear nerve terminals, but much less is known about whether excess glutamate signaling also contributes to pathological changes in sensory hair cells. I therefore examined whether glutamate excitotoxicity damages hair cells in zebrafish larvae exposed to drugs that mimic excitotoxic trauma. Exposure to ionotropic glutamate receptor (iGluR) agonists, kainic acid (KA) or N-methyl-D-aspartate (NMDA), contributed to significant, progressive hair cell loss in zebrafish lateral-line organs. To examine whether hair-cell loss was a secondary effect of excitotoxic damage to innervating neurons, I exposed neurog1a morphants-fish whose hair-cell organs are devoid of afferent and efferent innervation-to KA or NMDA. Significant, dose-dependent hair-cell loss occurred in neurog1a morphants exposed to either agonist, and the loss was comparable to wild-type siblings. A survey of iGluR gene expression revealed AMPA-, Kainate-, and NMDA-type subunits are expressed in zebrafish hair cells. Finally, hair cells exposed to KA or NMDA appear to undergo apoptotic cell death. Cumulatively, these data reveal that excess glutamate signaling through iGluRs induces hair-cell death independent of damage to postsynaptic terminals.
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29
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Zamora LY, Miguel KC, Lu Z. The alcohol-sensitive period during early octavolateral organ development in zebrafish (Danio rerio). J Neurosci Res 2017; 95:1194-1203. [PMID: 28105691 DOI: 10.1002/jnr.24017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 11/30/2016] [Accepted: 12/19/2016] [Indexed: 12/15/2022]
Abstract
Fetal alcohol exposure can cause Fetal Alcohol Spectrum Disorders (FASD), completely preventable developmental disabilities characterized by permanent birth defects. However, specific gestational timing when developing organs are most sensitive to alcohol exposure is unclear. In this study, we examined the temporal effects of embryonic alcohol exposure on octavolateral organs in zebrafish (Danio rerio), including inner ears and lateral line neuromasts that function in hearing, balance, and hydrodynamic detection, respectively. To determine an alcohol-sensitive period in the first 24 hours post fertilization (hpf), Et(krt4:EGFP)sqet4 zebrafish that express green fluorescent protein in sensory hair cells were treated in 2% alcohol for 2, 3, and 5-hours. Octavolateral organs of control and alcohol-exposed larvae were examined at 3, 5, and 7 days post fertilization (dpf). Using confocal and light microscopy, we found that alcohol-exposed larvae had significantly smaller otic vesicles and saccular otoliths than control larvae at 3 dpf. Only alcohol-exposed larvae from 12-17 hpf had smaller otic vesicles at 5 dpf, smaller saccular otoliths at 7 dpf and fewer saccular hair cells, neuromasts and hair cells per neuromast at 3 dpf. In addition, auditory function was assessed by microphonic potential recordings from inner ear hair cells in response to 200-Hz stimulation. Hearing sensitivity was reduced for alcohol-exposed larvae from 7-12 and 12-17 hpf. Our results show that 12-17 hpf is an alcohol-sensitive time window when morphology and function of zebrafish octavolateral organs are most vulnerable to alcohol exposure. This study implies that embryonic alcohol exposure timing during early development can influence severity of hearing deficits. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Lilliann Y Zamora
- University of Miami, Department of Biology, Coral Gables, Florida.,University of Miami, Neuroscience Program, Miami, Florida
| | - Kayla C Miguel
- University of Miami, Neuroscience Program, Miami, Florida
| | - Zhongmin Lu
- University of Miami, Department of Biology, Coral Gables, Florida.,University of Miami, Neuroscience Program, Miami, Florida.,International Center for Marine Studies, Shanghai Ocean University, Shanghai, China
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30
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Troconis EL, Ordoobadi AJ, Sommers TF, Aziz‐Bose R, Carter AR, Trapani JG. Intensity-dependent timing and precision of startle response latency in larval zebrafish. J Physiol 2017; 595:265-282. [PMID: 27228964 PMCID: PMC5199724 DOI: 10.1113/jp272466] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/17/2016] [Indexed: 01/12/2023] Open
Abstract
KEY POINTS Using high-speed videos time-locked with whole-animal electrical recordings, simultaneous measurement of behavioural kinematics and field potential parameters of C-start startle responses allowed for discrimination between short-latency and long-latency C-starts (SLCs vs. LLCs) in larval zebrafish. Apart from their latencies, SLC kinematics and SLC field potential parameters were intensity independent. Increasing stimulus intensity increased the probability of evoking an SLC and decreased mean SLC latencies while increasing their precision; subtraction of field potential latencies from SLC latencies revealed a fixed time delay between the two measurements that was intensity independent. The latency and the precision in the latency of the SLC field potentials were linearly correlated to the latencies and precision of the first evoked action potentials (spikes) in hair-cell afferent neurons of the lateral line. Together, these findings indicate that first spike latency (FSL) is a fast encoding mechanism that can serve to precisely initiate startle responses when speed is critical for survival. ABSTRACT Vertebrates rely on fast sensory encoding for rapid and precise initiation of startle responses. In afferent sensory neurons, trains of action potentials (spikes) encode stimulus intensity within the onset time of the first evoked spike (first spike latency; FSL) and the number of evoked spikes. For speed of initiation of startle responses, FSL would be the more advantageous mechanism to encode the intensity of a threat. However, the intensity dependence of FSL and spike number and whether either determines the precision of startle response initiation is not known. Here, we examined short-latency startle responses (SLCs) in larval zebrafish and tested the hypothesis that first spike latencies and their precision (jitter) determine the onset time and precision of SLCs. We evoked startle responses via activation of Channelrhodopsin (ChR2) expressed in ear and lateral line hair cells and acquired high-speed videos of head-fixed larvae while simultaneously recording underlying field potentials. This method allowed for discrimination between primary SLCs and less frequent, long-latency startle responses (LLCs). Quantification of SLC kinematics and field potential parameters revealed that, apart from their latencies, they were intensity independent. We found that increasing stimulus intensity decreased SLC latencies while increasing their precision, which was significantly correlated with corresponding changes in field potential latencies and their precision. Single afferent neuron recordings from the lateral line revealed a similar intensity-dependent decrease in first spike latencies and their jitter, which could account for the intensity-dependent changes in timing and precision of startle response latencies.
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Affiliation(s)
| | | | | | | | - Ashley R. Carter
- Department of Physics and AstronomyAmherst CollegeAmherstMA01002USA
| | - Josef G. Trapani
- Department of BiologyAmherst CollegeAmherstMA01002USA
- Neuroscience ProgramAmherst CollegeAmherstMA01002USA
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31
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Olt J, Allen CE, Marcotti W. In vivo physiological recording from the lateral line of juvenile zebrafish. J Physiol 2016; 594:5427-38. [PMID: 27161862 PMCID: PMC5043028 DOI: 10.1113/jp271794] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 05/04/2016] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS Zebrafish provide a unique opportunity to investigate in vivo sensory transduction in mature hair cells. We have developed a method for studying the biophysical properties of mature hair cells from the lateral line of juvenile zebrafish. The method involves application of the anaesthetic benzocaine and intubation to maintain ventilation and oxygenation through the gills. The same approach could be used for in vivo functional studies in other sensory and non-sensory systems from juvenile and adult zebrafish. ABSTRACT Hair cells are sensory receptors responsible for transducing auditory and vestibular information into electrical signals, which are then transmitted with remarkable precision to afferent neurons. The zebrafish lateral line is emerging as an excellent in vivo model for genetic and physiological analysis of hair cells and neurons. However, research has been limited to larval stages because zebrafish become protected from the time of independent feeding under European law (from 5.2 days post-fertilization (dpf) at 28.5°C). In larval zebrafish, the functional properties of most of hair cells, as well as those of other excitable cells, are still immature. We have developed an experimental protocol to record electrophysiological properties from hair cells of the lateral line in juvenile zebrafish. We found that the anaesthetic benzocaine at 50 mg l(-1) was an effective and safe anaesthetic to use on juvenile zebrafish. Concentrations up to 300 mg l(-1) did not affect the electrical properties or synaptic vesicle release of juvenile hair cells, unlike the commonly used anaesthetic MS-222, which reduces the size of basolateral membrane K(+) currents. Additionally, we implemented a method to maintain gill movement, and as such respiration and blood oxygenation, via the intubation of > 21 dpf zebrafish. The combination of benzocaine and intubation provides an experimental platform to investigate the physiology of mature hair cells from live zebrafish. More generally, this method would allow functional studies involving live imaging and electrophysiology from juvenile and adult zebrafish.
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Affiliation(s)
- Jennifer Olt
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Claire E Allen
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK.
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32
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Abstract
UNLABELLED The senses of hearing and balance are subject to modulation by efferent signaling, including the release of dopamine (DA). How DA influences the activity of the auditory and vestibular systems and its site of action are not well understood. Here we show that dopaminergic efferent fibers innervate the acousticolateralis epithelium of the zebrafish during development but do not directly form synapses with hair cells. However, a member of the D1-like receptor family, D1b, tightly localizes to ribbon synapses in inner ear and lateral-line hair cells. To assess modulation of hair-cell activity, we reversibly activated or inhibited D1-like receptors (D1Rs) in lateral-line hair cells. In extracellular recordings from hair cells, we observed that D1R agonist SKF-38393 increased microphonic potentials, whereas D1R antagonist SCH-23390 decreased microphonic potentials. Using ratiometric calcium imaging, we found that increased D1R activity resulted in larger calcium transients in hair cells. The increase of intracellular calcium requires Cav1.3a channels, as a Cav1 calcium channel antagonist, isradipine, blocked the increase in calcium transients elicited by the agonist SKF-38393. Collectively, our results suggest that DA is released in a paracrine fashion and acts at ribbon synapses, likely enhancing the activity of presynaptic Cav1.3a channels and thereby increasing neurotransmission. SIGNIFICANCE STATEMENT The neurotransmitter dopamine acts in a paracrine fashion (diffusion over a short distance) in several tissues and bodily organs, influencing and regulating their activity. The cellular target and mechanism of the action of dopamine in mechanosensory organs, such as the inner ear and lateral-line organ, is not clearly understood. Here we demonstrate that dopamine receptors are present in sensory hair cells at synaptic sites that are required for signaling to the brain. When nearby neurons release dopamine, activation of the dopamine receptors increases the activity of these mechanosensitive cells. The mechanism of dopamine activation requires voltage-gated calcium channels that are also present at hair-cell synapses.
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33
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Kruger M, Boney R, Ordoobadi AJ, Sommers TF, Trapani JG, Coffin AB. Natural Bizbenzoquinoline Derivatives Protect Zebrafish Lateral Line Sensory Hair Cells from Aminoglycoside Toxicity. Front Cell Neurosci 2016; 10:83. [PMID: 27065807 PMCID: PMC4811916 DOI: 10.3389/fncel.2016.00083] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 03/16/2016] [Indexed: 01/24/2023] Open
Abstract
Moderate to severe hearing loss affects 360 million people worldwide and most often results from damage to sensory hair cells. Hair cell damage can result from aging, genetic mutations, excess noise exposure, and certain medications including aminoglycoside antibiotics. Aminoglycosides are effective at treating infections associated with cystic fibrosis and other life-threatening conditions such as sepsis, but cause hearing loss in 20–30% of patients. It is therefore imperative to develop new therapies to combat hearing loss and allow safe use of these potent antibiotics. We approach this drug discovery question using the larval zebrafish lateral line because zebrafish hair cells are structurally and functionally similar to mammalian inner ear hair cells and respond similarly to toxins. We screened a library of 502 natural compounds in order to identify novel hair cell protectants. Our screen identified four bisbenzylisoquinoline derivatives: berbamine, E6 berbamine, hernandezine, and isotetrandrine, each of which robustly protected hair cells from aminoglycoside-induced damage. Using fluorescence microscopy and electrophysiology, we demonstrated that the natural compounds confer protection by reducing antibiotic uptake into hair cells and showed that hair cells remain functional during and after incubation in E6 berbamine. We also determined that these natural compounds do not reduce antibiotic efficacy. Together, these natural compounds represent a novel source of possible otoprotective drugs that may offer therapeutic options for patients receiving aminoglycoside treatment.
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Affiliation(s)
- Matthew Kruger
- School of Biological Sciences, Washington State University Vancouver, WA, USA
| | - Robert Boney
- College of Arts and Sciences, Washington State University Vancouver, WA, USA
| | | | - Thomas F Sommers
- Department of Biology and Neuroscience Program, Amherst College Amherst, MA, USA
| | - Josef G Trapani
- Department of Biology and Neuroscience Program, Amherst College Amherst, MA, USA
| | - Allison B Coffin
- School of Biological Sciences, Washington State UniversityVancouver, WA, USA; College of Arts and Sciences, Washington State UniversityVancouver, WA, USA; Department of Integrative Physiology and Neuroscience, Washington State UniversityVancouver, WA, USA
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Olt J, Ordoobadi AJ, Marcotti W, Trapani JG. Physiological recordings from the zebrafish lateral line. Methods Cell Biol 2016; 133:253-79. [PMID: 27263416 DOI: 10.1016/bs.mcb.2016.02.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During sensory transduction, external physical stimuli are translated into an internal biological signal. In vertebrates, hair cells are specialized mechanosensory receptors that transduce sound, gravitational forces, and head movements into electrical signals that are transmitted with remarkable precision and efficiency to afferent neurons. Hair cells have a conserved structure between species and are also found in the lateral line system of fish, including zebrafish, which serve as an ideal animal model to study sensory transmission in vivo. In this chapter, we describe the methods required to investigate the biophysical properties underlying mechanosensation in the lateral line of the zebrafish in vivo from microphonic potentials and single hair cell patch-clamp recordings to single afferent neuron recordings. These techniques provide real-time measurements of hair-cell transduction and transmission following delivery of controlled and defined stimuli and their combined use on the intact zebrafish provides a powerful platform to investigate sensory encoding in vivo.
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Affiliation(s)
- J Olt
- University of Sheffield, Sheffield, United Kingdom
| | | | - W Marcotti
- University of Sheffield, Sheffield, United Kingdom
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35
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Zhang QX, He XJ, Wong HC, Kindt KS. Functional calcium imaging in zebrafish lateral-line hair cells. Methods Cell Biol 2016; 133:229-52. [PMID: 27263415 DOI: 10.1016/bs.mcb.2015.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sensory hair-cell development, function, and regeneration are fundamental processes that are challenging to study in mammalian systems. Zebrafish are an excellent alternative model to study hair cells because they have an external auxiliary organ called the lateral line. The hair cells of the lateral line are easily accessible, which makes them suitable for live, function-based fluorescence imaging. In this chapter, we describe methods to perform functional calcium imaging in zebrafish lateral-line hair cells. We compare genetically encoded calcium indicators that have been used previously to measure calcium in lateral-line hair cells. We also outline equipment required for calcium imaging and compare different imaging systems. Lastly, we discuss how to set up optimal imaging parameters and how to process and visualize calcium signals. Overall, using these methods, in vivo calcium imaging is a powerful tool to examine sensory hair-cell function in an intact organism.
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Affiliation(s)
- Q X Zhang
- National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - X J He
- National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - H C Wong
- National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - K S Kindt
- National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
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Chemical Ototoxicity of the Fish Inner Ear and Lateral Line. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:419-37. [PMID: 26515324 DOI: 10.1007/978-3-319-21059-9_18] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hair cell-driven mechanosensory systems are crucial for successful execution of a number of behaviors in fishes, and have emerged as good models for exploring questions relevant to human hearing. This review focuses on ototoxic effects in the inner ear and lateral line system of fishes. We specifically examine studies where chemical ototoxins such as aminoglycoside antibiotics have been employed as tools to disable the lateral line. Lateral line ablation results in alterations to feeding behavior and orientation to water current in a variety of species. However, neither behavior is abolished in the presence of additional sensory cues, supporting the hypothesis that many fish behaviors are driven by multisensory integration. Within biomedical research, the larval zebrafish lateral line has become an important model system for understanding signaling mechanisms that contribute to hair cell death and for developing novel pharmacological therapies that protect hair cells from ototoxic damage. Furthermore, given that fishes robustly regenerate damaged hair cells, ototoxin studies in fishes have broadened our understanding of the molecular and genetic events in an innately regenerative system, offering potential targets for mammalian hair cell regeneration. Collectively, studies of fish mechanosensory systems have yielded insight into fish behavior and in mechanisms of hair cell death, protection, and regeneration.
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Zebrafish Models for the Mechanosensory Hair Cell Dysfunction in Usher Syndrome 3 Reveal That Clarin-1 Is an Essential Hair Bundle Protein. J Neurosci 2015; 35:10188-201. [PMID: 26180195 DOI: 10.1523/jneurosci.1096-15.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Usher syndrome type III (USH3) is characterized by progressive loss of hearing and vision, and varying degrees of vestibular dysfunction. It is caused by mutations that affect the human clarin-1 protein (hCLRN1), a member of the tetraspanin protein family. The missense mutation CLRN1(N48K), which affects a conserved N-glycosylation site in hCLRN1, is a common causative USH3 mutation among Ashkenazi Jews. The affected individuals hear at birth but lose that function over time. Here, we developed an animal model system using zebrafish transgenesis and gene targeting to provide an explanation for this phenotype. Immunolabeling demonstrated that Clrn1 localized to the hair cell bundles (hair bundles). The clrn1 mutants generated by zinc finger nucleases displayed aberrant hair bundle morphology with diminished function. Two transgenic zebrafish that express either hCLRN1 or hCLRN1(N48K) in hair cells were produced to examine the subcellular localization patterns of wild-type and mutant human proteins. hCLRN1 localized to the hair bundles similarly to zebrafish Clrn1; in contrast, hCLRN1(N48K) largely mislocalized to the cell body with a small amount reaching the hair bundle. We propose that this small amount of hCLRN1(N48K) in the hair bundle provides clarin-1-mediated function during the early stages of life; however, the presence of hCLRN1(N48K) in the hair bundle diminishes over time because of intracellular degradation of the mutant protein, leading to progressive loss of hair bundle integrity and hair cell function. These findings and genetic tools provide an understanding and path forward to identify therapies to mitigate hearing loss linked to the CLRN1 mutation. SIGNIFICANCE STATEMENT Mutations in the clarin-1 gene affect eye and ear function in humans. Individuals with the CLRN1(N48K) mutation are born able to hear but lose that function over time. Here, we develop an animal model system using zebrafish transgenesis and gene targeting to provide an explanation for this phenotype. This approach illuminates the role of clarin-1 and the molecular mechanism linked to the CLRN1(N48K) mutation in sensory hair cells of the inner ear. Additionally, the investigation provided an in vivo model to guide future drug discovery to rescue the hCLRN1(N48K) in hair cells.
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38
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Swinburne IA, Mosaliganti KR, Green AA, Megason SG. Improved Long-Term Imaging of Embryos with Genetically Encoded α-Bungarotoxin. PLoS One 2015; 10:e0134005. [PMID: 26244658 PMCID: PMC4526548 DOI: 10.1371/journal.pone.0134005] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 07/04/2015] [Indexed: 11/30/2022] Open
Abstract
Rapid advances in microscopy and genetic labeling strategies have created new opportunities for time-lapse imaging of embryonic development. However, methods for immobilizing embryos for long periods while maintaining normal development have changed little. In zebrafish, current immobilization techniques rely on the anesthetic tricaine. Unfortunately, prolonged tricaine treatment at concentrations high enough to immobilize the embryo produces undesirable side effects on development. We evaluate three alternative immobilization strategies: combinatorial soaking in tricaine and isoeugenol, injection of α-bungarotoxin protein, and injection of α-bungarotoxin mRNA. We find evidence for co-operation between tricaine and isoeugenol to give immobility with improved health. However, even in combination these anesthetics negatively affect long-term development. α-bungarotoxin is a small protein from snake venom that irreversibly binds and inactivates acetylcholine receptors. We find that α-bungarotoxin either as purified protein from snakes or endogenously expressed in zebrafish from a codon-optimized synthetic gene can immobilize embryos for extended periods of time with few health effects or developmental delays. Using α-bungarotoxin mRNA injection we obtain complete movies of zebrafish embryogenesis from the 1-cell stage to 3 days post fertilization, with normal health and no twitching. These results demonstrate that endogenously expressed α-bungarotoxin provides unprecedented immobility and health for time-lapse microscopy.
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Affiliation(s)
- Ian A. Swinburne
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kishore R. Mosaliganti
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Amelia A. Green
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sean G. Megason
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Nicolson T. Ribbon synapses in zebrafish hair cells. Hear Res 2015; 330:170-7. [PMID: 25916266 DOI: 10.1016/j.heares.2015.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/20/2015] [Accepted: 04/13/2015] [Indexed: 12/31/2022]
Abstract
The basic architecture and functionality of ribbon synapses of mechanosensitive hair cells are well conserved among vertebrates. Forward and reverse genetic methods in zebrafish (Danio rerio) have identified components that are critical for the development and function of ribbon synapses. This review will focus on the findings of these genetic approaches, and discuss some emergent concepts on the role of the ribbon body and calcium in synapse development, and how perturbations in synaptic vesicles lead to a loss of temporal fidelity at ribbon synapses. This article is part of a Special Issue entitled <Auditory Synaptology>.
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Affiliation(s)
- T Nicolson
- Oregon Hearing Research Center and Vollum Institute, 3181 SW Sam Jackson Park Road, Oregon Health & Science University, Portland, OR 97239, USA.
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Pujol-Martí J, Faucherre A, Aziz-Bose R, Asgharsharghi A, Colombelli J, Trapani JG, López-Schier H. Converging axons collectively initiate and maintain synaptic selectivity in a constantly remodeling sensory organ. Curr Biol 2014; 24:2968-74. [PMID: 25484295 DOI: 10.1016/j.cub.2014.11.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/19/2014] [Accepted: 11/05/2014] [Indexed: 10/24/2022]
Abstract
Sensory receptors are the functional link between the environment and the brain. The repair of sensory organs enables animals to continuously detect environmental stimuli. However, receptor cell turnover can affect sensory acuity by changing neural connectivity patterns. In zebrafish, two to four postsynaptic lateralis afferent axons converge into individual peripheral mechanosensory organs called neuromasts, which contain hair cell receptors of opposing planar polarity. Yet, each axon exclusively synapses with hair cells of identical polarity during development and regeneration to transmit unidirectional mechanical signals to the brain. The mechanism that governs this exceptionally accurate and resilient synaptic selectivity remains unknown. We show here that converging axons are mutually dependent for polarity-selective connectivity. If rendered solitary, these axons establish simultaneous functional synapses with hair cells of opposing polarities to transmit bidirectional mechanical signals. Remarkably, nonselectivity by solitary axons can be corrected upon the reintroduction of additional axons. Collectively, our results suggest that lateralis synaptogenesis is intrinsically nonselective and that interaxonal interactions continuously rectify mismatched synapses. This dynamic organization of neural connectivity may represent a general solution to maintain coherent synaptic transmission from sensory organs undergoing frequent variations in the number and spatial distribution of receptor cells.
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Affiliation(s)
- Jesús Pujol-Martí
- Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany
| | - Adèle Faucherre
- Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Razina Aziz-Bose
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA 01002-5000, USA
| | - Amir Asgharsharghi
- Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany
| | - Julien Colombelli
- Institute for Research in Biomedicine, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Josef G Trapani
- Department of Biology and Neuroscience Program, Amherst College, Amherst, MA 01002-5000, USA
| | - Hernán López-Schier
- Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany; Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain.
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Monesson-Olson BD, Browning-Kamins J, Aziz-Bose R, Kreines F, Trapani JG. Optical stimulation of zebrafish hair cells expressing channelrhodopsin-2. PLoS One 2014; 9:e96641. [PMID: 24791934 PMCID: PMC4008597 DOI: 10.1371/journal.pone.0096641] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/09/2014] [Indexed: 11/19/2022] Open
Abstract
Vertebrate hair cells are responsible for the high fidelity encoding of mechanical stimuli into trains of action potentials (spikes) in afferent neurons. Here, we generated a transgenic zebrafish line expressing Channelrhodopsin-2 (ChR2) under the control of the hair-cell specific myo6b promoter, in order to examine the role of the mechanoelectrical transduction (MET) channel in sensory encoding in afferent neurons. We performed in vivo recordings from afferent neurons of the zebrafish lateral line while activating hair cells with either mechanical stimuli from a waterjet or optical stimuli from flashes of ∼470-nm light. Comparison of the patterns of encoded spikes during 100-ms stimuli revealed no difference in mean first spike latency between the two modes of activation. However, there was a significant increase in the variability of first spike latency during optical stimulation as well as an increase in the mean number of spikes per stimulus. Next, we compared encoding of spikes during hair-cell stimulation at 10, 20, and 40-Hz. Consistent with the increased variability of first spike latency, we saw a significant decrease in the vector strength of phase-locked spiking during optical stimulation. These in vivo results support a physiological role for the MET channel in the high fidelity of first spike latency seen during encoding of mechanical sensory stimuli. Finally, we examined whether remote activation of hair cells via ChR2 activation was sufficient to elicit escape responses in free-swimming larvae. In transgenic larvae, 100-ms flashes of ∼470-nm light resulted in escape responses that occurred concomitantly with field recordings indicating Mauthner cell activity. Altogether, the myo6b:ChR2 transgenic line provides a platform to investigate hair-cell function and sensory encoding, hair-cell sensory input to the Mauthner cell, and the ability to remotely evoke behavior in free-swimming zebrafish.
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Affiliation(s)
| | - Jenna Browning-Kamins
- Neuroscience Program, Amherst College, Amherst, Massachusetts, United States of America
| | - Razina Aziz-Bose
- Neuroscience Program, Amherst College, Amherst, Massachusetts, United States of America
| | - Fabiana Kreines
- Neuroscience Program, Amherst College, Amherst, Massachusetts, United States of America
| | - Josef G. Trapani
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
- Neuroscience Program, Amherst College, Amherst, Massachusetts, United States of America
- * E-mail:
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Olt J, Johnson SL, Marcotti W. In vivo and in vitro biophysical properties of hair cells from the lateral line and inner ear of developing and adult zebrafish. J Physiol 2014; 592:2041-58. [PMID: 24566541 PMCID: PMC4027864 DOI: 10.1113/jphysiol.2013.265108] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Hair cells detect and process sound and movement information, and transmit this with remarkable precision and efficiency to afferent neurons via specialized ribbon synapses. The zebrafish is emerging as a powerful model for genetic analysis of hair cell development and function both in vitro and in vivo. However, the full exploitation of the zebrafish is currently limited by the difficulty in obtaining systematic electrophysiological recordings from hair cells under physiological recording conditions. Thus, the biophysical properties of developing and adult zebrafish hair cells are largely unknown. We investigated potassium and calcium currents, voltage responses and synaptic activity in hair cells from the lateral line and inner ear in vivo and using near-physiological in vitro recordings. We found that the basolateral current profile of hair cells from the lateral line becomes more segregated with age, and that cells positioned in the centre of the neuromast show more mature characteristics and those towards the edge retain a more immature phenotype. The proportion of mature-like hair cells within a given neuromast increased with zebrafish development. Hair cells from the inner ear showed a developmental change in current profile between the juvenile and adult stages. In lateral line hair cells from juvenile zebrafish, exocytosis also became more efficient and required less calcium for vesicle fusion. In hair cells from mature zebrafish, the biophysical characteristics of ion channels and exocytosis resembled those of hair cells from other lower vertebrates and, to some extent, those in the immature mammalian vestibular and auditory systems. We show that although the zebrafish provides a suitable animal model for studies on hair cell physiology, it is advisable to consider that the age at which the majority of hair cells acquire a mature-type configuration is reached only in the juvenile lateral line and in the inner ear from >2 months after hatching.
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Affiliation(s)
- Jennifer Olt
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Stuart L Johnson
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
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Kim MJ, Choi J, Kim N, Han GC. Behavioral changes of zebrafish according to cisplatin-induced toxicity of the balance system. Hum Exp Toxicol 2014; 33:1167-75. [DOI: 10.1177/0960327114521046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background and objectives: Zebrafish are commonly used as experimental animals in otolaryngology studies. However, the behavioral characteristics of these fish are not well known, especially those related to the vestibular system. The goal of this study was to evaluate behavioral changes in zebrafish due to toxicity in the balance system. Materials and methods: Zebrafish were exposed to 1000 μM cisplatin for 6 h. We, then, periodically monitored swimming depth, total swimming distance, peak swimming velocity, and mean swimming velocity of the fish for approximately 21 days. Results: Total swimming distance ( p < 0.0001), peak swimming velocity ( p = 0.0063), and mean swimming velocity ( p < 0.0001) in the cisplatin-administered group were significantly decreased when compared with control fish. Conclusion: Our findings demonstrate that cisplatin can alter the locomotion behavior of zebrafish.
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Affiliation(s)
- MJ Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - J Choi
- Department of Otolaryngology—Head and Neck Surgery, School of Medicine, Korea University, Ahn San, South Korea
| | - N Kim
- Neuroscience Research Institute, Graduate School of Medicine, Gachon University, Incheon, South Korea
| | - GC Han
- Department of Otolaryngology—Head and Neck Surgery, Graduate School of Medicine, Gachon University of Medicine and Science, Incheon, South Korea
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Rea AC, Vandenberg LN, Ball RE, Snouffer AA, Hudson AG, Zhu Y, McLain DE, Johnston LL, Lauderdale JD, Levin M, Dore TM. Light-activated serotonin for exploring its action in biological systems. ACTA ACUST UNITED AC 2013; 20:1536-46. [PMID: 24333002 DOI: 10.1016/j.chembiol.2013.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 10/29/2013] [Accepted: 11/01/2013] [Indexed: 11/17/2022]
Abstract
Serotonin (5-HT) is a neuromodulator involved in regulating mood, appetite, memory, learning, pain, and establishment of left-right (LR) asymmetry in embryonic development. To explore the role of 5-HT in physiology, we have created two forms of "caged" 5-HT, BHQ-O-5HT and BHQ-N-5HT. When exposed to 365 or 740 nm light, BHQ-O-5HT releases 5-HT through one- or two-photon excitation, respectively. BHQ-O-5HT mediated changes in neural activity in cultured mouse primary sensory neurons and the trigeminal ganglion and optic tectum of intact zebrafish larvae in the form of high-amplitude spiking in response to light. In Xenopus laevis embryos, light-activated 5-HT increased the occurrence of LR patterning defects. Maximal rates of LR defects were observed when 5-HT was released at stage 5 compared with stage 8. These experiments show the potential for BHQ-caged serotonins in studying 5-HT-regulated physiological processes.
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Affiliation(s)
- Adam C Rea
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA
| | - Laura N Vandenberg
- Biology Department and Tufts Center for Regenerative and Developmental Biology, Tufts University, Suite 4600, 200 Boston Avenue, Medford, MA 02155-4243, USA
| | - Rebecca E Ball
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ashley A Snouffer
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Alicia G Hudson
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Yue Zhu
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA
| | - Duncan E McLain
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA; New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | | | - James D Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Michael Levin
- Biology Department and Tufts Center for Regenerative and Developmental Biology, Tufts University, Suite 4600, 200 Boston Avenue, Medford, MA 02155-4243, USA
| | - Timothy M Dore
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA; New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
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45
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Development of aggressive phenotypes in zebrafish: interactions of age, experience and social status. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.04.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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46
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Lu Z, DeSmidt AA. Early development of hearing in zebrafish. J Assoc Res Otolaryngol 2013; 14:509-21. [PMID: 23575600 DOI: 10.1007/s10162-013-0386-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 03/17/2013] [Indexed: 01/27/2023] Open
Abstract
The zebrafish (Danio rerio) has become a valuable vertebrate model for human hearing and balance disorders because it combines powerful genetics, excellent embryology, and exceptional in vivo visualization in one organism. In this study, we investigated auditory function of zebrafish at early developmental stages using the microphonic potential method. This is the first study to report ontogeny of response of hair cells in any fish during the first week post fertilization. The right ear of each zebrafish embedded in agarose was linearly stimulated with a glass probe that was driven by a calibrated piezoelectric actuator. Using beveled micropipettes filled with standard fish saline, extracellular microphonic potentials were recorded from hair cells in the inner ear of zebrafish embryos or larvae in response to 20, 50, 100, and 200-Hz stimulation. Saccular hair cells expressing green fluorescent protein of the transgenic zebrafish from 2 to 7 days post fertilization (dpf) were visualized and quantified using confocal microscopy. The otic vesicles' areas, otoliths' areas, and saccular hair cell count and density increased linearly with age and standard body length. Microphonic responses increased monotonically with stimulus intensity, stimulus frequency, and age of zebrafish. Microphonic threshold at 200 Hz gradually decreased with zebrafish age. The increases in microphonic response and sensitivity correlate with the increases in number and density of hair cells in the saccule. These results enhance our knowledge of early development of auditory function in zebrafish and provide the control data that can be used to evaluate hearing of young zebrafish morphants or mutants.
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Affiliation(s)
- Zhongmin Lu
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA.
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47
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Rabconnectin3α promotes stable activity of the H+ pump on synaptic vesicles in hair cells. J Neurosci 2012; 32:11144-56. [PMID: 22875945 DOI: 10.1523/jneurosci.1705-12.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Acidification of synaptic vesicles relies on the vacuolar-type ATPase (V-ATPase) and provides the electrochemical driving force for neurotransmitter exchange. The regulatory mechanisms that ensure assembly of the V-ATPase holoenzyme on synaptic vesicles are unknown. Rabconnectin3α (Rbc3α) is a potential candidate for regulation of V-ATPase activity because of its association with synaptic vesicles and its requirement for acidification of intracellular compartments. Here, we provide the first evidence for a role of Rbc3α in synaptic vesicle acidification and neurotransmission. In this study, we characterized mutant alleles of rbc3α isolated from a large-scale screen for zebrafish with auditory/vestibular defects. We show that Rbc3α is localized to basal regions of hair cells in which synaptic vesicles are present. To determine whether Rbc3α regulates V-ATPase activity, we examined the acidification of synaptic vesicles and localization of the V-ATPase in hair cells. In contrast to wild-type hair cells, we observed that synaptic vesicles had elevated pH, and a cytosolic subunit of the V-ATPase was no longer enriched in synaptic regions of mutant hair cells. As a consequence of defective acidification of synaptic vesicles, afferent neurons in rbc3α mutants had reduced firing rates and reduced accuracy of phase-locked action potentials in response to mechanical stimulation of hair cells. Collectively, our data suggest that Rbc3α modulates synaptic transmission in hair cells by promoting V-ATPase activity in synaptic vesicles.
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48
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Brack C, Ramcharitar J. Assessment of lateral line function: A potential technique for studies in ototoxicity. J Clin Neurosci 2012; 19:333-5. [DOI: 10.1016/j.jocn.2011.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 06/26/2011] [Indexed: 10/15/2022]
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49
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Mechanism of spontaneous activity in afferent neurons of the zebrafish lateral-line organ. J Neurosci 2011; 31:1614-23. [PMID: 21289170 DOI: 10.1523/jneurosci.3369-10.2011] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many auditory, vestibular, and lateral-line afferent neurons display spontaneous action potentials. This spontaneous spiking is thought to result from hair-cell glutamate release in the absence of stimuli. Spontaneous release at hair-cell resting potentials presumably results from Ca(V)1.3 L-type calcium channel activity. Here, using intact zebrafish larvae, we recorded robust spontaneous spiking from lateral-line afferent neurons in the absence of external stimuli. Consistent with the above assumptions, spiking was absent in mutants that lacked either Vesicular glutamate transporter 3 (Vglut3) or Ca(V)1.3. We then tested the hypothesis that spontaneous spiking resulted from sustained Ca(V)1.3 activity due to depolarizing currents that are active at rest. Mechanotransduction currents (I(MET)) provide a depolarizing influence to the resting potential. However, following block of I(MET), spontaneous spiking persisted and was characterized by longer interspike intervals and increased periods of inactivity. These results suggest that an additional depolarizing influence maintains the resting potential within the activation range of Ca(V)1.3. To test whether the hyperpolarization-activated cation current, I(h) participates in setting the resting potential, we applied I(h) antagonists. Both ZD7288 and DK-AH 269 reduced spontaneous activity. Finally, concomitant block of I(MET) and I(h) essentially abolished spontaneous activity, ostensibly by hyperpolarization outside of the activation range for Ca(V)1.3. Together, our data support a mechanism for spontaneous spiking that results from Ca(2+)-dependent neurotransmitter release at hair-cell resting potentials that are maintained within the activation range of Ca(V)1.3 channels through active I(MET) and I(h).
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Sheets L, Trapani JG, Mo W, Obholzer N, Nicolson T. Ribeye is required for presynaptic Ca(V)1.3a channel localization and afferent innervation of sensory hair cells. Development 2011; 138:1309-19. [PMID: 21350006 DOI: 10.1242/dev.059451] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ribbon synapses of the ear, eye and pineal gland contain a unique protein component: Ribeye. Ribeye consists of a novel aggregation domain spliced to the transcription factor CtBP2 and is one of the most abundant proteins in synaptic ribbon bodies. Although the importance of Ribeye for the function and physical integrity of ribbon synapses has been shown, a specific role in synaptogenesis has not been described. Here, we have modulated Ribeye expression in zebrafish hair cells and have examined the role of Ribeye in synapse development. Knockdown of ribeye resulted in fewer stimulus-evoked action potentials from afferent neurons and loss of presynaptic Ca(V)1.3a calcium channel clusters in hair cells. Additionally, afferent innervation of hair cells was reduced in ribeye morphants, and the reduction was correlated with depletion of Ribeye punctae. By contrast, transgenic overexpression of Ribeye resulted in Ca(V)1.3a channels colocalized with ectopic aggregates of Ribeye protein. Overexpression of Ribeye, however, was not sufficient to create ectopic synapses. These findings reveal two distinct functions of Ribeye in ribbon synapse formation--clustering Ca(V)1.3a channels at the presynapse and stabilizing contacts with afferent neurons--and suggest that Ribeye plays an organizing role in synaptogenesis.
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Affiliation(s)
- Lavinia Sheets
- Howard Hughes Medical Institute, Oregon Hearing Research Center, 3181 SW Sam Jackson Park Road, Oregon Health & Science University, Portland, OR 97239, USA
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