title: Lhx2 Expression in Postmitotic Cortical Neurons Initiates Assembly of the Thalamocortical Somatosensory Circuit.
abstract: Cortical neurons must be specified and make the correct connections during development. Here, we examine a mechanism initiating neuronal circuit formation in the barrel cortex, a circuit comprising thalamocortical axons (TCAs) and layer 4 (L4) neurons. When Lhx2 is selectively deleted in postmitotic cortical neurons using conditional knockout (cKO) mice, L4 neurons in the barrel cortex are initially specified but fail to form cellular barrels or develop polarized dendrites. In Lhx2 cKO mice, TCAs from the thalamic ventral posterior nucleus reach the barrel cortex but fail to further arborize to form barrels. Several activity-regulated genes and genes involved in regulating barrel formation are downregulated in the Lhx2 cKO somatosensory cortex. Among them, Btbd3, an activity-regulated gene controlling dendritic development, is a direct downstream target of Lhx2. We find that Lhx2 confers neuronal competency for activity-dependent dendritic development in L4 neurons by inducing the expression of Btbd3.
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Chia-Fang
authors.initials: CF
authors.lastname: Wang
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Hsiang-Wei
authors.initials: HW
authors.lastname: Hsing
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Zi-Hui
authors.initials: ZH
authors.lastname: Zhuang
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Meng-Hsuan
authors.initials: MH
authors.lastname: Wen
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Chang
authors.affiliation: Centro Nacional de Biotecnología, CNB-CSIC, Darwin 3, Campus de Cantoblanco, Madrid 28049, Spain.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Briz
authors.affiliation: Centro Nacional de Biotecnología, CNB-CSIC, Darwin 3, Campus de Cantoblanco, Madrid 28049, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Nieto
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Bai Chuang
authors.initials: BC
authors.lastname: Shyu
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan. Electronic address: schou@gate.sinica.edu.tw.
authors.forename: Shen-Ju
authors.initials: SJ
authors.lastname: Chou
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D036386:Ephrin-A5 / Q000235:genetics / Q000378:metabolism; D005071:Evoked Potentials; D015870:Gene Expression; D017403:In Situ Hybridization; D060588:LIM Domain Proteins / Q000235:genetics / Q000378:metabolism; D060850:LIM-Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D057095:Nuclear Receptor Subfamily 1, Group F, Member 2 / Q000235:genetics / Q000378:metabolism; D018408:Patch-Clamp Techniques; D011401:Promoter Regions, Genetic; D013003:Somatosensory Cortex / Q000502:physiology*; D013788:Thalamus / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C584946:BTBD3 protein, mouse; D036386:Ephrin-A5; D060588:LIM Domain Proteins; D060850:LIM-Homeodomain Proteins; C489784:Lhx2 protein, mouse; C491976:Lmo4 protein, mouse; D009419:Nerve Tissue Proteins; D057095:Nuclear Receptor Subfamily 1, Group F, Member 2; C539741:Rorb protein, mouse; D014157:Transcription Factors; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1
keywords: Lhx2; barrel cortex; dendritic asymmetry; layer 4 neurons