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Lloyd E, McDole B, Privat M, Jaggard JB, Duboué ER, Sumbre G, Keene AC. Blind cavefish retain functional connectivity in the tectum despite loss of retinal input. Curr Biol 2022; 32:3720-3730.e3. [PMID: 35926509 DOI: 10.1016/j.cub.2022.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/07/2022] [Accepted: 07/07/2022] [Indexed: 11/26/2022]
Abstract
Sensory systems display remarkable plasticity and are under strong evolutionary selection. The Mexican cavefish, Astyanax mexicanus, consists of eyed river-dwelling surface populations and multiple independent cave populations that have converged on eye loss, providing the opportunity to examine the evolution of sensory circuits in response to environmental perturbation. Functional analysis across multiple transgenic populations expressing GCaMP6s showed that functional connectivity of the optic tectum largely did not differ between populations, except for the selective loss of negatively correlated activity within the cavefish tectum, suggesting positively correlated neural activity is resistant to an evolved loss of input from the retina. Furthermore, analysis of surface-cave hybrid fish reveals that changes in the tectum are genetically distinct from those encoding eye loss. Together, these findings uncover the independent evolution of multiple components of the visual system and establish the use of functional imaging in A. mexicanus to study neural circuit evolution.
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Affiliation(s)
- Evan Lloyd
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Biology, Texas A&M University, College Station, TX 77843, USA; Harriet Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Brittnee McDole
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Martin Privat
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - James B Jaggard
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Erik R Duboué
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - German Sumbre
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France.
| | - Alex C Keene
- Department of Biology, Texas A&M University, College Station, TX 77843, USA.
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2
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Bartley SC, Proctor MT, Xia H, Ho E, Kang DS, Schuster K, Bicca MA, Seckler HS, Viola KL, Patrie SM, Kelleher NL, De Mello FG, Klein WL. An Essential Role for Alzheimer’s-Linked Amyloid Beta Oligomers in Neurodevelopment: Transient Expression of Multiple Proteoforms during Retina Histogenesis. Int J Mol Sci 2022; 23:ijms23042208. [PMID: 35216328 PMCID: PMC8875314 DOI: 10.3390/ijms23042208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/04/2022] Open
Abstract
Human amyloid beta peptide (Aβ) is a brain catabolite that at nanomolar concentrations can form neurotoxic oligomers (AβOs), which are known to accumulate in Alzheimer’s disease. Because a predisposition to form neurotoxins seems surprising, we have investigated whether circumstances might exist where AβO accumulation may in fact be beneficial. Our investigation focused on the embryonic chick retina, which expresses the same Aβ as humans. Using conformation-selective antibodies, immunoblots, mass spectrometry, and fluorescence microscopy, we discovered that AβOs are indeed present in the developing retina, where multiple proteoforms are expressed in a highly regulated cell-specific manner. The expression of the AβO proteoforms was selectively associated with transiently expressed phosphorylated Tau (pTau) proteoforms that, like AβOs, are linked to Alzheimer’s disease (AD). To test whether the AβOs were functional in development, embryos were cultured ex ovo and then injected intravitreally with either a beta-site APP-cleaving enzyme 1 (BACE-1) inhibitor or an AβO-selective antibody to prematurely lower the levels of AβOs. The consequence was disrupted histogenesis resulting in dysplasia resembling that seen in various retina pathologies. We suggest the hypothesis that embryonic AβOs are a new type of short-lived peptidergic hormone with a role in neural development. Such a role could help explain why a peptide that manifests deleterious gain-of-function activity when it oligomerizes in the aging brain has been evolutionarily conserved.
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Affiliation(s)
- Samuel C. Bartley
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Madison T. Proctor
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Hongjie Xia
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Evelyn Ho
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Dong S. Kang
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Kristen Schuster
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Maíra A. Bicca
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Henrique S. Seckler
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA; (H.S.S.); (S.M.P.)
| | - Kirsten L. Viola
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
| | - Steven M. Patrie
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA; (H.S.S.); (S.M.P.)
| | - Neil L. Kelleher
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA;
| | - Fernando G. De Mello
- Instituto de Biofísica Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
| | - William L. Klein
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA; (S.C.B.); (M.T.P.); (H.X.); (E.H.); (D.S.K.); (K.S.); (M.A.B.); (K.L.V.)
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University, Chicago, IL 60611, USA
- Correspondence: ; Tel.: +1-847-591-5510
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3
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Di Donato V, De Santis F, Albadri S, Auer TO, Duroure K, Charpentier M, Concordet JP, Gebhardt C, Del Bene F. An Attractive Reelin Gradient Establishes Synaptic Lamination in the Vertebrate Visual System. Neuron 2018; 97:1049-1062.e6. [PMID: 29429939 DOI: 10.1016/j.neuron.2018.01.030] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 11/11/2017] [Accepted: 01/11/2018] [Indexed: 10/18/2022]
Abstract
A conserved organizational and functional principle of neural networks is the segregation of axon-dendritic synaptic connections into laminae. Here we report that targeting of synaptic laminae by retinal ganglion cell (RGC) arbors in the vertebrate visual system is regulated by a signaling system relying on target-derived Reelin and VLDLR/Dab1a on the projecting neurons. Furthermore, we find that Reelin is distributed as a gradient on the target tissue and stabilized by heparan sulfate proteoglycans (HSPGs) in the extracellular matrix (ECM). Through genetic manipulations, we show that this Reelin gradient is important for laminar targeting and that it is attractive for RGC axons. Finally, we suggest a comprehensive model of synaptic lamina formation in which attractive Reelin counter-balances repulsive Slit1, thereby guiding RGC axons toward single synaptic laminae. We establish a mechanism that may represent a general principle for neural network assembly in vertebrate species and across different brain areas.
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Affiliation(s)
- Vincenzo Di Donato
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France
| | - Flavia De Santis
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France
| | - Shahad Albadri
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France
| | - Thomas Oliver Auer
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France
| | - Karine Duroure
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France
| | - Marine Charpentier
- Muséum National d'Histoire Naturelle, INSERM U1154, CNRS UMR7196, Paris 75231, France
| | - Jean-Paul Concordet
- Muséum National d'Histoire Naturelle, INSERM U1154, CNRS UMR7196, Paris 75231, France
| | - Christoph Gebhardt
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France.
| | - Filippo Del Bene
- Institut Curie, PSL Research University, INSERM U934, CNRS UMR3215, UPMC Paris-Sorbonne, Paris 75005, France.
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4
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Astigarraga S, Douthit J, Tarnogorska D, Creamer MS, Mano O, Clark DA, Meinertzhagen IA, Treisman JE. Drosophila Sidekick is required in developing photoreceptors to enable visual motion detection. Development 2018; 145:dev.158246. [PMID: 29361567 DOI: 10.1242/dev.158246] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022]
Abstract
The assembly of functional neuronal circuits requires growth cones to extend in defined directions and recognize the correct synaptic partners. Homophilic adhesion between vertebrate Sidekick proteins promotes synapse formation between retinal neurons involved in visual motion detection. We show here that Drosophila Sidekick accumulates in specific synaptic layers of the developing motion detection circuit and is necessary for normal optomotor behavior. Sidekick is required in photoreceptors, but not in their target lamina neurons, to promote the alignment of lamina neurons into columns and subsequent sorting of photoreceptor axons into synaptic modules based on their precise spatial orientation. Sidekick is also localized to the dendrites of the direction-selective T4 and T5 cells, and is expressed in some of their presynaptic partners. In contrast to its vertebrate homologs, Sidekick is not essential for T4 and T5 to direct their dendrites to the appropriate layers or to receive synaptic contacts. These results illustrate a conserved requirement for Sidekick proteins in establishing visual motion detection circuits that is achieved through distinct cellular mechanisms in Drosophila and vertebrates.
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Affiliation(s)
- Sergio Astigarraga
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Jessica Douthit
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Dorota Tarnogorska
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - Matthew S Creamer
- Interdepartmental Neuroscience Program, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Omer Mano
- Department of Molecular, Cellular and Developmental Biology, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Damon A Clark
- Interdepartmental Neuroscience Program, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - Jessica E Treisman
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
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5
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Fairchild CL, Hino K, Han JS, Miltner AM, Peinado Allina G, Brown CE, Burns ME, La Torre A, Simó S. RBX2 maintains final retinal cell position in a DAB1-dependent and -independent fashion. Development 2018; 145:dev.155283. [PMID: 29361558 DOI: 10.1242/dev.155283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 12/28/2017] [Indexed: 01/13/2023]
Abstract
The laminated structure of the retina is fundamental for the organization of the synaptic circuitry that translates light input into patterns of action potentials. However, the molecular mechanisms underlying cell migration and layering of the retina are poorly understood. Here, we show that RBX2, a core component of the E3 ubiquitin ligase CRL5, is essential for retinal layering and function. RBX2 regulates the final cell position of rod bipolar cells, cone photoreceptors and Muller glia. Our data indicate that sustained RELN/DAB1 signaling, triggered by depletion of RBX2 or SOCS7 - a CRL5 substrate adaptor known to recruit DAB1 - causes rod bipolar cell misposition. Moreover, whereas SOCS7 also controls Muller glia cell lamination, it is not responsible for cone photoreceptor positioning, suggesting that RBX2, most likely through CRL5 activity, controls other signaling pathways required for proper cone localization. Furthermore, RBX2 depletion reduces the number of ribbon synapses and disrupts cone photoreceptor function. Together, these results uncover RBX2 as a crucial molecular regulator of retina morphogenesis and cone photoreceptor function.
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Affiliation(s)
- Corinne L Fairchild
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Keiko Hino
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Jisoo S Han
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Adam M Miltner
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Gabriel Peinado Allina
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Caileigh E Brown
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Marie E Burns
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA.,Department of Ophthalmology and Vision Science, University of California Davis, CA 95616, USA
| | - Anna La Torre
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
| | - Sergi Simó
- Department of Cell Biology and Human Anatomy, University of California Davis, CA 95616, USA
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6
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Gore BB, Soden ME, Zweifel LS. Manipulating gene expression in projection-specific neuronal populations using combinatorial viral approaches. ACTA ACUST UNITED AC 2016; 65:4.35.1-20. [PMID: 25429312 DOI: 10.1002/0471142301.ns0435s65] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The mammalian brain contains tremendous structural and genetic complexity that is vital for its function. The elucidation of gene expression profiles in the brain, coupled with the development of large-scale connectivity maps and emerging viral vector-based approaches for target-selective gene manipulation, now allow for detailed dissection of gene-circuit interfaces. This protocol details how to perform combinatorial viral injections to manipulate gene expression in subsets of neurons interconnecting two brain regions. This method utilizes stereotaxic injection of a retrograde transducing CAV2-Cre virus into one brain region, combined with injection of a locally transducing Cre-dependent AAV virus into another brain region. This technique is widely applicable to the genetic dissection of neural circuitry, as it enables selective expression of candidate genes, dominant-negatives, fluorescent reporters, or genetic tools within heterogeneous populations of neurons based upon their projection targets.
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Affiliation(s)
- Bryan B Gore
- Department of Pharmacology and Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA
| | - Marta E Soden
- Department of Pharmacology and Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA
| | - Larry S Zweifel
- Department of Pharmacology and Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA
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7
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Shang Y, Huang EJ. Mechanisms of FUS mutations in familial amyotrophic lateral sclerosis. Brain Res 2016; 1647:65-78. [PMID: 27033831 DOI: 10.1016/j.brainres.2016.03.036] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 12/13/2022]
Abstract
Recent advances in the genetics of amyotrophic lateral sclerosis (ALS) have provided key mechanistic insights to the pathogenesis of this devastating neurodegenerative disease. Among many etiologies for ALS, the identification of mutations and proteinopathies in two RNA binding proteins, TDP-43 (TARDBP or TAR DNA binding protein 43) and its closely related RNA/DNA binding protein FUS (fused in sarcoma), raises the intriguing possibility that perturbations to the RNA homeostasis and metabolism in neurons may contribute to the pathogenesis of these diseases. Although the similarities between TDP-43 and FUS suggest that mutations and proteinopathy involving these two proteins may converge on the same mechanisms leading to neurodegeneration, there is increasing evidence that FUS mutations target distinct mechanisms to cause early disease onset and aggressive progression of disease. This review focuses on the recent advances on the molecular, cellular and genetic approaches to uncover the mechanisms of wild type and mutant FUS proteins during development and in neurodegeneration. These findings provide important insights to understand how FUS mutations may perturb the maintenance of dendrites through fundamental processes in RNA splicing, RNA transport and DNA damage response/repair. These results contribute to the understanding of phenotypic manifestations in neurodegeneration related to FUS mutations, and to identify important directions for future investigations. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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Affiliation(s)
- Yulei Shang
- Department of Pathology, University of California San Francisco, San Francisco, CA, United States
| | - Eric J Huang
- Department of Pathology, University of California San Francisco, San Francisco, CA, United States; Pathology Service 113B, VA Medical Center, San Francisco, CA, United States.
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8
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de Wit J, Ghosh A. Specification of synaptic connectivity by cell surface interactions. Nat Rev Neurosci 2015; 17:22-35. [PMID: 26656254 DOI: 10.1038/nrn.2015.3] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The molecular diversification of cell surface molecules has long been postulated to impart specific surface identities on neuronal cell types. The existence of unique cell surface identities would allow neurons to distinguish one another and connect with their appropriate target cells. Although progress has been made in identifying cell type-specific surface molecule repertoires and in characterizing their extracellular interactions, determining how this molecular diversity contributes to the precise wiring of neural circuitry has proven challenging. Here, we review the role of the cadherin, neurexin, immunoglobulin and leucine-rich repeat protein superfamilies in the specification of connectivity. The emerging evidence suggests that the concerted actions of these proteins may critically contribute to the assembly of neural circuits.
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Affiliation(s)
- Joris de Wit
- VIB Center for the Biology of Disease and Center for Human Genetics, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Anirvan Ghosh
- Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffman-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
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9
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Cao Y, Sarria I, Fehlhaber KE, Kamasawa N, Orlandi C, James KN, Hazen JL, Gardner MR, Farzan M, Lee A, Baker S, Baldwin K, Sampath AP, Martemyanov KA. Mechanism for Selective Synaptic Wiring of Rod Photoreceptors into the Retinal Circuitry and Its Role in Vision. Neuron 2015; 87:1248-1260. [PMID: 26402607 PMCID: PMC4583715 DOI: 10.1016/j.neuron.2015.09.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/11/2015] [Accepted: 08/31/2015] [Indexed: 01/06/2023]
Abstract
In the retina, rod and cone photoreceptors form distinct connections with different classes of downstream bipolar cells. However, the molecular mechanisms responsible for their selective connectivity are unknown. Here we identify a cell-adhesion protein, ELFN1, to be essential for the formation of synapses between rods and rod ON-bipolar cells in the primary rod pathway. ELFN1 is expressed selectively in rods where it is targeted to the axonal terminals by the synaptic release machinery. At the synapse, ELFN1 binds in trans to mGluR6, the postsynaptic receptor on rod ON-bipolar cells. Elimination of ELFN1 in mice prevents the formation of synaptic contacts involving rods, but not cones, allowing a dissection of the contributions of primary and secondary rod pathways to retinal circuit function and vision. We conclude that ELFN1 is necessary for the selective wiring of rods into the primary rod pathway and is required for high sensitivity of vision.
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Affiliation(s)
- Yan Cao
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Ignacio Sarria
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Katherine E Fehlhaber
- Jules Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA
| | - Naomi Kamasawa
- Electron Microscopy Core Facility, Max Planck Florida Institute, 1 Max Planck Way, Jupiter, FL 33458, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Kiely N James
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Jennifer L Hazen
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Matthew R Gardner
- Department of Infectious Disease, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Michael Farzan
- Department of Infectious Disease, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
| | - Sheila Baker
- Department of Biochemistry, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
| | - Kristin Baldwin
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Alapakkam P Sampath
- Jules Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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10
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Chow RW, Almeida AD, Randlett O, Norden C, Harris WA. Inhibitory neuron migration and IPL formation in the developing zebrafish retina. Development 2015; 142:2665-77. [PMID: 26116662 PMCID: PMC4529032 DOI: 10.1242/dev.122473] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 06/11/2015] [Indexed: 12/22/2022]
Abstract
The mature vertebrate retina is a highly ordered neuronal network of cell bodies and synaptic neuropils arranged in distinct layers. Little, however, is known about the emergence of this spatial arrangement. Here, we investigate how the three main types of retinal inhibitory neuron (RIN) – horizontal cells (HCs), inner nuclear layer amacrine cells (iACs) and displaced amacrine cells (dACs) – reach their specific laminar positions during development. Using in vivo time-lapse imaging of zebrafish retinas, we show that RINs undergo distinct phases of migration. The first phase, common to all RINs, is bipolar migration directed towards the apicobasal centre of the retina. All RINs then transition to a less directionally persistent multipolar phase of migration. Finally, HCs, iACs and dACs each undergo cell type-specific migration. In contrast to current hypotheses, we find that most dACs send processes into the forming inner plexiform layer (IPL) before migrating through it and inverting their polarity. By imaging and quantifying the dynamics of HCs, iACs and dACs from birth to final position, this study thus provides evidence for distinct and new migration patterns during retinal lamination and insights into the initiation of IPL formation. Highlighted article: The quantification of cellular behaviour in real time provides new insights into interneuron migration and inner plexiform layer formation during the lamination of the zebrafish retina.
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Affiliation(s)
- Renee W Chow
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Alexandra D Almeida
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Owen Randlett
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Caren Norden
- MPI of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, Dresden 01307, Germany
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
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11
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Carrella S, D'Agostino Y, Barbato S, Huber-Reggi SP, Salierno FG, Manfredi A, Neuhauss SCF, Banfi S, Conte I. miR-181a/b control the assembly of visual circuitry by regulating retinal axon specification and growth. Dev Neurobiol 2015; 75:1252-67. [PMID: 25728313 PMCID: PMC5033011 DOI: 10.1002/dneu.22282] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 01/31/2023]
Abstract
Connectivity and function of neuronal circuitry require the correct specification and growth of axons and dendrites. Here, we identify the microRNAs miR‐181a and miR‐181b as key regulators of retinal axon specification and growth. Loss of miR‐181a/b in medaka fish (Oryzias latipes) failed to consolidate amacrine cell processes into axons and delayed the growth of retinal ganglion cell (RGC) axons. These alterations were accompanied by defects in visual connectivity and function. We demonstrated that miR‐181a/b exert these actions through negative modulation of MAPK/ERK signaling that in turn leads to RhoA reduction and proper neuritogenesis in both amacrine cells and RGCs via local cytoskeletal rearrangement. Our results identify a new pathway for axon specification and growth unraveling a crucial role of miR‐181a/b in the proper establishment of visual system connectivity and function. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1252–1267, 2015
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Affiliation(s)
- Sabrina Carrella
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
| | - Ylenia D'Agostino
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
| | - Sara Barbato
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
| | - Sabina P Huber-Reggi
- Institute of Molecular Life Sciences, Division of Neurobiology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Francesco G Salierno
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
| | - Anna Manfredi
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
| | - Stephan C F Neuhauss
- Institute of Molecular Life Sciences, Division of Neurobiology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy.,Medical Genetics, Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, via Luigi De Crecchio 7, 80138, Naples, Italy
| | - Ivan Conte
- Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli (Naples), 80078, Italy
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12
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Sun LO, Brady CM, Cahill H, Al-Khindi T, Sakuta H, Dhande OS, Noda M, Huberman AD, Nathans J, Kolodkin AL. Functional assembly of accessory optic system circuitry critical for compensatory eye movements. Neuron 2015; 86:971-984. [PMID: 25959730 DOI: 10.1016/j.neuron.2015.03.064] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 02/09/2015] [Accepted: 03/24/2015] [Indexed: 10/23/2022]
Abstract
Accurate motion detection requires neural circuitry that compensates for global visual field motion. Select subtypes of retinal ganglion cells perceive image motion and connect to the accessory optic system (AOS) in the brain, which generates compensatory eye movements that stabilize images during slow visual field motion. Here, we show that the murine transmembrane semaphorin 6A (Sema6A) is expressed in a subset of On direction-selective ganglion cells (On DSGCs) and is required for retinorecipient axonal targeting to the medial terminal nucleus (MTN) of the AOS. Plexin A2 and A4, two Sema6A binding partners, are expressed in MTN cells, attract Sema6A(+) On DSGC axons, and mediate MTN targeting of Sema6A(+) RGC projections. Furthermore, Sema6A/Plexin-A2/A4 signaling is required for the functional output of the AOS. These data reveal molecular mechanisms underlying the assembly of AOS circuits critical for moving image perception.
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Affiliation(s)
- Lu O Sun
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Colleen M Brady
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hugh Cahill
- Department of Molecular Biology and Genetics, Department of Neuroscience, Department of Ophthalmology, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Timour Al-Khindi
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hiraki Sakuta
- Division of Molecular Neuroscience, National Institute for Basic Biology, 5-1 Higashiyama, Myodaiji-cho, Okazaki 444-8787, Japan
| | - Onkar S Dhande
- Department of Neurosciences, Neurobiology Section in the Division of Biological Sciences, Department of Ophthalmology, University of California, San Diego, San Diego, CA 92093, USA
| | - Masaharu Noda
- Division of Molecular Neuroscience, National Institute for Basic Biology, 5-1 Higashiyama, Myodaiji-cho, Okazaki 444-8787, Japan
| | - Andrew D Huberman
- Department of Neurosciences, Neurobiology Section in the Division of Biological Sciences, Department of Ophthalmology, University of California, San Diego, San Diego, CA 92093, USA
| | - Jeremy Nathans
- Department of Molecular Biology and Genetics, Department of Neuroscience, Department of Ophthalmology, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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13
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Contactin-4 mediates axon-target specificity and functional development of the accessory optic system. Neuron 2015; 86:985-999. [PMID: 25959733 DOI: 10.1016/j.neuron.2015.04.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 02/19/2015] [Accepted: 03/31/2015] [Indexed: 12/31/2022]
Abstract
The mammalian eye-to-brain pathway includes more than 20 parallel circuits, each consisting of precise long-range connections between specific sets of retinal ganglion cells (RGCs) and target structures in the brain. The mechanisms that drive assembly of these parallel connections and the functional implications of their specificity remain unresolved. Here we show that in the absence of contactin 4 (CNTN4) or one of its binding partners, amyloid precursor protein (APP), a subset of direction-selective RGCs fail to target the nucleus of the optic tract (NOT)--the accessory optic system (AOS) target controlling horizontal image stabilization. Conversely, ectopic expression of CNTN4 biases RGCs to arborize in the NOT, and that process also requires APP. Our data reveal critical and novel roles for CNTN4/APP in promoting target-specific axon arborization, and they highlight the importance of this process for functional development of a behaviorally relevant parallel visual pathway.
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14
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Schmidt ERE, Brignani S, Adolfs Y, Lemstra S, Demmers J, Vidaki M, Donahoo ALS, Lilleväli K, Vasar E, Richards LJ, Karagogeos D, Kolk SM, Pasterkamp RJ. Subdomain-mediated axon-axon signaling and chemoattraction cooperate to regulate afferent innervation of the lateral habenula. Neuron 2014; 83:372-387. [PMID: 25033181 DOI: 10.1016/j.neuron.2014.05.036] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2014] [Indexed: 11/20/2022]
Abstract
A dominant feature of neural circuitry is the organization of neuronal projections and synapses into specific brain nuclei or laminae. Lamina-specific connectivity is controlled by the selective expression of extracellular guidance and adhesion molecules in the target field. However, how (sub)nucleus-specific connections are established and whether axon-derived cues contribute to subdomain targeting are largely unknown. Here, we demonstrate that the lateral subnucleus of the habenula (lHb) determines its own afferent innervation by sending out efferent projections that express the cell adhesion molecule LAMP to reciprocally collect and guide dopaminergic afferents to the lHb-a phenomenon we term subdomain-mediated axon-axon signaling. This process of reciprocal axon-axon interactions cooperates with lHb-specific chemoattraction mediated by Netrin-1, which controls axon target entry, to ensure specific innervation of the lHb. We propose that cooperation between pretarget reciprocal axon-axon signaling and subdomain-restricted instructive cues provides a highly precise and general mechanism to establish subdomain-specific neural circuitry.
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Affiliation(s)
- Ewoud Roberto Eduard Schmidt
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Sara Brignani
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Youri Adolfs
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Suzanne Lemstra
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Jeroen Demmers
- Proteomics Centre and Department of Cell Biology, Erasmus University Medical Centre, Dr Molewaterplein 50, 3015 GE Rotterdam, the Netherlands
| | - Marina Vidaki
- Department of Basic Science, Faculty of Medicine, University of Crete and Institute of Molecular Biology and Biotechnology, Vassilika Vouton, Heraklion GR-7110, Greece
| | - Amber-Lee Skye Donahoo
- Queensland Brain Institute and The School of Biomedical Sciences, University of Queensland, Building 79, St Lucia Campus, Brisbane, QLD 4067, Australia
| | - Kersti Lilleväli
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia
| | - Eero Vasar
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia
| | - Linda Jane Richards
- Queensland Brain Institute and The School of Biomedical Sciences, University of Queensland, Building 79, St Lucia Campus, Brisbane, QLD 4067, Australia
| | - Domna Karagogeos
- Department of Basic Science, Faculty of Medicine, University of Crete and Institute of Molecular Biology and Biotechnology, Vassilika Vouton, Heraklion GR-7110, Greece
| | - Sharon Margriet Kolk
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Ronald Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands.
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15
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Mei X, Westfall TA, Zhang Q, Sheffield VC, Bassuk AG, Slusarski DC. Functional characterization of Prickle2 and BBS7 identify overlapping phenotypes yet distinct mechanisms. Dev Biol 2014; 392:245-55. [PMID: 24938409 DOI: 10.1016/j.ydbio.2014.05.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/14/2014] [Accepted: 05/24/2014] [Indexed: 01/04/2023]
Abstract
Ciliopathies are genetic disorders that are caused by dysfunctional cilia and affect multiple organs. One type of ciliopathy, Bardet-Biedl syndrome, is a rare disorder characterized by obesity, retinitis pigmentosa, polydactyly, mental retardation and susceptibility to cardiovascular diseases. The Wnt/Planar cell polarity (PCP) has been associated with cilia function and ciliogenesis in directing the orientation of cilia and basal bodies. Yet the exact relationship between PCP and ciliopathy is not well understood. Here, we examine interactions between a core PCP component, Prickle2 (Pk2), and a central BBS gene, Bbs7, using gene knockdown in the zebrafish. pk2 and bbs7 knockdown both disrupt the formation of a ciliated organ, the Kupffer׳s vesicle (KV), but do not display a synergistic interaction. By measuring cell polarity in the neural tube, we find that bbs7 activity is not required for Pk asymmetric localization. Moreover, BBS protein complex formation is preserved in the Pk2-deficient (Pk2(-/-)) mouse. Previously we reported an intracellular melanosome transport delay as a cardinal feature of reduced bbs gene activity. We find that pk2 knockdown suppresses bbs7-related retrograde transport delay. Similarly, knockdown of ift22, an anterograde intraflagellar transport component, also suppresses the bbs7-related retrograde delay. Notably, we find that pk2 knockdown larvae show a delay in anterograde transport. These data suggest a novel role for Pk2 in directional intracellular transport and our analyses show that PCP and BBS function independently, yet result in overlapping phenotypes when knocked down in zebrafish.
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Affiliation(s)
- Xue Mei
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | - Trudi A Westfall
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | - Qihong Zhang
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Howard Hughes Medical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Val C Sheffield
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Howard Hughes Medical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Diane C Slusarski
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA.
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16
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Qiu H, Lee S, Shang Y, Wang WY, Au KF, Kamiya S, Barmada SJ, Finkbeiner S, Lui H, Carlton CE, Tang AA, Oldham MC, Wang H, Shorter J, Filiano AJ, Roberson ED, Tourtellotte WG, Chen B, Tsai LH, Huang EJ. ALS-associated mutation FUS-R521C causes DNA damage and RNA splicing defects. J Clin Invest 2014; 124:981-99. [PMID: 24509083 DOI: 10.1172/jci72723] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/27/2013] [Indexed: 12/20/2022] Open
Abstract
Autosomal dominant mutations of the RNA/DNA binding protein FUS are linked to familial amyotrophic lateral sclerosis (FALS); however, it is not clear how FUS mutations cause neurodegeneration. Using transgenic mice expressing a common FALS-associated FUS mutation (FUS-R521C mice), we found that mutant FUS proteins formed a stable complex with WT FUS proteins and interfered with the normal interactions between FUS and histone deacetylase 1 (HDAC1). Consequently, FUS-R521C mice exhibited evidence of DNA damage as well as profound dendritic and synaptic phenotypes in brain and spinal cord. To provide insights into these defects, we screened neural genes for nucleotide oxidation and identified brain-derived neurotrophic factor (Bdnf) as a target of FUS-R521C-associated DNA damage and RNA splicing defects in mice. Compared with WT FUS, mutant FUS-R521C proteins formed a more stable complex with Bdnf RNA in electrophoretic mobility shift assays. Stabilization of the FUS/Bdnf RNA complex contributed to Bdnf splicing defects and impaired BDNF signaling through receptor TrkB. Exogenous BDNF only partially restored dendrite phenotype in FUS-R521C neurons, suggesting that BDNF-independent mechanisms may contribute to the defects in these neurons. Indeed, RNA-seq analyses of FUS-R521C spinal cords revealed additional transcription and splicing defects in genes that regulate dendritic growth and synaptic functions. Together, our results provide insight into how gain-of-function FUS mutations affect critical neuronal functions.
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17
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Baier H. Synaptic laminae in the visual system: molecular mechanisms forming layers of perception. Annu Rev Cell Dev Biol 2013; 29:385-416. [PMID: 24099086 DOI: 10.1146/annurev-cellbio-101011-155748] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Synaptic connections between neurons form the basis for perception and behavior. Synapses are often clustered in space, forming stereotyped layers. In the retina and optic tectum, multiple such synaptic laminae are stacked on top of each other, giving rise to stratified neuropil regions in which each layer combines synapses responsive to a particular sensory feature. Recently, several cellular and molecular mechanisms that underlie the development of multilaminar arrays of synapses have been discovered. These mechanisms include neurite guidance and cell-cell recognition. Molecules of the Slit, Semaphorin, Netrin, and Hedgehog families, binding to their matching receptors, bring axons and dendrites into spatial register. These guidance cues may diffuse over short distances or bind to sheets of extracellular matrix, thus conditioning the local extracellular milieu, or are presented on the surface of cells bordering the future neuropil. In addition, mutual recognition of axons and dendrites through adhesion molecules with immunoglobulin domains ensures cell type-specific connections within a given layer. Thus, an elaborate genetic program assembles the parallel processing channels that underlie visual perception.
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Affiliation(s)
- Herwig Baier
- Genes - Circuits - Behavior, Max Planck Institute of Neurobiology, 82152 Martinsried near Munich, Germany;
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18
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Round J, Ross B, Angel M, Shields K, Lom B. Slitrk gene duplication and expression in the developing zebrafish nervous system. Dev Dyn 2013; 243:339-49. [PMID: 24123428 DOI: 10.1002/dvdy.24076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/03/2013] [Accepted: 10/03/2013] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The Slitrk family of leucine-rich repeat (LRR) transmembrane proteins bears structural similarity to the Slits and the Trk receptor families, which exert well-established roles in directing nervous system development. Slitrks are less well understood, although they are highly expressed in the developing vertebrate nervous system. Moreover, slitrk variants are associated with several sensory and neuropsychiatric disorders, including myopia, deafness, obsessive-compulsive disorder (OCD), schizophrenia, and Tourette syndrome. Loss-of-function studies in mice show that Slitrks modulate neurite outgrowth and inhibitory synapse formation, although the molecular mechanisms of Slitrk function remain poorly characterized. RESULTS As a prelude to examining the functional roles of Slitrks, we identified eight slitrk orthologs in zebrafish and observed that seven of the eight orthologs were actively transcribed in the nervous system at embryonic, larval, and adult stages. Similar to previous findings in mice and humans, zebrafish slitrks exhibited unique but overlapping spatial and temporal expression patterns in the developing brain, retina, and spinal cord. CONCLUSIONS Zebrafish express Slitrks in the developing central nervous system at times and locations important to neuronal morphogenesis and synaptogenesis. Future studies will use zebrafish as a convenient, cost-effective model organism to characterize the functional roles of Slitrks in nervous system development.
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Affiliation(s)
- Jennifer Round
- Department of Biology and Program in Neuroscience, Davidson College, Davidson, North Carolina
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