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Rodríguez-Morales R. Sensing in the dark: Constructive evolution of the lateral line system in blind populations of Astyanax mexicanus. Ecol Evol 2024; 14:e11286. [PMID: 38654714 PMCID: PMC11036076 DOI: 10.1002/ece3.11286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/26/2024] [Accepted: 04/03/2024] [Indexed: 04/26/2024] Open
Abstract
Cave-adapted animals evolve a suite of regressive and constructive traits that allow survival in the dark. Most studies aiming at understanding cave animal evolution have focused on the genetics and environmental underpinnings of regressive traits, with special emphasis on vision loss. Possibly as a result of vision loss, other non-visual sensory systems have expanded and compensated in cave species. For instance, in many cave-dwelling fish species, including the blind cavefish of the Mexican tetra, Astyanax mexicanus, a major non-visual mechanosensory system called the lateral line, compensated for vision loss through morphological expansions. While substantial work has shed light on constructive adaptation of this system, there are still many open questions regarding its developmental origin, synaptic plasticity, and overall adaptive value. This review provides a snapshot of the current state of knowledge of lateral line adaption in A. mexicanus, with an emphasis on anatomy, synaptic plasticity, and behavior. Multiple open avenues for future research in this system, and how these can be leveraged as tools for both evolutionary biology and evolutionary medicine, are discussed.
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Affiliation(s)
- Roberto Rodríguez-Morales
- Department of Anatomy & Neurobiology, School of Medicine University of Puerto Rico San Juan Puerto Rico
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2
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Davis SN, Zhu Y, Schoppik D. Multisensory strategies for postural compensation after lateral line loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576760. [PMID: 38328242 PMCID: PMC10849565 DOI: 10.1101/2024.01.23.576760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
To control elevation underwater, aquatic vertebrates integrate multisensory information (e.g., vestibular, visual, proprioceptive) to guide posture and swim kinematics. Here we characterized how larval zebrafish changed posture and locomotive strategies after imposed instability (decreased buoyancy) in the presence and absence of visual cues. We discovered that larvae sank more after acute loss of lateral line (flow-sensing) hair cells. In response, larvae engaged different compensatory strategies, depending on whether they were in the light or dark. In the dark, larvae swam more frequently, engaging their trunk to steer their nose up and climb more effectively. However, in the light, larvae climbed more often, engaging both pectoral fins and trunk to elevate. We conclude that larvae sense instability and use vestibular and visual information as available to control posture and trajectory. Our work is a step towards understanding the multisensory neural computations responsible for control strategies that allow orientation and navigation in depth.
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Affiliation(s)
- Samantha N. Davis
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - Yunlu Zhu
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - David Schoppik
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
- Lead Contact
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3
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Brehm N, Wenke N, Glessner K, Haehnel-Taguchi M. Physiological responses of mechanosensory systems in the head of larval zebrafish ( Danio rerio). Front Robot AI 2023; 10:1212626. [PMID: 37583713 PMCID: PMC10423815 DOI: 10.3389/frobt.2023.1212626] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/11/2023] [Indexed: 08/17/2023] Open
Abstract
The lateral line system of zebrafish consists of the anterior lateral line, with neuromasts distributed on the head, and the posterior lateral line, with neuromasts distributed on the trunk. The sensory afferent neurons are contained in the anterior and posterior lateral line ganglia, respectively. So far, the vast majority of physiological and developmental studies have focused on the posterior lateral line. However, studies that focus on the anterior lateral line, especially on its physiology, are very rare. The anterior lateral line involves different neuromast patterning processes, specific distribution of synapses, and a unique role in behavior. Here, we report our observations regarding the development of the lateral line and analyze the physiological responses of the anterior lateral line to mechanical and water jet stimuli. Sensing in the fish head may be crucial to avoid obstacles, catch prey, and orient in water current, especially in the absence of visual cues. Alongside the lateral line, the trigeminal system, with its fine nerve endings innervating the skin, could contribute to perceiving mechanosensory stimulation. Therefore, we compare the physiological responses of the lateral line afferent neurons to responses of trigeminal neurons and responsiveness of auditory neurons. We show that anterior lateral line neurons are tuned to the velocity of mechanosensory ramp stimulation, while trigeminal neurons either only respond to mechanical step stimuli or fast ramp and step stimuli. Auditory neurons did not respond to mechanical or water jet stimuli. These results may prove to be essential in designing underwater robots and artificial lateral lines, with respect to the spectra of stimuli that the different mechanosensory systems in the larval head are tuned to, and underline the importance and functionality of the anterior lateral line system in the larval fish head.
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Affiliation(s)
- Nils Brehm
- Department of Developmental Biology, Institute for Biology 1, University of Freiburg, Freiburg, Germany
| | | | | | - Melanie Haehnel-Taguchi
- Department of Developmental Biology, Institute for Biology 1, University of Freiburg, Freiburg, Germany
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4
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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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5
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Yang E, Zwart MF, James B, Rubinov M, Wei Z, Narayan S, Vladimirov N, Mensh BD, Fitzgerald JE, Ahrens MB. A brainstem integrator for self-location memory and positional homeostasis in zebrafish. Cell 2022; 185:5011-5027.e20. [PMID: 36563666 DOI: 10.1016/j.cell.2022.11.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/28/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022]
Abstract
To track and control self-location, animals integrate their movements through space. Representations of self-location are observed in the mammalian hippocampal formation, but it is unknown if positional representations exist in more ancient brain regions, how they arise from integrated self-motion, and by what pathways they control locomotion. Here, in a head-fixed, fictive-swimming, virtual-reality preparation, we exposed larval zebrafish to a variety of involuntary displacements. They tracked these displacements and, many seconds later, moved toward their earlier location through corrective swimming ("positional homeostasis"). Whole-brain functional imaging revealed a network in the medulla that stores a memory of location and induces an error signal in the inferior olive to drive future corrective swimming. Optogenetically manipulating medullary integrator cells evoked displacement-memory behavior. Ablating them, or downstream olivary neurons, abolished displacement corrections. These results reveal a multiregional hindbrain circuit in vertebrates that integrates self-motion and stores self-location to control locomotor behavior.
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Affiliation(s)
- En Yang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
| | - Maarten F Zwart
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; School of Psychology and Neuroscience, Centre for Biophotonics, University of St Andrews, St. Andrews, UK
| | - Ben James
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Mikail Rubinov
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Ziqiang Wei
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Sujatha Narayan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Nikita Vladimirov
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; URPP Adaptive Brain Circuits in Development and Learning (AdaBD), University of Zurich, Zurich, Switzerland
| | - Brett D Mensh
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - James E Fitzgerald
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Misha B Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
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Bijari K, Valera G, López-Schier H, Ascoli GA. Quantitative neuronal morphometry by supervised and unsupervised learning. STAR Protoc 2021; 2:100867. [PMID: 34647039 PMCID: PMC8496329 DOI: 10.1016/j.xpro.2021.100867] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We present a protocol to characterize the morphological properties of individual neurons reconstructed from microscopic imaging. We first describe a simple procedure to extract relevant morphological features from digital tracings of neural arbors. Then, we provide detailed steps on classification, clustering, and statistical analysis of the traced cells based on morphological features. We illustrate the pipeline design using specific examples from zebrafish anatomy. Our approach can be readily applied and generalized to the characterization of axonal, dendritic, or glial geometry. For complete context and scientific motivation for the studies and datasets used here, refer to Valera et al. (2021).
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Affiliation(s)
- Kayvan Bijari
- Center for Neural Informatics, Structures, & Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
| | - Gema Valera
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany
| | - Hernán López-Schier
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, & Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA 22032, USA
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Restoring Shank3 in the rostral brainstem of shank3ab-/- zebrafish autism models rescues sensory deficits. Commun Biol 2021; 4:1411. [PMID: 34921227 PMCID: PMC8683502 DOI: 10.1038/s42003-021-02920-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/24/2021] [Indexed: 11/22/2022] Open
Abstract
People with Phelan-McDermid Syndrome, caused by mutations in the SHANK3 gene, commonly exhibit reduced responses to sensory stimuli; yet the changes in brain-wide activity that link these symptoms to mutations in the shank3 gene remain unknown. Here we quantify movement in response to sudden darkness in larvae of two shank3 zebrafish mutant models and show that both models exhibit dampened responses to this stimulus. Using brain-wide activity mapping, we find that shank3−/− light-sensing brain regions show normal levels of activity while sensorimotor integration and motor regions are less active. Specifically restoring Shank3 function in a sensorimotor nucleus of the rostral brainstem enables the shank3−/− model to respond like wild-type. In sum, we find that reduced sensory responsiveness in shank3−/− models is associated with reduced activity in sensory processing brain regions and can be rescued by restoring Shank3 function in the rostral brainstem. These studies highlight the importance of Shank3 function in the rostral brainstem for integrating sensory inputs to generate behavioral adaptations to changing sensory stimuli. Robert Kozol et al. developed two zebrafish Shank3 models to characterize the basis of sensorimotor deficits, which are a consistent feature in SHANK3-deficient human patients (Phelan-McDermid Syndrome). Their results suggest that hindbrain regions require Shank3 for normal responses to light, and provide further insight toward the biology of sensory deficits in Shank3 mutants.
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McDermott BM. Lateral line: From water waves to brain waves. Curr Biol 2021; 31:R344-R347. [PMID: 33848490 DOI: 10.1016/j.cub.2021.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Fish use the highly stereotyped lateral line system to swim against a current. New research reveals that the order of the lateral line system is less important than brain response asymmetries for achieving this navigational feat.
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Affiliation(s)
- Brian M McDermott
- Department of Otolaryngology - Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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