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Tarusawa E, Sanbo M, Okayama A, Miyashita T, Kitsukawa T, Hirayama T, Hirabayashi T, Hasegawa S, Kaneko R, Toyoda S, Kobayashi T, Kato-Itoh M, Nakauchi H, Hirabayashi M, Yagi T, Yoshimura Y. Establishment of high reciprocal connectivity between clonal cortical neurons is regulated by the Dnmt3b DNA methyltransferase and clustered protocadherins. BMC Biol 2016; 14:103. [PMID: 27912755 PMCID: PMC5133762 DOI: 10.1186/s12915-016-0326-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/09/2016] [Indexed: 02/06/2023] Open
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.
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Affiliation(s)
- Etsuko Tarusawa
- Section of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 Japan
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
| | - Makoto Sanbo
- National Institute for Physiological Sciences, Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, Okazaki, Aichi 444-8787 Japan
| | - Atsushi Okayama
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Toshio Miyashita
- Section of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 Japan
| | - Takashi Kitsukawa
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Teruyoshi Hirayama
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Takahiro Hirabayashi
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Sonoko Hasegawa
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Ryosuke Kaneko
- Bioresource Center, Gunma University Graduate School of Medicine, Maebashi, 371-8511 Japan
| | - Shunsuke Toyoda
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Toshihiro Kobayashi
- Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639 Japan
| | - Megumi Kato-Itoh
- Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639 Japan
| | - Hiromitsu Nakauchi
- Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639 Japan
- 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
| | - Masumi Hirabayashi
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- National Institute for Physiological Sciences, Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, Okazaki, Aichi 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585 Japan
| | - Takeshi Yagi
- AMED-CREST, AMED, 1-3 Yamadaoka, Suita, 565-0871 Osaka Japan
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Yumiko Yoshimura
- Section of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585 Japan
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