151
|
Brain organoids as models to study human neocortex development and evolution. Curr Opin Cell Biol 2018; 55:8-16. [PMID: 30006054 DOI: 10.1016/j.ceb.2018.06.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 11/20/2022]
Abstract
Since their recent development, organoids that emulate human brain tissue have allowed in vitro neural development studies to go beyond the limits of monolayer culture systems, such as neural rosettes. We present here a review of organoid studies that focuses on cortical wall development, starting with a technical comparison between pre-patterning and self-patterning brain organoid protocols. We then follow neocortex development in space and time and list those aspects where organoids have succeeded in emulating in vivo development, as well as those aspects that continue to be pending tasks. Finally, we present a summary of medical and evolutionary insight made possible by organoid technology.
Collapse
|
152
|
Freret-Hodara B, Cui Y, Griveau A, Vigier L, Arai Y, Touboul J, Pierani A. Enhanced Abventricular Proliferation Compensates Cell Death in the Embryonic Cerebral Cortex. Cereb Cortex 2018; 27:4701-4718. [PMID: 27620979 DOI: 10.1093/cercor/bhw264] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 07/25/2016] [Indexed: 12/30/2022] Open
Abstract
Loss of neurons in the neocortex is generally thought to result in a final reduction of cerebral volume. Yet, little is known on how the developing cerebral cortex copes with death of early-born neurons. Here, we tackled this issue by taking advantage of a transgenic mouse model in which, from early embryonic stages to mid-corticogenesis, abundant apoptosis is induced in the postmitotic compartment. Unexpectedly, the thickness of the mutant cortical plate at E18.5 was normal, due to an overproduction of upper layer neurons at E14.5. We developed and simulated a mathematical model to investigate theoretically the recovering capacity of the system and found that a minor increase in the probability of proliferative divisions of intermediate progenitors (IPs) is a powerful compensation lever. We confirmed experimentally that mutant mice showed an enhanced number of abventricular progenitors including basal radial glia-like cells and IPs. The latter displayed increased proliferation rate, sustained Pax6 expression and shorter cell cycle duration. Altogether, these results demonstrate the remarkable plasticity of neocortical progenitors to adapt to major embryonic insults via the modulation of abventricular divisions thereby ensuring the production of an appropriate number of neurons.
Collapse
Affiliation(s)
- Betty Freret-Hodara
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion , 75205Paris Cedex, France
| | - Yi Cui
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion, 75205 Paris Cedex, France.,Center for Interdisciplinary Research in Biology (CIRB)-Collège de France and INRIA Paris, EPI MYCENAE, 11, Place Marcelin Berthelot, 75005 Paris, France.,Ecole Doctorale Cerveau Cognition Comportement (ED3C, ED n°158), Université Pierre et Marie Curie, 7 Quai Saint Bernard, 75005 Paris, France
| | - Amélie Griveau
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion , 75205Paris Cedex, France
| | - Lisa Vigier
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion , 75205Paris Cedex, France
| | - Yoko Arai
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion , 75205Paris Cedex, France
| | - Jonathan Touboul
- Center for Interdisciplinary Research in Biology (CIRB)-Collège de France and INRIA Paris, EPI MYCENAE, 11, Place Marcelin Berthelot , 75005Paris, France
| | - Alessandra Pierani
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion , 75205Paris Cedex, France
| |
Collapse
|
153
|
Chromatin Remodeling BAF155 Subunit Regulates the Genesis of Basal Progenitors in Developing Cortex. iScience 2018; 4:109-126. [PMID: 30240734 PMCID: PMC6147019 DOI: 10.1016/j.isci.2018.05.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/22/2018] [Accepted: 05/18/2018] [Indexed: 11/21/2022] Open
Abstract
The abundance of basal progenitors (BPs), basal radial glia progenitors (bRGs) and basal intermediate progenitors (bIPs), in primate brain has been correlated to the high degree of cortical folding. Here we examined the role of BAF155, a subunit of the chromatin remodeling BAF complex, in generation of cortical progenitor heterogeneity. The conditional deletion of BAF155 led to diminished bIP pool and increased number of bRGs, due to delamination of apical RGs. We found that BAF155 is required for normal activity of neurogenic transcription factor PAX6, thus controlling the expression of genes that are involved in bIP specification, cell-cell interaction, and establishment of adherens junction. In a PAX6-dependent manner, BAF155 regulates the expression of the CDC42 effector protein CEP4, thereby controlling progenitor delamination. Furthermore, BAF155-dependent chromatin remodeling seems to exert a specific role in the genesis of BPs through the regulation of human RG-specific genes (such as Foxn4) that possibly acquired evolutionary significance.
Collapse
|
154
|
Neural stem cell therapies and hypoxic-ischemic brain injury. Prog Neurobiol 2018; 173:1-17. [PMID: 29758244 DOI: 10.1016/j.pneurobio.2018.05.004] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 03/06/2018] [Accepted: 05/09/2018] [Indexed: 12/13/2022]
Abstract
Hypoxic-ischemic brain injury is a significant cause of morbidity and mortality in the adult as well as in the neonate. Extensive pre-clinical studies have shown promising therapeutic effects of neural stem cell-based treatments for hypoxic-ischemic brain injury. There are two major strategies of neural stem cell-based therapies: transplanting exogenous neural stem cells and boosting self-repair of endogenous neural stem cells. Neural stem cell transplantation has been proved to improve functional recovery after brain injury through multiple by-stander mechanisms (e.g., neuroprotection, immunomodulation), rather than simple cell-replacement. Endogenous neural stem cells reside in certain neurogenic niches of the brain and response to brain injury. Many molecules (e.g., neurotrophic factors) can stimulate or enhance proliferation and differentiation of endogenous neural stem cells after injury. In this review, we first present an overview of neural stem cells during normal brain development and the effect of hypoxic-ischemic injury on the activation and function of endogenous neural stem cells in the brain. We then summarize and discuss the current knowledge of strategies and mechanisms for neural stem cell-based therapies on brain hypoxic-ischemic injury, including neonatal hypoxic-ischemic brain injury and adult ischemic stroke.
Collapse
|
155
|
Abstract
Understanding the development of the human brain in relation with evolution is an important frontier field in developmental biology. In particular, investigating the mechanisms underlying the greatly increased relative size and complexity of the cerebral cortex, the seat of our enhanced cognitive abilities, remains a fascinating yet largely unsolved question. Though many advances in our understanding have been gained from the study of animal models, as well as human genetics and embryology, large gaps remain in our knowledge of the molecular mechanisms that control human cortical development. Interestingly, many aspects of corticogenesis can be recapitulated in vitro from mouse and human embryonic or induced pluripotent stem cells (PSCs), using a variety of experimental systems from 2D models to organoids to xenotransplantation. This has provided the opportunity to study these processes in an accessible and physiologically relevant setting. In this chapter, we will discuss how conserved and divergent features of primate/human corticogenesis can be modeled and studied mechanistically using PSC-based models of corticogenesis. We will also review what has been learned through these approaches about pathological defects of human corticogenesis, from early neurogenesis to late neuronal maturation and connectivity.
Collapse
|
156
|
Yoon KJ, Vissers C, Ming GL, Song H. Epigenetics and epitranscriptomics in temporal patterning of cortical neural progenitor competence. J Cell Biol 2018; 217:1901-1914. [PMID: 29666150 PMCID: PMC5987727 DOI: 10.1083/jcb.201802117] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022] Open
Abstract
Yoon et al. review epigenetic and epitranscriptomic mechanisms that regulate the lineage specification of neural progenitor cells in the developing brain. During embryonic brain development, neural progenitor/stem cells (NPCs) sequentially give rise to different subtypes of neurons and glia via a highly orchestrated process. To accomplish the ordered generation of distinct progenies, NPCs go through multistep transitions of their developmental competence. The molecular mechanisms driving precise temporal coordination of these transitions remains enigmatic. Epigenetic regulation, including changes in chromatin structures, DNA methylation, and histone modifications, has been extensively investigated in the context of cortical neurogenesis. Recent studies of chemical modifications on RNA, termed epitranscriptomics, have also revealed their critical roles in neural development. In this review, we discuss advances in understanding molecular regulation of the sequential lineage specification of NPCs in the embryonic mammalian brain with a focus on epigenetic and epitranscriptomic mechanisms. In particular, the discovery of lineage-specific gene transcripts undergoing rapid turnover in NPCs suggests that NPC developmental fate competence is determined much earlier, before the final cell division, and is more tightly controlled than previously appreciated. We discuss how multiple regulatory systems work in harmony to coordinate NPC behavior and summarize recent findings in the context of a model of epigenetic and transcriptional prepatterning to explain NPC developmental competence.
Collapse
Affiliation(s)
- Ki-Jun Yoon
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
| | - Caroline Vissers
- The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Cell and Developmental Biology, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,Institute for Regenerative Medicine, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA .,The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Cell and Developmental Biology, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,Institute for Regenerative Medicine, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,The Epigenetics Institute, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
157
|
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: 41] [Impact Index Per Article: 5.9] [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.
Collapse
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
| |
Collapse
|
158
|
Abstract
The noncoding portion of the genome, including microRNAs, has been fertile evolutionary soil for cortical development in primates. A major contribution to cortical expansion in primates is the generation of novel precursor cell populations. Because miRNA expression profiles track closely with cell identity, it is likely that numerous novel microRNAs have contributed to cellular diversity in the brain. The tools to determine the genomic context within which novel microRNAs emerge and how they become integrated into molecular circuitry are now in hand.
Collapse
Affiliation(s)
- Kenneth S Kosik
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA;
| | - Tomasz Nowakowski
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, California 94143, USA.,Department of Anatomy, University of California, San Francisco, California 94158, USA
| |
Collapse
|
159
|
The logistics of afferent cortical specification in mice and men. Semin Cell Dev Biol 2018; 76:112-119. [DOI: 10.1016/j.semcdb.2017.08.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 11/17/2022]
|
160
|
Florio M, Heide M, Pinson A, Brandl H, Albert M, Winkler S, Wimberger P, Huttner WB, Hiller M. Evolution and cell-type specificity of human-specific genes preferentially expressed in progenitors of fetal neocortex. eLife 2018; 7:32332. [PMID: 29561261 PMCID: PMC5898914 DOI: 10.7554/elife.32332] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 03/09/2018] [Indexed: 01/21/2023] Open
Abstract
Understanding the molecular basis that underlies the expansion of the neocortex during primate, and notably human, evolution requires the identification of genes that are particularly active in the neural stem and progenitor cells of the developing neocortex. Here, we have used existing transcriptome datasets to carry out a comprehensive screen for protein-coding genes preferentially expressed in progenitors of fetal human neocortex. We show that 15 human-specific genes exhibit such expression, and many of them evolved distinct neural progenitor cell-type expression profiles and levels compared to their ancestral paralogs. Functional studies on one such gene, NOTCH2NL, demonstrate its ability to promote basal progenitor proliferation in mice. An additional 35 human genes with progenitor-enriched expression are shown to have orthologs only in primates. Our study provides a resource of genes that are promising candidates to exert specific, and novel, roles in neocortical development during primate, and notably human, evolution.
Collapse
Affiliation(s)
- Marta Florio
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Michael Heide
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Anneline Pinson
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Holger Brandl
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Mareike Albert
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Sylke Winkler
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Pauline Wimberger
- Klinik und Poliklinik für Frauenheilkunde und Geburtshilfe, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| |
Collapse
|
161
|
Jeong H, Tiwari VK. Exploring the Complexity of Cortical Development Using Single-Cell Transcriptomics. Front Neurosci 2018; 12:31. [PMID: 29456488 PMCID: PMC5801402 DOI: 10.3389/fnins.2018.00031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 01/15/2018] [Indexed: 12/15/2022] Open
Abstract
The developing neocortex in the mammalian brain is composed of multiple cell types including apical progenitors (AP), basal progenitors (BP), and neurons that populate three different layers, the ventricular zone (VZ), the subventricular zone (SVZ), and the cortical plate (CP). Despite recent advances, the diversity of the existing cell populations including those which are differentiating and mature, their biogenesis and the underlying gene regulatory mechanisms remain poorly known. Recent studies have taken advantage of the rapidly emerging single-cell technologies to decode the heterogeneity of cell populations at the transcriptome level during cortical development and their molecular details. Here we review these studies and provide an overview of the steps in single-cell transcriptomics including both experimental and computational analysis. We also discuss how single-cell genomics holds a big potential in future for brain research and discuss its possible applications and biological insights that can be achieved from these approaches. We conclude this review by discussing the current challenges in the implementation of single-cell techniques toward a comprehensive understanding of the genetic and epigenetic mechanisms underlying neocortex development.
Collapse
|
162
|
Leung AW, Li JYH. The Molecular Pathway Regulating Bergmann Glia and Folia Generation in the Cerebellum. CEREBELLUM (LONDON, ENGLAND) 2018; 17:42-48. [PMID: 29218544 PMCID: PMC5809181 DOI: 10.1007/s12311-017-0904-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Evolution of complex behaviors in higher vertebrates and primates require the development of sophisticated neuronal circuitry and the expansion of brain surface area to accommodate the vast number of neuronal and glial populations. To achieve these goals, the neocortex in primates and the cerebellum in amniotes have developed specialized types of basal progenitors to aid the folding of their cortices. In the cerebellum, Bergmann glia constitute such a basal progenitor population, having a distinctive morphology and playing a critical role in cerebellar corticogenesis. Here, we review recent studies on the induction of Bergmann glia and their crucial role in mediating folding of the cerebellar cortex. These studies uncover a key function of FGF-ERK-ETV signaling cascade in the transformation of Bergmann glia from radial glia in the ventricular zone. Remarkably, in the neocortex, the same signaling axis operates to facilitate the transformation of ventricular radial glia into basal radial glia, a Bergmann glia-like basal progenitor population, which have been implicated in the establishment of neocortical gyri. These new findings draw a striking similarity in the function and ontogeny of the two basal progenitor populations born in distinct brain compartments.
Collapse
Affiliation(s)
- Alan W Leung
- Department of Genetics and Yale Stem Cell Center, Yale University, 10 Amistad Street, New Haven, CT, 06520-8073, USA
| | - James Y H Li
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT, 06030-6403, USA.
- Institute for Systems Genomics, University of Connecticut, 400 Farmington Avenue, Farmington, CT, 06030-6403, USA.
| |
Collapse
|
163
|
Adnani L, Han S, Li S, Mattar P, Schuurmans C. Mechanisms of Cortical Differentiation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 336:223-320. [DOI: 10.1016/bs.ircmb.2017.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
164
|
Abstract
Humans are a remarkable species, especially because of the remarkable properties of their brain. Since the split from the chimpanzee lineage, the human brain has increased three-fold in size and has acquired abilities for vocal learning, language and intense cooperation. To better understand the molecular basis of these changes is of great biological and biomedical interest. However, all the about 16 million fixed genetic changes that occurred during human evolution are fully correlated with all molecular, cellular, anatomical and behavioral changes that occurred during this time. Hence, as humans and chimpanzees cannot be crossed or genetically manipulated, no direct evidence for linking particular genetic and molecular changes to human brain evolution can be obtained. Here, I sketch a framework how indirect evidence can be obtained and review findings related to the molecular basis of human cognition, vocal learning and brain size. In particular, I discuss how a comprehensive comparative approach, leveraging cellular systems and genomic technologies, could inform the evolution of our brain in the future.
Collapse
Affiliation(s)
- Wolfgang Enard
- Department of Biology II, Ludwig Maximilian University Munich, Grosshaderner Str. 2, D-82152 Martinsried, Germany.
| |
Collapse
|
165
|
Heide M, Long KR, Huttner WB. Novel gene function and regulation in neocortex expansion. Curr Opin Cell Biol 2017; 49:22-30. [PMID: 29227861 DOI: 10.1016/j.ceb.2017.11.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/18/2017] [Accepted: 11/26/2017] [Indexed: 01/01/2023]
Abstract
The expansion of the neocortex during human evolution is due to changes in our genome that result in increased and prolonged proliferation of neural stem and progenitor cells during neocortex development. Three principal types of such genomic changes can be distinguished, first, novel gene regulation in human, second, novel function in human of genes existing in both human and non-human species, and third, novel, human-specific genes. The latter comprise both, increases in the copy number of genes existing also in non-human species, and the emergence of genes giving rise to unique, human-specific gene products. Examples of all these types of changes in the human genome have been identified, with ARHGAP11B constituting a paradigmatic example of a unique, human-specific protein.
Collapse
Affiliation(s)
- Michael Heide
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, D-01307 Dresden, Germany
| | - Katherine R Long
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, D-01307 Dresden, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, D-01307 Dresden, Germany.
| |
Collapse
|
166
|
Sugimoto J, Tanaka M, Sugiyama K, Ito Y, Aizawa H, Soma M, Shimizu T, Mitani A, Tanaka K. Region-specific deletions of the glutamate transporter GLT1 differentially affect seizure activity and neurodegeneration in mice. Glia 2017; 66:777-788. [PMID: 29214672 DOI: 10.1002/glia.23281] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 11/06/2022]
Abstract
Glial glutamate transporter GLT1 plays a key role in the maintenance of extracellular glutamate homeostasis. Recent human genetic studies have suggested that de novo mutations in GLT1 (EAAT2) cause early-onset epilepsy with multiple seizure types. Consistent with these findings, global GLT1 null mice show lethal spontaneous seizures. The consequences of GLT1 dysfunction vary between different brain regions, suggesting that the role of GLT1 dysfunction in epilepsy may also vary with brain regions. In this study, we generated region-specific GLT1 knockout mice by crossing floxed-GLT1 mice with mice that express the Cre recombinase in a particular domain of the ventricular zone. Selective deletion of GLT1 in the diencephalon, brainstem and spinal cord is sufficient to reproduce the phenotypes (excess mortality, decreased body weight, and lethal spontaneous seizure) of the global GLT1 null mice. By contrast, dorsal forebrain-specific GLT1 knockout mice showed nonlethal complex seizures including myoclonic jerks, hyperkinetic running, spasm and clonic convulsion via the activation of NMDA receptors during a limited period from P12 to P14 and selective neuronal death in cortical layer II/III and the hippocampus. Thus, GLT1 dysfunction in the dorsal forebrain is involved in the pathogenesis of infantile epilepsy and GLT1 in the diencephalon, brainstem and spinal cord may play a critical role in preventing seizure-induced sudden death.
Collapse
Affiliation(s)
- Junya Sugimoto
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Moeko Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Kaori Sugiyama
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Yukiko Ito
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Hidenori Aizawa
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Miho Soma
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Tomoko Shimizu
- Laboratory of Physiology, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Akira Mitani
- Laboratory of Physiology, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.,Center for Brain Integration Research (CBIR), TMDU, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| |
Collapse
|
167
|
Hardingham GE, Pruunsild P, Greenberg ME, Bading H. Lineage divergence of activity-driven transcription and evolution of cognitive ability. Nat Rev Neurosci 2017; 19:9-15. [PMID: 29167525 DOI: 10.1038/nrn.2017.138] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Excitation-transcription coupling shapes network formation during brain development and controls neuronal survival, synaptic function and cognitive skills in the adult. New studies have uncovered differences in the transcriptional responses to synaptic activity between humans and mice. These differences are caused both by the emergence of lineage-specific activity-regulated genes and by the acquisition of signal-responsive DNA elements in gene regulatory regions that determine whether a gene can be transcriptionally induced by synaptic activity or alter the extent of its inducibility. Such evolutionary divergence may have contributed to lineage-related advancements in cognitive abilities.
Collapse
Affiliation(s)
- Giles E Hardingham
- UK Dementia Research Institute at The University of Edinburgh, Edinburgh Medical School, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Priit Pruunsild
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany
| | - Michael E Greenberg
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany
| |
Collapse
|
168
|
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: 57] [Impact Index Per Article: 7.1] [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.
Collapse
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
| |
Collapse
|
169
|
Liu J, Liu W, Yang L, Wu Q, Zhang H, Fang A, Li L, Xu X, Sun L, Zhang J, Tang F, Wang X. The Primate-Specific Gene TMEM14B Marks Outer Radial Glia Cells and Promotes Cortical Expansion and Folding. Cell Stem Cell 2017; 21:635-649.e8. [DOI: 10.1016/j.stem.2017.08.013] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/06/2017] [Accepted: 04/16/2017] [Indexed: 12/18/2022]
|
170
|
Turrero García M, Harwell CC. Radial glia in the ventral telencephalon. FEBS Lett 2017; 591:3942-3959. [PMID: 28862741 DOI: 10.1002/1873-3468.12829] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 12/31/2022]
Abstract
The ventral telencephalon is the developmental origin of the basal ganglia and the source of neuronal and glial cells that integrate into developing circuits in other areas of the brain. Radial glia in the embryonic subpallium give rise to an enormous diversity of mature cell types, either directly or through other transit-amplifying progenitors. Here, we review current knowledge about these subpallial neural stem cells and their progeny, focusing on the period of neurogenesis. We describe their cell biological features and the extrinsic and intrinsic molecular codes that guide their fate specification in defined temporal and spatial sequences. We also discuss the role of clonal lineage in the organization and specification of mature neurons.
Collapse
Affiliation(s)
| | - Corey C Harwell
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
171
|
Enhancing our brains: Genomic mechanisms underlying cortical evolution. Semin Cell Dev Biol 2017; 76:23-32. [PMID: 28864345 DOI: 10.1016/j.semcdb.2017.08.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 08/24/2017] [Indexed: 12/31/2022]
Abstract
Our most distinguishing higher cognitive functions are controlled by the cerebral cortex. Comparative studies detail abundant anatomical and cellular features unique to the human developing and adult neocortex. Emerging genomic studies have further defined vast differences distinguishing developing human neocortices from related primates. These human-specific changes can affect gene function and/or expression, and result from structural variations such as chromosomal deletions and duplications, or from point mutations in coding and noncoding regulatory regions. Here, we review this rapidly growing field which aims to identify and characterize genetic loci unique to the human cerebral cortex. We catalog known human-specific genomic changes distinct from other primates, including those whose function has been interrogated in animal models. We also discuss how new model systems and technologies such as single cell RNA sequencing, primate iPSCs, and gene editing, are enabling the field to gain unprecedented resolution into function of these human-specific changes. Some neurological disorders are thought to uniquely present in humans, thus reinforcing the need to comprehensively understand human-specific gene expression in the developing brain.
Collapse
|
172
|
D'Souza RD, Burkhalter A. A Laminar Organization for Selective Cortico-Cortical Communication. Front Neuroanat 2017; 11:71. [PMID: 28878631 PMCID: PMC5572236 DOI: 10.3389/fnana.2017.00071] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/07/2017] [Indexed: 11/13/2022] Open
Abstract
The neocortex is central to mammalian cognitive ability, playing critical roles in sensory perception, motor skills and executive function. This thin, layered structure comprises distinct, functionally specialized areas that communicate with each other through the axons of pyramidal neurons. For the hundreds of such cortico-cortical pathways to underlie diverse functions, their cellular and synaptic architectures must differ so that they result in distinct computations at the target projection neurons. In what ways do these pathways differ? By originating and terminating in different laminae, and by selectively targeting specific populations of excitatory and inhibitory neurons, these “interareal” pathways can differentially control the timing and strength of synaptic inputs onto individual neurons, resulting in layer-specific computations. Due to the rapid development in transgenic techniques, the mouse has emerged as a powerful mammalian model for understanding the rules by which cortical circuits organize and function. Here we review our understanding of how cortical lamination constrains long-range communication in the mammalian brain, with an emphasis on the mouse visual cortical network. We discuss the laminar architecture underlying interareal communication, the role of neocortical layers in organizing the balance of excitatory and inhibitory actions, and highlight the structure and function of layer 1 in mouse visual cortex.
Collapse
Affiliation(s)
- Rinaldo D D'Souza
- Department of Neuroscience, Washington University School of MedicineSt. Louis, MO, United States
| | - Andreas Burkhalter
- Department of Neuroscience, Washington University School of MedicineSt. Louis, MO, United States
| |
Collapse
|
173
|
Sousa AMM, Meyer KA, Santpere G, Gulden FO, Sestan N. Evolution of the Human Nervous System Function, Structure, and Development. Cell 2017; 170:226-247. [PMID: 28708995 DOI: 10.1016/j.cell.2017.06.036] [Citation(s) in RCA: 281] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 04/21/2017] [Accepted: 06/22/2017] [Indexed: 12/22/2022]
Abstract
The nervous system-in particular, the brain and its cognitive abilities-is among humans' most distinctive and impressive attributes. How the nervous system has changed in the human lineage and how it differs from that of closely related primates is not well understood. Here, we consider recent comparative analyses of extant species that are uncovering new evidence for evolutionary changes in the size and the number of neurons in the human nervous system, as well as the cellular and molecular reorganization of its neural circuits. We also discuss the developmental mechanisms and underlying genetic and molecular changes that generate these structural and functional differences. As relevant new information and tools materialize at an unprecedented pace, the field is now ripe for systematic and functionally relevant studies of the development and evolution of human nervous system specializations.
Collapse
Affiliation(s)
- André M M Sousa
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Kyle A Meyer
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Gabriel Santpere
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Forrest O Gulden
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA; Department of Genetics, Yale School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA; Section of Comparative Medicine, Yale School of Medicine, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, CT, USA; Yale Child Study Center, Yale School of Medicine, New Haven, CT, USA; Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA.
| |
Collapse
|
174
|
In Utero Exposure to Valproic Acid Induces Neocortical Dysgenesis via Dysregulation of Neural Progenitor Cell Proliferation/Differentiation. J Neurosci 2017; 36:10908-10919. [PMID: 27798144 DOI: 10.1523/jneurosci.0229-16.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 09/12/2016] [Indexed: 11/21/2022] Open
Abstract
Valproic acid (VPA), a widely used antiepileptic drug, is an inhibitor of histone deacetylases, which epigenetically modify cell proliferation/differentiation in developing tissues. A series of recent clinical studies in humans reported that VPA exposure in utero impaired histogenesis and the development of the central nervous system, leading to increased risks of congenital malformation and the impairment of higher brain functions in children. In the present study conducted in mice, we report that VPA exposure in utero (1) increases the amount of acetylated histone proteins, (2) alters the expression of G1-phase regulatory proteins, (3) inhibits the cell cycle exit of neural progenitor cells during the early stage of neocortical histogenesis, and (4) increases the production of projection neurons distributed in the superficial neocortical layers in embryonic brains. Together, our findings show that VPA exposure in utero alters proliferation/differentiation characteristics of neural progenitor cells and hence leads to the neocortical dysgenesis. SIGNIFICANCE STATEMENT This study provides new insight into the mechanisms of how an altered in utero environment, such as drug exposure, affects the generation of neurons prenatally. The antiepileptic drug valproic acid (VPA) is a good target molecule as in utero exposure to VPA has been repeatedly reported to increase the risk of nervous system malformations and to impair higher brain functions in children. We show that VPA decreases the probability of differentiation of the neural progenitor cells (NPCs) in mice, resulting in an abnormally increased number of projection neurons in the superficial layers of the neocortex. Further, we suggest that histone deacetylase inhibition by VPA may be involved in the dysregulation of proliferation/differentiation characteristics of NPCs.
Collapse
|
175
|
Neural Stem Cells to Cerebral Cortex: Emerging Mechanisms Regulating Progenitor Behavior and Productivity. J Neurosci 2017; 36:11394-11401. [PMID: 27911741 DOI: 10.1523/jneurosci.2359-16.2016] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 08/23/2016] [Accepted: 08/30/2016] [Indexed: 12/16/2022] Open
Abstract
This review accompanies a 2016 SFN mini-symposium presenting examples of current studies that address a central question: How do neural stem cells (NSCs) divide in different ways to produce heterogeneous daughter types at the right time and in proper numbers to build a cerebral cortex with the appropriate size and structure? We will focus on four aspects of corticogenesis: cytokinesis events that follow apical mitoses of NSCs; coordinating abscission with delamination from the apical membrane; timing of neurogenesis and its indirect regulation through emergence of intermediate progenitors; and capacity of single NSCs to generate the correct number and laminar fate of cortical neurons. Defects in these mechanisms can cause microcephaly and other brain malformations, and understanding them is critical to designing diagnostic tools and preventive and corrective therapies.
Collapse
|
176
|
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: 3.3] [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.
Collapse
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
| |
Collapse
|
177
|
Rajman M, Schratt G. MicroRNAs in neural development: from master regulators to fine-tuners. Development 2017; 144:2310-2322. [DOI: 10.1242/dev.144337] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The proper formation and function of neuronal networks is required for cognition and behavior. Indeed, pathophysiological states that disrupt neuronal networks can lead to neurodevelopmental disorders such as autism, schizophrenia or intellectual disability. It is well-established that transcriptional programs play major roles in neural circuit development. However, in recent years, post-transcriptional control of gene expression has emerged as an additional, and probably equally important, regulatory layer. In particular, it has been shown that microRNAs (miRNAs), an abundant class of small regulatory RNAs, can regulate neuronal circuit development, maturation and function by controlling, for example, local mRNA translation. It is also becoming clear that miRNAs are frequently dysregulated in neurodevelopmental disorders, suggesting a role for miRNAs in the etiology and/or maintenance of neurological disease states. Here, we provide an overview of the most prominent regulatory miRNAs that control neural development, highlighting how they act as ‘master regulators’ or ‘fine-tuners’ of gene expression, depending on context, to influence processes such as cell fate determination, cell migration, neuronal polarization and synapse formation.
Collapse
Affiliation(s)
- Marek Rajman
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg 35043, Germany
| | - Gerhard Schratt
- Biochemisch-Pharmakologisches Centrum, Institut für Physiologische Chemie, Philipps-Universität Marburg, Marburg 35043, Germany
| |
Collapse
|
178
|
Kon E, Cossard A, Jossin Y. Neuronal Polarity in the Embryonic Mammalian Cerebral Cortex. Front Cell Neurosci 2017; 11:163. [PMID: 28670267 PMCID: PMC5472699 DOI: 10.3389/fncel.2017.00163] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/26/2017] [Indexed: 11/13/2022] Open
Abstract
The cerebral cortex is composed of billions of neurons that can grossly be subdivided into two broad classes: inhibitory GABAergic interneurons and excitatory glutamatergic neurons. The majority of cortical neurons in mammals are the excitatory type and they are the main focus of this review article. Like many of the cells in multicellular organisms, fully differentiated neurons are both morphologically and functionally polarized. However, they go through several changes in polarity before reaching this final mature differentiated state. Neurons are derived from polarized neuronal progenitor/stem cells and their commitment to neuronal fate is decided by cellular and molecular asymmetry during their last division in the neurogenic zone. They migrate from their birthplace using so-called multipolar migration, during which they switch direction of movement several times, and repolarize for bipolar migration when the axon is specified. Therefore, neurons have to break their previous symmetry, change their morphology and adequately respond to polarizing signals during migration in order to reach the correct position in the cortex and start making connections. Finally, the dendritic tree is elaborated and the axon/dendrite morphological polarity is set. Here we will describe the function, establishment and maintenance of polarity during the different developmental steps starting from neural stem cell (NSC) division, neuronal migration and axon specification at embryonic developmental stages.
Collapse
Affiliation(s)
- Elif Kon
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
| | - Alexia Cossard
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
| | - Yves Jossin
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
| |
Collapse
|
179
|
An update on stem cell biology and engineering for brain development. Mol Psychiatry 2017; 22:808-819. [PMID: 28373686 DOI: 10.1038/mp.2017.66] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 02/07/2023]
Abstract
Two recent technologies, induced-pluripotent stem cells (iPSCs) and direct somatic reprogramming, have shown enormous potential for cell-based therapies against intractable diseases such as those that affect the central nervous system. Already, methods that generate most major cell types of the human brain exist. Whether the cell types are directly reprogrammed from human somatic cells or differentiated from an iPSC intermediate, the overview presented here demonstrates how these protocols vary greatly in their efficiencies, purity and maturation of the resulting cells. Possible solutions including micro-RNA switch technologies that purify target cell types are also outlined. Further, an update on the transition from 2D to 3D cultures and current organoid (mini-brain) cultures are reviewed to give the stem cell and developmental engineering communities an up-to-date account of the progress and future perspectives for modeling of central nervous system disease and brain development in vitro.
Collapse
|
180
|
Nomura T, Izawa EI. Avian brains: Insights from development, behaviors and evolution. Dev Growth Differ 2017; 59:244-257. [DOI: 10.1111/dgd.12362] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/10/2017] [Accepted: 04/16/2017] [Indexed: 12/29/2022]
Affiliation(s)
- Tadashi Nomura
- Developmental Neurobiology; Kyoto Prefectural University of Medicine; INAMORI Memorial Building 1-5 Shimogamo-Hangi cho Sakyoku Kyoto 606-0823 Japan
| | - Ei-Ichi Izawa
- Department of Psychology; Keio University; 2-15-45 Mita Minatoku Tokyo 108-8345 Japan
| |
Collapse
|
181
|
Heng X, Guo Q, Leung AW, Li JY. Analogous mechanism regulating formation of neocortical basal radial glia and cerebellar Bergmann glia. eLife 2017; 6. [PMID: 28489004 PMCID: PMC5457141 DOI: 10.7554/elife.23253] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 05/09/2017] [Indexed: 12/29/2022] Open
Abstract
Neocortical basal radial glia (bRG) and cerebellar Bergmann glia (BG) are basal progenitors derived from ventricular apical radial glia (aRG) that selectively lose their apical processes. bRG and BG have been implicated in the expansion and folding of the cerebrum and cerebellum, respectively. Here, we analyzed the molecular characteristics and development of bRG and BG. Transcriptomic comparison revealed striking similarity of the molecular features of bRG and BG. We found that heightened ERK signaling activity in aRG is tightly linked to the temporal formation and the relative abundance of bRG in human and mouse cortices. Forced activation of an FGF-ERK-ETV axis that is crucial to BG induction specifically induced bRG with canonical human bRG features in mice. Therefore, our data point to a common mechanism of bRG and BG generation, bearing implications to the role for these basal progenitors in the evolution of cortical folding of the cerebrum and cerebellum. DOI:http://dx.doi.org/10.7554/eLife.23253.001 The outer layer of the brain of a mammal, called the cortex, helps support mental abilities such as memory, attention and thought. In rodents, the cortex is smooth whereas in primates it is organized into folds. These folds increase the surface area of the brain and thus the number of neurons it can contain, which may in turn increase its processing power. Folding occurs as the brain develops in the womb. Specialized cells called basal or outer radial glia, which are more abundant in humans than in rodents, are believed to trigger the folding process. Another area of the brain, called the cerebellum, is intricately folded in both rodents and humans. As the brain develops, cells within the cerebellum called Bergmann glia cause the tissue to fold. Bergmann glia and basal radial glia share a number of similarities, but it was not known whether the same molecular pathway might regulate both types of cell. Now, Heng et al. show that Bergmann glia in the cerebellums of mice and basal radial glia in human cortex contain similar sets of active genes. Moreover, the molecular pathway that gives rise to Bergmann glia in mice is also active in the cortex of both mice and humans. However, it is much more active in humans, leading Heng et al. to speculate that high levels of activity in this pathway might give rise to basal radial glia. Consistent with this prediction, artificially activating the pathway at high levels in mouse cortex triggered the formation of basal radial glia in mice too. These results thus suggest that a common mechanism generates both types of glial cells involved in brain folding. The work of Heng et al. lays the foundations for further studies into how these cells fold the brain and thus how they contribute to more complex mental abilities. Remaining questions to address are whether other species with Bergmann glia also have folded cerebellums, and whether incorrect development of basal radial glia in humans leads to disorders in which the cortex folds abnormally. DOI:http://dx.doi.org/10.7554/eLife.23253.002
Collapse
Affiliation(s)
- Xin Heng
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, United States
| | - Qiuxia Guo
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, United States
| | - Alan W Leung
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, United States
| | - James Yh Li
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, United States.,Institute for Systems Genomics, University of Connecticut, Farmington, United States
| |
Collapse
|
182
|
Fame RM, Dehay C, Kennedy H, Macklis JD. Subtype-Specific Genes that Characterize Subpopulations of Callosal Projection Neurons in Mouse Identify Molecularly Homologous Populations in Macaque Cortex. Cereb Cortex 2017; 27:1817-1830. [PMID: 26874185 DOI: 10.1093/cercor/bhw023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Callosal projection neurons (CPN) interconnect the neocortical hemispheres via the corpus callosum and are implicated in associative integration of multimodal information. CPN have undergone differential evolutionary elaboration, leading to increased diversity of cortical neurons-and more extensive and varied connections in neocortical gray and white matter-in primates compared with rodents. In mouse, distinct sets of genes are enriched in discrete subpopulations of CPN, indicating the molecular diversity of rodent CPN. Elements of rodent CPN functional and organizational diversity might thus be present in the further elaborated primate cortex. We address the hypothesis that genes controlling mouse CPN subtype diversity might reflect molecular patterns shared among mammals that arose prior to the divergence of rodents and primates. We find that, while early expression of the examined CPN-enriched genes, and postmigratory expression of these CPN-enriched genes in deep layers are highly conserved (e.g., Ptn, Nnmt, Cited2, Dkk3), in contrast, the examined genes expressed by superficial layer CPN show more variable levels of conservation (e.g., EphA3, Chn2). These results suggest that there has been evolutionarily differential retraction and elaboration of superficial layer CPN subpopulations between mouse and macaque, with independent derivation of novel populations in primates. Together, these data inform future studies regarding CPN subpopulations that are unique to primates and rodents, and indicate putative evolutionary relationships.
Collapse
Affiliation(s)
- Ryann M Fame
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Colette Dehay
- Inserm U1208, Stem Cell and Brain Research Institute, Bron, France.,Université de Lyon, Université Lyon 1, Bron, France
| | - Henry Kennedy
- Inserm U1208, Stem Cell and Brain Research Institute, Bron, France.,Université de Lyon, Université Lyon 1, Bron, France
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
183
|
Pilaz LJ, Silver DL. Moving messages in the developing brain-emerging roles for mRNA transport and local translation in neural stem cells. FEBS Lett 2017; 591:1526-1539. [PMID: 28304078 DOI: 10.1002/1873-3468.12626] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/06/2017] [Accepted: 03/11/2017] [Indexed: 11/10/2022]
Abstract
The mammalian cerebral cortex is a complex brain structure integral to our higher cognition. During embryonic cortical development, radial glial progenitors (RGCs) produce neurons and serve as physical structures for migrating neurons. Recent discoveries highlight new roles for RNA localization and local translation in RGCs, both at the cell body and at distal structures called basal endfeet. By implementing technologies from the field of RNA research to brain development, investigators can manipulate RNA-binding proteins as well as visualize single-molecule RNAs, live movement of mRNAs and their binding proteins, and translation. Going forward, these studies establish a framework for investigating how post-transcriptional RNA regulation helps shape RGC function and triggers neurodevelopmental diseases.
Collapse
Affiliation(s)
- Louis-Jan Pilaz
- Department of Molecular Genetics and Microbiology, Regeneration Next, Duke University Medical Center, Durham, NC, USA
| | - Debra L Silver
- Department of Molecular Genetics and Microbiology, Regeneration Next, Duke University Medical Center, Durham, NC, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.,Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.,Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
| |
Collapse
|
184
|
Ortega JA, Memi F, Radonjic N, Filipovic R, Bagasrawala I, Zecevic N, Jakovcevski I. The Subventricular Zone: A Key Player in Human Neocortical Development. Neuroscientist 2017; 24:156-170. [PMID: 29254416 DOI: 10.1177/1073858417691009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
One of the main characteristics of the developing brain is that all neurons and the majority of macroglia originate first in the ventricular zone (VZ), next to the lumen of the cerebral ventricles, and later on in a secondary germinal area above the VZ, the subventricular zone (SVZ). The SVZ is a transient compartment mitotically active in humans for several gestational months. It serves as a major source of cortical projection neurons as well as an additional source of glial cells and potentially some interneuron subpopulations. The SVZ is subdivided into the smaller inner (iSVZ) and the expanded outer SVZ (oSVZ). The enlargement of the SVZ and, in particular, the emergence of the oSVZ are evolutionary adaptations that were critical to the expansion and unique cellular composition of the primate cerebral cortex. In this review, we discuss the cell types and organization of the human SVZ during the first half of the 40 weeks of gestation that comprise intrauterine development. We focus on this period as it is when the bulk of neurogenesis in the human cerebral cortex takes place. We consider how the survival and fate of SVZ cells depend on environmental influences, by analyzing the results from in vitro experiments with human cortical progenitor cells. This in vitro model is a powerful tool to better understand human neocortex formation and the etiology of neurodevelopmental disorders, which in turn will facilitate the design of targeted preventive and/or therapeutic strategies.
Collapse
Affiliation(s)
- J Alberto Ortega
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Fani Memi
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Nevena Radonjic
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA.,2 Psychiatry Department, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Radmila Filipovic
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Inseyah Bagasrawala
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Nada Zecevic
- 1 Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Igor Jakovcevski
- 3 Institute for Molecular and Behavioral Neuroscience, University Hospital Cologne, Center for Molecular Medicine Cologne, Cologne, Germany.,4 Experimental Neurophysiology, German Center for Neurodegenerative Diseases, Bonn, Germany
| |
Collapse
|
185
|
Division modes and physical asymmetry in cerebral cortex progenitors. Curr Opin Neurobiol 2016; 42:75-83. [PMID: 27978481 DOI: 10.1016/j.conb.2016.11.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/26/2022]
Abstract
Neural stem cells go through a sequence of timely regulated gene expression and pattern of division mode to generate diverse neurons during brain development. During vertebrate cerebral cortex development, neural stem cells begin with proliferative symmetric divisions, subsequently undergo neurogenic asymmetric divisions, and finally gliogenic divisions. In this review, we explore the relationship between stem cell versus neural fate specification and the division mode. Specifically, we discuss recent findings on the mechanisms of asymmetric divisions, division mode, and developmental progression of neural progenitor identity.
Collapse
|
186
|
Florio M, Namba T, Pääbo S, Hiller M, Huttner WB. A single splice site mutation in human-specific ARHGAP11B causes basal progenitor amplification. SCIENCE ADVANCES 2016; 2:e1601941. [PMID: 27957544 PMCID: PMC5142801 DOI: 10.1126/sciadv.1601941] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/03/2016] [Indexed: 05/06/2023]
Abstract
The gene ARHGAP11B promotes basal progenitor amplification and is implicated in neocortex expansion. It arose on the human evolutionary lineage by partial duplication of ARHGAP11A, which encodes a Rho guanosine triphosphatase-activating protein (RhoGAP). However, a lack of 55 nucleotides in ARHGAP11B mRNA leads to loss of RhoGAP activity by GAP domain truncation and addition of a human-specific carboxy-terminal amino acid sequence. We show that these 55 nucleotides are deleted by mRNA splicing due to a single C→G substitution that creates a novel splice donor site. We reconstructed an ancestral ARHGAP11B complementary DNA without this substitution. Ancestral ARHGAP11B exhibits RhoGAP activity but has no ability to increase basal progenitors during neocortex development. Hence, a single nucleotide substitution underlies the specific properties of ARHGAP11B that likely contributed to the evolutionary expansion of the human neocortex.
Collapse
Affiliation(s)
- Marta Florio
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, D-01307 Dresden, Germany
| | - Takashi Namba
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, D-01307 Dresden, Germany
| | - Svante Pääbo
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, D-01307 Dresden, Germany
- Max Planck Institute for the Physics of Complex Systems, Noethnitzer Straße 38, D-01187 Dresden, Germany
| | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, D-01307 Dresden, Germany
- Corresponding author.
| |
Collapse
|
187
|
Florio M, Borrell V, Huttner WB. Human-specific genomic signatures of neocortical expansion. Curr Opin Neurobiol 2016; 42:33-44. [PMID: 27912138 DOI: 10.1016/j.conb.2016.11.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 10/20/2022]
Abstract
Neocortex evolutionary expansion is primarily due to increased proliferative capacity of neural progenitor cells during cortical development. Exploiting insights into the cell biology of cortical progenitors gained during the past two decades, recent studies uncovered a variety of gene expression differences that underlie differential cortical progenitor behavior. These comprise both, differences between cortical areas that likely provide a molecular basis for cortical folding, and differences across species thought to be responsible for increases in neocortex size. Human-specific signatures have been identified for gene regulatory elements, non-coding gene products, and protein-encoding genes, and have been functionally examined in in vivo as well as novel in vitro model systems.
Collapse
Affiliation(s)
- Marta Florio
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Víctor Borrell
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
| |
Collapse
|
188
|
Charvet CJ, Hof PR, Raghanti MA, Van Der Kouwe AJ, Sherwood CC, Takahashi E. Combining diffusion magnetic resonance tractography with stereology highlights increased cross-cortical integration in primates. J Comp Neurol 2016; 525:1075-1093. [PMID: 27615357 DOI: 10.1002/cne.24115] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 02/04/2023]
Abstract
The isocortex of primates is disproportionately expanded relative to many other mammals, yet little is known about what the expansion of the isocortex entails for differences in cellular composition and connectivity patterns in primates. Across the depth of the isocortex, neurons exhibit stereotypical patterns of projections. Upper-layer neurons (i.e., layers II-IV) project within and across cortical areas, whereas many lower-layer pyramidal neurons (i.e., layers V-VI) favor connections to subcortical regions. To identify evolutionary changes in connectivity patterns, we quantified upper (i.e., layers II-IV)- and lower (i.e., layers V-VI)-layer neuron numbers in primates and other mammals such as rodents and carnivores. We also used MR tractography based on high-angular resolution diffusion imaging and diffusion spectrum imaging to compare anterior-to-posterior corticocortical tracts between primates and other mammals. We found that primates possess disproportionately more upper-layer neurons as well as an expansion of anterior-to-posterior corticocortical tracts compared with other mammals. Taken together, these findings demonstrate that primates deviate from other mammals in exhibiting increased cross-cortical connectivity. J. Comp. Neurol. 525:1075-1093, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Christine J Charvet
- Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, 02115.,Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, 20052
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio, 44240
| | - Andre J Van Der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, 20052
| | - Emi Takahashi
- Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, 02115.,Department of Radiology, Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129
| |
Collapse
|
189
|
Abstract
Predictive coding theories of sensory brain function interpret the hierarchical construction of the cerebral cortex as a Bayesian, generative model capable of predicting the sensory data consistent with any given percept. Predictions are fed backward in the hierarchy and reciprocated by prediction error in the forward direction, acting to modify the representation of the outside world at increasing levels of abstraction, and so to optimize the nature of perception over a series of iterations. This accounts for many ‘illusory’ instances of perception where what is seen (heard, etc.) is unduly influenced by what is expected, based on past experience. This simple conception, the hierarchical exchange of prediction and prediction error, confronts a rich cortical microcircuitry that is yet to be fully documented. This article presents the view that, in the current state of theory and practice, it is profitable to begin a two-way exchange: that predictive coding theory can support an understanding of cortical microcircuit function, and prompt particular aspects of future investigation, whilst existing knowledge of microcircuitry can, in return, influence theoretical development. As an example, a neural inference arising from the earliest formulations of predictive coding is that the source populations of forward and backward pathways should be completely separate, given their functional distinction; this aspect of circuitry – that neurons with extrinsically bifurcating axons do not project in both directions – has only recently been confirmed. Here, the computational architecture prescribed by a generalized (free-energy) formulation of predictive coding is combined with the classic ‘canonical microcircuit’ and the laminar architecture of hierarchical extrinsic connectivity to produce a template schematic, that is further examined in the light of (a) updates in the microcircuitry of primate visual cortex, and (b) rapid technical advances made possible by transgenic neural engineering in the mouse. The exercise highlights a number of recurring themes, amongst them the consideration of interneuron diversity as a spur to theoretical development and the potential for specifying a pyramidal neuron’s function by its individual ‘connectome,’ combining its extrinsic projection (forward, backward or subcortical) with evaluation of its intrinsic network (e.g., unidirectional versus bidirectional connections with other pyramidal neurons).
Collapse
Affiliation(s)
- Stewart Shipp
- Laboratory of Visual Perceptual Mechanisms, Institute of Neuroscience, Chinese Academy of SciencesShanghai, China; INSERM U1208, Stem Cell and Brain Research InstituteBron, France; Department of Visual Neuroscience, UCL Institute of OphthalmologyLondon, UK
| |
Collapse
|
190
|
Namba T, Huttner WB. Neural progenitor cells and their role in the development and evolutionary expansion of the neocortex. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 6. [PMID: 27865053 DOI: 10.1002/wdev.256] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 09/02/2016] [Accepted: 09/07/2016] [Indexed: 01/16/2023]
Abstract
The evolutionary expansion of the mammalian brain, notably the neocortex, provides a platform for the higher cognitive abilities that characterize humans. Cortical expansion is accompanied by increased folding of the pial surface, which gives rise to a gyrencephalic (folded) rather than lissencephalic (unfolded) neocortex. This expansion reflects the prolonged and increased proliferation of neural stem and progenitor cells (NPCs). Distinct classes of NPCs can be distinguished based on either cell biological criteria (apical progenitors [APs], basal progenitors [BPs]) or lineage (primary progenitors and secondary progenitors). Cortical expansion in development and evolution is linked to an increased abundance and proliferative capacity of BPs, notably basal radial glial cells, a recently characterized type of secondary progenitor derived from apical radial glial cells, the primary progenitors. To gain insight into the molecular basis underlying the prolonged and increased proliferation of NPCs and in particular BPs, comparative genomic and transcriptomic approaches, mostly for human versus mouse, have been employed and applied to specific NPC types and subpopulations. These have revealed two principal sets of molecular changes. One concerns differences in the expression of common genes between species with different degrees of cortical expansion. The other comprises human-specific genes or genomic regulatory sequences. Various systems that allow functional testing of these genomic and gene expression differences between species have emerged, including transient and stable transgenesis, genome editing, cerebral organoids, and organotypic slice cultures. These provide future avenues for uncovering the molecular basis of cortical expansion. WIREs Dev Biol 2017, 6:e256. doi: 10.1002/wdev.256 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Takashi Namba
- 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
| |
Collapse
|
191
|
Carson R, Monaghan-Nichols AP, DeFranco DB, Rudine AC. Effects of antenatal glucocorticoids on the developing brain. Steroids 2016; 114:25-32. [PMID: 27343976 PMCID: PMC5052110 DOI: 10.1016/j.steroids.2016.05.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 05/25/2016] [Accepted: 05/30/2016] [Indexed: 01/13/2023]
Abstract
Glucocorticoids (GCs) regulate distinct physiological processes in the developing fetus, in particular accelerating organ maturation that enables the fetus to survive outside the womb. In preterm birth, the developing fetus does not receive sufficient exposure to endogenous GCs in utero for proper organ development predisposing the neonate to complications including intraventricular hemorrhage, respiratory distress syndrome (RDS) and necrotizing enterocolitis (NEC). Synthetic GCs (sGCs) have proven useful in the prevention of these complications since they are able to promote the rapid maturation of underdeveloped organs present in the fetus. While these drugs have proven to be clinically effective in the prevention of IVH, RDS and NEC, they may also trigger adverse developmental side effects. This review will examine the current clinical use of antenatal sGC therapy in preterm birth, their placental metabolism, and their effects on the developing brain.
Collapse
Affiliation(s)
- Ross Carson
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - A Paula Monaghan-Nichols
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Neurobiology, United States
| | - Donald B DeFranco
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Pharmacology and Chemical Biology, United States
| | - Anthony C Rudine
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Pediatrics, Division of Newborn Medicine, United States.
| |
Collapse
|
192
|
Han YG. Sonic hedgehog signaling: A conserved mechanism for the expansion of outer radial glia and intermediate progenitor cells and for the growth and folding of the neocortex. NEUROGENESIS 2016; 3:e1242957. [PMID: 28255571 PMCID: PMC5325666 DOI: 10.1080/23262133.2016.1242957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/12/2016] [Accepted: 09/25/2016] [Indexed: 11/23/2022]
Abstract
The expansion of outer radial glia (oRGs, also called basal RGs) and intermediate progenitor cells (IPCs) has played a key role in the evolutionary expansion and folding of the neocortex, resulting in superior sensorimotor and cognitive abilities. In particular, oRGs, which are critical for both the increased production and lateral dispersion of neurons, are rare in lisencephalic species but vastly expanded in gyrencephalic species. However, the mechanisms that expand oRGs and IPCs are not well understood. We recently identified Sonic hedgehog (Shh) signaling as the first known signaling pathway necessary and sufficient to expand both oRGs and IPCs. Elevated Shh signaling in the embryonic neocortex leads to neocortical expansion and folding with normal cytoarchitecture in otherwise smooth mouse neocortex, whereas the loss of Shh signaling decreases oRGs, IPCs, and neocortical size. We also showed that SHH signaling activity in fetal neocortex is stronger in humans than in mice and that blocking SHH signaling decreases oRGs in human cerebral organoids. Shh signaling may be a conserved mechanism that promotes oRG and IPC expansion, driving neocortical growth and folding in humans and other species. Understanding the mechanisms underlying species-specific differences in Shh signaling activity and how Shh signaling expands oRGs and IPCs will provide insights into the mechanisms of neocortical development and evolution.
Collapse
Affiliation(s)
- Young-Goo Han
- Department of Developmental Neurobiology, Neurobiology and Brain Tumor Program, St. Jude Children's Research Hospital , Memphis, TN, USA
| |
Collapse
|
193
|
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: 168] [Impact Index Per Article: 18.7] [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.
Collapse
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
| |
Collapse
|
194
|
Lins LC, Wianny F, Livi S, Dehay C, Duchet-Rumeau J, Gérard JF. Effect of polyvinylidene fluoride electrospun fiber orientation on neural stem cell differentiation. J Biomed Mater Res B Appl Biomater 2016; 105:2376-2393. [PMID: 27571576 DOI: 10.1002/jbm.b.33778] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 06/29/2016] [Accepted: 08/14/2016] [Indexed: 12/17/2022]
Abstract
Electrospun polymer piezoelectric fibers can be used in neural tissue engineering (NTE) to mimic the physical, biological, and material properties of the native extracellular matrix. In this work, we have developed scaffolds based on polymer fiber architectures for application in NTE. To study the role of such three-dimensional scaffolds, a rotating drum collector was used for electrospinning poly(vinylidene) fluoride (PVDF) polymer at various rotation speeds. The morphology, orientation, polymorphism, as well as the mechanical behavior of the nonaligned and aligned fiber-based architectures were characterized. We have demonstrated that the jet flow and the electrostatic forces generated by electrospinning of PVDF induced local conformation changes which promote the generation of the β-phase. Fiber anisotropy could be a critical feature for the design of suitable scaffolds for NTEs. We thus assessed the impact of PVDF fiber alignment on the behavior of monkey neural stem cells (NSCs). NSCs were seeded on nonaligned and aligned scaffolds and their morphology, adhesion, and differentiation capacities into the neuronal and glial pathways were studied using microscopic techniques. Significant changes in the growth and differentiation capacities of NSCs into neuronal and glial cells as a function of the fiber alignment were evidenced. These results demonstrate that PVDF scaffolds may serve as instructive scaffolds for NSC survival and differentiation, and may be valuable tools for the development of cell- and scaffold-based strategies for neural repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2376-2393, 2017.
Collapse
Affiliation(s)
- Luanda C Lins
- Université de Lyon, Ingénierie des Matériaux Polymères CNRS, UMR 5223; INSA Lyon, F-69621, Villeurbanne, France
| | - Florence Wianny
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500, Bron, France
| | - Sebastien Livi
- Université de Lyon, Ingénierie des Matériaux Polymères CNRS, UMR 5223; INSA Lyon, F-69621, Villeurbanne, France
| | - Colette Dehay
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500, Bron, France
| | - Jannick Duchet-Rumeau
- Université de Lyon, Ingénierie des Matériaux Polymères CNRS, UMR 5223; INSA Lyon, F-69621, Villeurbanne, France
| | - Jean-François Gérard
- Université de Lyon, Ingénierie des Matériaux Polymères CNRS, UMR 5223; INSA Lyon, F-69621, Villeurbanne, France
| |
Collapse
|
195
|
Severe NDE1-mediated microcephaly results from neural progenitor cell cycle arrests at multiple specific stages. Nat Commun 2016; 7:12551. [PMID: 27553190 PMCID: PMC4999518 DOI: 10.1038/ncomms12551] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/11/2016] [Indexed: 12/14/2022] Open
Abstract
Microcephaly is a cortical malformation disorder characterized by an abnormally small brain. Recent studies have revealed severe cases of microcephaly resulting from human mutations in the NDE1 gene, which is involved in the regulation of cytoplasmic dynein. Here using in utero electroporation of NDE1 short hairpin RNA (shRNA) in embryonic rat brains, we observe cell cycle arrest of proliferating neural progenitors at three distinct stages: during apical interkinetic nuclear migration, at the G2-to-M transition and in regulation of primary cilia at the G1-to-S transition. RNAi against the NDE1 paralogue NDEL1 has no such effects. However, NDEL1 overexpression can functionally compensate for NDE1, except at the G2-to-M transition, revealing a unique NDE1 role. In contrast, NDE1 and NDEL1 RNAi have comparable effects on postmitotic neuronal migration. These results reveal that the severity of NDE1-associated microcephaly results not from defects in mitosis, but rather the inability of neural progenitors to ever reach this stage. Human mutations in the NDE1 gene have been associated with cortical malformations and severe microcephaly. Here, the authors show in embryonic rat brains that NDE1-depleted neural progenitors arrest at three specific cell cycle stages before mitosis, resulting in a severe decrease in neurogenesis.
Collapse
|
196
|
Betizeau M, Dehay C. From stem cells to comparative corticogenesis: a bridge too far? Stem Cell Investig 2016; 3:39. [PMID: 27668246 DOI: 10.21037/sci.2016.08.02] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/03/2016] [Indexed: 11/06/2022]
Abstract
It has been hypothesized that the higher number of neurons in human cortex compared to the chimpanzee and other primate species is key to high cognitive function. Are human cortical precursors endowed with specific properties that drive greater neuronal expansion than in other non-human primates? Otani et al. 2016 addressed this issue taking advantage of comparative in vitro corticogenesis models based on human, chimpanzee and macaque pluripotent stem cells. Clonal analysis revealed a heterochrony of early developmental events possibly leading to a relatively higher expansion of human cortical precursor population. In absence of evidence going beyond putative correlation, the claim that stem cell models of cortical development indicate mechanism of cortical size regulation needs to be further examined notably with respect to in vivo observations of cortical precursor lineages.
Collapse
Affiliation(s)
- Marion Betizeau
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Colette Dehay
- Univ Lyon, Universite Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| |
Collapse
|
197
|
Mason JO, Price DJ. Building brains in a dish: Prospects for growing cerebral organoids from stem cells. Neuroscience 2016; 334:105-118. [PMID: 27506142 DOI: 10.1016/j.neuroscience.2016.07.048] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/22/2016] [Accepted: 07/30/2016] [Indexed: 11/27/2022]
Abstract
The recent development of organoid techniques, in which embryonic brain-like tissue can be grown from human or mouse stem cells in vitro offers the potential to transform the way in which brain development is studied. In this review, we summarize key aspects of the embryonic development of mammalian forebrains, focussing in particular on the cerebral cortex and highlight significant differences between mouse and primates, including human. We discuss recent work using cerebral organoids that has revealed key similarities and differences between their development and that of the brain in vivo. Finally, we outline the ways in which cerebral organoids can be used in combination with CRISPR/Cas9 genome editing to unravel genetic mechanisms that control embryonic development of the cerebral cortex, how this can help us understand the causes of neurodevelopmental disorders and some of the key challenges which will have to be resolved before organoids can become a mainstream tool to study brain development.
Collapse
Affiliation(s)
- John O Mason
- Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
| | - David J Price
- Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
| |
Collapse
|
198
|
Wilsch-Bräuninger M, Florio M, Huttner WB. Neocortex expansion in development and evolution — from cell biology to single genes. Curr Opin Neurobiol 2016; 39:122-32. [DOI: 10.1016/j.conb.2016.05.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/15/2016] [Indexed: 02/06/2023]
|
199
|
Jiang X, Nardelli J. Cellular and molecular introduction to brain development. Neurobiol Dis 2016; 92:3-17. [PMID: 26184894 PMCID: PMC4720585 DOI: 10.1016/j.nbd.2015.07.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 07/07/2015] [Accepted: 07/09/2015] [Indexed: 12/13/2022] Open
Abstract
Advances in the study of brain development over the last decades, especially recent findings regarding the evolutionary expansion of the human neocortex, and large-scale analyses of the proteome/transcriptome in the human brain, have offered novel insights into the molecular mechanisms guiding neural maturation, and the pathophysiology of multiple forms of neurological disorders. As a preamble to reviews of this issue, we provide an overview of the cellular, molecular and genetic bases of brain development with an emphasis on the major mechanisms associated with landmarks of normal neural development in the embryonic stage and early postnatal life, including neural stem/progenitor cell proliferation, cortical neuronal migration, evolution and folding of the cerebral cortex, synaptogenesis and neural circuit development, gliogenesis and myelination. We will only briefly depict developmental disorders that result from perturbations of these cellular or molecular mechanisms, and the most common perinatal brain injuries that could disturb normal brain development.
Collapse
Affiliation(s)
- Xiangning Jiang
- Department of Pediatrics, University of California, San Francisco, CA 94158, USA
| | - Jeannette Nardelli
- Inserm, U1141, Paris 75019, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS 1141, Paris 75019, France.
| |
Collapse
|
200
|
Nomura T, Ohtaka-Maruyama C, Yamashita W, Wakamatsu Y, Murakami Y, Calegari F, Suzuki K, Gotoh H, Ono K. The evolution of basal progenitors in the developing non-mammalian brain. Development 2016; 143:66-74. [PMID: 26732839 PMCID: PMC4725208 DOI: 10.1242/dev.127100] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The amplification of distinct neural stem/progenitor cell subtypes during embryogenesis is essential for the intricate brain structures present in various vertebrate species. For example, in both mammals and birds, proliferative neuronal progenitors transiently appear on the basal side of the ventricular zone of the telencephalon (basal progenitors), where they contribute to the enlargement of the neocortex and its homologous structures. In placental mammals, this proliferative cell population can be subdivided into several groups that include Tbr2+ intermediate progenitors and basal radial glial cells (bRGs). Here, we report that basal progenitors in the developing avian pallium show unique morphological and molecular characteristics that resemble the characteristics of bRGs, a progenitor population that is abundant in gyrencephalic mammalian neocortex. Manipulation of LGN (Leu-Gly-Asn repeat-enriched protein) and Cdk4/cyclin D1, both essential regulators of neural progenitor dynamics, revealed that basal progenitors and Tbr2+ cells are distinct cell lineages in the developing avian telencephalon. Furthermore, we identified a small population of subapical mitotic cells in the developing brains of a wide variety of amniotes and amphibians. Our results suggest that unique progenitor subtypes are amplified in mammalian and avian lineages by modifying common mechanisms of neural stem/progenitor regulation during amniote brain evolution. Highlighted article: In the developing chick pallium, a basal progenitor population resembles mammalian cortical basal radial glia, suggesting a more ancient evolutionary origin for this cell type.
Collapse
Affiliation(s)
- Tadashi Nomura
- Developmental Neurobiology, Kyoto Prefectural University of Medicine, INAMORI Memorial Building, 1-5 Shimogamo-hangi cho, Sakyo-ku, Kyoto 606-0823, Japan Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Chiaki Ohtaka-Maruyama
- Neural Network Project, Department of Neural Development and Regeneration, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Wataru Yamashita
- Developmental Neurobiology, Kyoto Prefectural University of Medicine, INAMORI Memorial Building, 1-5 Shimogamo-hangi cho, Sakyo-ku, Kyoto 606-0823, Japan
| | - Yoshio Wakamatsu
- Department of Developmental Neuroscience, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
| | - Yasunori Murakami
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Federico Calegari
- DFG-Centre for Regenerative Therapies Dresden, Faculty of Medicine, TUD, Fetscherstrasse 105, 01307 Dresden, Germany
| | - Kunihiro Suzuki
- Department of Biology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan Division of Companion Diagnostics, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo 173-8610, Japan
| | - Hitoshi Gotoh
- Developmental Neurobiology, Kyoto Prefectural University of Medicine, INAMORI Memorial Building, 1-5 Shimogamo-hangi cho, Sakyo-ku, Kyoto 606-0823, Japan
| | - Katsuhiko Ono
- Developmental Neurobiology, Kyoto Prefectural University of Medicine, INAMORI Memorial Building, 1-5 Shimogamo-hangi cho, Sakyo-ku, Kyoto 606-0823, Japan
| |
Collapse
|