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Kageyama J, Wollny D, Treutlein B, Camp JG. ShinyCortex: Exploring Single-Cell Transcriptome Data From the Developing Human Cortex. Front Neurosci 2018; 12:315. [PMID: 29867326 PMCID: PMC5962798 DOI: 10.3389/fnins.2018.00315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 04/24/2018] [Indexed: 11/22/2022] Open
Abstract
Single-cell mRNA sequencing (scRNA-seq) is a powerful method to identify and classify cell types and reconstruct differentiation trajectories within complex tissues, such as the developing human cortex. scRNA-seq data also enables the discovery of cell type-specific marker genes and genes that regulate developmental transitions. Here we provide a brief overview of how scRNA-seq has been shaping the study of human cortex development, and present ShinyCortex, a resource that brings together data from recent scRNA-seq studies of the developing cortex for further analysis. ShinyCortex is based in R and displays recently published scRNA-seq data from the human and mouse cortex in a comprehensible, dynamic and accessible way, suitable for data exploration by biologists.
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Affiliation(s)
- Jorge Kageyama
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Damian Wollny
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Barbara Treutlein
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Department of Biosciences, Technical University Munich, Munich, Germany
| | - J Gray Camp
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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52
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Römer S, Bender H, Knabe W, Zimmermann E, Rübsamen R, Seeger J, Fietz SA. Neural Progenitors in the Developing Neocortex of the Northern Tree Shrew ( Tupaia belangeri) Show a Closer Relationship to Gyrencephalic Primates Than to Lissencephalic Rodents. Front Neuroanat 2018; 12:29. [PMID: 29725291 PMCID: PMC5917011 DOI: 10.3389/fnana.2018.00029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/03/2018] [Indexed: 01/03/2023] Open
Abstract
The neocortex is the most complex part of the mammalian brain and as such it has undergone tremendous expansion during evolution, especially in primates. The majority of neocortical neurons originate from distinct neural stem and progenitor cells (NPCs) located in the ventricular and subventricular zone (SVZ). Previous studies revealed that the SVZ thickness as well as the abundance and distribution of NPCs, especially that of basal radial glia (bRG), differ markedly between the lissencephalic rodent and gyrencephalic primate neocortex. The northern tree shrew (Tupaia belangeri) is a rat-sized mammal with a high brain to body mass ratio, which stands phylogenetically mid-way between rodents and primates. Our study provides – for the first time – detailed data on the presence, abundance and distribution of bRG and other distinct NPCs in the developing neocortex of the northern tree shrew (Tupaia belangeri). We show that the developing tree shrew neocortex is characterized by an expanded SVZ, a high abundance of Pax6+ NPCs in the SVZ, and a relatively high percentage of bRG at peak of upper-layer neurogenesis. We further demonstrate that key features of tree shrew neocortex development, e.g., the presence, abundance and distribution of distinct NPCs, are closer related to those of gyrencephalic primates than to those of ferret and lissencephalic rodents. Together, our study provides novel insight into the evolution of bRG and other distinct NPCs in the neocortex development of Euarchontoglires and introduces the tree shrew as a potential novel model organism in the area of human brain development and developmental disorders.
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Affiliation(s)
- Sebastian Römer
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Hannah Bender
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Wolfgang Knabe
- Prosektur Anatomie, Medizinische Fakultät, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Elke Zimmermann
- Institute of Zoology, University of Veterinary Medicine Hanover, Hanover, Germany
| | - Rudolf Rübsamen
- Institute of Biology, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany
| | - Johannes Seeger
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Simone A Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
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53
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Sokpor G, Castro-Hernandez R, Rosenbusch J, Staiger JF, Tuoc T. ATP-Dependent Chromatin Remodeling During Cortical Neurogenesis. Front Neurosci 2018; 12:226. [PMID: 29686607 PMCID: PMC5900035 DOI: 10.3389/fnins.2018.00226] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/22/2018] [Indexed: 12/20/2022] Open
Abstract
The generation of individual neurons (neurogenesis) during cortical development occurs in discrete steps that are subtly regulated and orchestrated to ensure normal histogenesis and function of the cortex. Notably, various gene expression programs are known to critically drive many facets of neurogenesis with a high level of specificity during brain development. Typically, precise regulation of gene expression patterns ensures that key events like proliferation and differentiation of neural progenitors, specification of neuronal subtypes, as well as migration and maturation of neurons in the developing cortex occur properly. ATP-dependent chromatin remodeling complexes regulate gene expression through utilization of energy from ATP hydrolysis to reorganize chromatin structure. These chromatin remodeling complexes are characteristically multimeric, with some capable of adopting functionally distinct conformations via subunit reconstitution to perform specific roles in major aspects of cortical neurogenesis. In this review, we highlight the functions of such chromatin remodelers during cortical development. We also bring together various proposed mechanisms by which ATP-dependent chromatin remodelers function individually or in concert, to specifically modulate vital steps in cortical neurogenesis.
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Affiliation(s)
- Godwin Sokpor
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Ricardo Castro-Hernandez
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Joachim Rosenbusch
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
| | - Tran Tuoc
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
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54
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Zhong S, Zhang S, Fan X, Wu Q, Yan L, Dong J, Zhang H, Li L, Sun L, Pan N, Xu X, Tang F, Zhang J, Qiao J, Wang X. A single-cell RNA-seq survey of the developmental landscape of the human prefrontal cortex. Nature 2018. [PMID: 29539641 DOI: 10.1038/nature25980] [Citation(s) in RCA: 416] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian prefrontal cortex comprises a set of highly specialized brain areas containing billions of cells and serves as the centre of the highest-order cognitive functions, such as memory, cognitive ability, decision-making and social behaviour. Although neural circuits are formed in the late stages of human embryonic development and even after birth, diverse classes of functional cells are generated and migrate to the appropriate locations earlier in development. Dysfunction of the prefrontal cortex contributes to cognitive deficits and the majority of neurodevelopmental disorders; there is therefore a need for detailed knowledge of the development of the prefrontal cortex. However, it is still difficult to identify cell types in the developing human prefrontal cortex and to distinguish their developmental features. Here we analyse more than 2,300 single cells in the developing human prefrontal cortex from gestational weeks 8 to 26 using RNA sequencing. We identify 35 subtypes of cells in six main classes and trace the developmental trajectories of these cells. Detailed analysis of neural progenitor cells highlights new marker genes and unique developmental features of intermediate progenitor cells. We also map the timeline of neurogenesis of excitatory neurons in the prefrontal cortex and detect the presence of interneuron progenitors in early developing prefrontal cortex. Moreover, we reveal the intrinsic development-dependent signals that regulate neuron generation and circuit formation using single-cell transcriptomic data analysis. Our screening and characterization approach provides a blueprint for understanding the development of the human prefrontal cortex in the early and mid-gestational stages in order to systematically dissect the cellular basis and molecular regulation of prefrontal cortex function in humans.
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Affiliation(s)
- Suijuan Zhong
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shu Zhang
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China
| | - Xiaoying Fan
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China
| | - Qian Wu
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liying Yan
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China
| | - Ji Dong
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China
| | - Haofeng Zhang
- Obstetrics and Gynecology, Medical Center of Severe Cardiovascular of Beijing Anzhen Hospital, Capital Medical University, Beijing, 100029, China
| | - Long Li
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Le Sun
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Na Pan
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaohui Xu
- Obstetrics and Gynecology, Medical Center of Severe Cardiovascular of Beijing Anzhen Hospital, Capital Medical University, Beijing, 100029, China
| | - Fuchou Tang
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China.,Biomedical Institute for Pioneering Investigation via Convergence and Center for Reproductive Medicine, Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, 100871, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jun Zhang
- Obstetrics and Gynecology, Medical Center of Severe Cardiovascular of Beijing Anzhen Hospital, Capital Medical University, Beijing, 100029, China
| | - Jie Qiao
- Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Department of Obstetrics and Gynecology, Third Hospital, Peking University, Beijing, 100871, China.,Biomedical Institute for Pioneering Investigation via Convergence and Center for Reproductive Medicine, Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, 100871, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Xiaoqun Wang
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Beijing Institute for Brain Disorders, Beijing, 100069, China
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55
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Bal-Price A, Hogberg HT, Crofton KM, Daneshian M, FitzGerald RE, Fritsche E, Heinonen T, Hougaard Bennekou S, Klima S, Piersma AH, Sachana M, Shafer TJ, Terron A, Monnet-Tschudi F, Viviani B, Waldmann T, Westerink RHS, Wilks MF, Witters H, Zurich MG, Leist M. Recommendation on test readiness criteria for new approach methods in toxicology: Exemplified for developmental neurotoxicity. ALTEX-ALTERNATIVES TO ANIMAL EXPERIMENTATION 2018; 35:306-352. [PMID: 29485663 DOI: 10.14573/altex.1712081] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/29/2018] [Indexed: 01/06/2023]
Abstract
Multiple non-animal-based test methods have never been formally validated. In order to use such new approach methods (NAMs) in a regulatory context, criteria to define their readiness are necessary. The field of developmental neurotoxicity (DNT) testing is used to exemplify the application of readiness criteria. The costs and number of untested chemicals are overwhelming for in vivo DNT testing. Thus, there is a need for inexpensive, high-throughput NAMs, to obtain initial information on potential hazards, and to allow prioritization for further testing. A background on the regulatory and scientific status of DNT testing is provided showing different types of test readiness levels, depending on the intended use of data from NAMs. Readiness criteria, compiled during a stakeholder workshop, uniting scientists from academia, industry and regulatory authorities are presented. An important step beyond the listing of criteria, was the suggestion for a preliminary scoring scheme. On this basis a (semi)-quantitative analysis process was assembled on test readiness of 17 NAMs with respect to various uses (e.g. prioritization/screening, risk assessment). The scoring results suggest that several assays are currently at high readiness levels. Therefore, suggestions are made on how DNT NAMs may be assembled into an integrated approach to testing and assessment (IATA). In parallel, the testing state in these assays was compiled for more than 1000 compounds. Finally, a vision is presented on how further NAM development may be guided by knowledge of signaling pathways necessary for brain development, DNT pathophysiology, and relevant adverse outcome pathways (AOP).
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Affiliation(s)
- Anna Bal-Price
- European Commission, Joint Research Centre (EC JRC), Ispra (VA), Italy
| | - Helena T Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | - Kevin M Crofton
- National Centre for Computational Toxicology, US EPA, RTP, Washington, NC, USA
| | - Mardas Daneshian
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Rex E FitzGerald
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine & Heinrich-Heine-University, Düsseldorf, Germany
| | - Tuula Heinonen
- Finnish Centre for Alternative Methods (FICAM), University of Tampere, Tampere, Finland
| | | | - Stefanie Klima
- In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Aldert H Piersma
- RIVM, National Institute for Public Health and the Environment, Bilthoven, and Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Magdalini Sachana
- Organisation for Economic Co-operation and Development (OECD), Paris, France
| | - Timothy J Shafer
- National Centre for Computational Toxicology, US EPA, RTP, Washington, NC, USA
| | | | - Florianne Monnet-Tschudi
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland.,Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Barbara Viviani
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Italy
| | - Tanja Waldmann
- In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Remco H S Westerink
- Neurotoxicology Research Group, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Martin F Wilks
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland
| | - Hilda Witters
- VITO, Flemish Institute for Technological Research, Unit Environmental Risk and Health, Mol, Belgium
| | - Marie-Gabrielle Zurich
- Swiss Centre for Human Applied Toxicology, SCAHT, University of Basle, Switzerland.,Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Marcel Leist
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany.,In vitro Toxicology and Biomedicine, Department of Biology, University of Konstanz, Konstanz, Germany
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56
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Clark BS, Blackshaw S. Understanding the Role of lncRNAs in Nervous System Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1008:253-282. [PMID: 28815543 DOI: 10.1007/978-981-10-5203-3_9] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The diversity of lncRNAs has expanded within mammals in tandem with the evolution of increased brain complexity, suggesting that lncRNAs play an integral role in this process. In this chapter, we will highlight the identification and characterization of lncRNAs in nervous system development. We discuss the potential role of lncRNAs in nervous system and brain evolution, along with efforts to create comprehensive catalogues that analyze spatial and temporal changes in lncRNA expression during nervous system development. Additionally, we focus on recent endeavors that attempt to assign function to lncRNAs during nervous system development. We highlight discrepancies that have been observed between in vitro and in vivo studies of lncRNA function and the challenges facing researchers in conducting mechanistic analyses of lncRNAs in the developing nervous system. Altogether, this chapter highlights the emerging role of lncRNAs in the developing brain and sheds light on novel, RNA-mediated mechanisms by which nervous system development is controlled.
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Affiliation(s)
- Brian S Clark
- Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Seth Blackshaw
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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57
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González-Arnay E, González-Gómez M, Meyer G. A Radial Glia Fascicle Leads Principal Neurons from the Pallial-Subpallial Boundary into the Developing Human Insula. Front Neuroanat 2017; 11:111. [PMID: 29259547 PMCID: PMC5723317 DOI: 10.3389/fnana.2017.00111] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 11/17/2017] [Indexed: 12/29/2022] Open
Abstract
The human insular lobe, in the depth of the Sylvian fissure, displays three main cytoarchitectonic divisions defined by the differentiation of granular layers II and IV. These comprise a rostro-ventral agranular area, an intermediate dysgranular area, and a dorso-caudal granular area. Immunohistochemistry in human embryos and fetuses using antibodies against PCNA, Vimentin, Nestin, Tbr1, and Tb2 reveals that the insular cortex is unique in that it develops far away from the ventricular zone (VZ), with most of its principal neurons deriving from the subventricular zone (SVZ) of the pallial-subpallial boundary (PSB). In human embryos (Carnegie stage 16/17), the rostro-ventral insula is the first cortical region to develop; its Tbr1+ neurons migrate from the PSB along the lateral cortical stream. From 10 gestational weeks (GW) onward, lateral ventricle, ganglionic eminences, and PSB grow forming a C-shaped curvature. The SVZ of the PSB gives rise to a distinct radial glia fiber fascicle (RGF), which courses lateral to the putamen in the external capsule. In the RGF, four components can be established: PF, descending from the prefrontal PSB to the anterior insula; FP, descending from the fronto-parietal PSB toward the intermediate insula; PT, coursing from the PSB near the parieto-temporal junction to the posterior insula, and T, ascending from the temporal PSB and merging with components FP and PT. The RGF fans out at different dorso-ventral and rostro-caudal levels of the insula, with descending fibers predominating over ascending ones. The RGF guides migrating principal neurons toward the future agranular, dysgranular, and granular insular areas, which show an adult-like definition at 32 GW. Despite the narrow subplate, and the absence of an intermediate zone except in the caudal insula, most insular subdivisions develop into a 6-layered isocortex, possibly due to the well developed outer SVZ at the PSB, which is particularly prominent at the level of the dorso-caudal insula. The small size of the initial PSB sector may, however, determine the limited surface expansion of the insula, which is in contrast to the exuberant growth of the opercula deriving from the adjacent frontal-parietal and temporal VZ/SVZ.
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Affiliation(s)
- Emilio González-Arnay
- Unit of Pathology, Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, San Cristóbal de La Laguna, Spain
| | - Miriam González-Gómez
- Unit of Anatomy, Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, San Cristóbal de La Laguna, Spain
| | - Gundela Meyer
- Unit of Histology, Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, San Cristóbal de La Laguna, Spain
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58
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Beattie R, Hippenmeyer S. Mechanisms of radial glia progenitor cell lineage progression. FEBS Lett 2017; 591:3993-4008. [PMID: 29121403 PMCID: PMC5765500 DOI: 10.1002/1873-3468.12906] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 10/31/2017] [Accepted: 11/06/2017] [Indexed: 12/11/2022]
Abstract
The mammalian cerebral cortex is responsible for higher cognitive functions such as perception, consciousness, and acquiring and processing information. The neocortex is organized into six distinct laminae, each composed of a rich diversity of cell types which assemble into highly complex cortical circuits. Radial glia progenitors (RGPs) are responsible for producing all neocortical neurons and certain glia lineages. Here, we discuss recent discoveries emerging from clonal lineage analysis at the single RGP cell level that provide us with an inaugural quantitative framework of RGP lineage progression. We further discuss the importance of the relative contribution of intrinsic gene functions and non‐cell‐autonomous or community effects in regulating RGP proliferation behavior and lineage progression.
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Affiliation(s)
- Robert Beattie
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Simon Hippenmeyer
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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59
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Matsumoto N, Shinmyo Y, Ichikawa Y, Kawasaki H. Gyrification of the cerebral cortex requires FGF signaling in the mammalian brain. eLife 2017; 6. [PMID: 29132503 PMCID: PMC5685484 DOI: 10.7554/elife.29285] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 10/24/2017] [Indexed: 12/31/2022] Open
Abstract
Although it has been believed that the evolution of cortical folds was a milestone, allowing for an increase in the number of neurons in the cerebral cortex, the mechanisms underlying the formation of cortical folds are largely unknown. Here we show regional differences in the expression of fibroblast growth factor receptors (FGFRs) in the developing cerebral cortex of ferrets even before cortical folds are formed. By taking the advantage of our in utero electroporation technique for ferrets, we found that cortical folding was impaired in the ferret cerebral cortex when FGF signaling was inhibited. We also found that FGF signaling was crucial for producing Pax6-positive neural progenitors in the outer subventricular zone (OSVZ) of the developing cerebral cortex. Furthermore, we found that upper layers of the cerebral cortex were preferentially reduced by inhibiting FGF signaling. Our results shed light on the mechanisms of cortical folding in gyrencephalic mammalian brains.
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Affiliation(s)
- Naoyuki Matsumoto
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan
| | - Yohei Shinmyo
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan
| | - Yoshie Ichikawa
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan
| | - Hiroshi Kawasaki
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan
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60
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Mortazavi F, Romano SE, Rosene DL, Rockland KS. A Survey of White Matter Neurons at the Gyral Crowns and Sulcal Depths in the Rhesus Monkey. Front Neuroanat 2017; 11:69. [PMID: 28860975 PMCID: PMC5559435 DOI: 10.3389/fnana.2017.00069] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/31/2017] [Indexed: 12/14/2022] Open
Abstract
Gyrencephalic brains exhibit deformations of the six neocortical laminae at gyral crowns and sulcal depths, where the deeper layers are, respectively, expanded and compressed. The present study addresses: (1) the degree to which the underlying white matter neurons (WMNs) observe the same changes at gyral crowns and sulcal depths; and (2) whether these changes are consistent or variable across different cortical regions. WMNs were visualized by immunohistochemistry using the pan-neuronal label NeuN, and their density was quantified in eight rhesus monkey brains for four regions; namely, frontal (FR), superior frontal gyrus (SFG), parietal (Par) and temporal (TE). In all four regions, there were about 50% fewer WMNs in the sulcal depth, but there was also distinct variability from region to region. For the gyral crown, we observed an average density per 0.21 mm2 of 82 WMNs for the FR, 51 WMNs for SFG, 80 WMNs for Par and 93 WMNs for TE regions. By contrast, for the sulcal depth, the average number of WMNs per 0.21 mm2 was 41 for FR, 31 for cingulate sulcus (underlying the SFG), 54 for Par and 63 for TE cortical regions. Since at least some WMNs participate in cortical circuitry, these results raise the possibility of their differential influence on cortical circuitry in the overlying gyral and sulcal locations. The results also point to a possible role of WMNs in the differential vulnerability of gyral vs. sulcal regions in disease processes, and reinforce the increasing awareness of the WMNs as part of a complex, heterogeneous and structured microenvironment.
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Affiliation(s)
- Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Samantha E. Romano
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Douglas L. Rosene
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Kathleen S. Rockland
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
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61
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Guerra M, Blázquez JL, Rodríguez EM. Blood-brain barrier and foetal-onset hydrocephalus, with a view on potential novel treatments beyond managing CSF flow. Fluids Barriers CNS 2017; 14:19. [PMID: 28701191 PMCID: PMC5508761 DOI: 10.1186/s12987-017-0067-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/24/2017] [Indexed: 12/12/2022] Open
Abstract
Despite decades of research, no compelling non-surgical therapies have been developed for foetal hydrocephalus. So far, most efforts have pointed to repairing disturbances in the cerebrospinal fluid (CSF) flow and to avoid further brain damage. There are no reports trying to prevent or diminish abnormalities in brain development which are inseparably associated with hydrocephalus. A key problem in the treatment of hydrocephalus is the blood–brain barrier that restricts the access to the brain for therapeutic compounds or systemically grafted cells. Recent investigations have started to open an avenue for the development of a cell therapy for foetal-onset hydrocephalus. Potential cells to be used for brain grafting include: (1) pluripotential neural stem cells; (2) mesenchymal stem cells; (3) genetically-engineered stem cells; (4) choroid plexus cells and (5) subcommissural organ cells. Expected outcomes are a proper microenvironment for the embryonic neurogenic niche and, consequent normal brain development.
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Affiliation(s)
- M Guerra
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
| | - J L Blázquez
- Departamento de Anatomía e Histología Humana, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
| | - E M Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
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62
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Hatakeyama J, Sato H, Shimamura K. Developing guinea pig brain as a model for cortical folding. Dev Growth Differ 2017; 59:286-301. [PMID: 28585227 DOI: 10.1111/dgd.12371] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/05/2017] [Accepted: 05/06/2017] [Indexed: 12/31/2022]
Abstract
The cerebral cortex in mammals, the neocortex specifically, is highly diverse among species with respect to its size and morphology, likely reflecting the immense adaptiveness of this lineage. In particular, the pattern and number of convoluted ridges and fissures, called gyri and sulci, respectively, on the surface of the cortex are variable among species and even individuals. However, little is known about the mechanism of cortical folding, although there have been several hypotheses proposed. Recent studies on embryonic neurogenesis revealed the differences in cortical progenitors as a critical factor of the process of gyrification. Here, we investigated the gyrification processes using developing guinea pig brains that form a simple but fundamental pattern of gyri. In addition, we established an electroporation-mediated gene transfer method for guinea pig embryos. We introduce the guinea pig brain as a useful model system to understand the mechanisms and basic principle of cortical folding.
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Affiliation(s)
- Jun Hatakeyama
- Department of Brain Morphogenesis, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Haruka Sato
- Department of Brain Morphogenesis, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Kenji Shimamura
- Department of Brain Morphogenesis, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
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63
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Hirano K, Namihira M. New insight into LSD1 function in human cortical neurogenesis. NEUROGENESIS 2016; 3:e1249195. [PMID: 27900345 DOI: 10.1080/23262133.2016.1249195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 02/04/2023]
Abstract
The cerebral cortex of primates has evolved massively and intricately in comparison to that of other species. Accumulating evidence indicates that this is caused by changes in cell biological features of neural stem cells (NSCs), which differentiate into neurons and glial cells during development. The fate of NSCs during rodent cortical development is stringently regulated by epigenetic factors, such as histone modification enzymes, but the role of these factors in human corticogenesis is largely unknown. We have recently discovered that a lysine-specific demethylase 1 (LSD1), which catalyzes the demethylation of methyl groups in the histone tail, plays a unique role in human fetal NSCs (hfNSCs). We show that, unlike the role previously reported in mice, LSD1 in hfNSCs is necessary for neuronal differentiation and controls the expression of HEYL, one of the NOTCH target genes, by modulating the methylation level of histones on its promoter region. Interestingly, LSD1-regulation of Heyl expression is not observed in mouse NSCs. Furthermore, we first demonstrated that HEYL is able to maintain the undifferentiated state of hfNSCs. Our findings provide a new insight indicating that LSD1 may be a key player in the development and characterization of the evolved cerebral cortex.
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Affiliation(s)
- Kazumi Hirano
- Molecular Neurophysiology Research Group, Biomedical Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST) , Japan
| | - Masakazu Namihira
- Molecular Neurophysiology Research Group, Biomedical Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST) , Japan
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64
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Mora-Bermúdez F, Badsha F, Kanton S, Camp JG, Vernot B, Köhler K, Voigt B, Okita K, Maricic T, He Z, Lachmann R, Pääbo S, Treutlein B, Huttner WB. Differences and similarities between human and chimpanzee neural progenitors during cerebral cortex development. eLife 2016; 5:e18683. [PMID: 27669147 PMCID: PMC5110243 DOI: 10.7554/elife.18683] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/22/2016] [Indexed: 12/25/2022] Open
Abstract
Human neocortex expansion likely contributed to the remarkable cognitive abilities of humans. This expansion is thought to primarily reflect differences in proliferation versus differentiation of neural progenitors during cortical development. Here, we have searched for such differences by analysing cerebral organoids from human and chimpanzees using immunohistofluorescence, live imaging, and single-cell transcriptomics. We find that the cytoarchitecture, cell type composition, and neurogenic gene expression programs of humans and chimpanzees are remarkably similar. Notably, however, live imaging of apical progenitor mitosis uncovered a lengthening of prometaphase-metaphase in humans compared to chimpanzees that is specific to proliferating progenitors and not observed in non-neural cells. Consistent with this, the small set of genes more highly expressed in human apical progenitors points to increased proliferative capacity, and the proportion of neurogenic basal progenitors is lower in humans. These subtle differences in cortical progenitors between humans and chimpanzees may have consequences for human neocortex evolution.
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Affiliation(s)
| | - Farhath Badsha
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Sabina Kanton
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - J Gray Camp
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Benjamin Vernot
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Kathrin Köhler
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Birger Voigt
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Keisuke Okita
- Department of Reprogramming Science, Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Tomislav Maricic
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Zhisong He
- CAS-MPG Partner Institute for Computational Biology, Shanghai, China
| | - Robert Lachmann
- Universitätsklinikum Carl Gustav Carus, Klinik und Poliklinik für Frauenheilkunde und Geburtshilfe, Technische Universität Dresden, Dresden, Germany
| | - Svante Pääbo
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Barbara Treutlein
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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65
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Chandrasekaran A, Avci HX, Leist M, Kobolák J, Dinnyés A. Astrocyte Differentiation of Human Pluripotent Stem Cells: New Tools for Neurological Disorder Research. Front Cell Neurosci 2016; 10:215. [PMID: 27725795 PMCID: PMC5035736 DOI: 10.3389/fncel.2016.00215] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/30/2016] [Indexed: 12/22/2022] Open
Abstract
Astrocytes have a central role in brain development and function, and so have gained increasing attention over the past two decades. Consequently, our knowledge about their origin, differentiation and function has increased significantly, with new research showing that astrocytes cultured alone or co-cultured with neurons have the potential to improve our understanding of various central nervous system diseases, such as amyotrophic lateral sclerosis, Alzheimer’s disease, or Alexander disease. The generation of astrocytes derived from pluripotent stem cells (PSCs) opens up a new area for studying neurologic diseases in vitro; these models could be exploited to identify and validate potential drugs by detecting adverse effects in the early stages of drug development. However, as it is now known that a range of astrocyte populations exist in the brain, it will be important in vitro to develop standardized protocols for the in vitro generation of astrocyte subsets with defined maturity status and phenotypic properties. This will then open new possibilities for co-cultures with neurons and the generation of neural organoids for research purposes. The aim of this review article is to compare and summarize the currently available protocols and their strategies to generate human astrocytes from PSCs. Furthermore, we discuss the potential role of human-induced PSCs derived astrocytes in disease modeling.
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Affiliation(s)
| | - Hasan X Avci
- BioTalentum LtdGödöllő, Hungary; Department of Medical Chemistry, University of SzegedSzeged, Hungary
| | - Marcel Leist
- Dorenkamp-Zbinden Chair, Faculty of Mathematics and Sciences, University of Konstanz Konstanz, Germany
| | | | - Andras Dinnyés
- BioTalentum LtdGödöllő, Hungary; Molecular Animal Biotechnology Laboratory, Szent Istvan UniversityGödöllő, Hungary
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66
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Schneider E, Dittrich M, Böck J, Nanda I, Müller T, Seidmann L, Tralau T, Galetzka D, El Hajj N, Haaf T. CpG sites with continuously increasing or decreasing methylation from early to late human fetal brain development. Gene 2016; 592:110-118. [PMID: 27468947 DOI: 10.1016/j.gene.2016.07.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/28/2016] [Accepted: 07/23/2016] [Indexed: 01/03/2023]
Abstract
Normal human brain development is dependent on highly dynamic epigenetic processes for spatial and temporal gene regulation. Recent work identified wide-spread changes in DNA methylation during fetal brain development. We profiled CpG methylation in frontal cortex of 27 fetuses from gestational weeks 12-42, using Illumina 450K methylation arrays. Sites showing genome-wide significant correlation with gestational age were compared to a publicly available data set from gestational weeks 3-26. Altogether, we identified 2016 matching developmentally regulated differentially methylated positions (m-dDMPs): 1767m-dDMPs were hypermethylated and 1149 hypomethylated during fetal development. M-dDMPs are underrepresented in CpG islands and gene promoters, and enriched in gene bodies. They appear to cluster in certain chromosome regions. M-dDMPs are significantly enriched in autism-associated genes and CpGs. Our results promote the idea that reduced methylation dynamics during fetal brain development may predispose to autism. In addition, m-dDMPs are enriched in genes with human-specific brain expression patterns and/or histone modifications. Collectively, we defined a subset of dDMPs exhibiting constant methylation changes from early to late pregnancy. The same epigenetic mechanisms involving methylation changes in cis-regulatory regions may have been adopted for human brain evolution and ontogeny.
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Affiliation(s)
- Eberhard Schneider
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Marcus Dittrich
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany; Department of Bioinformatics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Julia Böck
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Indrajit Nanda
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Tobias Müller
- Department of Bioinformatics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Larissa Seidmann
- Department of Pathology, University Medical Center, 55131 Mainz, Germany
| | - Tim Tralau
- Department of Pathology, University Medical Center, 55131 Mainz, Germany; Rehabilitation Clinic for Children and Adolescents, 25980 Westerland/Sylt, Germany
| | - Danuta Galetzka
- Department of Radiation Oncology and Radiotherapy, University Medical Center, 55131 Mainz, Germany
| | - Nady El Hajj
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany
| | - Thomas Haaf
- Institute of Human Genetics, Julius Maximilians University, 97074 Würzburg, Germany.
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67
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The Tortuous Routes of Migrating Neurons in the Folding Neocortex. J Neurosci 2016; 36:3887-9. [PMID: 27053197 DOI: 10.1523/jneurosci.4628-15.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 02/06/2016] [Indexed: 11/21/2022] Open
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68
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Mota B, Herculano-Houzel S. Response to Comments on "Cortical folding scales universally with surface area and thickness, not number of neurons". Science 2016; 351:826. [PMID: 26912888 DOI: 10.1126/science.aad2346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
De Lussanet claims that our model that accounts for the degree of folding of the cerebral cortex based on the product of cortical surface area and the square root of cortical thickness is better reduced to the product of gray-matter proportion and folding index. Lewitus et al., in turn, claim that the assumptions of our model are in conflict with experimental data; that the model does not accurately fit the data; and that the ancestral mammalian brain was gyrencephalic. Here, we show that both claims are inappropriate.
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Affiliation(s)
- Bruno Mota
- Instituto de Física, Universidade Federal do Rio de Janeiro, Brasil
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69
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Lewitus E, Kelava I, Kalinka AT, Tomancak P, Huttner WB. Comment on "Cortical folding scales universally with surface area and thickness, not number of neurons". Science 2016; 351:825. [PMID: 26912886 PMCID: PMC4881813 DOI: 10.1126/science.aad2029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mota and Herculano-Houzel (Reports, 3 July 2015, p. 74) assign power functions to neuroanatomical data and present a model to account for evolutionary patterns of cortical folding in the mammalian brain. We detail how the model assumptions are in conflict with experimental and observational work and show that the model itself does not accurately fit the data.
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Affiliation(s)
- Eric Lewitus
- Institut de Biologie, École Normale Supérieure, Paris, France.
| | - Iva Kelava
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Alex T Kalinka
- Institute of Population Genetics, Vetmeduni, Vienna, Austria
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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70
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Pollen AA, Nowakowski TJ, Chen J, Retallack H, Sandoval-Espinosa C, Nicholas CR, Shuga J, Liu SJ, Oldham MC, Diaz A, Lim DA, Leyrat AA, West JA, Kriegstein AR. Molecular identity of human outer radial glia during cortical development. Cell 2015; 163:55-67. [PMID: 26406371 DOI: 10.1016/j.cell.2015.09.004] [Citation(s) in RCA: 568] [Impact Index Per Article: 63.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/04/2015] [Accepted: 08/31/2015] [Indexed: 01/17/2023]
Abstract
Radial glia, the neural stem cells of the neocortex, are located in two niches: the ventricular zone and outer subventricular zone. Although outer subventricular zone radial glia may generate the majority of human cortical neurons, their molecular features remain elusive. By analyzing gene expression across single cells, we find that outer radial glia preferentially express genes related to extracellular matrix formation, migration, and stemness, including TNC, PTPRZ1, FAM107A, HOPX, and LIFR. Using dynamic imaging, immunostaining, and clonal analysis, we relate these molecular features to distinctive behaviors of outer radial glia, demonstrate the necessity of STAT3 signaling for their cell cycle progression, and establish their extensive proliferative potential. These results suggest that outer radial glia directly support the subventricular niche through local production of growth factors, potentiation of growth factor signals by extracellular matrix proteins, and activation of self-renewal pathways, thereby enabling the developmental and evolutionary expansion of the human neocortex.
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Affiliation(s)
- Alex A Pollen
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Tomasz J Nowakowski
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jiadong Chen
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hanna Retallack
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carmen Sandoval-Espinosa
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Cory R Nicholas
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joe Shuga
- Fluidigm Corporation, South San Francisco, CA 94080, USA
| | - Siyuan John Liu
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael C Oldham
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aaron Diaz
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Daniel A Lim
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anne A Leyrat
- Fluidigm Corporation, South San Francisco, CA 94080, USA
| | - Jay A West
- Fluidigm Corporation, South San Francisco, CA 94080, USA
| | - Arnold R Kriegstein
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
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71
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Charvet CJ, Reep RL, Finlay BL. Evolution of cytoarchitectural landscapes in the mammalian isocortex: Sirenians (Trichechus manatus) in comparison with other mammals. J Comp Neurol 2015. [PMID: 26223206 DOI: 10.1002/cne.23864] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The isocortex of several primates and rodents shows a systematic increase in the number of neurons per unit of cortical surface area from its rostrolateral to caudomedial border. The steepness of the gradient in neuronal number and density is positively correlated with cortical volume. The relative duration of neurogenesis along the same rostrocaudal gradient predicts a substantial fraction of this variation in neuron number and laminar position, which is produced principally from layers II-IV neurons. However, virtually all of our quantitative knowledge about total and laminar variation in cortical neuron numbers and neurogenesis comes from rodents and primates, leaving whole taxonomic groups and many intermediate-sized brains unexplored. Thus, the ubiquity in mammals of the covariation of longer cortical neurogenesis and increased cortical neuron number deriving from cortical layers II-IV is undetermined. To begin to address this gap, we examined the isocortex of the manatee using the optical disector method in sectioned tissue, and also assembled partial data from published reports of the domestic cat brain. The manatee isocortex has relatively fewer neurons per total volume, and fewer II-IV neurons than primates with equivalently sized brains. The gradient in number of neurons from the rostral to the caudal pole is intermediate between primates and rodents, and, like those species, is observed only in the upper cortical layers. The cat isocortex (Felis domesticus) shows a similar structure. Key species for further tests of the origin, ubiquity, and significance of this organizational feature are discussed.
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Affiliation(s)
- Christine J Charvet
- Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, 20052
| | - Roger L Reep
- Department of Physiological Sciences, University of Florida, Gainesville, Florida, 32610
| | - Barbara L Finlay
- Behavioral and Evolutionary Neuroscience Group, Department of Psychology, Cornell University, Ithaca, NY, 14853
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72
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Mota B, Herculano-Houzel S. BRAIN STRUCTURE. Cortical folding scales universally with surface area and thickness, not number of neurons. Science 2015; 349:74-7. [PMID: 26138976 DOI: 10.1126/science.aaa9101] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Larger brains tend to have more folded cortices, but what makes the cortex fold has remained unknown. We show that the degree of cortical folding scales uniformly across lissencephalic and gyrencephalic species, across individuals, and within individual cortices as a function of the product of cortical surface area and the square root of cortical thickness. This relation is derived from the minimization of the effective free energy associated with cortical shape according to a simple physical model, based on known mechanisms of axonal elongation. This model also explains the scaling of the folding index of crumpled paper balls. We discuss the implications of this finding for the evolutionary and developmental origin of folding, including the newfound continuum between lissencephaly and gyrencephaly, and for pathologies such as human lissencephaly.
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Affiliation(s)
- Bruno Mota
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Instituto Nacional de Neurociência Translacional, INCT/MCT, São Paulo, Brazil.
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73
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Okamoto M, Shinoda T, Kawaue T, Nagasaka A, Miyata T. Ferret-mouse differences in interkinetic nuclear migration and cellular densification in the neocortical ventricular zone. Neurosci Res 2015; 86:88-95. [PMID: 24780233 DOI: 10.1016/j.neures.2014.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 01/23/2014] [Accepted: 02/28/2014] [Indexed: 11/19/2022]
Abstract
The thick outer subventricular zone (OSVZ) is characteristic of the development of human neocortex. How this region originates from the ventricular zone (VZ) is largely unknown. Recently, we showed that over-proliferation-induced acute nuclear densification and thickening of the VZ in neocortical walls of mice, which lack an OSVZ, causes reactive delamination of undifferentiated progenitors and invasion by these cells of basal areas outside the VZ. In this study, we sought to determine how VZ cells behave in non-rodent animals that have an OSVZ. A comparison of mid-embryonic mice and ferrets revealed: (1) the VZ is thicker and more pseudostratified in ferrets. (2) The soma and nuclei of VZ cells were horizontally and apicobasally denser in ferrets. (3) Individual endfeet were also denser on the apical (ventricular) surface in ferrets. (4) In ferrets, apicalward nucleokinesis was less directional, whereas basalward nucleokinesis was more directional; consequently, the nuclear density in the periventricular space (within 16 μm of the apical surface) was smaller in ferrets than in mice, despite the nuclear densification seen basally in ferrets. These results suggest that species-specific differences in nucleokinesis strategies may have evolved in close association with the magnitudes and patterns of nuclear stratification in the VZ.
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74
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Affiliation(s)
| | - Shyam Srinivasan
- The Salk Institute for Biological Sciences, La Jolla, California 92037;
- Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, California 92037
| | - Edwin S. Monuki
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California 92697; ,
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75
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Neurodevelopmental LincRNA Microsyteny Conservation and Mammalian Brain Size Evolution. PLoS One 2015; 10:e0131818. [PMID: 26134977 PMCID: PMC4489927 DOI: 10.1371/journal.pone.0131818] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/07/2015] [Indexed: 11/19/2022] Open
Abstract
The mammalian neocortex has undergone repeated selection for increases and decreases in size and complexity, often over relatively short evolutionary time. But because probing developmental mechanisms across many species is experimentally unfeasible, it is unknown whether convergent morphologies in distantly related species are regulated by conserved developmental programs. In this work, we have taken advantage of the abundance of available mammalian genomes to find evidence of selection on genomic regions putatively regulating neurogenesis in large- versus small-brained species. Using published fetal human RNA-seq data, we show that the gene-neighborhood (i.e., microsynteny) of long intergenic non-coding RNAs (lincRNAs) implicated in cortical development is differentially conserved in large-brained species, lending support to the hypothesis that lincRNAs regulating neurogenesis are selectively lost in small-brained species. We provide evidence that this is not a phenomenon attributable to lincRNA expressed in all tissue types and is therefore likely to represent an adaptive function in the evolution of neurogenesis. A strong correlation between transcription factor-adjacency and lincRNA sequence conservation reinforces this conclusion.
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76
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Turrero García M, Chang Y, Arai Y, Huttner WB. S-phase duration is the main target of cell cycle regulation in neural progenitors of developing ferret neocortex. J Comp Neurol 2015; 524:456-70. [PMID: 25963823 PMCID: PMC5008145 DOI: 10.1002/cne.23801] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 04/30/2015] [Accepted: 05/06/2015] [Indexed: 01/22/2023]
Abstract
The evolutionary expansion of the neocortex primarily reflects increases in abundance and proliferative capacity of cortical progenitors and in the length of the neurogenic period during development. Cell cycle parameters of neocortical progenitors are an important determinant of cortical development. The ferret (Mustela putorius furo), a gyrencephalic mammal, has gained increasing importance as a model for studying corticogenesis. Here, we have studied the abundance, proliferation, and cell cycle parameters of different neural progenitor types, defined by their differential expression of the transcription factors Pax6 and Tbr2, in the various germinal zones of developing ferret neocortex. We focused our analyses on postnatal day 1, a late stage of cortical neurogenesis when upper‐layer neurons are produced. Based on cumulative 5‐ethynyl‐2′‐deoxyuridine (EdU) labeling as well as Ki67 and proliferating cell nuclear antigen (PCNA) immunofluorescence, we determined the duration of the various cell cycle phases of the different neocortical progenitor subpopulations. Ferret neocortical progenitors were found to exhibit longer cell cycles than those of rodents and little variation in the duration of G1 among distinct progenitor types, also in contrast to rodents. Remarkably, the main difference in cell cycle parameters among the various progenitor types was the duration of S‐phase, which became shorter as progenitors progressively changed transcription factor expression from patterns characteristic of self‐renewal to those of neuron production. Hence, S‐phase duration emerges as major target of cell cycle regulation in cortical progenitors of this gyrencephalic mammal. J. Comp. Neurol. 524:456–470, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Miguel Turrero García
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - YoonJeung Chang
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Yoko Arai
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
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77
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Muellner J, Delmaire C, Valabrégue R, Schüpbach M, Mangin JF, Vidailhet M, Lehéricy S, Hartmann A, Worbe Y. Altered structure of cortical sulci in gilles de la Tourette syndrome: Further support for abnormal brain development. Mov Disord 2015; 30:655-61. [DOI: 10.1002/mds.26207] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 02/02/2023] Open
Affiliation(s)
- Julia Muellner
- Assistance Publique Hôpitaux de Paris (APHP), INSERM, ICM, Centre d'Investigation Clinique Pitié Neurosciences, CIC-1422, Département des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière; Paris France
- Department of Neurology; Inselspital; University Hospital Bern; Bern Switzerland
| | | | - Romain Valabrégue
- Center for Neuroimaging Research-CENIR, Groupe Hospitalier Pitié-Salpêtrière; Paris France
| | - Michael Schüpbach
- Department of Neurology; Inselspital; University Hospital Bern; Bern Switzerland
| | | | - Marie Vidailhet
- Assistance Publique Hôpitaux de Paris (APHP), INSERM, ICM, Centre d'Investigation Clinique Pitié Neurosciences, CIC-1422, Département des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière; Paris France
- Centre de Référence «Syndrome Gilles de la Tourette», Département de Neurologie, Pôle des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris (APHP); Paris France
- Inserm U 1127, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière; Paris France
| | - Stéphane Lehéricy
- Center for Neuroimaging Research-CENIR, Groupe Hospitalier Pitié-Salpêtrière; Paris France
- Inserm U 1127, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière; Paris France
| | - Andreas Hartmann
- Assistance Publique Hôpitaux de Paris (APHP), INSERM, ICM, Centre d'Investigation Clinique Pitié Neurosciences, CIC-1422, Département des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière; Paris France
- Centre de Référence «Syndrome Gilles de la Tourette», Département de Neurologie, Pôle des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris (APHP); Paris France
- Inserm U 1127, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière; Paris France
| | - Yulia Worbe
- Assistance Publique Hôpitaux de Paris (APHP), INSERM, ICM, Centre d'Investigation Clinique Pitié Neurosciences, CIC-1422, Département des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière; Paris France
- Centre de Référence «Syndrome Gilles de la Tourette», Département de Neurologie, Pôle des Maladies du Système Nerveux, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris (APHP); Paris France
- Inserm U 1127, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière; Paris France
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78
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Miyata T, Okamoto M, Shinoda T, Kawaguchi A. Interkinetic nuclear migration generates and opposes ventricular-zone crowding: insight into tissue mechanics. Front Cell Neurosci 2015; 8:473. [PMID: 25674051 PMCID: PMC4309187 DOI: 10.3389/fncel.2014.00473] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 12/31/2014] [Indexed: 01/26/2023] Open
Abstract
The neuroepithelium (NE) or ventricular zone (VZ), from which multiple types of brain cells arise, is pseudostratified. In the NE/VZ, neural progenitor cells are elongated along the apicobasal axis, and their nuclei assume different apicobasal positions. These nuclei move in a cell cycle-dependent manner, i.e., apicalward during G2 phase and basalward during G1 phase, a process called interkinetic nuclear migration (INM). This review will summarize and discuss several topics: the nature of the INM exhibited by neural progenitor cells, the mechanical difficulties associated with INM in the developing cerebral cortex, the community-level mechanisms underlying collective and efficient INM, the impact on overall brain formation when NE/VZ is overcrowded due to loss of INM, and whether and how neural progenitor INM varies among mammalian species. These discussions will be based on recent findings obtained in live, three-dimensional specimens using quantitative and mechanical approaches. Experiments in which overcrowding was induced in mouse neocortical NE/VZ, as well as comparisons of neocortical INM between mice and ferrets, have revealed that the behavior of NE/VZ cells can be affected by cellular densification. A consideration of the physical aspects in the NE/VZ and the mechanical difficulties associated with high-degree pseudostratification (PS) is important for achieving a better understanding of neocortical development and evolution.
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Affiliation(s)
- Takaki Miyata
- Anatomy and Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Aichi, Japan
| | - Mayumi Okamoto
- Anatomy and Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Aichi, Japan
| | - Tomoyasu Shinoda
- Anatomy and Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Aichi, Japan
| | - Ayano Kawaguchi
- Anatomy and Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Aichi, Japan
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79
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Lewitus E, Kelava I, Kalinka AT, Tomancak P, Huttner WB. An adaptive threshold in mammalian neocortical evolution. PLoS Biol 2014; 12:e1002000. [PMID: 25405475 PMCID: PMC4236020 DOI: 10.1371/journal.pbio.1002000] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 10/09/2014] [Indexed: 01/19/2023] Open
Abstract
A study of the evolutionary history of cortical folding in mammals, its relationship to physiological and life-history traits and the underlying cortical progenitor behavior during embryogenesis, explains the diversity of folding we see across modern mammals. The diversity of neocortical folding among mammals can be explained by two distinct neurogenic programs, which give rise to mammals with a highly folded neocortex and mammals with slightly folded or unfolded neocortex, each occupying a distinct ecological niche. Expansion of the neocortex is a hallmark of human evolution. However, determining which adaptive mechanisms facilitated its expansion remains an open question. Here we show, using the gyrencephaly index (GI) and other physiological and life-history data for 102 mammalian species, that gyrencephaly is an ancestral mammalian trait. We find that variation in GI does not evolve linearly across species, but that mammals constitute two principal groups above and below a GI threshold value of 1.5, approximately equal to 109 neurons, which may be characterized by distinct constellations of physiological and life-history traits. By integrating data on neurogenic period, neuroepithelial founder pool size, cell-cycle length, progenitor-type abundances, and cortical neuron number into discrete mathematical models, we identify symmetric proliferative divisions of basal progenitors in the subventricular zone of the developing neocortex as evolutionarily necessary for generating a 14-fold increase in daily prenatal neuron production, traversal of the GI threshold, and thus establishment of two principal groups. We conclude that, despite considerable neuroanatomical differences, changes in the length of the neurogenic period alone, rather than any novel neurogenic progenitor lineage, are sufficient to explain differences in neuron number and neocortical size between species within the same principal group. What are the key differences in the development and evolution of the cerebral cortex that underlie the differences in its size and degree of folding across mammals? Here, we present phylogenetic evidence that the Jurassic era mammalian ancestor may have been a relatively large-brained species with a folded neocortex. We then show that variation in the degree of cortical folding (gyrencephaly index [GI]) does not evolve linearly across species, as previously assumed, but that mammals fall into two principal groups associated with distinct ecological niches: low-GI mammals (such as mice and tarsiers) and high-GI mammals (such as dolphins and humans), which are found to generate on average 14-fold more brain weight per day of gestation. This greater daily brain weight production in mammals with a highly folded neocortex requires a specific class of progenitor cell-type to adopt a special mode of cell division, which is absent in mammals with slightly folded or unfolded neocortices. Differences among mammals within the same GI group (high or low) are not due to different programming, but rather the result of differences in the length of the neurogenic period. So, the impressively large and folded human neocortex, which is three times the size of the chimpanzee neocortex, can be explained by a modest evolutionary extension of the neurogenic period with respect to its closest primate ancestors.
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Affiliation(s)
- Eric Lewitus
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EL); (WBH)
| | - Iva Kelava
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Alex T. Kalinka
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EL); (WBH)
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80
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Kazu RS, Maldonado J, Mota B, Manger PR, Herculano-Houzel S. Cellular scaling rules for the brain of Artiodactyla include a highly folded cortex with few neurons. Front Neuroanat 2014; 8:128. [PMID: 25429261 PMCID: PMC4228855 DOI: 10.3389/fnana.2014.00128] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 10/20/2014] [Indexed: 11/30/2022] Open
Abstract
Quantitative analysis of the cellular composition of rodent, primate, insectivore, and afrotherian brains has shown that non-neuronal scaling rules are similar across these mammalian orders that diverged about 95 million years ago, and therefore appear to be conserved in evolution, while neuronal scaling rules appear to be free to vary in a clade-specific manner. Here we analyze the cellular scaling rules that apply to the brain of artiodactyls, a group within the order Cetartiodactyla, believed to be a relatively recent radiation from the common Eutherian ancestor. We find that artiodactyls share non-neuronal scaling rules with all groups analyzed previously. Artiodactyls share with afrotherians and rodents, but not with primates, the neuronal scaling rules that apply to the cerebral cortex and cerebellum. The neuronal scaling rules that apply to the remaining brain areas are, however, distinct in artiodactyls. Importantly, we show that the folding index of the cerebral cortex scales with the number of neurons in the cerebral cortex in distinct fashions across artiodactyls, afrotherians, rodents, and primates, such that the artiodactyl cerebral cortex is more convoluted than primate cortices of similar numbers of neurons. Our findings suggest that the scaling rules found to be shared across modern afrotherians, glires, and artiodactyls applied to the common Eutherian ancestor, such as the relationship between the mass of the cerebral cortex as a whole and its number of neurons. In turn, the distribution of neurons along the surface of the cerebral cortex, which is related to its degree of gyrification, appears to be a clade-specific characteristic. If the neuronal scaling rules for artiodactyls extend to all cetartiodactyls, we predict that the large cerebral cortex of cetaceans will still have fewer neurons than the human cerebral cortex.
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Affiliation(s)
- Rodrigo S Kazu
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Neurociência Translacional, CNPq/MCT, São Paulo, Brazil
| | | | - Bruno Mota
- Instituto de Física, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Paul R Manger
- School of Anatomical Sciences, University of the Witwatersrand Johannesburg, South Africa
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Neurociência Translacional, CNPq/MCT, São Paulo, Brazil
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81
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Progenitor genealogy in the developing cerebral cortex. Cell Tissue Res 2014; 359:17-32. [PMID: 25141969 DOI: 10.1007/s00441-014-1979-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
The mammalian cerebral cortex is characterized by a complex histological organization that reflects the spatio-temporal stratifications of related stem and neural progenitor cells, which are responsible for the generation of distinct glial and neuronal subtypes during development. Some work has been done to shed light on the existing filiations between these progenitors as well as their respective contribution to cortical neurogenesis. The aim of the present review is to summarize the current views of progenitor hierarchy and relationship in the developing cortex and to further discuss future research directions that would help us to understand the molecular and cellular regulating mechanisms involved in cerebral corticogenesis.
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82
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Florio M, Huttner WB. Neural progenitors, neurogenesis and the evolution of the neocortex. Development 2014; 141:2182-94. [PMID: 24866113 DOI: 10.1242/dev.090571] [Citation(s) in RCA: 433] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The neocortex is the seat of higher cognitive functions and, in evolutionary terms, is the youngest part of the mammalian brain. Since its origin, the neocortex has expanded in several mammalian lineages, and this is particularly notable in humans. This expansion reflects an increase in the number of neocortical neurons, which is determined during development and primarily reflects the number of neurogenic divisions of distinct classes of neural progenitor cells. Consequently, the evolutionary expansion of the neocortex and the concomitant increase in the numbers of neurons produced during development entail interspecies differences in neural progenitor biology. Here, we review the diversity of neocortical neural progenitors, their interspecies variations and their roles in determining the evolutionary increase in neuron numbers and neocortex size.
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Affiliation(s)
- Marta Florio
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
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83
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Ferret–mouse differences in interkinetic nuclear migration and cellular densification in the neocortical ventricular zone. Neurosci Res 2014. [DOI: 10.1016/j.neures.2014.03.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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84
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Enard W. Comparative genomics of brain size evolution. Front Hum Neurosci 2014; 8:345. [PMID: 24904382 PMCID: PMC4033227 DOI: 10.3389/fnhum.2014.00345] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/06/2014] [Indexed: 01/12/2023] Open
Abstract
Which genetic changes took place during mammalian, primate and human evolution to build a larger brain? To answer this question, one has to correlate genetic changes with brain size changes across a phylogeny. Such a comparative genomics approach provides unique information to better understand brain evolution and brain development. However, its statistical power is limited for example due to the limited number of species, the presumably complex genetics of brain size evolution and the large search space of mammalian genomes. Hence, it is crucial to add functional information, for example by limiting the search space to genes and regulatory elements known to play a role in the relevant cell types during brain development. Similarly, it is crucial to experimentally follow up on hypotheses generated by such a comparative approach. Recent progress in understanding the molecular and cellular mechanisms of mammalian brain development, in genome sequencing and in genome editing, promises to make a close integration of evolutionary and experimental methods a fruitful approach to better understand the genetics of mammalian brain size evolution.
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Affiliation(s)
- Wolfgang Enard
- Department of Biology II, Ludwig Maximilian University MunichMunich, Germany
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85
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Sun T, Hevner RF. Growth and folding of the mammalian cerebral cortex: from molecules to malformations. Nat Rev Neurosci 2014; 15:217-32. [PMID: 24646670 DOI: 10.1038/nrn3707] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The size and extent of folding of the mammalian cerebral cortex are important factors that influence a species' cognitive abilities and sensorimotor skills. Studies in various animal models and in humans have provided insight into the mechanisms that regulate cortical growth and folding. Both protein-coding genes and microRNAs control cortical size, and recent progress in characterizing basal progenitor cells and the genes that regulate their proliferation has contributed to our understanding of cortical folding. Neurological disorders linked to disruptions in cortical growth and folding have been associated with novel neurogenetic mechanisms and aberrant signalling pathways, and these findings have changed concepts of brain evolution and may lead to new medical treatments for certain disorders.
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Affiliation(s)
- Tao Sun
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, BOX 60, New York, New York 10065, USA
| | - Robert F Hevner
- Department of Neurological Surgery and Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98101, USA
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