20
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Establishment of high reciprocal connectivity between clonal cortical neurons is regulated by the Dnmt3b DNA methyltransferase and clustered protocadherins

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          The specificity of synaptic connections is fundamental for proper neural circuit function. Specific neuronal connections that underlie information processing in the sensory cortex are initially established without sensory experiences to a considerable extent, and then the connections are individually refined through sensory experiences. Excitatory neurons arising from the same single progenitor cell are preferentially connected in the postnatal cortex, suggesting that cell lineage contributes to the initial wiring of neurons. However, the postnatal developmental process of lineage-dependent connection specificity is not known, nor how clonal neurons, which are derived from the same neural stem cell, are stamped with the identity of their common neural stem cell and guided to form synaptic connections.

          Results

          We show that cortical excitatory neurons that arise from the same neural stem cell and reside within the same layer preferentially establish reciprocal synaptic connections in the mouse barrel cortex. We observed a transient increase in synaptic connections between clonal but not nonclonal neuron pairs during postnatal development, followed by selective stabilization of the reciprocal connections between clonal neuron pairs. Furthermore, we demonstrate that selective stabilization of the reciprocal connections between clonal neuron pairs is impaired by the deficiency of DNA methyltransferase 3b (Dnmt3b), which determines DNA-methylation patterns of genes in stem cells during early corticogenesis. Dnmt3b regulates the postnatal expression of clustered protocadherin (cPcdh) isoforms, a family of adhesion molecules. We found that cPcdh deficiency in clonal neuron pairs impairs the whole process of the formation and stabilization of connections to establish lineage-specific connection reciprocity.

          Conclusions

          Our results demonstrate that local, reciprocal neural connections are selectively formed and retained between clonal neurons in layer 4 of the barrel cortex during postnatal development, and that Dnmt3b and cPcdhs are required for the establishment of lineage-specific reciprocal connections. These findings indicate that lineage-specific connection reciprocity is predetermined by Dnmt3b during embryonic development, and that the cPcdhs contribute to postnatal cortical neuron identification to guide lineage-dependent synaptic connections in the neocortex.

          Electronic supplementary material

          The online version of this article (doi:10.1186/s12915-016-0326-6) contains supplementary material, which is available to authorized users.

          Related collections

          Most cited references45

          • Record: found
          • Abstract: found
          • Article: not found

          The neocortical circuit: themes and variations.

          Similarities in neocortical circuit organization across areas and species suggest a common strategy to process diverse types of information, including sensation from diverse modalities, motor control and higher cognitive processes. Cortical neurons belong to a small number of main classes. The properties of these classes, including their local and long-range connectivity, developmental history, gene expression, intrinsic physiology and in vivo activity patterns, are remarkably similar across areas. Each class contains subclasses; for a rapidly growing number of these, conserved patterns of input and output connections are also becoming evident. The ensemble of circuit connections constitutes a basic circuit pattern that appears to be repeated across neocortical areas, with area- and species-specific modifications. Such 'serially homologous' organization may adapt individual neocortical regions to the type of information each must process.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The excitatory neuronal network of the C2 barrel column in mouse primary somatosensory cortex.

            Local microcircuits within neocortical columns form key determinants of sensory processing. Here, we investigate the excitatory synaptic neuronal network of an anatomically defined cortical column, the C2 barrel column of mouse primary somatosensory cortex. This cortical column is known to process tactile information related to the C2 whisker. Through multiple simultaneous whole-cell recordings, we quantify connectivity maps between individual excitatory neurons located across all cortical layers of the C2 barrel column. Synaptic connectivity depended strongly upon somatic laminar location of both presynaptic and postsynaptic neurons, providing definitive evidence for layer-specific signaling pathways. The strongest excitatory influence upon the cortical column was provided by presynaptic layer 4 neurons. In all layers we found rare large-amplitude synaptic connections, which are likely to contribute strongly to reliable information processing. Our data set provides the first functional description of the excitatory synaptic wiring diagram of a physiologically relevant and anatomically well-defined cortical column at single-cell resolution.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              A highly efficient recombineering-based method for generating conditional knockout mutations.

              Phage-based Escherichia coli homologous recombination systems have recently been developed that now make it possible to subclone or modify DNA cloned into plasmids, BACs, or PACs without the need for restriction enzymes or DNA ligases. This new form of chromosome engineering, termed recombineering, has many different uses for functional genomic studies. Here we describe a new recombineering-based method for generating conditional mouse knockout (cko) mutations. This method uses homologous recombination mediated by the lambda phage Red proteins, to subclone DNA from BACs into high-copy plasmids by gap repair, and together with Cre or Flpe recombinases, to introduce loxP or FRT sites into the subcloned DNA. Unlike other methods that use short 45-55-bp regions of homology for recombineering, our method uses much longer regions of homology. We also make use of several new E. coli strains, in which the proteins required for recombination are expressed from a defective temperature-sensitive lambda prophage, and the Cre or Flpe recombinases from an arabinose-inducible promoter. We also describe two new Neo selection cassettes that work well in both E. coli and mouse ES cells. Our method is fast, efficient, and reliable and makes it possible to generate cko-targeting vectors in less than 2 wk. This method should also facilitate the generation of knock-in mutations and transgene constructs, as well as expedite the analysis of regulatory elements and functional domains in or near genes.
                Bookmark

                Author and article information

                Contributors
                tarusawa@nips.ac.jp
                sanbo@nips.ac.jp
                a-okayama@hhc.eisai.co.jp
                tmiyashi@nips.ac.jp
                kit@fbs.osaka-u.ac.jp
                hirayama@fbs.osaka-u.ac.jp
                hira@fbs.osaka-u.ac.jp
                hasesono@fbs.osaka-u.ac.jp
                rkaneko@gunma-u.ac.jp
                toyodas-as@yamanashi.ac.jp
                tk429@cam.ac.uk
                katomegu@ims.u-tokyo.ac.jp
                nakauchi@stanford.edu
                mhirarin@nips.ac.jp
                yagi@fbs.osaka-u.ac.jp
                yumikoy@nips.ac.jp
                Journal
                BMC Biol
                BMC Biol
                BMC Biology
                BioMed Central (London )
                1741-7007
                2 December 2016
                2 December 2016
                2016
                : 14
                : 103
                Affiliations
                [1 ]Section of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 Japan
                [2 ]AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
                [3 ]National Institute for Physiological Sciences, Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, Okazaki, Aichi 444-8787 Japan
                [4 ]KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
                [5 ]Bioresource Center, Gunma University Graduate School of Medicine, Maebashi, 371-8511 Japan
                [6 ]Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639 Japan
                [7 ]Department of Genetics, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, 291 Campus Drive, Li Ka Shing Building, Stanford, CA 94305-5101 USA
                [8 ]Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585 Japan
                Article
                326
                10.1186/s12915-016-0326-6
                5133762
                27912755
                0d8d5dcb-5e1f-4e46-96e4-a0912055c3e8
                © Yoshimura et al. 2016

                Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

                History
                : 27 September 2016
                : 9 November 2016
                Categories
                Research Article
                Custom metadata
                © The Author(s) 2016

                Life sciences
                barrel cortex,spiny stellate cell,clonal neuron,ips cells,connection specificity,reciprocity,dnmt3b,clustered protocadherin

                Comments

                Comment on this article