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Ni Z, McCabe S, Novak C, Baltzer HL, Jegatheeswaran G, Isayama R, Vesia M, Gunraj C, Saha U, Hallett M, Chen R. Plastic changes in the brain after human hand allotransplantation. Neurology 2020; 95:547-550. [PMID: 32796128 DOI: 10.1212/wnl.0000000000010583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/02/2020] [Indexed: 11/15/2022] Open
Affiliation(s)
- Zhen Ni
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Steven McCabe
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor.
| | - Christine Novak
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Heather L Baltzer
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Gaayathiri Jegatheeswaran
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Reina Isayama
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Michael Vesia
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Carolyn Gunraj
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Utpal Saha
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Mark Hallett
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor
| | - Robert Chen
- From the Division of Neurology (Z.N., G.J., R.I., M.V., C.G., U.S., R.C.), Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; Human Motor Control Section (Z.N., M.H.), National Institute of Neurological Disorders and Stroke, National Institutes of Health; Hand Program (S.M., C.N., H.L.B.), Division of Plastic & Reconstructive Surgery, University of Toronto and Krembil Research Institute, University Health Network, Ontario, Canada; and School of Kinesiology (M.V.), University of Michigan, Ann Arbor.
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102
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Wang K, Smolker HR, Brown MS, Snyder HR, Hankin BL, Banich MT. Association of γ-aminobutyric acid and glutamate/glutamine in the lateral prefrontal cortex with patterns of intrinsic functional connectivity in adults. Brain Struct Funct 2020; 225:1903-1919. [PMID: 32803293 PMCID: PMC8765125 DOI: 10.1007/s00429-020-02084-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 05/04/2020] [Indexed: 01/04/2023]
Abstract
This study examined how levels of neurotransmitters in the lateral prefrontal cortex (LPFC), a region underlying higher-order cognition, are related to the brain's intrinsic functional organization. Using magnetic resonance spectroscopy (MRS), GABA+ and Glx (glutamate + glutamine) levels in the left dorsal (DLPFC) and left ventral (VLPFC) lateral prefrontal cortex were obtained in a sample of 64 female adults (mean age = 48.5). We measured intrinsic connectivity via resting-state fMRI in three ways: (a) via seed-based connectivity for each of the two spectroscopy voxels; (b) via the spatial configurations of 17 intrinsic networks defined by a well-known template; and (c) via examination of the temporal inter-relationships between these intrinsic networks. The results showed that different neurotransmitter indexes (Glx-specific, GABA+-specific, Glx-GABA+ average and Glx-GABA+ ratio) were associated with distinct patterns of intrinsic connectivity. Neurotransmitter levels in the left LPFC are mainly associated with connectivity of right hemisphere prefrontal (e.g., DLPFC) or striatal (e.g., putamen) regions, two areas of the brain connected to LPFC via large white matter tracts. While the directions of these associations were mixed, in most cases, higher Glx levels are related to reduced connectivity. Prefrontal neurotransmitter levels are also associated with the degree of connectivity between non-prefrontal regions. These results suggest robust relationships between the brain's intrinsic functional organization and local neurotransmitters in the LPFC which may be constrained by white matter neuroanatomy.
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Affiliation(s)
- Kai Wang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, China; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, No. 55 West Zhongshan Avenue, Guangzhou, 510631, Guangdong, China.
- Institute of Cognitive Science, University of Colorado Boulder, 344 UCB, Boulder, CO, 80309-0344, USA.
| | - Harry R Smolker
- Institute of Cognitive Science, University of Colorado Boulder, 344 UCB, Boulder, CO, 80309-0344, USA
- Department of Psychology and Neuroscience, University of Colorado Boulder, E230 Muenzinger Hall, UCB 345, Boulder, CO, 80309-0345, USA
- Institute for Behavioral Genetics, University of Colorado Boulder, 1480 30th Street, Boulder, CO, 80303, USA
| | - Mark S Brown
- Department of Radiology, University of Colorado Anschutz Medical Campus, 12401 E 17th Place, Aurora, CO, 80045, USA
| | - Hannah R Snyder
- Department of Psychology, Brandeis University, 415 South Street, Waltham, MA, 02453, USA
| | - Benjamin L Hankin
- Psychology Department, University of Illinois-Urbana Champaign, 603 E. Daniel Street, Champaign, IL, 61820, USA
| | - Marie T Banich
- Institute of Cognitive Science, University of Colorado Boulder, 344 UCB, Boulder, CO, 80309-0344, USA.
- Department of Psychology and Neuroscience, University of Colorado Boulder, E230 Muenzinger Hall, UCB 345, Boulder, CO, 80309-0345, USA.
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103
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Carson RG. Inter‐hemispheric inhibition sculpts the output of neural circuits by co‐opting the two cerebral hemispheres. J Physiol 2020; 598:4781-4802. [DOI: 10.1113/jp279793] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/04/2020] [Indexed: 01/11/2023] Open
Affiliation(s)
- Richard G. Carson
- Trinity College Institute of Neuroscience and School of Psychology Trinity College Dublin Dublin 2 Ireland
- School of Psychology Queen's University Belfast Belfast BT7 1NN UK
- School of Human Movement and Nutrition Sciences University of Queensland St Lucia QLD 4072 Australia
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104
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Costa RO, Martins H, Martins LF, Cwetsch AW, Mele M, Pedro JR, Tomé D, Jeon NL, Cancedda L, Jaffrey SR, Almeida RD. Synaptogenesis Stimulates a Proteasome-Mediated Ribosome Reduction in Axons. Cell Rep 2020; 28:864-876.e6. [PMID: 31340150 PMCID: PMC6686882 DOI: 10.1016/j.celrep.2019.06.080] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 12/21/2018] [Accepted: 06/21/2019] [Indexed: 11/19/2022] Open
Abstract
Ribosomes and a subset of cellular mRNAs are trafficked into axons of developing neurons. The axonal localization of translational machinery allows new proteins to be rapidly and locally synthesized during axonal growth and pathfinding. However, in mature neurons, axonal ribosomes are significantly reduced or even absent. The mechanism that elicits this removal is currently unknown. Here, we demonstrate that synapse formation is the trigger for ribosome reduction in mature axons. In vivo analysis shows that axonal ribosome levels decrease in rat brain at a developmental stage coincident with synapse formation. Next, we observe in vitro that different synaptogenic inducers trigger an overall decrease of ribosomal proteins and rRNA in the axons of spinal motor neurons. We further observe that this process is dependent on the ubiquitin-proteasome system but not on autophagy. Together, these data identify synaptogenesis as the long missing biological trigger that leads to ribosome disappearance during axonal maturation. The mechanism behind the striking loss of ribosomes from axons during neuronal maturation is unknown. Using in vivo and in vitro models, including neuron-muscle co-cultures and combining biochemistry and imaging techniques, Costa et al. demonstrate that synapse formation triggers ribosome reduction by a mechanism involving the ubiquitin-proteasome system.
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Affiliation(s)
- Rui O Costa
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.
| | - Helena Martins
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Luís F Martins
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Andrzej W Cwetsch
- NBT - Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Miranda Mele
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Joana R Pedro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Diogo Tomé
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Noo Li Jeon
- Institute of Advanced Machinery and Design, Seoul National University, Seoul, Republic of Korea; Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Laura Cancedda
- NBT - Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy; Dulbecco Telethon Institute, Roma, Italy
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Ramiro D Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal; iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
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105
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Staiger JF, Petersen CCH. Neuronal Circuits in Barrel Cortex for Whisker Sensory Perception. Physiol Rev 2020; 101:353-415. [PMID: 32816652 DOI: 10.1152/physrev.00019.2019] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a 'barrel' (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.
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Affiliation(s)
- Jochen F Staiger
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carl C H Petersen
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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106
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Measuring latency distribution of transcallosal fibers using transcranial magnetic stimulation. Brain Stimul 2020; 13:1453-1460. [PMID: 32791313 PMCID: PMC7417270 DOI: 10.1016/j.brs.2020.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Neuroimaging technology is being developed to enable non-invasive mapping of the latency distribution of cortical projection pathways in white matter, and correlative clinical neurophysiological techniques would be valuable for mutual verification. Interhemispheric interaction through the corpus callosum can be measured with interhemispheric facilitation and inhibition using transcranial magnetic stimulation. OBJECTIVE To develop a method for determining the latency distribution of the transcallosal fibers with transcranial magnetic stimulation. METHODS We measured the precise time courses of interhemispheric facilitation and inhibition with a conditioning-test paired-pulse magnetic stimulation paradigm. The conditioning stimulus was applied to the right primary motor cortex and the test stimulus was applied to the left primary motor cortex. The interstimulus interval was set at 0.1 ms resolution. The proportions of transcallosal fibers with different conduction velocities were calculated by measuring the changes in magnitudes of interhemispheric facilitation and inhibition with interstimulus interval. RESULTS Both interhemispheric facilitation and inhibition increased with increment in interstimulus interval. The magnitude of interhemispheric facilitation was correlated with that of interhemispheric inhibition. The latency distribution of transcallosal fibers measured with interhemispheric facilitation was also correlated with that measured with interhemispheric inhibition. CONCLUSIONS The data can be interpreted as latency distribution of transcallosal fibers. Interhemispheric interaction measured with transcranial magnetic stimulation is a promising technique to determine the latency distribution of the transcallosal fibers. Similar techniques could be developed for other cortical pathways.
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107
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Axonal Extensions along Corticospinal Tracts from Transplanted Human Cerebral Organoids. Stem Cell Reports 2020; 15:467-481. [PMID: 32679062 PMCID: PMC7419717 DOI: 10.1016/j.stemcr.2020.06.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 01/23/2023] Open
Abstract
The reconstruction of lost neural circuits by cell replacement is a possible treatment for neurological deficits after cerebral cortex injury. Cerebral organoids can be a novel source for cell transplantation, but because the cellular composition of the organoids changes along the time course of the development, it remains unclear which developmental stage of the organoids is most suitable for reconstructing the corticospinal tract. Here, we transplanted human embryonic stem cell-derived cerebral organoids at 6 or 10 weeks after differentiation (6w- or 10w-organoids) into mouse cerebral cortices. 6w-organoids extended more axons along the corticospinal tract but caused graft overgrowth with a higher percentage of proliferative cells. Axonal extensions from 10w-organoids were smaller in number but were enhanced when the organoids were grafted 1 week after brain injury. Finally, 10w-organoids extended axons in cynomolgus monkey brains. These results contribute to the development of a cell-replacement therapy for brain injury and stroke.
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108
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Chen Y, Sobczak F, Pais-Roldán P, Schwarz C, Koretsky AP, Yu X. Mapping the Brain-Wide Network Effects by Optogenetic Activation of the Corpus Callosum. Cereb Cortex 2020; 30:5885-5898. [PMID: 32556241 DOI: 10.1093/cercor/bhaa164] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/25/2020] [Accepted: 05/25/2020] [Indexed: 12/18/2022] Open
Abstract
Optogenetically driven manipulation of circuit-specific activity enables causality studies, but its global brain-wide effect is rarely reported. Here, we applied simultaneous functional magnetic resonance imaging (fMRI) and calcium recording with optogenetic activation of the corpus callosum (CC) connecting barrel cortices (BC). Robust positive BOLD was detected in the ipsilateral BC due to antidromic activity, spreading to the ipsilateral motor cortex (MC), and posterior thalamus (PO). In the orthodromic target, positive BOLD was reliably evoked by 2 Hz light pulses, whereas 40 Hz light pulses led to reduced calcium, indicative of CC-mediated inhibition. This presumed optogenetic CC-mediated inhibition was further elucidated by pairing light pulses with whisker stimulation at varied interstimulus intervals. Whisker-induced positive BOLD and calcium signals were reduced at intervals of 50/100 ms. The calcium-amplitude-modulation-based correlation with whole-brain fMRI signal revealed that the inhibitory effects spread to contralateral BC, ipsilateral MC, and PO. This work raises the need for fMRI to elucidate the brain-wide network activation in response to optogenetic stimulation.
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Affiliation(s)
- Yi Chen
- Research Group of Translational Neuroimaging and Neural Control, High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Baden-Württemberg 72076, Germany.,Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Baden-Württemberg 72074, Germany
| | - Filip Sobczak
- Research Group of Translational Neuroimaging and Neural Control, High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Baden-Württemberg 72076, Germany.,Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Baden-Württemberg 72074, Germany
| | - Patricia Pais-Roldán
- Research Group of Translational Neuroimaging and Neural Control, High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Baden-Württemberg 72076, Germany.,Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Baden-Württemberg 72074, Germany
| | - Cornelius Schwarz
- Werner Reichardt Center for Integrative Neuroscience, Tübingen, Baden-Württemberg 72076, Germany
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Xin Yu
- Research Group of Translational Neuroimaging and Neural Control, High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Baden-Württemberg 72076, Germany.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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109
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Primary Cilia Signaling Promotes Axonal Tract Development and Is Disrupted in Joubert Syndrome-Related Disorders Models. Dev Cell 2020; 51:759-774.e5. [PMID: 31846650 DOI: 10.1016/j.devcel.2019.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/08/2019] [Accepted: 11/10/2019] [Indexed: 12/18/2022]
Abstract
Appropriate axonal growth and connectivity are essential for functional wiring of the brain. Joubert syndrome-related disorders (JSRD), a group of ciliopathies in which mutations disrupt primary cilia function, are characterized by axonal tract malformations. However, little is known about how cilia-driven signaling regulates axonal growth and connectivity. We demonstrate that the deletion of related JSRD genes, Arl13b and Inpp5e, in projection neurons leads to de-fasciculated and misoriented axonal tracts. Arl13b deletion disrupts the function of its downstream effector, Inpp5e, and deregulates ciliary-PI3K/AKT signaling. Chemogenetic activation of ciliary GPCR signaling and cilia-specific optogenetic modulation of downstream second messenger cascades (PI3K, AKT, and AC3) commonly regulated by ciliary signaling receptors induce rapid changes in axonal dynamics. Further, Arl13b deletion leads to changes in transcriptional landscape associated with dysregulated PI3K/AKT signaling. These data suggest that ciliary signaling acts to modulate axonal connectivity and that impaired primary cilia signaling underlies axonal tract defects in JSRD.
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110
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Dou X, Yao H, Feng F, Wang P, Zhou B, Jin D, Yang Z, Li J, Zhao C, Wang L, An N, Liu B, Zhang X, Liu Y. Characterizing white matter connectivity in Alzheimer's disease and mild cognitive impairment: An automated fiber quantification analysis with two independent datasets. Cortex 2020; 129:390-405. [PMID: 32574842 DOI: 10.1016/j.cortex.2020.03.032] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 12/13/2019] [Accepted: 03/31/2020] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by progressive dementia. Diffusion tensor imaging (DTI) has been widely used to show structural integrity and delineate white matter (WM) degeneration in AD. The automated fiber quantification (AFQ) method is a fully automated approach that can rapidly and reliably identify major WM fiber tracts and evaluate WM properties. The main aim of this study was to assess WM integrity and abnormities in a cohort of patients with amnestic mild cognitive impairment (aMCI) and AD as well as normal controls (NCs). For this purpose, we first used AFQ to identify 20 major WM tracts and assessed WM integrity and abnormalities in a cohort of 120 subjects (39 NCs, 34 aMCI patients and 47 AD patients) in a discovery dataset and 122 subjects (43 NCs, 37 aMCI patients and 42 AD patients) in a replicated dataset. Pointwise differences along WM tracts were identified in the discovery dataset and simultaneously confirmed in the replicated dataset. Next, we investigated the utility of DTI measures along WM tracts as features to distinguish patients with AD from NCs via multilevel cross validation using a support vector machine. Correlation analysis revealed the identified microstructural WM alterations and classification output to be highly associated with cognitive ability in the patient groups, suggesting that they may be a robust biomarker of AD. This systematic study provides a pipeline to examine WM integrity and its potential clinical application in AD and may be useful for studying other neurological and psychiatric disorders.
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Affiliation(s)
- Xuejiao Dou
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, China
| | - Hongxiang Yao
- Department of Radiology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Feng Feng
- Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Pan Wang
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, 300350, China; Department of Neurology, Nankai University Huanhu Hospital, Tianjin, China
| | - Bo Zhou
- Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Dan Jin
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, China
| | - Zhengyi Yang
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Jin Li
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Cui Zhao
- Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Luning Wang
- Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Ningyu An
- Department of Radiology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China
| | - Bing Liu
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Xi Zhang
- Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, China.
| | - Yong Liu
- Brainnetome Center & National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
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111
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Vitamin D Supplementation Rescues Aberrant NF-κB Pathway Activation and Partially Ameliorates Rett Syndrome Phenotypes in Mecp2 Mutant Mice. eNeuro 2020; 7:ENEURO.0167-20.2020. [PMID: 32393583 PMCID: PMC7253640 DOI: 10.1523/eneuro.0167-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 01/28/2023] Open
Abstract
Rett syndrome (RTT) is a severe, progressive X-linked neurodevelopmental disorder caused by mutations in the transcriptional regulator MECP2. We previously identified aberrant NF-κB pathway upregulation in brains of Mecp2-null mice and demonstrated that genetically attenuating NF-κB rescues some characteristic neuronal RTT phenotypes. These results raised the intriguing question of whether NF-κB pathway inhibitors might provide a therapeutic avenue in RTT. Here, we investigate whether the known NF-κB pathway inhibitor vitamin D ameliorates neuronal phenotypes in Mecp2-mutant mice. Vitamin D deficiency is prevalent among RTT patients, and we find that Mecp2-null mice similarly have significantly reduced 25(OH)D serum levels compared with wild-type littermates. We identify that vitamin D rescues aberrant NF-κB pathway activation and reduced neurite outgrowth of Mecp2 knock-down cortical neurons in vitro. Further, dietary supplementation with vitamin D in early symptomatic male Mecp2 hemizygous null and female Mecp2 heterozygous mice ameliorates reduced neocortical dendritic morphology and soma size phenotypes and modestly improves reduced lifespan of Mecp2-nulls. These results elucidate fundamental neurobiology of RTT and provide foundation that NF-κB pathway inhibition might be a therapeutic target for RTT.
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112
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Anatomically revealed morphological patterns of pyramidal neurons in layer 5 of the motor cortex. Sci Rep 2020; 10:7916. [PMID: 32405029 PMCID: PMC7220918 DOI: 10.1038/s41598-020-64665-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 04/17/2020] [Indexed: 11/24/2022] Open
Abstract
Neuronal cell types are essential to the comprehensive understanding of the neuronal function and neuron can be categorized by their anatomical property. However, complete morphology data for neurons with a whole brain projection, for example the pyramidal neurons in the cortex, are sparse because it is difficult to trace the neuronal fibers across the whole brain and acquire the neuron morphology at the single axon resolution. Thus the cell types of pyramidal neurons have yet to be studied at the single axon resolution thoroughly. In this work, we acquire images for a Thy1 H-line mouse brain using a fluorescence micro-optical sectioning tomography system. Then we sample 42 pyramidal neurons whose somata are in the layer 5 of the motor cortex and reconstruct their morphology across the whole brain. Based on the reconstructed neuronal anatomy, we analyze the axonal and dendritic fibers of the neurons in addition to the soma spatial distributions, and identify two axonal projection pattern of pyramidal tract neurons and two dendritic spreading patterns of intratelencephalic neurons. The raw image data are available upon request as an additional asset to the community. The morphological patterns identified in this work can be a typical representation of neuron subtypes and reveal the possible input-output function of a single pyramidal neuron.
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113
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Qian X, Su Y, Adam CD, Deutschmann AU, Pather SR, Goldberg EM, Su K, Li S, Lu L, Jacob F, Nguyen PTT, Huh S, Hoke A, Swinford-Jackson SE, Wen Z, Gu X, Pierce RC, Wu H, Briand LA, Chen HI, Wolf JA, Song H, Ming GL. Sliced Human Cortical Organoids for Modeling Distinct Cortical Layer Formation. Cell Stem Cell 2020; 26:766-781.e9. [PMID: 32142682 PMCID: PMC7366517 DOI: 10.1016/j.stem.2020.02.002] [Citation(s) in RCA: 240] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/18/2019] [Accepted: 02/10/2020] [Indexed: 01/08/2023]
Abstract
Human brain organoids provide unique platforms for modeling development and diseases by recapitulating the architecture of the embryonic brain. However, current organoid methods are limited by interior hypoxia and cell death due to insufficient surface diffusion, preventing generation of architecture resembling late developmental stages. Here, we report the sliced neocortical organoid (SNO) system, which bypasses the diffusion limit to prevent cell death over long-term cultures. This method leads to sustained neurogenesis and formation of an expanded cortical plate that establishes distinct upper and deep cortical layers for neurons and astrocytes, resembling the third trimester embryonic human neocortex. Using the SNO system, we further identify a critical role of WNT/β-catenin signaling in regulating human cortical neuron subtype fate specification, which is disrupted by a psychiatric-disorder-associated genetic mutation in patient induced pluripotent stem cell (iPSC)-derived SNOs. These results demonstrate the utility of SNOs for investigating previously inaccessible human-specific, late-stage cortical development and disease-relevant mechanisms.
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Affiliation(s)
- Xuyu Qian
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Biomedical Engineering Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yijing Su
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher D Adam
- Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Sarshan R Pather
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ethan M Goldberg
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kenong Su
- Department of Computer Science, Emory University College of Arts and Sciences, Atlanta, GA 30322, USA
| | - Shiying Li
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Lu Lu
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Fadi Jacob
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Phuong T T Nguyen
- Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sooyoung Huh
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ahmet Hoke
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Zhexing Wen
- Department of Psychiatry and Behavioral Science, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xiaosong Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - R Christopher Pierce
- Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Lisa A Briand
- Department of Psychology, Temple University, Philadelphia, PA 19122, USA
| | - H Isaac Chen
- Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - John A Wolf
- Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA; Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Neuroscience Graduate Program, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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114
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Lennox AL, Hoye ML, Jiang R, Johnson-Kerner BL, Suit LA, Venkataramanan S, Sheehan CJ, Alsina FC, Fregeau B, Aldinger KA, Moey C, Lobach I, Afenjar A, Babovic-Vuksanovic D, Bézieau S, Blackburn PR, Bunt J, Burglen L, Campeau PM, Charles P, Chung BHY, Cogné B, Curry C, D'Agostino MD, Di Donato N, Faivre L, Héron D, Innes AM, Isidor B, Keren B, Kimball A, Klee EW, Kuentz P, Küry S, Martin-Coignard D, Mirzaa G, Mignot C, Miyake N, Matsumoto N, Fujita A, Nava C, Nizon M, Rodriguez D, Blok LS, Thauvin-Robinet C, Thevenon J, Vincent M, Ziegler A, Dobyns W, Richards LJ, Barkovich AJ, Floor SN, Silver DL, Sherr EH. Pathogenic DDX3X Mutations Impair RNA Metabolism and Neurogenesis during Fetal Cortical Development. Neuron 2020; 106:404-420.e8. [PMID: 32135084 PMCID: PMC7331285 DOI: 10.1016/j.neuron.2020.01.042] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 11/05/2019] [Accepted: 01/29/2020] [Indexed: 12/16/2022]
Abstract
De novo germline mutations in the RNA helicase DDX3X account for 1%-3% of unexplained intellectual disability (ID) cases in females and are associated with autism, brain malformations, and epilepsy. Yet, the developmental and molecular mechanisms by which DDX3X mutations impair brain function are unknown. Here, we use human and mouse genetics and cell biological and biochemical approaches to elucidate mechanisms by which pathogenic DDX3X variants disrupt brain development. We report the largest clinical cohort to date with DDX3X mutations (n = 107), demonstrating a striking correlation between recurrent dominant missense mutations, polymicrogyria, and the most severe clinical outcomes. We show that Ddx3x controls cortical development by regulating neuron generation. Severe DDX3X missense mutations profoundly disrupt RNA helicase activity, induce ectopic RNA-protein granules in neural progenitors and neurons, and impair translation. Together, these results uncover key mechanisms underlying DDX3X syndrome and highlight aberrant RNA metabolism in the pathogenesis of neurodevelopmental disease.
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Affiliation(s)
- Ashley L Lennox
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Mariah L Hoye
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ruiji Jiang
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Lindsey A Suit
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Srivats Venkataramanan
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Charles J Sheehan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Fernando C Alsina
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Brieana Fregeau
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kimberly A Aldinger
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Ching Moey
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD 4072, Australia
| | - Iryna Lobach
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Alexandra Afenjar
- Centre de référence des malformations et maladies congénitales du cervelet et Département de génétique et embryologie médicale, APHP, Sorbonne Université, Hôpital Armand Trousseau, 75012 Paris, France
| | - Dusica Babovic-Vuksanovic
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA; Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Stéphane Bézieau
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | - Patrick R Blackburn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Jens Bunt
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD 4072, Australia
| | - Lydie Burglen
- Centre de référence des malformations et maladies congénitales du cervelet et Département de génétique et embryologie médicale, APHP, Sorbonne Université, Hôpital Armand Trousseau, 75012 Paris, France
| | - Philippe M Campeau
- Department of Pediatrics, University of Montreal and CHU Sainte-Justine, Montreal, QC, Canada
| | - Perrine Charles
- Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié Salpêtrière et Hôpital Trousseau, APHP, Sorbonne Université, Paris, France
| | - Brian H Y Chung
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Benjamin Cogné
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | - Cynthia Curry
- Genetic Medicine, University of California San Francisco/Fresno, Fresno, CA 93701, USA
| | - Maria Daniela D'Agostino
- Division of Medical Genetics, Departments of Specialized Medicine and Human Genetics, McGill University, Montreal, QC, Canada
| | | | - Laurence Faivre
- Centre de référence Anomalies du Développement et Syndromes Malformatifs, INSERM UMR 1231 GAD, CHU de Dijon et Université de Bourgogne, Dijon, France
| | - Delphine Héron
- APHP, Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France
| | - A Micheil Innes
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Bertrand Isidor
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | - Boris Keren
- APHP, Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France
| | - Amy Kimball
- Harvey Institute of Human Genetics, Greater Baltimore Medical Center, Baltimore, MD, USA
| | - Eric W Klee
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA; Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Health Sciences Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Paul Kuentz
- UMR-INSERM 1231 GAD, Génétique des Anomalies du développement, Université de Bourgogne Franche-Comté, Dijon, France
| | - Sébastien Küry
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | | | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA; Department of Pediatrics, University of Washington, Seattle, WA 98101, USA
| | - Cyril Mignot
- Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié Salpêtrière et Hôpital Trousseau, APHP, Sorbonne Université, Paris, France
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Atsushi Fujita
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Caroline Nava
- APHP, Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France
| | - Mathilde Nizon
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | - Diana Rodriguez
- Centre de Référence Neurogénétique & Service de Neurologie Pédiatrique, APHP, Sorbonne Université, Hôpital Armand Trousseau, 75012 Paris, France
| | - Lot Snijders Blok
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands
| | - Christel Thauvin-Robinet
- Centre de référence Déficience Intellectuelle, INSERM UMR 1231 GAD, CHU de Dijon et Université de Bourgogne, Dijon, France
| | - Julien Thevenon
- Centre de référence Anomalies du Développement et Syndromes Malformatifs, INSERM UMR 1231 GAD, CHU de Dijon et Université de Bourgogne, Dijon, France
| | - Marie Vincent
- Service de Génétique Médicale, CHU Nantes, 9 quai Moncousu, 44093 Nantes Cedex 1, France; Université de Nantes, CNRS, INSERM, l'institut du thorax, 44000 Nantes, France
| | | | - William Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA; Departments of Pediatrics and Neurology, University of Washington, Seattle, WA 98101, USA
| | - Linda J Richards
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD 4072, Australia; The University of Queensland, School of Biomedical Sciences, Brisbane 4072, QLD, Australia
| | - A James Barkovich
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94158, USA; Helen Diller Family Comprehensive Cancer Center, San Francisco, CA 94158, USA
| | - Debra L Silver
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Duke Institute for Brain Sciences, Duke University, Durham, NC 27710, USA.
| | - Elliott H Sherr
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA; Institute of Human Genetics and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA.
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115
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Böhm M, Chung DY, Gómez CA, Qin T, Takizawa T, Sadeghian H, Sugimoto K, Sakadžić S, Yaseen MA, Ayata C. Neurovascular coupling during optogenetic functional activation: Local and remote stimulus-response characteristics, and uncoupling by spreading depression. J Cereb Blood Flow Metab 2020; 40:808-822. [PMID: 31063009 PMCID: PMC7168797 DOI: 10.1177/0271678x19845934] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neurovascular coupling is a fundamental response that links activity to perfusion. Traditional paradigms of neurovascular coupling utilize somatosensory stimulation to activate the primary sensory cortex through subcortical relays. Therefore, examination of neurovascular coupling in disease models can be confounded if the disease process affects these multisynaptic pathways. Optogenetic stimulation is an alternative to directly activate neurons, bypassing the subcortical relays. We employed minimally invasive optogenetic cortical activation through intact skull in Thy1-channelrhodopsin-2 transgenic mice, examined the blood flow changes using laser speckle imaging, and related these to evoked electrophysiological activity. Our data show that optogenetic activation of barrel cortex triggers intensity- and frequency-dependent hyperemia both locally within the barrel cortex (>50% CBF increase), and remotely within the ipsilateral motor cortex (>30% CBF increase). Intriguingly, activation of the barrel cortex causes a small (∼10%) but reproducible hypoperfusion within the contralateral barrel cortex, electrophysiologically linked to transhemispheric inhibition. Cortical spreading depression, known to cause neurovascular uncoupling, diminishes optogenetic hyperemia by more than 50% for up to an hour despite rapid recovery of evoked electrophysiological activity, recapitulating a unique feature of physiological neurovascular coupling. Altogether, these data establish a minimally invasive paradigm to investigate neurovascular coupling for longitudinal characterization of cerebrovascular pathologies.
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Affiliation(s)
- Maximilian Böhm
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - David Y Chung
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Carlos A Gómez
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Tao Qin
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Tsubasa Takizawa
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Homa Sadeghian
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kazutaka Sugimoto
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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116
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Charvet CJ, Das A, Song JW, Tindal-Burgess DJ, Kabaria P, Dai G, Kane T, Takahashi E. High Angular Resolution Diffusion MRI Reveals Conserved and Deviant Programs in the Paths that Guide Human Cortical Circuitry. Cereb Cortex 2020; 30:1447-1464. [PMID: 31667494 PMCID: PMC7132938 DOI: 10.1093/cercor/bhz178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/13/2019] [Accepted: 07/10/2019] [Indexed: 02/07/2023] Open
Abstract
Diffusion magnetic resonance (MR) tractography represents a novel opportunity to investigate conserved and deviant developmental programs between humans and other species such as mice. To that end, we acquired high angular resolution diffusion MR scans of mice [embryonic day (E) 10.5 to postnatal week 4] and human brains [gestational week (GW) 17-30] at successive stages of fetal development to investigate potential evolutionary changes in radial organization and emerging pathways between humans and mice. We compare radial glial development as well as commissural development (e.g., corpus callosum), primarily because our findings can be integrated with previous work. We also compare corpus callosal growth trajectories across primates (i.e., humans and rhesus macaques) and rodents (i.e., mice). One major finding is that the developing cortex of humans is predominated by pathways likely associated with a radial glial organization at GW 17-20, which is not as evident in age-matched mice (E 16.5, 17.5). Another finding is that, early in development, the corpus callosum follows a similar developmental timetable in primates (i.e., macaques and humans) as in mice. However, the corpus callosum grows for an extended period of time in primates compared with rodents. Taken together, these findings highlight deviant developmental programs underlying the emergence of cortical pathways in the human brain.
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Affiliation(s)
| | - Avilash Das
- Medical Sciences in the College of Arts and Sciences, Boston University, Boston, MA 02215, USA
- Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Fetal-Neonatal Brain Imaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Jae W Song
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | - Priya Kabaria
- Department of Behavioral Neuroscience, Northeastern University, Boston, MA 02115, USA
| | - Guangping Dai
- Science Center, Wellesley College, Wellesley, MA 02481, USA
| | - Tara Kane
- Department of Behavioral Neuroscience, Northeastern University, Boston, MA 02115, USA
| | - Emi Takahashi
- Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Fetal-Neonatal Brain Imaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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117
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Putoux A, Baas D, Paschaki M, Morlé L, Maire C, Attié-Bitach T, Thomas S, Durand B. Altered GLI3 and FGF8 signaling underlies acrocallosal syndrome phenotypes in Kif7 depleted mice. Hum Mol Genet 2020; 28:877-887. [PMID: 30445565 DOI: 10.1093/hmg/ddy392] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/31/2018] [Accepted: 11/08/2018] [Indexed: 11/14/2022] Open
Abstract
Acrocallosal syndrome (ACLS) is a rare genetic disorder characterized by agenesis or hypoplasia of corpus callosum (CC), polydactyly, craniofacial dysmorphism and severe intellectual deficiency. We previously identified KIF7, a key ciliary component of the Sonic hedgehog (SHH) pathway, as being a causative gene for this syndrome, thus including ACLS in the group of ciliopathies. In both humans and mice, KIF7 depletion leads to abnormal GLI3 processing and over-activation of SHH target genes. To understand the pathological mechanisms involved in CC defects in this syndrome, we took advantage of a previously described Kif7-/- mouse model to demonstrate that in addition to polydactyly and neural tube closure defects, these mice present CC agenesis with characteristic Probst bundles, thus recapitulating major ACLS features. We show that CC agenesis in these mice is associated with specific patterning defects of the cortical septum boundary leading to altered distribution of guidepost cells required to guide the callosal axons through the midline. Furthermore, by crossing Kif7-/- mice with Gli3Δ699 mice exclusively producing the repressive isoform of GLI3 (GLI3R), we demonstrate that decreased GLI3R signaling is fully responsible for the ACLS features in these mice, as all phenotypes are rescued by increasing GLI3R activity. Moreover, we show that increased FGF8 signaling is responsible in part for CC defects associated to KIF7 depletion, as modulating FGF8 signaling rescued CC formation anteriorly in Kif7-/- mice. Taken together our data demonstrate that ACLS features rely on defective GLI3R and FGF8 signaling.
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Affiliation(s)
- Audrey Putoux
- Centre de Recherche en Neurosciences de Lyon, Équipe GENDEV, INSERM U1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Lyon, France.,Service de Génétique et Centre de Référence des Anomalies du Développement de la Région Auvergne-Rhône-Alpes, CHU de Lyon, France
| | - Dominique Baas
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U-1217, Lyon, France
| | - Marie Paschaki
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U-1217, Lyon, France
| | - Laurette Morlé
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U-1217, Lyon, France
| | - Charline Maire
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U-1217, Lyon, France
| | - Tania Attié-Bitach
- Laboratory of Embryology and Genetics of Congenital Malformations, INSERM UMR1163, Sorbonne Paris Cité University, Imagine Institute, Paris, France.,Department of Histology-Embryology and Cytogenetics, Necker Hospital, AP-HP, Paris, France
| | - Sophie Thomas
- Laboratory of Embryology and Genetics of Congenital Malformations, INSERM UMR1163, Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Bénédicte Durand
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U-1217, Lyon, France
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118
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Sanchez-Aguilera A, Menendez de la Prida L. The Beauty and the Dish: Brain Organoids Go Active. Epilepsy Curr 2020; 20:105-107. [PMID: 32313507 PMCID: PMC7160880 DOI: 10.1177/1535759720901502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Complex Oscillatory Waves Emerging From Cortical Organoids Model Early Human Brain Network Development Trujillo CA, Gao R, Negraes PD, et al. Cell Stem Cell . 2019;25(4):558-569.e7. doi:10.1016/j.stem.2019.08.002 . Structural and transcriptional changes during early brain maturation follow fixed developmental programs defined by genetics. However, whether this is true for functional network activity remains unknown, primarily due to experimental inaccessibility of the initial stages of the living human brain. Here, we developed human cortical organoids that dynamically change cellular populations during maturation and exhibited consistent increases in electrical activity over the span of several months. The spontaneous network formation displayed periodic and regular oscillatory events that were dependent on glutamatergic and GABAergic signaling. The oscillatory activity transitioned to more spatiotemporally irregular patterns, and synchronous network events resembled features similar to those observed in preterm human electroencephalography. These results show that the development of structured network activity in a human neocortex model may follow stable genetic programming. Our approach provides opportunities for investigating and manipulating the role of network activity in the developing human cortex.
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119
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Veeraval L, O'Leary CJ, Cooper HM. Adherens Junctions: Guardians of Cortical Development. Front Cell Dev Biol 2020; 8:6. [PMID: 32117958 PMCID: PMC7025593 DOI: 10.3389/fcell.2020.00006] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/10/2020] [Indexed: 12/01/2022] Open
Abstract
Apical radial glia comprise the pseudostratified neuroepithelium lining the embryonic lateral ventricles and give rise to the extensive repertoire of pyramidal neuronal subtypes of the neocortex. The establishment of a highly apicobasally polarized radial glial morphology is a mandatory prerequisite for cortical development as it governs neurogenesis, neural migration and the integrity of the ventricular wall. As in all epithelia, cadherin-based adherens junctions (AJs) play an obligate role in the maintenance of radial glial apicobasal polarity and neuroepithelial cohesion. In addition, the assembly of resilient AJs is critical to the integrity of the neuroepithelium which must resist the tensile forces arising from increasing CSF volume and other mechanical stresses associated with the expansion of the ventricles in the embryo and neonate. Junctional instability leads to the collapse of radial glial morphology, disruption of the ventricular surface and cortical lamination defects due to failed neuronal migration. The fidelity of cortical development is therefore dependent on AJ assembly and stability. Mutations in genes known to control radial glial junction formation are causative for a subset of inherited cortical malformations (neuronal heterotopias) as well as perinatal hydrocephalus, reinforcing the concept that radial glial junctions are pivotal determinants of successful corticogenesis. In this review we explore the key animal studies that have revealed important insights into the role of AJs in maintaining apical radial glial morphology and function, and as such, have provided a deeper understanding of the aberrant molecular and cellular processes contributing to debilitating cortical malformations. We highlight the reciprocal interactions between AJs and the epithelial polarity complexes that impose radial glial apicobasal polarity. We also discuss the critical molecular networks promoting AJ assembly in apical radial glia and emphasize the role of the actin cytoskeleton in the stabilization of cadherin adhesion – a crucial factor in buffering the mechanical forces exerted as a consequence of cortical expansion.
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Affiliation(s)
- Lenin Veeraval
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Conor J O'Leary
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Helen M Cooper
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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120
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Govaert P, Triulzi F, Dudink J. The developing brain by trimester. HANDBOOK OF CLINICAL NEUROLOGY 2020; 171:245-289. [PMID: 32736754 DOI: 10.1016/b978-0-444-64239-4.00014-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transient anatomical entities play a role in the maturation of brain regions and early functional fetal networks. At the postmenstrual age of 7 weeks, major subdivisions of the brain are visible. At the end of the embryonic period, the cortical plate covers the neopallium. The choroid plexus develops in concert with it, and the dorsal thalamus covers about half the diencephalic third ventricle surface. In addition to the fourth ventricle neuroepithelium the rhombic lips are an active neuroepithelial production site. Early reciprocal connections between the thalamus and cortex are present. The corticospinal tract has reached the pyramidal decussation, and the arteries forming the mature circle of Willis are seen. Moreover, the superior sagittal sinus has formed, and at the rostral neuropore the massa commissuralis is growing. At the viable preterm age of around 24 weeks PMA, white matter tracts are in full development. Asymmetric progenitor division permits production of neurons, subventricular zone precursors, and glial cells. Myelin is present in the ventral spinal quadrant, cuneate fascicle, and spinal motor fibers. The neopallial mantle has been separated into transient layers (stratified transitional fields) between the neuroepithelium and the cortical plate. The subplate plays an important role in organizing the structuring of the cortical plate. Commissural tracts have shaped the corpus callosum, early primary gyri are present, and opercularization has started caudally, forming the lateral fissure. Thalamic and striatal nuclei have formed, although GABAergic neurons continue to migrate into the thalamus from the corpus gangliothalamicum. Near-term PMA cerebral sublobulation is active. Between 24 and 32 weeks, primary sulci develop. Myelin is present in the superior cerebellar peduncle, rubrospinal tract, and inferior olive. Germinal matrix disappears from the telencephalon, except for the GABAergic frontal cortical subventricular neuroepithelium.
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Affiliation(s)
- Paul Govaert
- Department of Neonatology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Neonatology, ZNA Middelheim, Antwerp, Belgium; Department of Rehabilitation and Physical Therapy, Gent University Hospital, Gent, Belgium.
| | - Fabio Triulzi
- Department of Pediatric Neuroradiology, Università Degli Studi di Milano, Milan, Italy
| | - Jeroen Dudink
- Department of Neonatology, University Medical Center, Utrecht, The Netherlands
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121
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Panagiotakos G, Haveles C, Arjun A, Petrova R, Rana A, Portmann T, Paşca SP, Palmer TD, Dolmetsch RE. Aberrant calcium channel splicing drives defects in cortical differentiation in Timothy syndrome. eLife 2019; 8:51037. [PMID: 31868578 PMCID: PMC6964969 DOI: 10.7554/elife.51037] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/21/2019] [Indexed: 01/02/2023] Open
Abstract
The syndromic autism spectrum disorder (ASD) Timothy syndrome (TS) is caused by a point mutation in the alternatively spliced exon 8A of the calcium channel Cav1.2. Using mouse brain and human induced pluripotent stem cells (iPSCs), we provide evidence that the TS mutation prevents a normal developmental switch in Cav1.2 exon utilization, resulting in persistent expression of gain-of-function mutant channels during neuronal differentiation. In iPSC models, the TS mutation reduces the abundance of SATB2-expressing cortical projection neurons, leading to excess CTIP2+ neurons. We show that expression of TS-Cav1.2 channels in the embryonic mouse cortex recapitulates these differentiation defects in a calcium-dependent manner and that in utero Cav1.2 gain-and-loss of function reciprocally regulates the abundance of these neuronal populations. Our findings support the idea that disruption of developmentally regulated calcium channel splicing patterns instructively alters differentiation in the developing cortex, providing important in vivo insights into the pathophysiology of a syndromic ASD.
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Affiliation(s)
- Georgia Panagiotakos
- Department of Neurobiology, Stanford University School of Medicine, Stanford, United States.,Eli & Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Christos Haveles
- Eli & Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Arpana Arjun
- Eli & Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States.,Graduate Program in Developmental and Stem Cell Biology, University of California, San Francisco, San Francisco, United States
| | - Ralitsa Petrova
- Eli & Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Anshul Rana
- Graduate Program in Biochemistry, Stanford University School of Medicine, Stanford, United States
| | - Thomas Portmann
- Department of Neurobiology, Stanford University School of Medicine, Stanford, United States
| | - Sergiu P Paşca
- Department of Neurobiology, Stanford University School of Medicine, Stanford, United States.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, United States
| | - Theo D Palmer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, United States
| | - Ricardo E Dolmetsch
- Department of Neurobiology, Stanford University School of Medicine, Stanford, United States
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122
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Abstract
Mapping the circuits underlying the generation and propagation of seizures is critically important for understanding their pathophysiology. We review evidence to suggest that circuits engaged in secondarily generalized seizures are likely to be more complex than those currently proposed. Focal seizures have been proposed to engage canonical thalamocortical circuits that mediate primarily generalized absence seizures, leading to secondarily generalized tonic-clonic seizures. In addition to traveling through the canonical thalamocortical circuits, secondarily generalized seizures could also travel through the striatum, globus pallidus, substantia nigra reticulata, and corpus callosum to the contralateral hemisphere. Recruitment of principal neurons in superficial layers 2/3 of the cortex can play a critical role in corticocortical seizure spread. Understanding the neuronal structures engaged in generating secondarily generalized seizures could provide novel targets for neuromodulation for the treatment of seizures. Furthermore, these sites may be loci of neuronal plasticity facilitating epileptogenesis. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
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Affiliation(s)
- Anastasia Brodovskaya
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
| | - Jaideep Kapur
- Departments of Neurology, University of Virginia, Charlottesville, VA 22908, USA; Neuroscience, University of Virginia, Charlottesville, VA 22908, USA; UVA Brain Institute, University of Virginia, Charlottesville, VA 22908, USA.
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123
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Differences in GluN2B-Containing NMDA Receptors Result in Distinct Long-Term Plasticity at Ipsilateral versus Contralateral Cortico-Striatal Synapses. eNeuro 2019; 6:ENEURO.0118-19.2019. [PMID: 31744842 PMCID: PMC6883172 DOI: 10.1523/eneuro.0118-19.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/14/2019] [Accepted: 11/06/2019] [Indexed: 12/24/2022] Open
Abstract
Excitatory neurons in the primary motor cortex project bilaterally to the striatum. However, whether synaptic structure and function in ipsilateral and contralateral cortico-striatal pathways is identical or different remains largely unknown. Here, we describe that excitatory synapses in the mouse contralateral pathway have higher levels of NMDA-type of glutamate receptors (NMDARs) than those in the ipsilateral pathway, although both synapses utilize the same presynaptic vesicular glutamate transporter (VGLUT). We also show that NMDARs containing the GluN2B subunit, but not GluN2A, contribute to this difference. The altered NMDAR subunit composition in these two pathways results in opposite synaptic plasticity induced by θ-burst stimulus: long-term depression in the ipsilateral pathway and long-term potentiation (LTP) in the contralateral pathway. The standard long-term depression (LTD)-inducing protocol using paired postsynaptic and presynaptic activity triggers synaptic depression at ipsilateral pathway synapses, but not at those of the contralateral pathway. Altogether, our results provide novel and unexpected evidence for the lack of bilaterality of NMDAR-mediated synaptic transmission at cortico-striatal pathways due to differences in the expression of GluN2B subunits, which results in differences in bidirectional synaptic plasticity.
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124
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Ellender TJ, Avery SV, Mahfooz K, Scaber J, von Klemperer A, Nixon SL, Buchan MJ, van Rheede JJ, Gatti A, Waites C, Pavlou HJ, Sims D, Newey SE, Akerman CJ. Embryonic progenitor pools generate diversity in fine-scale excitatory cortical subnetworks. Nat Commun 2019; 10:5224. [PMID: 31745093 PMCID: PMC6863870 DOI: 10.1038/s41467-019-13206-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/28/2019] [Indexed: 12/02/2022] Open
Abstract
The mammalian neocortex is characterized by a variety of neuronal cell types and precise arrangements of synaptic connections, but the processes that generate this diversity are poorly understood. Here we examine how a pool of embryonic progenitor cells consisting of apical intermediate progenitors (aIPs) contribute to diversity within the upper layers of mouse cortex. In utero labeling combined with single-cell RNA-sequencing reveals that aIPs can generate transcriptionally defined glutamatergic cell types, when compared to neighboring neurons born from other embryonic progenitor pools. Whilst sharing layer-associated morphological and functional properties, simultaneous patch clamp recordings and optogenetic studies reveal that aIP-derived neurons exhibit systematic biases in both their intralaminar monosynaptic connectivity and the post-synaptic partners that they target within deeper layers of cortex. Multiple cortical progenitor pools therefore represent an important factor in establishing diversity amongst local and long-range fine-scale glutamatergic connectivity, which generates subnetworks for routing excitatory synaptic information.
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Affiliation(s)
- Tommas J Ellender
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Sophie V Avery
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Kashif Mahfooz
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Jakub Scaber
- MRC Computational Genomics Analysis and Training Programme (CGAT), MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | | | - Sophie L Nixon
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Matthew J Buchan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Joram J van Rheede
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Aleksandra Gatti
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Cameron Waites
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Hania J Pavlou
- MRC Computational Genomics Analysis and Training Programme (CGAT), MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - David Sims
- MRC Computational Genomics Analysis and Training Programme (CGAT), MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK
| | - Sarah E Newey
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Colin J Akerman
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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125
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"Females Are Not Just 'Protected' Males": Sex-Specific Vulnerabilities in Placenta and Brain after Prenatal Immune Disruption. eNeuro 2019; 6:ENEURO.0358-19.2019. [PMID: 31611335 PMCID: PMC6838689 DOI: 10.1523/eneuro.0358-19.2019] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/27/2019] [Indexed: 11/21/2022] Open
Abstract
Current perceptions of genetic and environmental vulnerabilities in the developing fetus are biased toward male outcomes. An argument is made that males are more vulnerable to gestational complications and neurodevelopmental disorders, the implication being that an understanding of disrupted development in males is sufficient to understand causal mechanisms that are assumed to be similar but attenuated in females. Here we examine this assumption in the context of immune-driven alterations in fetal brain development and related outcomes in female and male mice. Pregnant C57BL/6 mice were treated with low-dose lipopolysaccharide at embryonic day 12.5. Placental pathology, acute fetal brain inflammation and hypoxia, long-term changes in adult cortex cytoarchitecture, altered densities and ratio of excitatory (Satb2+) to inhibitory (parvalbumin+) neuronal subtypes, postnatal growth, and behavior outcomes were compared between male and female offspring. We find that while males experience more pronounced placental pathology, fetal brain hypoxia, depleted PV and Satb2+ densities, and social and learning-related behavioral abnormalities, females exhibit unique acute inflammatory signaling in fetal brain, postnatal growth delay, opposite alterations in cortical PV densities, changes in juvenile behavior, delayed postnatal body growth, and elevated anxiety-related behavior as adults. While males are more severely impacted by prenatal immune disruption by several measures, females exposed to the same insult exhibit a unique set of vulnerabilities and developmental consequences that is not present in males. Our results clearly outline disparate sex-specific features of prenatal vulnerability to inflammatory insults and warn against the casual extrapolation of male disease mechanisms to females.
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126
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Alvarez-Saavedra M, Yan K, De Repentigny Y, Hashem LE, Chaudary N, Sarwar S, Yang D, Ioshikhes I, Kothary R, Hirayama T, Yagi T, Picketts DJ. Snf2h Drives Chromatin Remodeling to Prime Upper Layer Cortical Neuron Development. Front Mol Neurosci 2019; 12:243. [PMID: 31680852 PMCID: PMC6811508 DOI: 10.3389/fnmol.2019.00243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/20/2019] [Indexed: 01/23/2023] Open
Abstract
Alterations in the homeostasis of either cortical progenitor pool, namely the apically located radial glial (RG) cells or the basal intermediate progenitors (IPCs) can severely impair cortical neuron production. Such changes are reflected by microcephaly and are often associated with cognitive defects. Genes encoding epigenetic regulators are a frequent cause of intellectual disability and many have been shown to regulate progenitor cell growth, including our inactivation of the Smarca1 gene encoding Snf2l, which is one of two ISWI mammalian orthologs. Loss of the Snf2l protein resulted in dysregulation of Foxg1 and IPC proliferation leading to macrocephaly. Here we show that inactivation of the closely related Smarca5 gene encoding the Snf2h chromatin remodeler is necessary for embryonic IPC expansion and subsequent specification of callosal projection neurons. Telencephalon-specific Smarca5 cKO embryos have impaired cell cycle kinetics and increased cell death, resulting in fewer Tbr2+ and FoxG1+ IPCs by mid-neurogenesis. These deficits give rise to adult mice with a dramatic reduction in Satb2+ upper layer neurons, and partial agenesis of the corpus callosum. Mice survive into adulthood but molecularly display reduced expression of the clustered protocadherin genes that may further contribute to altered dendritic arborization and a hyperactive behavioral phenotype. Our studies provide novel insight into the developmental function of Snf2h-dependent chromatin remodeling processes during brain development.
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Affiliation(s)
- Matías Alvarez-Saavedra
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Yves De Repentigny
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Lukas E. Hashem
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Nidhi Chaudary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Shihab Sarwar
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Doo Yang
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Ilya Ioshikhes
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Rashmi Kothary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Teruyoshi Hirayama
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
- Department of Anatomy and Developmental Neurobiology, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Integrated Biology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - David J. Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Departments of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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127
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De León Reyes NS, Mederos S, Varela I, Weiss LA, Perea G, Galazo MJ, Nieto M. Transient callosal projections of L4 neurons are eliminated for the acquisition of local connectivity. Nat Commun 2019; 10:4549. [PMID: 31591398 PMCID: PMC6779895 DOI: 10.1038/s41467-019-12495-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 09/15/2019] [Indexed: 12/11/2022] Open
Abstract
Interhemispheric axons of the corpus callosum (CC) facilitate the higher order functions of the cerebral cortex. According to current views, callosal and non-callosal fates are determined early after a neuron's birth, and certain populations, such as cortical layer (L) 4 excitatory neurons of the primary somatosensory (S1) barrel, project only ipsilaterally. Using a novel axonal-retrotracing strategy and GFP-targeted visualization of Rorb+ neurons, we instead demonstrate that L4 neurons develop transient interhemispheric axons. Locally restricted L4 connectivity emerges when exuberant contralateral axons are refined in an area- and layer-specific manner during postnatal development. Surgical and genetic interventions of sensory circuits demonstrate that refinement rates depend on distinct inputs from sensory-specific thalamic nuclei. Reductions in input-dependent refinement result in mature functional interhemispheric hyperconnectivity, demonstrating the plasticity and bona fide callosal potential of L4 neurons. Thus, L4 neurons discard alternative interhemispheric circuits as instructed by thalamic input. This may ensure optimal wiring.
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Affiliation(s)
- N S De León Reyes
- Department of Cellular and Molecular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Campus de Cantoblanco, Darwin 3, 28049, Madrid, Spain
| | - S Mederos
- Instituto Cajal, CSIC. Av. Doctor Arce, 37, 28002, Madrid, Spain
| | - I Varela
- Department of Cellular and Molecular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Campus de Cantoblanco, Darwin 3, 28049, Madrid, Spain
| | - L A Weiss
- Department of Cellular and Molecular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Campus de Cantoblanco, Darwin 3, 28049, Madrid, Spain
| | - G Perea
- Instituto Cajal, CSIC. Av. Doctor Arce, 37, 28002, Madrid, Spain
| | - M J Galazo
- Department of Cell and Molecular Biology and Tulane Brain Institute, Tulane University, 6400 Freret Street, Percival Stern Hall suite 2000, New Orleans, LA, 70118, USA
| | - M Nieto
- Department of Cellular and Molecular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Campus de Cantoblanco, Darwin 3, 28049, Madrid, Spain.
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128
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Kaur R, Surala M, Hoger S, Grössmann N, Grimm A, Timaeus L, Kallina W, Hummel T. Pioneer interneurons instruct bilaterality in the Drosophila olfactory sensory map. SCIENCE ADVANCES 2019; 5:eaaw5537. [PMID: 31681838 PMCID: PMC6810332 DOI: 10.1126/sciadv.aaw5537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
Interhemispheric synaptic connections, a prominent feature in animal nervous systems for the rapid exchange and integration of neuronal information, can appear quite suddenly during brain evolution, raising the question about the underlying developmental mechanism. Here, we show in the Drosophila olfactory system that the induction of a bilateral sensory map, an evolutionary novelty in dipteran flies, is mediated by a unique type of commissural pioneer interneurons (cPINs) via the localized activity of the cell adhesion molecule Neuroglian. Differential Neuroglian signaling in cPINs not only prepatterns the olfactory contralateral tracts but also prevents the targeting of ingrowing sensory axons to their ipsilateral synaptic partners. These results identified a sensitive cellular interaction to switch the sequential assembly of diverse neuron types from a unilateral to a bilateral brain circuit organization.
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Affiliation(s)
- Rashmit Kaur
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Michael Surala
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Sebastian Hoger
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Nicole Grössmann
- Ludwig Boltzmann Institute, Health Technology Assessment (LBI-HTA), Garnisongasse7/20, 1090 Vienna, Austria
- Department of Health Economics, Center for Public Health, Medical University of Vienna, Vienna, Austria
| | - Alexandra Grimm
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Lorin Timaeus
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Wolfgang Kallina
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
| | - Thomas Hummel
- Department of Neurobiology, University of Vienna, Althanstrasse 14A, 1090 Vienna, Austria
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129
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Velona T, Altounian M, Roque M, Hocine M, Bellon A, Briz CG, Salin P, Nieto M, Chauvet S, Mann F. PlexinD1 and Sema3E determine laminar positioning of heterotopically projecting callosal neurons. Mol Cell Neurosci 2019; 100:103397. [DOI: 10.1016/j.mcn.2019.103397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/05/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023] Open
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130
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Evans TA, Bury LA, Huang AY, Sabo SL. Spatio-temporal dynamics of neocortical presynaptic terminal development using multi-photon imaging of the corpus callosum in vivo. Sci Rep 2019; 9:14028. [PMID: 31575884 PMCID: PMC6773694 DOI: 10.1038/s41598-019-50431-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 09/12/2019] [Indexed: 11/25/2022] Open
Abstract
Within the developing central nervous system, the dynamics of synapse formation and elimination are insufficiently understood. It is ideal to study these processes in vivo, where neurons form synapses within appropriate behavioral and anatomical contexts. In vivo analysis is particularly important for long-range connections, since their development cannot be adequately studied in vitro. The corpus callosum (CC) represents a clinically-relevant long-range connection since several neurodevelopmental diseases involve CC defects. Here, we present a novel strategy for in vivo longitudinal and rapid time-lapse imaging of CC presynaptic terminal development. In postnatal mice, the time-course of CC presynaptic terminal formation and elimination was highly variable between axons or groups of axons. Young presynaptic terminals were remarkably dynamic - moving, dividing to generate more boutons, and merging to consolidate small terminals into large boutons. As synaptic networks matured, presynaptic mobility decreased. These rapid dynamics may be important for establishing initial synaptic contacts with postsynaptic partners, refining connectivity patterns or modifying synapse strength during development. Ultimately, this in vivo imaging approach will facilitate investigation of synapse development in other long-range connections and neurodevelopmental disease models.
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Affiliation(s)
- Teresa A Evans
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA
- Department of Pediatrics, Stanford University, Stanford, USA
| | - Luke A Bury
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA
| | - Alex Y Huang
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, USA
| | - Shasta L Sabo
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA.
- Department of Biology, Central Michigan University, Mount Pleasant, USA.
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131
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In vivo epigenetic editing of Sema6a promoter reverses transcallosal dysconnectivity caused by C11orf46/Arl14ep risk gene. Nat Commun 2019; 10:4112. [PMID: 31511512 PMCID: PMC6739341 DOI: 10.1038/s41467-019-12013-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 08/12/2019] [Indexed: 12/15/2022] Open
Abstract
Many neuropsychiatric risk genes contribute to epigenetic regulation but little is known about specific chromatin-associated mechanisms governing the formation of neuronal connectivity. Here we show that transcallosal connectivity is critically dependent on C11orf46, a nuclear protein encoded in the chromosome 11p13 WAGR risk locus. C11orf46 haploinsufficiency was associated with hypoplasia of the corpus callosum. C11orf46 knockdown disrupted transcallosal projections and was rescued by wild type C11orf46 but not the C11orf46R236H mutant associated with intellectual disability. Multiple genes encoding key regulators of axonal development, including Sema6a, were hyperexpressed in C11orf46-knockdown neurons. RNA-guided epigenetic editing of Sema6a gene promoters via a dCas9-SunTag system with C11orf46 binding normalized SEMA6A expression and rescued transcallosal dysconnectivity via repressive chromatin remodeling by the SETDB1 repressor complex. Our study demonstrates that interhemispheric communication is sensitive to locus-specific remodeling of neuronal chromatin, revealing the therapeutic potential for shaping the brain's connectome via gene-targeted designer activators and repressor proteins.
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132
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Winnubst J, Bas E, Ferreira TA, Wu Z, Economo MN, Edson P, Arthur BJ, Bruns C, Rokicki K, Schauder D, Olbris DJ, Murphy SD, Ackerman DG, Arshadi C, Baldwin P, Blake R, Elsayed A, Hasan M, Ramirez D, Dos Santos B, Weldon M, Zafar A, Dudman JT, Gerfen CR, Hantman AW, Korff W, Sternson SM, Spruston N, Svoboda K, Chandrashekar J. Reconstruction of 1,000 Projection Neurons Reveals New Cell Types and Organization of Long-Range Connectivity in the Mouse Brain. Cell 2019; 179:268-281.e13. [PMID: 31495573 DOI: 10.1016/j.cell.2019.07.042] [Citation(s) in RCA: 270] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/14/2019] [Accepted: 07/23/2019] [Indexed: 01/15/2023]
Abstract
Neuronal cell types are the nodes of neural circuits that determine the flow of information within the brain. Neuronal morphology, especially the shape of the axonal arbor, provides an essential descriptor of cell type and reveals how individual neurons route their output across the brain. Despite the importance of morphology, few projection neurons in the mouse brain have been reconstructed in their entirety. Here we present a robust and efficient platform for imaging and reconstructing complete neuronal morphologies, including axonal arbors that span substantial portions of the brain. We used this platform to reconstruct more than 1,000 projection neurons in the motor cortex, thalamus, subiculum, and hypothalamus. Together, the reconstructed neurons constitute more than 85 meters of axonal length and are available in a searchable online database. Axonal shapes revealed previously unknown subtypes of projection neurons and suggest organizational principles of long-range connectivity.
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Affiliation(s)
- Johan Winnubst
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Erhan Bas
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Tiago A Ferreira
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Zhuhao Wu
- Laboratory of Molecular Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Michael N Economo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | | | - Ben J Arthur
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Christopher Bruns
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Konrad Rokicki
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - David Schauder
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Donald J Olbris
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Sean D Murphy
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - David G Ackerman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Cameron Arshadi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Perry Baldwin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Regina Blake
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ahmad Elsayed
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Mashtura Hasan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Daniel Ramirez
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Bruno Dos Santos
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Monet Weldon
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Amina Zafar
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Joshua T Dudman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Charles R Gerfen
- Intramural Research Program, National Institute of Mental Health, Bethesda, MD 20892, USA
| | - Adam W Hantman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Wyatt Korff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
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133
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Culjat M, Milošević NJ. Callosal septa express guidance cues and are paramedian guideposts for human corpus callosum development. J Anat 2019; 235:670-686. [PMID: 31070791 PMCID: PMC6704273 DOI: 10.1111/joa.13011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2019] [Indexed: 12/18/2022] Open
Abstract
The early development and growth of the corpus callosum are supported by several midline transient structures in mammals that include callosal septa (CS), which are present only in the second half of gestation in humans. Here we provide new data that support the guidance role of CS in corpus callosum development, derived from the analysis of 46 postmortem fetal brains, ranging in age from 16 to 40 post conception weeks (PCW). Using immunohistochemical methods, we show the expression pattern of guidance cues ephrinA4 and neogenin, extracellular protein fibronectin, as well as non-activated microglia in the CS. We found that the dynamic changes in expression of guidance cues, cellular and extracellular matrix constituents in the CS correlate well with the growth course of the corpus callosum at midsagittal level. The CS reach and maintain their developmental maximum between 20 and 26 PCW and can be visualized as hypointense structures in the ventral callosal portion with ex vivo (in vitro) T2-weighted 3T magnetic resonance imaging (MRI). The maximum of septal development overlaps with an increase in the callosal midsagittal area, whereas the slow, gradual resolution of CS coincides with a plateau of midsagittal callosal growth. The recognition of CS existence in human fetal brain and the ability to visualize them by ex vivoMRI attributes a potential diagnostic value to these transient structures, as advancement in imaging technologies will likely also enable in vivoMRI visualization of the CS in the near future.
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Affiliation(s)
- Marko Culjat
- MedStar Georgetown University HospitalWashingtonDCUSA
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134
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Zhang Y, Jiang S, Xu Z, Gong H, Li A, Luo Q, Ren M, Li X, Wu H, Yuan J, Chen S. Pinpointing Morphology and Projection of Excitatory Neurons in Mouse Visual Cortex. Front Neurosci 2019; 13:912. [PMID: 31555081 PMCID: PMC6727359 DOI: 10.3389/fnins.2019.00912] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 08/16/2019] [Indexed: 01/10/2023] Open
Abstract
The excitatory neurons in the visual cortex are of great significance for us in understanding brain functions. However, the diverse neuron types and their morphological properties have not been fully deciphered. In this paper, we applied the brain-wide positioning system (BPS) to image the entire brain of two Thy1-eYFP H-line male mice at 0.2 μm × 0.2 μm × 1 μm voxel resolution. A total of 103 neurons were reconstructed in layers 5 and 6 of the visual cortex with single-axon-level resolution. Based on the complete topology of neurons and the inherent positioning function of the imaging method, we classified the observed neurons into six types according to their apical dendrites and somata location: star pyramidal cells in layer 5 (L5-sp), slender-tufted pyramidal cells in layer 5 (L5-st), tufted pyramidal cells in layer 5 (L5-tt), spiny stellate-like cells in layer 6 (L6-ss), star pyramidal cells in layer 6 (L6-sp), and slender-tufted pyramidal cells in layer 6 (L6-st). By examining the axonal projection patterns of individual neurons, they can be categorized into three modes: ipsilateral circuit connection neurons, callosal projection neurons and corticofugal projection neurons. Correlating the two types of classifications, we have found that there are at least two projection modes comprised in the former defined neuron types except for L5-tt. On the other hand, each projection mode may consist of four dendritic types defined in this study. The axon projection mode only partially correlates with the apical dendrite feature. This work has demonstrated a paradigm for resolving the visual cortex through single-neuron-level quantification and has shown potential to be extended to reveal the connectome of other defined sensory and motor systems.
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Affiliation(s)
- Yalun Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Siqi Jiang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Zhengchao Xu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Gong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Anan Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Miao Ren
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangning Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Hao Wu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Yuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Shangbin Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
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135
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Donovan LJ, Spencer WC, Kitt MM, Eastman BA, Lobur KJ, Jiao K, Silver J, Deneris ES. Lmx1b is required at multiple stages to build expansive serotonergic axon architectures. eLife 2019; 8:e48788. [PMID: 31355748 PMCID: PMC6685705 DOI: 10.7554/elife.48788] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/27/2019] [Indexed: 01/18/2023] Open
Abstract
Formation of long-range axons occurs over multiple stages of morphological maturation. However, the intrinsic transcriptional mechanisms that temporally control different stages of axon projection development are unknown. Here, we addressed this question by studying the formation of mouse serotonin (5-HT) axons, the exemplar of long-range profusely arborized axon architectures. We report that LIM homeodomain factor 1b (Lmx1b)-deficient 5-HT neurons fail to generate axonal projections to the forebrain and spinal cord. Stage-specific targeting demonstrates that Lmx1b is required at successive stages to control 5-HT axon primary outgrowth, selective routing, and terminal arborization. We show a Lmx1b→Pet1 regulatory cascade is temporally required for 5-HT arborization and upregulation of the 5-HT axon arborization gene, Protocadherin-alphac2, during postnatal development of forebrain 5-HT axons. Our findings identify a temporal regulatory mechanism in which a single continuously expressed transcription factor functions at successive stages to orchestrate the progressive development of long-range axon architectures enabling expansive neuromodulation.
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Affiliation(s)
- Lauren J Donovan
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - William C Spencer
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Meagan M Kitt
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Brent A Eastman
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Katherine J Lobur
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Kexin Jiao
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Jerry Silver
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Evan S Deneris
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
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136
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Jin J, Ravindran P, Di Meo D, Püschel AW. Igf1R/InsR function is required for axon extension and corpus callosum formation. PLoS One 2019; 14:e0219362. [PMID: 31318893 PMCID: PMC6638864 DOI: 10.1371/journal.pone.0219362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 06/21/2019] [Indexed: 12/02/2022] Open
Abstract
One of the earliest steps during the development of the nervous system is the establishment of neuronal polarity and the formation of an axon. The intrinsic mechanisms that promote axon formation have been extensively analyzed. However, much less is known about the extrinsic signals that initiate axon formation. One of the candidates for these signals is Insulin-like growth factor 1 (Igf1) that acts through the Igf1 (Igf1R) and insulin receptors (InsR). Since Igf1R and InsR may act redundantly we analyzed conditional cortex-specific knockout mice that are deficient for both Igf1r and Insr to determine if they regulate the development of the cortex and the formation of axons in vivo. Our results show that Igf1R/InsR function is required for the normal development of the embryonic hippocampus and cingulate cortex while the lateral cortex does not show apparent defects in the Igf1r;Insr knockout. In the cingulate cortex, the number of intermediate progenitors and deep layer neurons is reduced and the corpus callosum is absent at E17. However, cortical organization and axon formation are not impaired in knockout embryos. In culture, cortical and hippocampal neurons from Igf1r;Insr knockout embryos extend an axon but the length of this axon is severely reduced. Our results indicate that Igf1R/InsR function is required for brain development in a region-specific manner and promotes axon growth but is not essential for neuronal polarization and migration in the developing brain.
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Affiliation(s)
- Jing Jin
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
| | | | - Danila Di Meo
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
| | - Andreas W. Püschel
- Institut für Molekulare Zellbiologie, University of Münster, Münster, Germany
- Cells-in-Motion Cluster of Excellence, University of Münster, Münster, Germany
- * E-mail:
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137
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Polioudakis D, de la Torre-Ubieta L, Langerman J, Elkins AG, Shi X, Stein JL, Vuong CK, Nichterwitz S, Gevorgian M, Opland CK, Lu D, Connell W, Ruzzo EK, Lowe JK, Hadzic T, Hinz FI, Sabri S, Lowry WE, Gerstein MB, Plath K, Geschwind DH. A Single-Cell Transcriptomic Atlas of Human Neocortical Development during Mid-gestation. Neuron 2019; 103:785-801.e8. [PMID: 31303374 DOI: 10.1016/j.neuron.2019.06.011] [Citation(s) in RCA: 276] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/20/2019] [Accepted: 06/12/2019] [Indexed: 01/05/2023]
Abstract
We performed RNA sequencing on 40,000 cells to create a high-resolution single-cell gene expression atlas of developing human cortex, providing the first single-cell characterization of previously uncharacterized cell types, including human subplate neurons, comparisons with bulk tissue, and systematic analyses of technical factors. These data permit deconvolution of regulatory networks connecting regulatory elements and transcriptional drivers to single-cell gene expression programs, significantly extending our understanding of human neurogenesis, cortical evolution, and the cellular basis of neuropsychiatric disease. We tie cell-cycle progression with early cell fate decisions during neurogenesis, demonstrating that differentiation occurs on a transcriptomic continuum; rather than only expressing a few transcription factors that drive cell fates, differentiating cells express broad, mixed cell-type transcriptomes before telophase. By mapping neuropsychiatric disease genes to cell types, we implicate dysregulation of specific cell types in ASD, ID, and epilepsy. We developed CoDEx, an online portal to facilitate data access and browsing.
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Affiliation(s)
- Damon Polioudakis
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Luis de la Torre-Ubieta
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Justin Langerman
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Andrew G Elkins
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Xu Shi
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Jason L Stein
- Department of Genetics & UNC Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, NC, USA
| | - Celine K Vuong
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, USA
| | - Susanne Nichterwitz
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Melinda Gevorgian
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Biology, CSUN, Northridge, CA, USA
| | - Carli K Opland
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Daning Lu
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - William Connell
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Elizabeth K Ruzzo
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Jennifer K Lowe
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Tarik Hadzic
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Flora I Hinz
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Shan Sabri
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - William E Lowry
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, USA
| | - Mark B Gerstein
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA; Department of Computer Science, Yale University, New Haven, CT 06520, USA; Department of Statistics and Data Science, Yale University, New Haven, CT 06520, USA
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Daniel H Geschwind
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
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138
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Cell-Type Specificity of Callosally Evoked Excitation and Feedforward Inhibition in the Prefrontal Cortex. Cell Rep 2019; 22:679-692. [PMID: 29346766 PMCID: PMC5828174 DOI: 10.1016/j.celrep.2017.12.073] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/16/2017] [Accepted: 12/20/2017] [Indexed: 11/23/2022] Open
Abstract
Excitation and inhibition are highly specific in the cortex, with distinct synaptic connections made onto subtypes of projection neurons. The functional consequences of this selective connectivity depend on both synaptic strength and the intrinsic properties of targeted neurons but remain poorly understood. Here, we examine responses to callosal inputs at cortico-cortical (CC) and cortico-thalamic (CT) neurons in layer 5 of mouse prelimbic prefrontal cortex (PFC). We find callosally evoked excitation and feedforward inhibition are much stronger at CT neurons compared to neighboring CC neurons. Elevated inhibition at CT neurons reflects biased synaptic inputs from parvalbumin and somatostatin positive interneurons. The intrinsic properties of postsynaptic targets equalize excitatory and inhibitory response amplitudes but selectively accelerate decays at CT neurons. Feedforward inhibition further reduces response amplitude and balances action potential firing across these projection neurons. Our findings highlight the synaptic and cellular mechanisms regulating callosal recruitment of layer 5 microcircuits in PFC.
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139
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Rock C, Zurita H, Lebby S, Wilson CJ, Apicella AJ. Cortical Circuits of Callosal GABAergic Neurons. Cereb Cortex 2019; 28:1154-1167. [PMID: 28174907 DOI: 10.1093/cercor/bhx025] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
Anatomical studies have shown that the majority of callosal axons are glutamatergic. However, a small proportion of callosal axons are also immunoreactive for glutamic acid decarboxylase, an enzyme required for gamma-aminobutyric acid (GABA) synthesis and a specific marker for GABAergic neurons. Here, we test the hypothesis that corticocortical parvalbumin-expressing (CC-Parv) neurons connect the two hemispheres of multiple cortical areas, project through the corpus callosum, and are a functional part of the local cortical circuit. Our investigation of this hypothesis takes advantage of viral tracing and optogenetics to determine the anatomical and electrophysiological properties of CC-Parv neurons of the mouse auditory, visual, and motor cortices. We found a direct inhibitory pathway made up of parvalbumin-expressing (Parv) neurons which connects corresponding cortical areas (CC-Parv neurons → contralateral cortex). Like other Parv cortical neurons, these neurons provide local inhibition onto nearby pyramidal neurons and receive thalamocortical input. These results demonstrate a previously unknown long-range inhibitory circuit arising from a genetically defined type of GABAergic neuron that is engaged in interhemispheric communication.
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Affiliation(s)
- Crystal Rock
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Hector Zurita
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Sharmon Lebby
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Charles J Wilson
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
| | - Alfonso Junior Apicella
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio, Biosciences Building 1.03.26, One UTSA Circle, San Antonio, TX 78249, USA
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140
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Miller DJ, Bhaduri A, Sestan N, Kriegstein A. Shared and derived features of cellular diversity in the human cerebral cortex. Curr Opin Neurobiol 2019; 56:117-124. [PMID: 30677551 PMCID: PMC6996583 DOI: 10.1016/j.conb.2018.12.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/11/2018] [Accepted: 12/15/2018] [Indexed: 12/11/2022]
Abstract
The cerebral cortex is the hallmark of the mammalian nervous system, and its large size and cellular diversity in humans support our most sophisticated cognitive abilities. Although the basic cellular organization of the cortex is conserved across mammals, cells have diversified during evolution. An increasingly integrated taxonomy of cell types, especially with the advent of single-cell transcriptomic data, has revealed an unprecedented variety of human cortical cell subtypes. Here, we broadly review the cellular composition and diversity of the mammalian brain, and how progenitor pools generate cell subtypes during development. We then discuss human cortical cells that are distinct from rodent cells, as well as the challenges and advantages of using model systems to study human cell types in health and disease.
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Affiliation(s)
- Daniel J Miller
- Department of Neuroscience and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | - Aparna Bhaduri
- Department of Neurology and the Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco, San Francisco, CA, USA
| | - Nenad Sestan
- Department of Neuroscience and Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT, USA; Departments of Genetics, of Psychiatry, and of Comparative Medicine, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale Child Study Center, Yale School of Medicine, New Haven, CT, USA.
| | - Arnold Kriegstein
- Department of Neurology and the Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco, San Francisco, CA, USA.
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141
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Abstract
The corpus callosum is the largest of the 3 telencephalic commissures in eutherian (placental) mammals. Although the anterior commissure, and the hippocampal commissure before being pushed dorsally by the expanding frontal lobes, cross through the lamina reuniens (upper part of the lamina terminalis), the callosal fibers need a transient interhemispheric cellular bridge to cross. This review describes the molecular pathways that initiate the specification of the cells comprising this bridge, the specification of the callosal neurons, and the repulsive and attractive guidance molecules that convey the callosal axons toward, across, and away from the midline to connect with their targets.
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142
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Oberst P, Agirman G, Jabaudon D. Principles of progenitor temporal patterning in the developing invertebrate and vertebrate nervous system. Curr Opin Neurobiol 2019; 56:185-193. [PMID: 30999235 DOI: 10.1016/j.conb.2019.03.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 10/27/2022]
Abstract
During the development of the central nervous system, progenitors successively generate distinct types of neurons which assemble into the circuits that underlie our ability to interact with the environment. Spatial and temporal patterning mechanisms are partially evolutionarily conserved processes that allow generation of neuronal diversity from a limited set of progenitors. Here, we review examples of temporal patterning in neuronal progenitors in the Drosophila ventral nerve cord and in the mammalian cerebral cortex. We discuss cell-autonomous mechanisms and environmental influences on the temporal transitions of neuronal progenitors. Identifying the principles controlling the temporal specification of progenitors across species, as highlighted here, may help understand the evolutionary constraints over brain circuit design and function.
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Affiliation(s)
- Polina Oberst
- Department of Basic Neurosciences, University of Geneva, Switzerland
| | - Gulistan Agirman
- Department of Basic Neurosciences, University of Geneva, Switzerland; GIGA-Neurosciences, University of Liège, C.H.U. Sart-Tilman, Liège, Belgium
| | - Denis Jabaudon
- Department of Basic Neurosciences, University of Geneva, Switzerland; Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
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143
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Poulopoulos A, Murphy AJ, Ozkan A, Davis P, Hatch J, Kirchner R, Macklis JD. Subcellular transcriptomes and proteomes of developing axon projections in the cerebral cortex. Nature 2019; 565:356-360. [PMID: 30626971 DOI: 10.1038/s41586-018-0847-y] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/05/2018] [Indexed: 11/09/2022]
Abstract
The development of neural circuits relies on axon projections establishing diverse, yet well-defined, connections between areas of the nervous system. Each projection is formed by growth cones-subcellular specializations at the tips of growing axons, encompassing sets of molecules that control projection-specific growth, guidance, and target selection1. To investigate the set of molecules within native growth cones that form specific connections, here we developed growth cone sorting and subcellular RNA-proteome mapping, an approach that identifies and quantifies local transcriptomes and proteomes from labelled growth cones of single projections in vivo. Using this approach on the developing callosal projection of the mouse cerebral cortex, we mapped molecular enrichments in trans-hemispheric growth cones relative to their parent cell bodies, producing paired subcellular proteomes and transcriptomes from single neuron subtypes directly from the brain. These data provide generalizable proof-of-principle for this approach, and reveal molecular specializations of the growth cone, including accumulations of the growth-regulating kinase mTOR2, together with mRNAs that contain mTOR-dependent motifs3,4. These findings illuminate the relationships between subcellular distributions of RNA and protein in developing projection neurons, and provide a systems-level approach for the discovery of subtype- and stage-specific molecular substrates of circuit wiring, miswiring, and the potential for regeneration.
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Affiliation(s)
- Alexandros Poulopoulos
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA. .,Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Alexander J Murphy
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Abdulkadir Ozkan
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Patrick Davis
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - John Hatch
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Rory Kirchner
- Bioinformatics core, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA.
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144
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Klingler E, De la Rossa A, Fièvre S, Devaraju K, Abe P, Jabaudon D. A Translaminar Genetic Logic for the Circuit Identity of Intracortically Projecting Neurons. Curr Biol 2019; 29:332-339.e5. [DOI: 10.1016/j.cub.2018.11.071] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 10/11/2018] [Accepted: 11/29/2018] [Indexed: 11/26/2022]
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145
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Abstract
To understand how neurons assemble to form functional circuits, it is necessary to obtain a detailed knowledge of their diversity and to define the developmental specification programs that give rise to this diversity. Invertebrates and vertebrates appear to share common developmental principles of neuronal specification in which cascades of transcription factors temporally pattern progenitors, while spatial cues modify the outcomes of this temporal patterning. Here, we highlight these conserved mechanisms and describe how they are used in distinct neural structures. We present the questions that remain for a better understanding of neuronal specification. Single-cell RNA profiling approaches will potentially shed light on these questions, allowing not only the characterization of neuronal diversity in adult brains, but also the investigation of the developmental trajectories leading to the generation and maintenance of this diversity.
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Affiliation(s)
- Isabel Holguera
- Department of Biology, New York University, New York, NY 10003, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA. .,Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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146
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Kalebic N, Gilardi C, Albert M, Namba T, Long KR, Kostic M, Langen B, Huttner WB. Human-specific ARHGAP11B induces hallmarks of neocortical expansion in developing ferret neocortex. eLife 2018; 7:e41241. [PMID: 30484771 PMCID: PMC6303107 DOI: 10.7554/elife.41241] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 11/23/2018] [Indexed: 01/09/2023] Open
Abstract
The evolutionary increase in size and complexity of the primate neocortex is thought to underlie the higher cognitive abilities of humans. ARHGAP11B is a human-specific gene that, based on its expression pattern in fetal human neocortex and progenitor effects in embryonic mouse neocortex, has been proposed to have a key function in the evolutionary expansion of the neocortex. Here, we study the effects of ARHGAP11B expression in the developing neocortex of the gyrencephalic ferret. In contrast to its effects in mouse, ARHGAP11B markedly increases proliferative basal radial glia, a progenitor cell type thought to be instrumental for neocortical expansion, and results in extension of the neurogenic period and an increase in upper-layer neurons. Consequently, the postnatal ferret neocortex exhibits increased neuron density in the upper cortical layers and expands in both the radial and tangential dimensions. Thus, human-specific ARHGAP11B can elicit hallmarks of neocortical expansion in the developing ferret neocortex.
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Affiliation(s)
- Nereo Kalebic
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Carlotta Gilardi
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Mareike Albert
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Takashi Namba
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Katherine R Long
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Milos Kostic
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Barbara Langen
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
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147
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Lin HM, Kuang JX, Sun P, Li N, Lv X, Zhang YH. Reconstruction of Intratelencephalic Neurons in the Mouse Secondary Motor Cortex Reveals the Diverse Projection Patterns of Single Neurons. Front Neuroanat 2018; 12:86. [PMID: 30425624 PMCID: PMC6218457 DOI: 10.3389/fnana.2018.00086] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/01/2018] [Indexed: 12/13/2022] Open
Abstract
The secondary motor cortex (MOs) plays crucial roles in cognitive and executive processes and has reciprocal connections with numerous cortices in rodents. However, descriptions of the neuronal morphologies and projection patterns of the MOs at the level of a single neuron are lacking, severely hindering the comprehensive understanding of the wiring diagram of the MOs. Herein, we used a Cre-dependent adeno-associated virus (AAV) to fluorescently label ~80 pyramidal neurons nearby or in the MOs and acquired an uninterrupted whole-brain 3D dataset at a voxel resolution of 0.2 × 0.2 × 1 μm with a whole-brain fluorescence imaging system (fMOST). Based on our 3D dataset, we reconstructed the complete morphologies of 36 individual intratelencephalic (IT) neurons nearby or in the MOs and analyzed the projection patterns and projection strengths of these neurons at a single-neuron level based on several parameters, including the projection areas, the total number of branches, the fiber length, and the total number of terminal tips. We obtained a neuron with an axonal length of 318.43 mm, which is by far the longest reported axonal length. Our results show that all individual neurons in the MOs, regardless of whether they are located in layer 2/3 or layer 5, display diverse projection patterns and projection strengths, implying that these neurons might be involved in different brain circuits at different intensities. The results lay a solid foundation for exploring the relationship between neuronal morphologies and behavioral functions of the MOs at the level of a single neuron.
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Affiliation(s)
- Hui-Min Lin
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Xia Kuang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Pei Sun
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Ning Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaohua Lv
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Hui Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong, University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
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148
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Hirata T, Iwai L. Timing matters: A strategy for neurons to make diverse connections. Neurosci Res 2018; 138:79-83. [PMID: 30227163 DOI: 10.1016/j.neures.2018.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 08/21/2018] [Accepted: 08/21/2018] [Indexed: 11/18/2022]
Abstract
Neurogenesis proceeds like a continuous wave, in which each type of neurons is produced over a few days to several days. During this protracted time window, early-born and late-born neurons are sequentially produced with a considerable time lag. Even if they are identical in their genetic and molecular specifications, they could develop different characteristics under the influences of the timing of their birth. In this review, we discuss the potential influences of "timing" as a generic parameter affecting neuronal differentiation, particularly on axon guidance and connections. These ideas have rarely been tested experimentally, but may provide a new strategy by which phenotypic diversity is increased in neurons.
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Affiliation(s)
- Tatsumi Hirata
- Division of Brain Function, National Institute of Genetics, 1111 Yata, Mishima, 411-8540, Japan; SOKENDAI (Graduate University for Advanced Studies), Japan.
| | - Lena Iwai
- Division of Brain Function, National Institute of Genetics, 1111 Yata, Mishima, 411-8540, Japan
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149
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Yabut OR, Pleasure SJ. Sonic Hedgehog Signaling Rises to the Surface: Emerging Roles in Neocortical Development. Brain Plast 2018; 3:119-128. [PMID: 30151337 PMCID: PMC6091060 DOI: 10.3233/bpl-180064] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The mammalian neocortex is composed of a diverse population of neuronal and glial cells that are crucial for cognition and consciousness. Orchestration of molecular events that lead to the production of distinct cell lineages is now a major research focus. Recent studies in mammalian animal models reveal that Sonic Hedgehog (Shh) signaling plays crucial roles in this process. In this review, we will evaluate these studies and provide insights on how Shh signaling specifically influence cortical development, beyond its established roles in telencephalic patterning, by specifically focusing on its impact on cells derived from the cortical radial glial (RG) cells. We will also assess how these findings further advance our knowledge of neurological diseases and discuss potential roles of targeting Shh signaling in therapies.
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Affiliation(s)
- Odessa R Yabut
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.,Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Samuel J Pleasure
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.,Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA.,Programs in Neuroscience and Developmental Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Kavli Institute for Fundamental Neuroscience, University of California San Francisco, CA, USA
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150
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Ducharme P, Zarruk JG, David S, Paquin J. The ferroxidase ceruloplasmin influences Reelin processing, cofilin phosphorylation and neuronal organization in the developing brain. Mol Cell Neurosci 2018; 92:104-113. [PMID: 30077770 DOI: 10.1016/j.mcn.2018.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/10/2018] [Accepted: 07/30/2018] [Indexed: 12/09/2022] Open
Abstract
Ceruloplasmin (Cp) is an important extracellular regulator of iron metabolism. We showed previously that it stimulates Reelin proteolytic processing and cell aggregation in cultures of developing neurons. Reelin is a secreted protein required for the correct positioning of neurons in the brain. It is cleaved in vivo into N-terminally-derived 300K and 180K fragments through incompletely known mechanisms. One of Reelin signaling targets is the actin-binding protein cofilin, the phosphorylation of which is diminished in Reelin-deficient mice. This work looked for in vivo evidence of a relationship between Cp, Reelin and neuronal organization during brain development by analyzing wild-type and Cp-null mice. Cp as well as the full-length, 300K and 180K Reelin species appeared together in wild-type brains at embryonic day (E) 12.5 by immunoblotting. In wild-type compared to Cp-null brains, there was more 300K Reelin from E12.5 to E17.5, a period characterized by extensive, radially directed neuronal migration in the cerebral cortex. Immunofluorescence labeling of tissue sections at E16.5 revealed the localization of Cp with radial glia and meningeal cells adjacent to Reelin-producing Cajal-Retzius neurons, underlining the proximity of Cp and Reelin. Cofilin phosphorylation was seen starting at E10.5-E12.5 and lasted longer until postnatal day 7 in wild-type than Cp-null mice. Finally, using CUX1 as a marker revealed defective accumulation of neurons in layers II/III in neonatal and adult Cp-null mice. These results combined with our earlier work point to a potentially new role of Cp in Reelin processing and signaling and neuronal organization in the cerebral cortex in vivo.
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Affiliation(s)
- Philippe Ducharme
- Département de Chimie and Centre BioMed, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montreal, Quebec H3C 3P8, Canada.
| | - Juan G Zarruk
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
| | - Samuel David
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Center, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
| | - Joanne Paquin
- Département de Chimie and Centre BioMed, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montreal, Quebec H3C 3P8, Canada.
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