1
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Yoo J, Dombrovski M, Mirshahidi P, Nern A, LoCascio SA, Zipursky SL, Kurmangaliyev YZ. Brain wiring determinants uncovered by integrating connectomes and transcriptomes. Curr Biol 2023; 33:3998-4005.e6. [PMID: 37647901 DOI: 10.1016/j.cub.2023.08.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/12/2023] [Accepted: 08/04/2023] [Indexed: 09/01/2023]
Abstract
Advances in brain connectomics have demonstrated the extraordinary complexity of neural circuits.1,2,3,4,5 Developing neurons encounter the axons and dendrites of many different neuron types and form synapses with only a subset of them. During circuit assembly, neurons express cell-type-specific repertoires comprising many cell adhesion molecules (CAMs) that can mediate interactions between developing neurites.6,7,8 Many CAM families have been shown to contribute to brain wiring in different ways.9,10 It has been challenging, however, to identify receptor-ligand pairs directly matching neurons with their synaptic targets. Here, we integrated the synapse-level connectome of the neural circuit11,12 with the developmental expression patterns7 and binding specificities of CAMs6,13 on pre- and postsynaptic neurons in the Drosophila visual system. To overcome the complexity of neural circuits, we focus on pairs of genetically related neurons that make differential wiring choices. In the motion detection circuit,14 closely related subtypes of T4/T5 neurons choose between alternative synaptic targets in adjacent layers of neuropil.12 This choice correlates with the matching expression in synaptic partners of different receptor-ligand pairs of the Beat and Side families of CAMs. Genetic analysis demonstrated that presynaptic Side-II and postsynaptic Beat-VI restrict synaptic partners to the same layer. Removal of this receptor-ligand pair disrupts layers and leads to inappropriate targeting of presynaptic sites and postsynaptic dendrites. We propose that different Side/Beat receptor-ligand pairs collaborate with other recognition molecules to determine wiring specificities in the fly brain. Combining transcriptomes, connectomes, and protein interactome maps allow unbiased identification of determinants of brain wiring.
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Affiliation(s)
- Juyoun Yoo
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mark Dombrovski
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Parmis Mirshahidi
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Aljoscha Nern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Samuel A LoCascio
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - S Lawrence Zipursky
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Yerbol Z Kurmangaliyev
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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2
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Guedes JR, Ferreira PA, Costa JM, Cardoso AL, Peça J. Microglia-dependent remodeling of neuronal circuits. J Neurochem 2022; 163:74-93. [PMID: 35950924 PMCID: PMC9826178 DOI: 10.1111/jnc.15689] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 08/05/2022] [Accepted: 08/09/2022] [Indexed: 01/11/2023]
Abstract
Microglia are tissue-resident macrophages responsible for the surveillance, neuronal support, and immune defense of the brain parenchyma. Recently, the role played by microglia in the formation and function of neuronal circuits has garnered substantial attention. During development, microglia have been shown to engulf neuronal precursors and participate in pruning mechanisms while, in the mature brain, they influence synaptic signaling, provide trophic support and shape synaptic plasticity. Recently, studies have unveiled different microglial characteristics associated with specific brain regions. This emerging view suggests that the maturation and function of distinct neuronal circuits may be potentially associated with the molecular identity microglia adopts across the brain. Here, we review and summarize the known role of these cells in the thalamus, hippocampus, cortex, and cerebellum. We focus on in vivo studies to highlight the characteristics of microglia that may be important in the remodeling of these neuronal circuits and in relation to neurodevelopmental and neuropsychiatric disorders.
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Affiliation(s)
- Joana R. Guedes
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal,Institute of Interdisciplinary Research (IIIUC), University of CoimbraCoimbraPortugal
| | - Pedro A. Ferreira
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal,Department of Life SciencesUniversity of CoimbraCoimbraPortugal
| | - Jéssica M. Costa
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal,Institute of Interdisciplinary Research (IIIUC), University of CoimbraCoimbraPortugal
| | - Ana L. Cardoso
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal,Institute of Interdisciplinary Research (IIIUC), University of CoimbraCoimbraPortugal
| | - João Peça
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal,Department of Life SciencesUniversity of CoimbraCoimbraPortugal
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3
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Kiral FR, Dutta SB, Linneweber GA, Hilgert S, Poppa C, Duch C, von Kleist M, Hassan BA, Hiesinger PR. Brain connectivity inversely scales with developmental temperature in Drosophila. Cell Rep 2021; 37:110145. [PMID: 34936868 DOI: 10.1016/j.celrep.2021.110145] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 10/04/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022] Open
Abstract
Variability of synapse numbers and partners despite identical genes reveals the limits of genetic determinism. Here, we use developmental temperature as a non-genetic perturbation to study variability of brain wiring and behavior in Drosophila. Unexpectedly, slower development at lower temperatures increases axo-dendritic branching, synapse numbers, and non-canonical synaptic partnerships of various neurons, while maintaining robust ratios of canonical synapses. Using R7 photoreceptors as a model, we show that changing the relative availability of synaptic partners using a DIPγ mutant that ablates R7's preferred partner leads to temperature-dependent recruitment of non-canonical partners to reach normal synapse numbers. Hence, R7 synaptic specificity is not absolute but based on the relative availability of postsynaptic partners and presynaptic control of synapse numbers. Behaviorally, movement precision is temperature robust, while movement activity is optimized for the developmentally encountered temperature. These findings suggest genetically encoded relative and scalable synapse formation to develop functional, but not identical, brains and behaviors.
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Affiliation(s)
- Ferdi Ridvan Kiral
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Suchetana B Dutta
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Gerit Arne Linneweber
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Selina Hilgert
- Institute of Developmental Biology and Neurobiology (iDN), Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Caroline Poppa
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Carsten Duch
- Institute of Developmental Biology and Neurobiology (iDN), Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Max von Kleist
- MF1 Bioinformatics, Robert Koch-Institute, 13353 Berlin, Germany
| | - Bassem A Hassan
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany; Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - P Robin Hiesinger
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany.
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4
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Levitt JJ, Zhang F, Vangel M, Nestor PG, Rathi Y, Kubicki M, Shenton ME, O'Donnell LJ. The Organization of Frontostriatal Brain Wiring in Healthy Subjects Using a Novel Diffusion Imaging Fiber Cluster Analysis. Cereb Cortex 2021; 31:5308-5318. [PMID: 34180506 DOI: 10.1093/cercor/bhab159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/14/2022] Open
Abstract
To assess normal organization of frontostriatal brain wiring, we analyzed diffusion magnetic resonance imaging (dMRI) scans in 100 young adult healthy subjects (HSs). We identified fiber clusters intersecting the frontal cortex and caudate, a core component of associative striatum, and quantified their degree of deviation from a strictly topographic pattern. Using whole brain dMRI tractography and an automated tract parcellation clustering method, we extracted 17 white matter fiber clusters per hemisphere connecting the frontal cortex and caudate. In a novel approach to quantify the geometric relationship among clusters, we measured intercluster endpoint distances between corresponding cluster pairs in the frontal cortex and caudate. We show first, the overall frontal cortex wiring pattern of the caudate deviates from a strictly topographic organization due to significantly greater convergence in regionally specific clusters; second, these significantly convergent clusters originate in subregions of ventrolateral, dorsolateral, and orbitofrontal prefrontal cortex (PFC); and, third, a similar organization in both hemispheres. Using a novel tractography method, we find PFC-caudate brain wiring in HSs deviates from a strictly topographic organization due to a regionally specific pattern of cluster convergence. We conjecture cortical subregions projecting to the caudate with greater convergence subserve functions that benefit from greater circuit integration.
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Affiliation(s)
- J J Levitt
- Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton MA 02301, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA.,Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - F Zhang
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - M Vangel
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - P G Nestor
- Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton MA 02301, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA.,Department of Psychology, University of Massachusetts, Boston, MA 02125, USA
| | - Y Rathi
- Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - M Kubicki
- Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.,Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - M E Shenton
- Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.,Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - L J O'Donnell
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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5
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Wildenberg GA, Rosen MR, Lundell J, Paukner D, Freedman DJ, Kasthuri N. Primate neuronal connections are sparse in cortex as compared to mouse. Cell Rep 2021; 36:109709. [PMID: 34525373 DOI: 10.1016/j.celrep.2021.109709] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/30/2021] [Accepted: 08/20/2021] [Indexed: 12/29/2022] Open
Abstract
Detailing how primate and mouse neurons differ is critical for creating generalized models of how neurons process information. We reconstruct 15,748 synapses in adult Rhesus macaques and mice and ask how connectivity differs on identified cell types in layer 2/3 of primary visual cortex. Primate excitatory and inhibitory neurons receive 2-5 times fewer excitatory and inhibitory synapses than similar mouse neurons. Primate excitatory neurons have lower excitatory-to-inhibitory (E/I) ratios than mouse but similar E/I ratios in inhibitory neurons. In both species, properties of inhibitory axons such as synapse size and frequency are unchanged, and inhibitory innervation of excitatory neurons is local and specific. Using artificial recurrent neural networks (RNNs) optimized for different cognitive tasks, we find that penalizing networks for creating and maintaining synapses, as opposed to neuronal firing, reduces the number of connections per node as the number of nodes increases, similar to primate neurons compared with mice.
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Affiliation(s)
- Gregg A Wildenberg
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; Argonne National Laboratory, Lemont, IL 60439, USA.
| | - Matt R Rosen
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Jack Lundell
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Dawn Paukner
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - David J Freedman
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Narayanan Kasthuri
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; Argonne National Laboratory, Lemont, IL 60439, USA.
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6
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Levitt JJ, Nestor PG, Kubicki M, Lyall AE, Zhang F, Riklin-Raviv T, O′Donnell LJ, McCarley RW, Shenton ME, Rathi Y. Miswiring of Frontostriatal Projections in Schizophrenia. Schizophr Bull 2020; 46:990-998. [PMID: 31990358 PMCID: PMC7342176 DOI: 10.1093/schbul/sbz129] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We investigated brain wiring in chronic schizophrenia and healthy controls in frontostriatal circuits using diffusion magnetic resonance imaging tractography in a novel way. We extracted diffusion streamlines in 27 chronic schizophrenia and 26 healthy controls connecting 4 frontal subregions to the striatum. We labeled the projection zone striatal surface voxels into 2 subtypes: dominant-input from a single cortical subregion, and, functionally integrative, with mixed-input from diverse cortical subregions. We showed: 1) a group difference for total striatal surface voxel number (P = .045) driven by fewer mixed-input voxels in the left (P = .007), but not right, hemisphere; 2) a group by hemisphere interaction for the ratio quotient between voxel subtypes (P = .04) with a left (P = .006), but not right, hemisphere increase in schizophrenia, also reflecting fewer mixed-input voxels; and 3) fewer mixed-input voxel counts in schizophrenia (P = .045) driven by differences in left hemisphere limbic (P = .007) and associative (P = .01), but not sensorimotor, striatum. These results demonstrate a less integrative pattern of frontostriatal structural connectivity in chronic schizophrenia. A diminished integrative pattern yields a less complex input pattern to the striatum from the cortex with less circuit integration at the level of the striatum. Further, as brain wiring occurs during early development, aberrant brain wiring could serve as a developmental biomarker for schizophrenia.
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Affiliation(s)
- James J Levitt
- Clinical Neuroscience Division, Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton, MA, Harvard Medical School, Boston, MA,Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,To whom correspondence should be addressed; Department of Psychiatry-116A, VA Boston Healthcare System, Harvard Medical School, 940 Belmont Street, Brockton, MA 02301; tel: (508) 583-4500 x61798, fax: 617-525-6150, e-mail:
| | - Paul G Nestor
- Clinical Neuroscience Division, Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton, MA, Harvard Medical School, Boston, MA,Department of Psychology, University of Massachusetts, Boston, MA
| | - Marek Kubicki
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Amanda E Lyall
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Fan Zhang
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Tammy Riklin-Raviv
- Department of Electrical and Computer Engineering, Ben Gurion University, Beer-Sheva, Israel
| | - Lauren J O′Donnell
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Robert W McCarley
- Clinical Neuroscience Division, Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton, MA, Harvard Medical School, Boston, MA
| | - Martha E Shenton
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA,VA Boston Healthcare System, Brockton Division, Brockton, MA
| | - Yogesh Rathi
- Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA
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7
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Guo J, Otis JM, Suciu SK, Catalano C, Xing L, Constable S, Wachten D, Gupton S, Lee J, Lee A, Blackley KH, Ptacek T, Simon JM, Schurmans S, Stuber GD, Caspary T, Anton ES. Primary Cilia Signaling Promotes Axonal Tract Development and Is Disrupted in Joubert Syndrome-Related Disorders Models. Dev Cell 2019; 51:759-774.e5. [PMID: 31846650 DOI: 10.1016/j.devcel.2019.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/08/2019] [Accepted: 11/10/2019] [Indexed: 12/18/2022]
Abstract
Appropriate axonal growth and connectivity are essential for functional wiring of the brain. Joubert syndrome-related disorders (JSRD), a group of ciliopathies in which mutations disrupt primary cilia function, are characterized by axonal tract malformations. However, little is known about how cilia-driven signaling regulates axonal growth and connectivity. We demonstrate that the deletion of related JSRD genes, Arl13b and Inpp5e, in projection neurons leads to de-fasciculated and misoriented axonal tracts. Arl13b deletion disrupts the function of its downstream effector, Inpp5e, and deregulates ciliary-PI3K/AKT signaling. Chemogenetic activation of ciliary GPCR signaling and cilia-specific optogenetic modulation of downstream second messenger cascades (PI3K, AKT, and AC3) commonly regulated by ciliary signaling receptors induce rapid changes in axonal dynamics. Further, Arl13b deletion leads to changes in transcriptional landscape associated with dysregulated PI3K/AKT signaling. These data suggest that ciliary signaling acts to modulate axonal connectivity and that impaired primary cilia signaling underlies axonal tract defects in JSRD.
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8
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Bellon A, Iyer A, Bridi S, Lee FCY, Ovando-Vázquez C, Corradi E, Longhi S, Roccuzzo M, Strohbuecker S, Naik S, Sarkies P, Miska E, Abreu-Goodger C, Holt CE, Baudet ML. miR-182 Regulates Slit2-Mediated Axon Guidance by Modulating the Local Translation of a Specific mRNA. Cell Rep 2017; 18:1171-1186. [PMID: 28147273 PMCID: PMC5300892 DOI: 10.1016/j.celrep.2016.12.093] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 12/07/2016] [Accepted: 12/27/2016] [Indexed: 11/15/2022] Open
Abstract
During brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mRNA translation. Different guidance cues elicit translation of subsets of mRNAs that differentially regulate the cytoskeleton, yet little is understood about how specific mRNAs are selected for translation. MicroRNAs (miRNAs) are critical translational regulators that act through a sequence-specific mechanism. Here, we investigate the local role of miRNAs in mRNA-specific translation during pathfinding of Xenopus laevis retinal ganglion cell (RGC) axons. Among a rich repertoire of axonal miRNAs, miR-182 is identified as the most abundant. Loss of miR-182 causes RGC axon targeting defects in vivo and impairs Slit2-induced growth cone (GC) repulsion. We find that miR-182 targets cofilin-1 mRNA, silencing its translation, and Slit2 rapidly relieves the repression without causing miR-182 degradation. Our data support a model whereby miR-182 reversibly gates the selection of transcripts for fast translation depending on the extrinsic cue. Small RNA-seq analysis reveals that miR-182 is the most abundant miRNA in RGC axons miR-182 regulates Slit2-mediated axon guidance of RGCs in vitro and in vivo miR-182 silences cofilin-1 local protein synthesis in growth cones Slit2 rapidly lifts miR-182-mediated repression of cofilin-1 without degrading it
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Affiliation(s)
- Anaïs Bellon
- PDN Department, University of Cambridge, Cambridge CB23DY, UK
| | - Archana Iyer
- CIBIO, University of Trento, Trento 38123, Italy
| | - Simone Bridi
- CIBIO, University of Trento, Trento 38123, Italy
| | - Flora C Y Lee
- PDN Department, University of Cambridge, Cambridge CB23DY, UK
| | | | | | - Sara Longhi
- CIBIO, University of Trento, Trento 38123, Italy
| | | | | | - Sindhu Naik
- CIBIO, University of Trento, Trento 38123, Italy
| | - Peter Sarkies
- Gurdon Institute, University of Cambridge, Cambridge CB21QN, UK
| | - Eric Miska
- Gurdon Institute, University of Cambridge, Cambridge CB21QN, UK
| | - Cei Abreu-Goodger
- Unidad de Genómica Avanzada (Langebio), Cinvestav, Irapuato 36821, Mexico
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9
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Oliva C, Soldano A, Mora N, De Geest N, Claeys A, Erfurth ML, Sierralta J, Ramaekers A, Dascenco D, Ejsmont RK, Schmucker D, Sanchez-Soriano N, Hassan BA. Regulation of Drosophila Brain Wiring by Neuropil Interactions via a Slit-Robo-RPTP Signaling Complex. Dev Cell 2016; 39:267-78. [PMID: 27780041 DOI: 10.1016/j.devcel.2016.09.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 03/29/2016] [Accepted: 08/25/2016] [Indexed: 11/05/2022]
Abstract
The axonal wiring molecule Slit and its Round-About (Robo) receptors are conserved regulators of nerve cord patterning. Robo receptors also contribute to wiring brain circuits. Whether molecular mechanisms regulating these signals are modified to fit more complex brain wiring processes is unclear. We investigated the role of Slit and Robo receptors in wiring Drosophila higher-order brain circuits and identified differences in the cellular and molecular mechanisms of Robo/Slit function. First, we find that signaling by Robo receptors in the brain is regulated by the Receptor Protein Tyrosine Phosphatase RPTP69d. RPTP69d increases membrane availability of Robo3 without affecting its phosphorylation state. Second, we detect no midline localization of Slit during brain development. Instead, Slit is enriched in the mushroom body, a neuronal structure covering large areas of the brain. Thus, a divergent molecular mechanism regulates neuronal circuit wiring in the Drosophila brain, partly in response to signals from the mushroom body. In the Drosophila brain, mushroom bodies are a source of the Slit guidance cue Slit regulates axon growth in the vicinity of mushroom bodies via Robo receptors The phosphatase RPTP69D regulates Robo signaling in the brain RPTP69D regulates Robo3 membrane presentation independent of its enzymatic activity
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10
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Abstract
Visual systems have a rich history as model systems for the discovery and understanding of basic principles underlying neuronal connectivity. The compound eyes of insects consist of up to thousands of small unit eyes that are connected by photoreceptor axons to set up a visual map in the brain. The photoreceptor axon terminals thereby represent neighboring points seen in the environment in neighboring synaptic units in the brain. Neural superposition is a special case of such a wiring principle, where photoreceptors from different unit eyes that receive the same input converge upon the same synaptic units in the brain. This wiring principle is remarkable, because each photoreceptor in a single unit eye receives different input and each individual axon, among thousands others in the brain, must be sorted together with those few axons that have the same input. Key aspects of neural superposition have been described as early as 1907. Since then neuroscientists, evolutionary and developmental biologists have been fascinated by how such a complicated wiring principle could evolve, how it is genetically encoded, and how it is developmentally realized. In this review article, we will discuss current ideas about the evolutionary origin and developmental program of neural superposition. Our goal is to identify in what way the special case of neural superposition can help us answer more general questions about the evolution and development of genetically “hard-wired” synaptic connectivity in the brain.
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Affiliation(s)
- Egemen Agi
- Green Center for Systems Biology, University of Texas Southwestern Medical Center , Dallas, TX , USA
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11
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Cristovão G, Pinto MJ, Cunha RA, Almeida RD, Gomes CA. Activation of microglia bolsters synapse formation. Front Cell Neurosci 2014; 8:153. [PMID: 24917790 PMCID: PMC4040490 DOI: 10.3389/fncel.2014.00153] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 05/13/2014] [Indexed: 11/20/2022] Open
Affiliation(s)
- Gonçalo Cristovão
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - Maria J Pinto
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal ; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal ; Faculty of Medicine, Biochemistry, University of Coimbra Coimbra, Portugal
| | - Ramiro D Almeida
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - Catarina A Gomes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal ; Faculty of Medicine, Pharmacology and Experimental Therapeutics, University of Coimbra Coimbra, Portugal
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