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Wouterlood FG. Techniques to Render Dendritic Spines Visible in the Microscope. ADVANCES IN NEUROBIOLOGY 2023; 34:69-102. [PMID: 37962794 DOI: 10.1007/978-3-031-36159-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
A tiny detail visible on certain neurons at the limit of resolution in light microscopy went in 130 years of neuroscience research through a dazzling career from suspicious staining artifact to what we recognize today as a complex postsynaptic molecular machine: the dendritic spine.This chapter deals with techniques to make spines visible. The original technique, Golgi silver staining, is still being used today. Electron microscopy and automated field ion beam scanning electron microscopy are ultrahigh resolution techniques, albeit specialized. Other methods are intracellular injection, uptake of dyes, and recently the exploitation of genetically modified animals in which certain neurons express fluorescent protein in all their processes, including the nooks and crannies of their dendritic spines.
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Affiliation(s)
- Floris G Wouterlood
- Department of Anatomy & Neurosciences, Amsterdam UMC, Amsterdam, The Netherlands
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2
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Ribeiro EA, Salery M, Scarpa JR, Calipari ES, Hamilton PJ, Ku SM, Kronman H, Purushothaman I, Juarez B, Heshmati M, Doyle M, Lardner C, Burek D, Strat A, Pirpinias S, Mouzon E, Han MH, Neve RL, Bagot RC, Kasarskis A, Koo JW, Nestler EJ. Transcriptional and physiological adaptations in nucleus accumbens somatostatin interneurons that regulate behavioral responses to cocaine. Nat Commun 2018; 9:3149. [PMID: 30089879 PMCID: PMC6082848 DOI: 10.1038/s41467-018-05657-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 07/12/2018] [Indexed: 11/20/2022] Open
Abstract
The role of somatostatin interneurons in nucleus accumbens (NAc), a key brain reward region, remains poorly understood due to the fact that these cells account for < 1% of NAc neurons. Here, we use optogenetics, electrophysiology, and RNA-sequencing to characterize the transcriptome and functioning of NAc somatostatin interneurons after repeated exposure to cocaine. We find that the activity of somatostatin interneurons regulates behavioral responses to cocaine, with repeated cocaine reducing the excitability of these neurons. Repeated cocaine also induces transcriptome-wide changes in gene expression within NAc somatostatin interneurons. We identify the JUND transcription factor as a key regulator of cocaine action and confirmed, by use of viral-mediated gene transfer, that JUND activity in somatostatin interneurons influences behavioral responses to cocaine. Our results identify alterations in NAc induced by cocaine in a sparse population of somatostatin interneurons, and illustrate the value of studying brain diseases using cell type-specific whole transcriptome RNA-sequencing.
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Affiliation(s)
- Efrain A Ribeiro
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Marine Salery
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Joseph R Scarpa
- Department of Genetics and Genomic Science, Icahn Institute of Genomics and Multiscale Biology, New York, 10029, NY, USA
| | - Erin S Calipari
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Peter J Hamilton
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Stacy M Ku
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, 10029, NY, USA
| | - Hope Kronman
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | | | - Barbara Juarez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, 10029, NY, USA
| | - Mitra Heshmati
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Marie Doyle
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Casey Lardner
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Dominicka Burek
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Ana Strat
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Stephen Pirpinias
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Ezekiell Mouzon
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
| | - Ming-Hu Han
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, 10029, NY, USA
| | - Rachael L Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Rosemary C Bagot
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
- Department of Psychology, McGill University, Québec, H3A 1B1, Montreal, Canada
| | - Andrew Kasarskis
- Department of Genetics and Genomic Science, Icahn Institute of Genomics and Multiscale Biology, New York, 10029, NY, USA
| | - Ja Wook Koo
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
| | - Eric J Nestler
- Department of Neuroscience, Friedman Brain Institute, New York, 10029, NY, USA.
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3
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Mitchell AC, Javidfar B, Pothula V, Ibi D, Shen EY, Peter CJ, Bicks L, Fehr T, Jiang Y, Brennand KJ, Neve RL, Gonzalez-Maeso J, Akbarian S. MEF2C transcription factor is associated with the genetic and epigenetic risk architecture of schizophrenia and improves cognition in mice. Mol Psychiatry 2018; 23:123-132. [PMID: 28115742 PMCID: PMC5966823 DOI: 10.1038/mp.2016.254] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/30/2016] [Accepted: 12/06/2016] [Indexed: 12/20/2022]
Abstract
Large-scale consortia mapping the genomic risk architectures of schizophrenia provide vast amounts of molecular information, with largely unexplored therapeutic potential. We harnessed publically available information from the Psychiatric Genomics Consortium, and report myocyte enhancer factor 2C (MEF2C) motif enrichment in sequences surrounding the top scoring single-nucleotide polymorphisms within risk loci contributing by individual small effect to disease heritability. Chromatin profiling at base-pair resolution in neuronal nucleosomes extracted from prefrontal cortex of 34 subjects, including 17 cases diagnosed with schizophrenia, revealed MEF2C motif enrichment within cis-regulatory sequences, including neuron-specific promoters and superenhancers, affected by histone H3K4 hypermethylation in disease cases. Vector-induced short- and long-term Mef2c upregulation in mouse prefrontal projection neurons consistently resulted in enhanced cognitive performance in working memory and object recognition paradigms at baseline and after psychotogenic drug challenge, in conjunction with remodeling of local connectivity. Neuronal genome tagging in vivo by Mef2c-Dam adenine methyltransferase fusion protein confirmed the link between cognitive enhancement and MEF2C occupancy at promoters harboring canonical and variant MEF2C motifs. The multilayered integrative approaches presented here provide a roadmap to uncover the therapeutic potential of transcriptional regulators for schizophrenia and related disorders.
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Affiliation(s)
- Amanda C. Mitchell
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Behnam Javidfar
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Venu Pothula
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Daisuke Ibi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Erica Y. Shen
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Cyril J. Peter
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Lucy Bicks
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Tristan Fehr
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Yan Jiang
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Kristen J. Brennand
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Rachael L. Neve
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge MA02139, USA
| | - Javier Gonzalez-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University Medical School, Richmond, Virginia 23298, USA
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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4
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Jiang Y, Loh YHE, Rajarajan P, Hirayama T, Liao W, Kassim BS, Javidfar B, Hartley BJ, Kleofas L, Park RB, Labonte B, Ho SM, Chandrasekaran S, Do C, Ramirez BR, Peter CJ, C W JT, Safaie BM, Morishita H, Roussos P, Nestler EJ, Schaefer A, Tycko B, Brennand KJ, Yagi T, Shen L, Akbarian S. The methyltransferase SETDB1 regulates a large neuron-specific topological chromatin domain. Nat Genet 2017; 49:1239-1250. [PMID: 28671686 PMCID: PMC5560095 DOI: 10.1038/ng.3906] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/05/2017] [Indexed: 12/14/2022]
Abstract
We report locus-specific disintegration of megabase-scale chromosomal conformations in brain after neuronal ablation of Kmt1e/Setdb1 histone H3-lysine 9 methyltransferase, including a large topologically associated 1.2Mb domain conserved in human and mouse and encompassing >70 genes at the clustered Protocadherin (cPcdh) locus. TADcPcdh in mutant neurons showed abnormal accumulations of CTCF transcriptional regulator and 3D genome organizer at cryptic binding sites, converted into permissive state with DNA cytosine hypomethylation and histone hyperacetylation. Broadly upregulated expression across cPcdh included defective S-type Protocadherin single-cell stochastic constraint. Setdb1-dependent loop formations, bypassing 0.2–1Mb of linear genome, radiated from TADPcdh fringes towards cPcdh cis-regulatory sequences, counterbalanced shorter-range facilitative promoter-enhancer contacts and carried loop-bound polymorphisms associated with genetic risk for schizophrenia. We show that KRAB-zinc finger Setdb1 repressor complex, shielding neuronal 3D genomes from excess CTCF binding, is critically required for structural maintenance of TADcPcdh.
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Affiliation(s)
- Yan Jiang
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yong-Hwee Eddie Loh
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Prashanth Rajarajan
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Teruyoshi Hirayama
- Kokoro-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Will Liao
- New York Genome Center, New York, New York, USA
| | - Bibi S Kassim
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Behnam Javidfar
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Brigham J Hartley
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Lisa Kleofas
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Royce B Park
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benoit Labonte
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Seok-Man Ho
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Sandhya Chandrasekaran
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Catherine Do
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA.,Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York, USA
| | - Brianna R Ramirez
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Cyril J Peter
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Julia T C W
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Brian M Safaie
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hirofumi Morishita
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Panos Roussos
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Mental Illness Research, Education and Clinical Center, James J. Peters Virginia Medical Center, New York, New York, USA
| | - Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Anne Schaefer
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin Tycko
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA.,Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York, USA
| | - Kristen J Brennand
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Takeshi Yagi
- Kokoro-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Li Shen
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Schahram Akbarian
- Friedman Brain Institute and Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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5
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Saiepour MH, Chakravarthy S, Min R, Levelt CN. Competition and Homeostasis of Excitatory and Inhibitory Connectivity in the Adult Mouse Visual Cortex. Cereb Cortex 2014; 25:3713-22. [PMID: 25316336 PMCID: PMC4585512 DOI: 10.1093/cercor/bhu245] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
During cortical development, synaptic competition regulates the formation and adjustment of neuronal connectivity. It is unknown whether synaptic competition remains active in the adult brain and how inhibitory neurons participate in this process. Using morphological and electrophysiological measurements, we show that expressing a dominant-negative form of the TrkB receptor (TrkB.T1) in the majority of pyramidal neurons in the adult visual cortex does not affect excitatory synapse densities. This is in stark contrast to the previously reported loss of excitatory input which occurs if the exact same transgene is expressed in sparse neurons at the same age. This indicates that synaptic competition remains active in adulthood. Additionally, we show that interneurons not expressing the TrkB.T1 transgene may have a competitive advantage and obtain more excitatory synapses when most neighboring pyramidal neurons do express the transgene. Finally, we demonstrate that inhibitory synapses onto pyramidal neurons are reduced when TrkB signaling is interfered with in most pyramidal neurons but not when few pyramidal neurons have this deficit. This adjustment of inhibitory innervation is therefore not a cell-autonomous consequence of decreased TrkB signaling but more likely a homeostatic mechanism compensating for activity changes at the population level.
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Affiliation(s)
- M Hadi Saiepour
- Department of Molecular Visual Plasticity, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105, The Netherlands
| | - Sridhara Chakravarthy
- Department of Molecular Visual Plasticity, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105, The Netherlands
| | - Rogier Min
- Department of Molecular Visual Plasticity, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105, The Netherlands
| | - Christiaan N Levelt
- Department of Molecular Visual Plasticity, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105, The Netherlands
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Kim JY, Ash RT, Ceballos-Diaz C, Levites Y, Golde TE, Smirnakis SM, Jankowsky JL. Viral transduction of the neonatal brain delivers controllable genetic mosaicism for visualising and manipulating neuronal circuits in vivo. Eur J Neurosci 2013; 37:1203-20. [PMID: 23347239 DOI: 10.1111/ejn.12126] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/09/2012] [Accepted: 12/12/2012] [Indexed: 12/19/2022]
Abstract
The neonatal intraventricular injection of adeno-associated virus has been shown to transduce neurons widely throughout the brain, but its full potential for experimental neuroscience has not been adequately explored. We report a detailed analysis of the method's versatility with an emphasis on experimental applications where tools for genetic manipulation are currently lacking. Viral injection into the neonatal mouse brain is fast, easy, and accesses regions of the brain including the cerebellum and brainstem that have been difficult to target with other techniques such as electroporation. We show that viral transduction produces an inherently mosaic expression pattern that can be exploited by varying the titer to transduce isolated neurons or densely-packed populations. We demonstrate that the expression of virally-encoded proteins is active much sooner than previously believed, allowing genetic perturbation during critical periods of neuronal plasticity, but is also long-lasting and stable, allowing chronic studies of aging. We harness these features to visualise and manipulate neurons in the hindbrain that have been recalcitrant to approaches commonly applied in the cortex. We show that viral labeling aids the analysis of postnatal dendritic maturation in cerebellar Purkinje neurons by allowing individual cells to be readily distinguished, and then demonstrate that the same sparse labeling allows live in vivo imaging of mature Purkinje neurons at a resolution sufficient for complete analytical reconstruction. Given the rising availability of viral constructs, packaging services, and genetically modified animals, these techniques should facilitate a wide range of experiments into brain development, function, and degeneration.
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Affiliation(s)
- Ji-Yoen Kim
- Department of Neuroscience, Baylor College of Medicine, BCM295, One Baylor Plaza, Houston, TX 77030, USA
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7
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A half century of experimental neuroanatomical tracing. J Chem Neuroanat 2011; 42:157-83. [PMID: 21782932 DOI: 10.1016/j.jchemneu.2011.07.001] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 07/04/2011] [Accepted: 07/04/2011] [Indexed: 01/05/2023]
Abstract
Most of our current understanding of brain function and dysfunction has its firm base in what is so elegantly called the 'anatomical substrate', i.e. the anatomical, histological, and histochemical domains within the large knowledge envelope called 'neuroscience' that further includes physiological, pharmacological, neurochemical, behavioral, genetical and clinical domains. This review focuses mainly on the anatomical domain in neuroscience. To a large degree neuroanatomical tract-tracing methods have paved the way in this domain. Over the past few decades, a great number of neuroanatomical tracers have been added to the technical arsenal to fulfill almost any experimental demand. Despite this sophisticated arsenal, the decision which tracer is best suited for a given tracing experiment still represents a difficult choice. Although this review is obviously not intended to provide the last word in the tract-tracing field, we provide a survey of the available tracing methods including some of their roots. We further summarize our experience with neuroanatomical tracers, in an attempt to provide the novice user with some advice to help this person to select the most appropriate criteria to choose a tracer that best applies to a given experimental design.
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8
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Dahlhaus M, Levelt CN. Structure and function relationships during ocular dominance plasticity in the visual cortex. Rev Neurosci 2010; 21:223-37. [PMID: 20879693 DOI: 10.1515/revneuro.2010.21.3.223] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Our ability to learn relies on the potential of the neocortex to change its neuronal circuits through experience. This change is mediated by the loss or formation of synaptic contacts or the adjustment of their synaptic strength. In recent decades, the primary visual cortex has proven an excellent system for studying structure/function relationships during plasticity in the neocortex. Here we describe current knowledge about the structural changes in inhibitory or excitatory synapses that accompany experience dependent plasticity in the visual cortex. We discuss unresolved issues and technical developments that will help to provide answers in the near future.
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Affiliation(s)
- Martijn Dahlhaus
- Department of Molecular Visual Plasticity, Netherlands Institute for Neuroscience an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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9
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Notch1 signaling in pyramidal neurons regulates synaptic connectivity and experience-dependent modifications of acuity in the visual cortex. J Neurosci 2008; 28:10794-802. [PMID: 18945887 DOI: 10.1523/jneurosci.1348-08.2008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
How the visual cortex responds to specific stimuli is strongly influenced by visual experience during development. Monocular deprivation, for example, changes the likelihood of neurons in the visual cortex to respond to input from the deprived eye and reduces its visual acuity. Because these functional changes are accompanied by extensive reorganization of neurite morphology and dendritic spine turnover, genes regulating neuronal morphology are likely to be involved in visual plasticity. In recent years, Notch1 has been shown to mediate contact inhibition of neurite outgrowth in postmitotic neurons and implicated in the pathogenesis of various degenerative diseases of the CNS. Here, we provide the first evidence for the involvement of neuronal Notch1 signaling in synaptic morphology and plasticity in the visual cortex. By making use of the Cre/Lox system, we expressed an active form of Notch1 in cortical pyramidal neurons several weeks after birth. We show that neuronal Notch1 signals reduce dendritic spine and filopodia densities in a cell-autonomous manner and limit long-term potentiation in the visual cortex. After monocular deprivation, these effects of Notch1 activity predominantly affect responses to visual stimuli with higher spatial frequencies. This results in an enhanced effect of monocular deprivation on visual acuity.
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