title: Nectin-1 spots regulate the branching of olfactory mitral cell dendrites.
abstract: Olfactory mitral cells extend lateral secondary dendrites that contact the lateral secondary and apical primary dendrites of other mitral cells in the external plexiform layer (EPL) of the olfactory bulb. The lateral dendrites further contact granule cell dendrites, forming dendrodendritic reciprocal synapses in the EPL. These dendritic structures are critical for odor information processing, but it remains unknown how they are formed. We recently showed that the immunoglobulin-like cell adhesion molecule nectin-1 constitutes a novel adhesion apparatus at the contacts between mitral cell lateral dendrites, between mitral cell lateral and apical dendrites, and between mitral cell lateral dendrites and granule cell dendritic spine necks in the deep sub-lamina of the EPL of the developing mouse olfactory bulb and named them nectin-1 spots. We investigated here the role of the nectin-1 spots in the formation of dendritic structures in the EPL of the mouse olfactory bulb. We showed that in cultured nectin-1-knockout mitral cells, the number of branching points of mitral cell dendrites was reduced compared to that in the control cells. In the deep sub-lamina of the EPL in the nectin-1-knockout olfactory bulb, the number of branching points of mitral cell lateral dendrites and the number of dendrodendritic reciprocal synapses were reduced compared to those in the control olfactory bulb. These results indicate that the nectin-1 spots regulate the branching of mitral cell dendrites in the deep sub-lamina of the EPL and suggest that the nectin-1 spots are required for odor information processing in the olfactory bulb.
authors.affiliation: Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Mie, Japan; CREST, Japan Science and Technology Agency, Kobe, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Inoue
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Maruo
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Division of Signal Transduction, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Rikitake
authors.affiliation: Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; CREST, Japan Science and Technology Agency, Tokyo, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Ieki
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Mandai
authors.affiliation: Department of Physical Therapy, Faculty of Human Science, Hokkaido Bunkyo University, Eniwa, Hokkaido, Japan.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Medical Rehabilitation, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Hyogo, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kayahara
authors.affiliation: Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Mie, Japan; CREST, Japan Science and Technology Agency, Kobe, Japan.
authors.forename: Shujie
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Mie, Japan; CREST, Japan Science and Technology Agency, Kobe, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Itoh
authors.affiliation: Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
authors.forename: Kousyoku
authors.initials: K
authors.lastname: Sai
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Faculty of Health Sciences, Kobe University Graduate School of Health Sciences, Kobe, Hyogo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; CREST, Japan Science and Technology Agency, Tokyo, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
authors.affiliation: CREST, Japan Science and Technology Agency, Kobe, Japan; Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan. Electronic address: ytakai@med.kobe-u.ac.jp.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Mie, Japan; CREST, Japan Science and Technology Agency, Kobe, Japan. Electronic address: amizomie@doc.medic.mie-u.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Mizoguchi
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003712:Dendrites / Q000502:physiology*; D003911:Dextrans; D004622:Embryo, Mammalian; D005786:Gene Expression Regulation / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D021621:Imaging, Three-Dimensional; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D000075983:Nectins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology*; D009830:Olfactory Bulb / Q000166:cytology*; D043222:Ubiquitin Thiolesterase / Q000378:metabolism; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D015815:Cell Adhesion Molecules; D003911:Dextrans; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; C000619015:Nectin1 protein, mouse; D000075983:Nectins; D009419:Nerve Tissue Proteins; C493465:Slc17a7 protein, mouse; D050598:Vesicular Glutamate Transport Protein 1; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; C076397:biotinylated dextran amine; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D001710:Biotin; D043222:Ubiquitin Thiolesterase; C496976:Uchl1 protein, mouse
keywords: Dendrite; Mitral cell; Nectin-1; Olfactory bulb; Reciprocal synapse