1
|
Dasgupta A, Reagor CC, Paik SP, Snow LM, Jacobo A, Hudspeth AJ. Semaphorin7A patterns neural circuitry in the lateral line of the zebrafish. eLife 2024; 12:RP89926. [PMID: 39133541 PMCID: PMC11318972 DOI: 10.7554/elife.89926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024] Open
Abstract
In a developing nervous system, axonal arbors often undergo complex rearrangements before neural circuits attain their final innervation topology. In the lateral line sensory system of the zebrafish, developing sensory axons reorganize their terminal arborization patterns to establish precise neural microcircuits around the mechanosensory hair cells. However, a quantitative understanding of the changes in the sensory arbor morphology and the regulators behind the microcircuit assembly remain enigmatic. Here, we report that Semaphorin7A (Sema7A) acts as an important mediator of these processes. Utilizing a semi-automated three-dimensional neurite tracing methodology and computational techniques, we have identified and quantitatively analyzed distinct topological features that shape the network in wild-type and Sema7A loss-of-function mutants. In contrast to those of wild-type animals, the sensory axons in Sema7A mutants display aberrant arborizations with disorganized network topology and diminished contacts to hair cells. Moreover, ectopic expression of a secreted form of Sema7A by non-hair cells induces chemotropic guidance of sensory axons. Our findings propose that Sema7A likely functions both as a juxtracrine and as a secreted cue to pattern neural circuitry during sensory organ development.
Collapse
Affiliation(s)
- Agnik Dasgupta
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
| | - Caleb C Reagor
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
- Tri-Institutional PhD Program in Computational Biology and MedicineNew YorkUnited States
| | - Sang Peter Paik
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
| | - Lauren M Snow
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
| | - Adrian Jacobo
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
- Chan Zuckerberg Biohub San FranciscoSan FranciscoUnited States
| | - AJ Hudspeth
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller UniversityNew York CityUnited States
| |
Collapse
|
2
|
Zhou J, Zhang Z, Wu M, Liu H, Pang Y, Bartlett A, Peng Z, Ding W, Rivkin A, Lagos WN, Williams E, Lee CT, Miyazaki PA, Aldridge A, Zeng Q, Salinda JLA, Claffey N, Liem M, Fitzpatrick C, Boggeman L, Yao Z, Smith KA, Tasic B, Altshul J, Kenworthy MA, Valadon C, Nery JR, Castanon RG, Patne NS, Vu M, Rashid M, Jacobs M, Ito T, Osteen J, Emerson N, Lee J, Cho S, Rink J, Huang HH, Pinto-Duartec A, Dominguez B, Smith JB, O'Connor C, Zeng H, Chen S, Lee KF, Mukamel EA, Jin X, Margarita Behrens M, Ecker JR, Callaway EM. Brain-wide correspondence of neuronal epigenomics and distant projections. Nature 2023; 624:355-365. [PMID: 38092919 PMCID: PMC10719087 DOI: 10.1038/s41586-023-06823-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 11/01/2023] [Indexed: 12/17/2023]
Abstract
Single-cell analyses parse the brain's billions of neurons into thousands of 'cell-type' clusters residing in different brain structures1. Many cell types mediate their functions through targeted long-distance projections allowing interactions between specific cell types. Here we used epi-retro-seq2 to link single-cell epigenomes and cell types to long-distance projections for 33,034 neurons dissected from 32 different regions projecting to 24 different targets (225 source-to-target combinations) across the whole mouse brain. We highlight uses of these data for interrogating principles relating projection types to transcriptomics and epigenomics, and for addressing hypotheses about cell types and connections related to genetics. We provide an overall synthesis with 926 statistical comparisons of discriminability of neurons projecting to each target for every source. We integrate this dataset into the larger BRAIN Initiative Cell Census Network atlas, composed of millions of neurons, to link projection cell types to consensus clusters. Integration with spatial transcriptomics further assigns projection-enriched clusters to smaller source regions than the original dissections. We exemplify this by presenting in-depth analyses of projection neurons from the hypothalamus, thalamus, hindbrain, amygdala and midbrain to provide insights into properties of those cell types, including differentially expressed genes, their associated cis-regulatory elements and transcription-factor-binding motifs, and neurotransmitter use.
Collapse
Affiliation(s)
- Jingtian Zhou
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA, USA
| | - Zhuzhu Zhang
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
- Department of Human Genetics, The University of Chicago, Chicago, IL, USA
| | - May Wu
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Hanqing Liu
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Yan Pang
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Anna Bartlett
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Zihao Peng
- School of Mathematics and Computer Science, Nanchang University, Nanchang, China
- Henan Engineering Research Center of Intelligent Technology and Application, Henan University, Kaifeng, China
| | - Wubin Ding
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Angeline Rivkin
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Will N Lagos
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Elora Williams
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Cheng-Ta Lee
- Peptide Biology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Paula Assakura Miyazaki
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Andrew Aldridge
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Qiurui Zeng
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - J L Angelo Salinda
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Naomi Claffey
- Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Michelle Liem
- Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Conor Fitzpatrick
- Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Lara Boggeman
- Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Zizhen Yao
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Jordan Altshul
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Mia A Kenworthy
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Cynthia Valadon
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Joseph R Nery
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Rosa G Castanon
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Neelakshi S Patne
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Minh Vu
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Mohammad Rashid
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Matthew Jacobs
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Tony Ito
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Julia Osteen
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nora Emerson
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Jasper Lee
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Silvia Cho
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Jon Rink
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Hsiang-Hsuan Huang
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - António Pinto-Duartec
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Bertha Dominguez
- Peptide Biology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Jared B Smith
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Carolyn O'Connor
- Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Shengbo Chen
- Henan Engineering Research Center of Intelligent Technology and Application, Henan University, Kaifeng, China
- School of Computer and Information Engineering, Henan University, Kaifeng, China
| | - Kuo-Fen Lee
- Peptide Biology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Eran A Mukamel
- Department of Cognitive Science, University of California San Diego, La Jolla, CA, USA
| | - Xin Jin
- Center for Motor Control and Disease, Key Laboratory of Brain Functional Genomics, East China Normal University, Shanghai, China
- NYU-ECNU Institute of Brain and Cognitive Science, New York University Shanghai, Shanghai, China
| | - M Margarita Behrens
- Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Joseph R Ecker
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, USA.
| | - Edward M Callaway
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA.
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA.
| |
Collapse
|
3
|
Young TR, Yamamoto M, Kikuchi SS, Yoshida AC, Abe T, Inoue K, Johansen JP, Benucci A, Yoshimura Y, Shimogori T. Thalamocortical control of cell-type specificity drives circuits for processing whisker-related information in mouse barrel cortex. Nat Commun 2023; 14:6077. [PMID: 37770450 PMCID: PMC10539368 DOI: 10.1038/s41467-023-41749-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 09/15/2023] [Indexed: 09/30/2023] Open
Abstract
Excitatory spiny stellate neurons are prominently featured in the cortical circuits of sensory modalities that provide high salience and high acuity representations of the environment. These specialized neurons are considered developmentally linked to bottom-up inputs from the thalamus, however, the molecular mechanisms underlying their diversification and function are unknown. Here, we investigated this in mouse somatosensory cortex, where spiny stellate neurons and pyramidal neurons have distinct roles in processing whisker-evoked signals. Utilizing spatial transcriptomics, we identified reciprocal patterns of gene expression which correlated with these cell-types and were linked to innervation by specific thalamic inputs during development. Genetic manipulation that prevents the acquisition of spiny stellate fate highlighted an important role for these neurons in processing distinct whisker signals within functional cortical columns, and as a key driver in the formation of specific whisker-related circuits in the cortex.
Collapse
Affiliation(s)
- Timothy R Young
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Mariko Yamamoto
- Division of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Satomi S Kikuchi
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Aya C Yoshida
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takaya Abe
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 6500047, Japan
| | - Kenichi Inoue
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 6500047, Japan
| | - Joshua P Johansen
- Laboratory for Neural Circuitry of Learning and Memory, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Andrea Benucci
- Laboratory for Neural Circuits and Behavior, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Yumiko Yoshimura
- Division of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Tomomi Shimogori
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
| |
Collapse
|
4
|
Witteveen IF, McCoy E, Holsworth TD, Shen CZ, Chang W, Nance MG, Belkowitz AR, Dougald A, Puglia MH, Ribic A. Preterm birth accelerates the maturation of spontaneous and resting activity in the visual cortex. Front Integr Neurosci 2023; 17:1149159. [PMID: 37255843 PMCID: PMC10225509 DOI: 10.3389/fnint.2023.1149159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/25/2023] [Indexed: 06/01/2023] Open
Abstract
Prematurity is among the leading risks for poor neurocognitive outcomes. The brains of preterm infants show alterations in structure and electrical activity, but the underlying circuit mechanisms are unclear. To address this, we performed a cross-species study of the electrophysiological activity in the visual cortices of prematurely born infants and mice. Using electroencephalography (EEG) in a sample of healthy preterm (N = 29) and term (N = 28) infants, we found that the maturation of the aperiodic EEG component was accelerated in the preterm cohort, with a significantly flatter 1/f slope when compared to the term infants. The flatter slope was a result of decreased spectral power in the theta and alpha bands and was correlated with the degree of prematurity. To determine the circuit and cellular changes that potentially mediate the changes in 1/f slope after preterm birth, we used in vivo electrophysiology in preterm mice and found that, similar to infants, preterm birth results in a flattened 1/f slope. We analyzed neuronal activity in the visual cortex of preterm (N = 6) and term (N = 9) mice and found suppressed spontaneous firing of neurons. Using immunohistochemistry, we further found an accelerated maturation of inhibitory circuits. In both preterm mice and infants, the functional maturation of the cortex was accelerated, underscoring birth as a critical checkpoint in cortical maturation. Our study points to a potential mechanism of preterm birth-related changes in resting neural activity, highlighting the utility of a cross-species approach in studying the neural circuit mechanisms of preterm birth-related neurodevelopmental conditions.
Collapse
Affiliation(s)
- Isabelle F. Witteveen
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
| | - Emily McCoy
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Troy D. Holsworth
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
| | - Catherine Z. Shen
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
| | - Winnie Chang
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Madelyn G. Nance
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Allison R. Belkowitz
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Avery Dougald
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Meghan H. Puglia
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Adema Ribic
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
| |
Collapse
|
5
|
Witteveen IF, McCoy E, Holsworth TD, Shen CZ, Chang W, Nance MG, Belkowitz AR, Dougald A, Puglia MH, Ribic A. Preterm birth accelerates the maturation of spontaneous and resting activity in the visual cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524993. [PMID: 36711801 PMCID: PMC9882279 DOI: 10.1101/2023.01.20.524993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Prematurity is among the leading risks for poor neurocognitive outcomes. The brains of preterm infants show alterations in structure and electrical activity, but the underlying circuit mechanisms are unclear. To address this, we performed a cross-species study of the electrophysiological activity in the visual cortices of prematurely born infants and mice. Using electroencephalography (EEG) in a sample of healthy preterm (N=29) and term (N=28) infants, we found that the maturation of the aperiodic EEG component was accelerated in the preterm cohort, with a significantly flatter 1/f slope when compared to the term infants. The flatter slope was a result of decreased spectral power in the theta and alpha bands and was correlated with the degree of prematurity. To determine the circuit and cellular changes that potentially mediate the changes in 1/f slope after preterm birth, we used in vivo electrophysiology in preterm mice and found that, similar to infants, preterm birth results in a flattened 1/f slope. We analyzed neuronal activity in the visual cortex of preterm mice (N=6 preterm and 9 term mice) and found suppressed spontaneous firing of neurons. Using immunohistochemistry, we further found an accelerated maturation of inhibitory circuits. In both preterm mice and infants, the functional maturation of the cortex was accelerated, underscoring birth as a critical checkpoint in cortical maturation. Our study points to a potential mechanism of preterm birth-related changes in resting neural activity, highlighting the utility of a cross-species approach in studying the neural circuit mechanisms of preterm birth-related neurodevelopmental conditions.
Collapse
Affiliation(s)
- Isabelle F. Witteveen
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA 22904
| | - Emily McCoy
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA 22904
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA 22903
| | - Troy D. Holsworth
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA 22904
| | - Catherine Z. Shen
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA 22904
| | - Winnie Chang
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Madelyn G. Nance
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Allison R. Belkowitz
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Avery Dougald
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Meghan H. Puglia
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA 22903
- Department of Neurology, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Adema Ribic
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA 22904
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA 22903
| |
Collapse
|
6
|
Wang CF, Yang JW, Zhuang ZH, Hsing HW, Luhmann HJ, Chou SJ. Activity-dependent feedback regulation of thalamocortical axon development by Lhx2 in cortical layer 4 neurons. Cereb Cortex 2023; 33:1693-1707. [PMID: 35512682 DOI: 10.1093/cercor/bhac166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Establishing neuronal circuits requires interactions between pre- and postsynaptic neurons. While presynaptic neurons were shown to play instructive roles for the postsynaptic neurons, how postsynaptic neurons provide feedback to regulate the presynaptic neuronal development remains elusive. To elucidate the mechanisms for circuit formation, we study the development of barrel cortex (the primary sensory cortex, S1), whose development is instructed by presynaptic thalamocortical axons (TCAs). In the first postnatal weeks, TCA terminals arborize in layer (L) 4 to fill in the barrel center, but it is unclear how TCA development is regulated. Here, we reported that the deletion of Lhx2 specifically in the cortical neurons in the conditional knockout (cKO) leads to TCA arborization defects, which is accompanied with deficits in sensory-evoked and spontaneous cortical activities and impaired lesion-induced plasticity following early whisker follicle ablation. Reintroducing Lhx2 back in L4 neurons in cKO ameliorated TCA arborization and plasticity defects. By manipulating L4 neuronal activity, we further demonstrated that Lhx2 induces TCA arborization via an activity-dependent mechanism. Additionally, we identified the extracellular signaling protein Sema7a as an activity-dependent downstream target of Lhx2 in regulating TCA branching. Thus, we discovered a bottom-up feedback mechanism for the L4 neurons to regulate TCA development.
Collapse
Affiliation(s)
- Chia-Fang Wang
- Neuroscience Program of Academia Sinica (NPAS), Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Zi-Hui Zhuang
- Neuroscience Program of Academia Sinica (NPAS), Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hsiang-Wei Hsing
- Neuroscience Program of Academia Sinica (NPAS), Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Shen-Ju Chou
- Neuroscience Program of Academia Sinica (NPAS), Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
7
|
Brown JA, Lee AJ, Pasquini L, Seeley WW. A dynamic gradient architecture generates brain activity states. Neuroimage 2022; 261:119526. [PMID: 35914669 PMCID: PMC9585924 DOI: 10.1016/j.neuroimage.2022.119526] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 11/24/2022] Open
Abstract
The human brain exhibits a diverse yet constrained range of activity states. While these states can be faithfully represented in a low-dimensional latent space, our understanding of the constitutive functional anatomy is still evolving. Here we applied dimensionality reduction to task-free and task fMRI data to address whether latent dimensions reflect intrinsic systems and if so, how these systems may interact to generate different activity states. We find that each dimension represents a dynamic activity gradient, including a primary unipolar sensory-association gradient underlying the global signal. The gradients appear stable across individuals and cognitive states, while recapitulating key functional connectivity properties including anticorrelation, modularity, and regional hubness. We then use dynamical systems modeling to show that gradients causally interact via state-specific coupling parameters to create distinct brain activity patterns. Together, these findings indicate that a set of dynamic, intrinsic spatial gradients interact to determine the repertoire of possible brain activity states.
Collapse
Affiliation(s)
- Jesse A Brown
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA.
| | - Alex J Lee
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
| | - Lorenzo Pasquini
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
| | - William W Seeley
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
| |
Collapse
|
8
|
Molecular mechanisms regulating the spatial configuration of neurites. Semin Cell Dev Biol 2022; 129:103-114. [PMID: 35248463 DOI: 10.1016/j.semcdb.2022.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 02/08/2023]
Abstract
Precise neural networks, composed of axons and dendrites, are the structural basis for information processing in the brain. Therefore, the correct formation of neurites is critical for accurate neural function. In particular, the three-dimensional structures of dendrites vary greatly among neuron types, and the unique shape of each dendrite is tightly linked to specific synaptic connections with innervating axons and is correlated with its information processing. Although many systems are involved in neurite formation, the developmental mechanisms that control the orientation, size, and arborization pattern of neurites definitively defines their three-dimensional structure in tissues. In this review, we summarize these regulatory mechanisms that establish proper spatial configurations of neurites, especially dendrites, in invertebrates and vertebrates.
Collapse
|
9
|
Fourneau J, Bareyre FM. Semaphorin7A: its role in the control of serotonergic circuits and functional recovery following spinal cord injury. Neural Regen Res 2021; 17:959-962. [PMID: 34558508 PMCID: PMC8552865 DOI: 10.4103/1673-5374.324828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Serotonin is a monoamine neurotransmitter synthetized in various populations of brainstem neurons. In the spinal cord, descending serotonergic projections regulate postural muscle tone, locomotion and rhythm and coordination of movements via the Central Pattern Generator. Following a spinal cord injury, serotonergic projections to the lumbar spinal cord, where the Central Pattern Generators are located, are interrupted resulting in devastating locomotor impairments and changes in the expression and activation of serotonin and its spinal receptors. The molecular cues that control the precise patterning and targeting of serotonergic inputs onto Central Pattern Generator networks in healthy animals or after injury are still unknown. In our recent research work, we have been particularly interested in Semaphorin7A, which belongs to the Semaphorins family involved in guiding growing axons and controlling plasticity of synaptic connections. In this review, we discuss the role of Semaphorin7A signaling as an important molecular actor that instructs the patterning of serotonin inputs to spinal Central Pattern Generator networks. We show that Semaphorin7A controls the wiring of descending serotonin axons in the spinal cord. Our results reveal that mistargetting of serotonin fibers in the spinal cord is compensated in healthy uninjured Semaphorin7A deficient mice so that their gross locomotion proceeds accurately. We also demonstrate that when the system is challenged with a spinal lesion, the pattern of post-injury serotonin expression is significantly altered in Semaphorin7A deficient mice with specific ectopic targeting of serotonin fibers in the lumbar spinal cord. Compensatory mechanisms in place in uninjured Semaphorin7A deficient mice are lost and injured Semaphorin7A deficient mice exhibit a worsening of their post-injury locomotor abilities. Our findings identify Semaphorin7A as a critical determinant of serotonergic circuit formation in healthy or spinal cord injured mice.
Collapse
Affiliation(s)
- Julie Fourneau
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich, Germany
| | - Florence M Bareyre
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München; Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
10
|
Pantazopoulos H, Katsel P, Haroutunian V, Chelini G, Klengel T, Berretta S. Molecular signature of extracellular matrix pathology in schizophrenia. Eur J Neurosci 2021; 53:3960-3987. [PMID: 33070392 PMCID: PMC8359380 DOI: 10.1111/ejn.15009] [Citation(s) in RCA: 36] [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: 04/28/2020] [Accepted: 10/04/2020] [Indexed: 02/06/2023]
Abstract
Growing evidence points to a critical involvement of the extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Decreases of perineuronal nets (PNNs) and altered expression of chondroitin sulphate proteoglycans (CSPGs) in glial cells have been identified in several brain regions. GWAS data have identified several SZ vulnerability variants of genes encoding for ECM molecules. Given the potential relevance of ECM functions to the pathophysiology of this disorder, it is necessary to understand the extent of ECM changes across brain regions, their region- and sex-specificity and which ECM components contribute to these changes. We tested the hypothesis that the expression of genes encoding for ECM molecules may be broadly disrupted in SZ across several cortical and subcortical brain regions and include key ECM components as well as factors such as ECM posttranslational modifications and regulator factors. Gene expression profiling of 14 neocortical brain regions, caudate, putamen and hippocampus from control subjects (n = 14/region) and subjects with SZ (n = 16/region) was conducted using Affymetrix microarray analysis. Analysis across brain regions revealed widespread dysregulation of ECM gene expression in cortical and subcortical brain regions in SZ, impacting several ECM functional key components. SRGN, CD44, ADAMTS1, ADAM10, BCAN, NCAN and SEMA4G showed some of the most robust changes. Region-, sex- and age-specific gene expression patterns and correlation with cognitive scores were also detected. Taken together, these findings contribute to emerging evidence for large-scale ECM dysregulation in SZ and point to molecular pathways involved in PNN decreases, glial cell dysfunction and cognitive impairment in SZ.
Collapse
Affiliation(s)
- Harry Pantazopoulos
- Department of Neurobiology and Anatomical SciencesUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Pavel Katsel
- Department of PsychiatryThe Icahn School of Medicine at Mount SinaiNew YorkNYUSA
- Department of NeuroscienceThe Icahn School of Medicine at Mount SinaiNew YorkNYUSA
- Mental Illness Research Education ClinicalCenters of Excellence (MIRECC)JJ Peters VA Medical CenterBronxNYUSA
| | - Vahram Haroutunian
- Department of PsychiatryThe Icahn School of Medicine at Mount SinaiNew YorkNYUSA
- Department of NeuroscienceThe Icahn School of Medicine at Mount SinaiNew YorkNYUSA
- Mental Illness Research Education ClinicalCenters of Excellence (MIRECC)JJ Peters VA Medical CenterBronxNYUSA
| | - Gabriele Chelini
- Translational Neuroscience LaboratoryMclean HospitalBelmontMAUSA
- Department of PsychiatryHarvard Medical SchoolBostonMAUSA
| | - Torsten Klengel
- Department of PsychiatryHarvard Medical SchoolBostonMAUSA
- Translational Molecular Genomics LaboratoryMclean HospitalBelmontMAUSA
- Department of PsychiatryUniversity Medical Center GöttingenGöttingenGermany
| | - Sabina Berretta
- Translational Neuroscience LaboratoryMclean HospitalBelmontMAUSA
- Department of PsychiatryHarvard Medical SchoolBostonMAUSA
- Program in NeuroscienceHarvard Medical SchoolBostonMAUSA
| |
Collapse
|
11
|
Carulli D, de Winter F, Verhaagen J. Semaphorins in Adult Nervous System Plasticity and Disease. Front Synaptic Neurosci 2021; 13:672891. [PMID: 34045951 PMCID: PMC8148045 DOI: 10.3389/fnsyn.2021.672891] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
Semaphorins, originally discovered as guidance cues for developing axons, are involved in many processes that shape the nervous system during development, from neuronal proliferation and migration to neuritogenesis and synapse formation. Interestingly, the expression of many Semaphorins persists after development. For instance, Semaphorin 3A is a component of perineuronal nets, the extracellular matrix structures enwrapping certain types of neurons in the adult CNS, which contribute to the closure of the critical period for plasticity. Semaphorin 3G and 4C play a crucial role in the control of adult hippocampal connectivity and memory processes, and Semaphorin 5A and 7A regulate adult neurogenesis. This evidence points to a role of Semaphorins in the regulation of adult neuronal plasticity. In this review, we address the distribution of Semaphorins in the adult nervous system and we discuss their function in physiological and pathological processes.
Collapse
Affiliation(s)
- Daniela Carulli
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
- Department of Neuroscience Rita Levi-Montalcini and Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Turin, Italy
| | - Fred de Winter
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Joost Verhaagen
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
| |
Collapse
|
12
|
Inoue N, Nishizumi H, Ooyama R, Mogi K, Nishimori K, Kikusui T, Sakano H. The olfactory critical period is determined by activity-dependent Sema7A/PlxnC1 signaling within glomeruli. eLife 2021; 10:65078. [PMID: 33780330 PMCID: PMC8007213 DOI: 10.7554/elife.65078] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 03/18/2021] [Indexed: 12/26/2022] Open
Abstract
In mice, early exposure to environmental odors affects social behaviors later in life. A signaling molecule, Semaphorin 7A (Sema7A), is induced in the odor-responding olfactory sensory neurons. Plexin C1 (PlxnC1), a receptor for Sema7A, is expressed in mitral/tufted cells, whose dendrite-localization is restricted to the first week after birth. Sema7A/PlxnC1 signaling promotes post-synaptic events and dendrite selection in mitral/tufted cells, resulting in glomerular enlargement that causes an increase in sensitivity to the experienced odor. Neonatal odor experience also induces positive responses to the imprinted odor. Knockout and rescue experiments indicate that oxytocin in neonates is responsible for imposing positive quality on imprinted memory. In the oxytocin knockout mice, the sensitivity to the imprinted odor increases, but positive responses cannot be promoted, indicating that Sema7A/PlxnC1 signaling and oxytocin separately function. These results give new insights into our understanding of olfactory imprinting during the neonatal critical period.
Collapse
Affiliation(s)
- Nobuko Inoue
- Department of Brain Function, School of Medical Sciences, University of Fukui, Matsuoka, Japan
| | - Hirofumi Nishizumi
- Department of Brain Function, School of Medical Sciences, University of Fukui, Matsuoka, Japan
| | - Rumi Ooyama
- Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Kazutaka Mogi
- Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Katsuhiko Nishimori
- Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Takefumi Kikusui
- Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Hitoshi Sakano
- Department of Brain Function, School of Medical Sciences, University of Fukui, Matsuoka, Japan
| |
Collapse
|
13
|
Abstract
Maternal care, including by non-biological parents, is important for offspring survival1-8. Oxytocin1,2,9-15, which is released by the hypothalamic paraventricular nucleus (PVN), is a critical maternal hormone. In mice, oxytocin enables neuroplasticity in the auditory cortex for maternal recognition of pup distress15. However, it is unclear how initial parental experience promotes hypothalamic signalling and cortical plasticity for reliable maternal care. Here we continuously monitored the behaviour of female virgin mice co-housed with an experienced mother and litter. This documentary approach was synchronized with neural recordings from the virgin PVN, including oxytocin neurons. These cells were activated as virgins were enlisted in maternal care by experienced mothers, who shepherded virgins into the nest and demonstrated pup retrieval. Virgins visually observed maternal retrieval, which activated PVN oxytocin neurons and promoted alloparenting. Thus rodents can acquire maternal behaviour by social transmission, providing a mechanism for adapting the brains of adult caregivers to infant needs via endogenous oxytocin.
Collapse
|
14
|
Loy K, Fourneau J, Meng N, Denecke C, Locatelli G, Bareyre FM. Semaphorin 7A restricts serotonergic innervation and ensures recovery after spinal cord injury. Cell Mol Life Sci 2020; 78:2911-2927. [PMID: 33128105 PMCID: PMC8004489 DOI: 10.1007/s00018-020-03682-w] [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: 05/26/2020] [Revised: 09/15/2020] [Accepted: 10/09/2020] [Indexed: 11/25/2022]
Abstract
Descending serotonergic (5-HT) projections originating from the raphe nuclei form an important input to the spinal cord that control basic locomotion. The molecular signals that control this projection pattern are currently unknown. Here, we identify Semaphorin7A (Sema7A) as a critical cue that restricts serotonergic innervation in the spinal cord. Sema7A deficient mice show a marked increase in serotonergic fiber density in all layers of the spinal cord while the density of neurons expressing the corresponding 5-HTR2α receptor remains unchanged. These alterations appear to be successfully compensated as no obvious changes in rhythmic locomotion and skilled stepping are observed in adult mice. When the system is challenged with a spinal lesion, serotonergic innervation patterns in both Sema7A-deficient and -competent mice evolve over time with excessive innervation becoming most pronounced in the dorsal horn of Sema7A-deficient mice. These altered serotonergic innervation patterns correlate with diminished functional recovery that predominantly affects rhythmic locomotion. Our findings identify Sema7A as a critical regulator of serotonergic circuit formation in the injured spinal cord.
Collapse
Affiliation(s)
- Kristina Loy
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany.,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany.,Graduate School of Systemic Neurosciences, LMU Munich, 82152, Planegg-Martinsried, Germany
| | - Julie Fourneau
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany.,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany
| | - Ning Meng
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany.,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany
| | - Carmen Denecke
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany.,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany.,Graduate School of Systemic Neurosciences, LMU Munich, 82152, Planegg-Martinsried, Germany
| | - Giuseppe Locatelli
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany.,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany
| | - Florence M Bareyre
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, 81377, Munich, Germany. .,Faculty of Medicine, Biomedical Center Munich (BMC), LMU Munich, 82152, Planegg-Martinsried, Germany. .,Munich Cluster of Systems Neurology (SyNergy), 81377, Munich, Germany.
| |
Collapse
|
15
|
Erzurumlu RS, Gaspar P. How the Barrel Cortex Became a Working Model for Developmental Plasticity: A Historical Perspective. J Neurosci 2020; 40:6460-6473. [PMID: 32817388 PMCID: PMC7486654 DOI: 10.1523/jneurosci.0582-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 01/08/2023] Open
Abstract
For half a century now, the barrel cortex of common laboratory rodents has been an exceptionally useful model for studying the formation of topographically organized maps, neural patterning, and plasticity, both in development and in maturity. We present a historical perspective on how barrels were discovered, and how thereafter, they became a workhorse for developmental neuroscientists and for studies on brain plasticity and activity-dependent modeling of brain circuits. What is particularly remarkable about this sensory system is a cellular patterning that is induced by signals derived from the sensory receptors surrounding the snout whiskers and transmitted centrally to the brainstem (barrelettes), the thalamus (barreloids), and the neocortex (barrels). Injury to the sensory receptors shortly after birth leads to predictable pattern alterations at all levels of the system. Mouse genetics have increased our understanding of how barrels are constructed and revealed the interplay of the molecular programs that direct axon growth and cell specification, with activity-dependent mechanisms. There is an ever-rising interest in this sensory system as a neurobiological model to study development of somatotopy, patterning, and plasticity at both the morphologic and physiological levels. This article is part of a group of articles commemorating the 50th anniversary of the Society for Neuroscience.
Collapse
Affiliation(s)
- Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Patricia Gaspar
- Institut National de la Santé et de la Recherche Médicale, Paris Brain Institute, Sorbonne Universités, Paris, France 75013
| |
Collapse
|
16
|
Vitalis T, Dauphinot L, Gressens P, Potier MC, Mariani J, Gaspar P. RORα Coordinates Thalamic and Cortical Maturation to Instruct Barrel Cortex Development. Cereb Cortex 2019; 28:3994-4007. [PMID: 29040410 DOI: 10.1093/cercor/bhx262] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The retinoic acid-related orphan receptor alpha (RORα) is well-known for its role in cerebellar development and maturation as revealed in staggerer mice. However, its potential involvement in the development of other brain regions has hardly been assessed. Here, we describe a new role of RORα in the development of primary somatosensory maps. Staggerer mice showed a complete disruption of barrels in the somatosensory cortex and of barreloids in the thalamus. This phenotype results from a severe reduction of thalamocortical axon (TCA) branching and a defective maturation of layer IV cortical neurons during postnatal development. Conditional deletion of RORα was conducted in the thalamus or the cortex to determine the specific contribution of RORα in each of these structures to these phenotypes. This showed that RORα is cell-autonomously required in the thalamus for the organization of TCAs into periphery-related clusters and in the somatosensory cortex for the dendritic maturation of layer IV neurons. Microarray analyses revealed that Sema7a, Neph, and Adcy8 are RORα regulated genes that could be implicated in TCA and cortical maturation. Overall, our study outlines a new role of RORα for the coordinated maturation of the somatosensory thalamus and cortex during the assembly of columnar barrel structures.
Collapse
Affiliation(s)
- Tania Vitalis
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Université Pierre et Marie Curie, Sorbonne Université, Paris, France
| | - Luce Dauphinot
- Université Pierre et Marie Curie, Sorbonne Université, Paris, France
- CNRS UMR 7225, INSERM U1127, Institut du Cerveau et de la Moelle, Paris, France
| | - Pierre Gressens
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Marie-Claude Potier
- Université Pierre et Marie Curie, Sorbonne Université, Paris, France
- CNRS UMR 7225, INSERM U1127, Institut du Cerveau et de la Moelle, Paris, France
| | - Jean Mariani
- Université Pierre et Marie Curie, Sorbonne Université, Paris, France
- CNRS, UMR 8256, Institut de Biologie de Paris Seine (IBPS), Biological adaptation and ageing (B2A), Team Brain Development, Repair and Ageing, Paris, France
- APHP, DHU FAST, Institut de la Longévité, Ivry-Sur-Seine, France
| | - Patricia Gaspar
- Université Pierre et Marie Curie, Sorbonne Université, Paris, France
- INSERM, UMR-S839, Institut du Fer à Moulin, Paris, France
| |
Collapse
|
17
|
Deng J, Xu T, Yang J, Zhang KM, Li Q, Yu XY, Li R, Fu J, Jiang Q, Ma JX, Chen YM. Sema7A, a brain immune regulator, regulates seizure activity in PTZ-kindled epileptic rats. CNS Neurosci Ther 2019; 26:101-116. [PMID: 31179640 PMCID: PMC6930824 DOI: 10.1111/cns.13181] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/15/2019] [Accepted: 05/21/2019] [Indexed: 12/11/2022] Open
Abstract
Aims Semaphorin7A (Sema7A) plays an important role in the immunoregulation of the brain. In our study, we aimed to investigate the expression patterns of Sema7A in epilepsy and further explore the roles of Sema7A in the regulation of seizure activity and the inflammatory response in PTZ‐kindled epileptic rats. Methods First, we measured the Sema7A expression levels in patients with temporal lobe epilepsy (TLE) and in rats of a PTZ‐kindled epilepsy rat model. Second, to explore the role of Sema7A in the regulation of seizure activity, we conducted epilepsy‐related behavioral experiments after knockdown and overexpression of Sema7A in the rat hippocampal dentate gyrus (DG). Possible Sema7A‐related brain immune regulators (eg, ERK phosphorylation, IL‐6, and TNF‐α) were also investigated. Additionally, the growth of mossy fibers was visualized by anterograde tracing using injections of biotinylated dextran amine (BDA) into the DG region. Results Sema7A expression was markedly upregulated in the brain tissues of TLE patients and rats of the epileptic model after PTZ kindling. After knockdown of Sema7A, seizure activity was suppressed based on the latency to the first epileptic seizure, number of seizures, and duration of seizures. Conversely, overexpression of Sema7A promoted seizures. Overexpression of Sema7A increased the expression levels of the inflammatory cytokines, IL‐6 and TNF‐α, ERK phosphorylation, and growth of mossy fibers in PTZ‐kindled epileptic rats. Conclusion Sema7A is upregulated in the epileptic brain and plays a potential role in the regulation of seizure activity in PTZ‐kindled epileptic rats, which may be related to neuroinflammation. Sema7A promotes the inflammatory cytokines TNF‐α and IL‐6 as well as the growth of mossy fibers through the ERK pathway, suggesting that Sema7A may promote seizures by increasing neuroinflammation and activating pathological neural circuits. Sema7A plays a critical role in epilepsy and could be a potential therapeutic target for this neurological disorder.
Collapse
Affiliation(s)
- Jing Deng
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China.,Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chonqing, China
| | - Tao Xu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Juan Yang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Ke-Ming Zhang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Qi Li
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Xin-Yuan Yu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Rong Li
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Jie Fu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Qian Jiang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| | - Jing-Xi Ma
- Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chonqing, China.,Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
| | - Yang-Mei Chen
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chonqing, China
| |
Collapse
|
18
|
Simi A, Studer M. Developmental genetic programs and activity-dependent mechanisms instruct neocortical area mapping. Curr Opin Neurobiol 2018; 53:96-102. [DOI: 10.1016/j.conb.2018.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/07/2018] [Accepted: 06/14/2018] [Indexed: 12/18/2022]
|
19
|
Movassagh H, Koussih L, Shan L, Gounni AS. The regulatory role of semaphorin 3E in allergic asthma. Int J Biochem Cell Biol 2018; 106:68-73. [PMID: 30447428 DOI: 10.1016/j.biocel.2018.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 11/06/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
Abstract
Semaphorins were originally discovered as essential mediators involved in regulation of axonal growth during development of the nervous system. Ubiquitously expressed on various organs, they control several cellular functions by regulating essential signaling pathways. Among them, semaphorin3E binds plexinD1 as the primary receptor and mediates regulatory effects on cell migration, proliferation, and angiogenesis considered major physiological and pathological features in health and disease. Recent in vitro and in vivo experimental evidence demonstrate a key regulator role of semaphorin3E on airway inflammation, hyperresponsivenss and remodeling in allergic asthma. Herein, we aim to provide a broad overview of the biology of semaphorin family and review the recently discovered regulatory role of semaphorin3E in modulating immune cells and structural cells function in the airways. These findings support the concept of semaphorin3E/plexinD1 axis as a therapeutic target in allergic asthma.
Collapse
Affiliation(s)
- Hesam Movassagh
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Latifa Koussih
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lianyu Shan
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Abdelilah S Gounni
- Department of Immunology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
| |
Collapse
|
20
|
Gaspar P, Renier N. Constraints on somatosensory map development: mutants lead the way. Curr Opin Neurobiol 2018; 53:43-49. [PMID: 29753205 DOI: 10.1016/j.conb.2018.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/23/2018] [Accepted: 04/24/2018] [Indexed: 12/31/2022]
Abstract
In the rodent somatosensory system, the disproportionally large whisker representation and their specialization into barrel-shaped units in the different sensory relays has offered experimentalists with an ideal tool to identify mechanisms involved in brain map formation. These combine three intertwined constraints: Firstly, fasciculation of the incoming axons; secondly, early neural activity; finally, molecular patterning. Sophisticated genetic manipulations in mice have now allowed dissecting these mechanisms with greater accuracy. Here we discuss some recent papers that provided novel insights into how these different mapping rules and constraints interact to shape the barrel map.
Collapse
Affiliation(s)
- Patricia Gaspar
- Inserm, U839, Institut du Fer à Moulin, Paris, France; Sorbonne Universités, Paris, France.
| | - Nicolas Renier
- Sorbonne Universités, Paris, France; Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Inserm, CNRS, Paris, France
| |
Collapse
|
21
|
Synaptic and circuit development of the primary sensory cortex. Exp Mol Med 2018; 50:1-9. [PMID: 29628505 PMCID: PMC5938038 DOI: 10.1038/s12276-018-0029-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 01/06/2023] Open
Abstract
Animals, including humans, optimize their primary sensory cortex through the use of input signals, which allow them to adapt to the external environment and survive. The time window at the beginning of life in which external input signals are connected sensitively and strongly to neural circuit optimization is called the critical period. The critical period has attracted the attention of many neuroscientists due to the rapid activity-/experience-dependent circuit development that occurs, which is clearly differentiated from other developmental time periods and brain areas. This process involves various types of GABAergic inhibitory neurons, the extracellular matrix, neuromodulators, transcription factors, and neurodevelopmental factors. In this review, I discuss recent progress regarding the biological nature of the critical period that contribute to a better understanding of brain development.
Collapse
|
22
|
Lovell PV, Huizinga NA, Friedrich SR, Wirthlin M, Mello CV. The constitutive differential transcriptome of a brain circuit for vocal learning. BMC Genomics 2018; 19:231. [PMID: 29614959 PMCID: PMC5883274 DOI: 10.1186/s12864-018-4578-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/02/2018] [Indexed: 01/25/2023] Open
Abstract
Background The ability to imitate the vocalizations of other organisms, a trait known as vocal learning, is shared by only a few organisms, including humans, where it subserves the acquisition of speech and language, and 3 groups of birds. In songbirds, vocal learning requires the coordinated activity of a set of specialized brain nuclei referred to as the song control system. Recent efforts have revealed some of the genes that are expressed in these vocal nuclei, however a thorough characterization of the transcriptional specializations of this system is still missing. We conducted a rigorous and comprehensive analysis of microarrays, and conducted a separate analysis of 380 genes by in situ hybridizations in order to identify molecular specializations of the major nuclei of the song system of zebra finches (Taeniopygia guttata), a songbird species. Results Our efforts identified more than 3300 genes that are differentially regulated in one or more vocal nuclei of adult male birds compared to the adjacent brain regions. Bioinformatics analyses provided insights into the possible involvement of these genes in molecular pathways such as cellular morphogenesis, intrinsic cellular excitability, neurotransmission and neuromodulation, axonal guidance and cela-to-cell interactions, and cell survival, which are known to strongly influence the functional properties of the song system. Moreover, an in-depth analysis of specific gene families with known involvement in regulating the development and physiological properties of neuronal circuits provides further insights into possible modulators of the song system. Conclusion Our study represents one of the most comprehensive molecular characterizations of a brain circuit that evolved to facilitate a learned behavior in a vertebrate. The data provide novel insights into possible molecular determinants of the functional properties of the song control circuitry. It also provides lists of compelling targets for pharmacological and genetic manipulations to elucidate the molecular regulation of song behavior and vocal learning. Electronic supplementary material The online version of this article (10.1186/s12864-018-4578-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Peter V Lovell
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 Sam Jackson Park Rd L470, Portland, OR, USA
| | - Nicole A Huizinga
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 Sam Jackson Park Rd L470, Portland, OR, USA
| | - Samantha R Friedrich
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 Sam Jackson Park Rd L470, Portland, OR, USA
| | - Morgan Wirthlin
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 Sam Jackson Park Rd L470, Portland, OR, USA.,Current affiliation: Computational Biology, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Claudio V Mello
- Department of Behavioral Neuroscience, Oregon Health and Sciences University, 3181 Sam Jackson Park Rd L470, Portland, OR, USA.
| |
Collapse
|
23
|
Abstract
In mammals, taste buds typically contain 50-100 tightly packed taste receptor cells (TRCs) representing all five basic qualities: sweet, sour, bitter, salty and umami1,2. Notably, mature taste cells have life spans of only 5-20 days, and consequently, are constantly replenished by differentiation of taste stem cells3. Given the importance of establishing and maintaining appropriate connectivity between TRCs and their partner ganglion neurons (i.e. ensuring that a labeled line from sweet TRCs connects to sweet neurons, bitter TRCs to bitter neurons, sour to sour, etc.), we examined how new connections are specified to retain fidelity of signal transmission. Our results show that bitter and sweet TRCs provide instructive signals to bitter and sweet target neurons via different guidance molecules (Sema3A and Sema7A)4-6. Here, we demonstrate that targeted expression of Sema3A or Sema7A in different classes of TRCs produce peripheral taste systems with miswired sweet or bitter cells. Indeed, we engineered animals whereby bitter neurons now respond to sweet tastants, sweet neurons respond to bitter, or with sweet neurons responding to sour stimuli. Together, these results uncover the basic logic of the wiring of the taste system at the periphery, and illustrate how a labeled-line sensory circuit preserves signaling integrity despite rapid and stochastic turnover of receptor cells.
Collapse
|
24
|
Neural Glycosylphosphatidylinositol-Anchored Proteins in Synaptic Specification. Trends Cell Biol 2017; 27:931-945. [PMID: 28743494 DOI: 10.1016/j.tcb.2017.06.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 12/15/2022]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins are a specialized class of lipid-associated neuronal membrane proteins that perform diverse functions in the dynamic control of axon guidance, synaptic adhesion, cytoskeletal remodeling, and localized signal transduction, particularly at lipid raft domains. Recent studies have demonstrated that a subset of GPI-anchored proteins act as critical regulators of synapse development by modulating specific synaptic adhesion pathways via direct interactions with key synapse-organizing proteins. Additional studies have revealed that alteration of these regulatory mechanisms may underlie various brain disorders. In this review, we highlight the emerging role of GPI-anchored proteins as key synapse organizers that aid in shaping the properties of various types of synapses and circuits in mammals.
Collapse
|
25
|
Bibollet-Bahena O, Okafuji T, Hokamp K, Tear G, Mitchell KJ. A dual-strategy expression screen for candidate connectivity labels in the developing thalamus. PLoS One 2017; 12:e0177977. [PMID: 28558017 PMCID: PMC5448750 DOI: 10.1371/journal.pone.0177977] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 05/05/2017] [Indexed: 12/13/2022] Open
Abstract
The thalamus or “inner chamber” of the brain is divided into ~30 discrete nuclei, with highly specific patterns of afferent and efferent connectivity. To identify genes that may direct these patterns of connectivity, we used two strategies. First, we used a bioinformatics pipeline to survey the predicted proteomes of nematode, fruitfly, mouse and human for extracellular proteins containing any of a list of motifs found in known guidance or connectivity molecules. Second, we performed clustering analyses on the Allen Developing Mouse Brain Atlas data to identify genes encoding surface proteins expressed with temporal profiles similar to known guidance or connectivity molecules. In both cases, we then screened the resultant genes for selective expression patterns in the developing thalamus. These approaches identified 82 candidate connectivity labels in the developing thalamus. These molecules include many members of the Ephrin, Eph-receptor, cadherin, protocadherin, semaphorin, plexin, Odz/teneurin, Neto, cerebellin, calsyntenin and Netrin-G families, as well as diverse members of the immunoglobulin (Ig) and leucine-rich receptor (LRR) superfamilies, receptor tyrosine kinases and phosphatases, a variety of growth factors and receptors, and a large number of miscellaneous membrane-associated or secreted proteins not previously implicated in axonal guidance or neuronal connectivity. The diversity of their expression patterns indicates that thalamic nuclei are highly differentiated from each other, with each one displaying a unique repertoire of these molecules, consistent with a combinatorial logic to the specification of thalamic connectivity.
Collapse
Affiliation(s)
| | - Tatsuya Okafuji
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Karsten Hokamp
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Guy Tear
- Department of Developmental Neurobiology, New Hunt’s House, Guy’s Campus, King’s College, London, United Kingdom
| | - Kevin J. Mitchell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
- * E-mail:
| |
Collapse
|
26
|
Jongbloets BC, Lemstra S, Schellino R, Broekhoven MH, Parkash J, Hellemons AJCGM, Mao T, Giacobini P, van Praag H, De Marchis S, Ramakers GMJ, Pasterkamp RJ. Stage-specific functions of Semaphorin7A during adult hippocampal neurogenesis rely on distinct receptors. Nat Commun 2017; 8:14666. [PMID: 28281529 PMCID: PMC5353663 DOI: 10.1038/ncomms14666] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023] Open
Abstract
The guidance protein Semaphorin7A (Sema7A) is required for the proper development of the immune and nervous systems. Despite strong expression in the mature brain, the role of Sema7A in the adult remains poorly defined. Here we show that Sema7A utilizes different cell surface receptors to control the proliferation and differentiation of neural progenitors in the adult hippocampal dentate gyrus (DG), one of the select regions of the mature brain where neurogenesis occurs. PlexinC1 is selectively expressed in early neural progenitors in the adult mouse DG and mediates the inhibitory effects of Sema7A on progenitor proliferation. Subsequently, during differentiation of adult-born DG granule cells, Sema7A promotes dendrite growth, complexity and spine development through β1-subunit-containing integrin receptors. Our data identify Sema7A as a key regulator of adult hippocampal neurogenesis, providing an example of how differential receptor usage spatiotemporally controls and diversifies the effects of guidance cues in the adult brain.
Collapse
Affiliation(s)
- Bart C. Jongbloets
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Suzanne Lemstra
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Roberta Schellino
- Dipartimento di Scienze della Vita e Biologia dei Sistemi and Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10100 Torino, Italy
| | - Mark H. Broekhoven
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Jyoti Parkash
- Centre for Animal Sciences, School of Basic and Applied Sciences, Central University Punjab, City Campus, Mansa Road, Bathinda 151001, India
| | - Anita J. C. G. M. Hellemons
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Paolo Giacobini
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, 59045 Lille, France
- University of Lille, 59045 Lille, France
| | - Henriette van Praag
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Silvia De Marchis
- Dipartimento di Scienze della Vita e Biologia dei Sistemi and Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10100 Torino, Italy
| | - Geert M. J. Ramakers
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - R. Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| |
Collapse
|
27
|
Wagener RJ, Witte M, Guy J, Mingo-Moreno N, Kügler S, Staiger JF. Thalamocortical Connections Drive Intracortical Activation of Functional Columns in the Mislaminated Reeler Somatosensory Cortex. Cereb Cortex 2015; 26:820-37. [PMID: 26564256 PMCID: PMC4712806 DOI: 10.1093/cercor/bhv257] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Neuronal wiring is key to proper neural information processing. Tactile information from the rodent's whiskers reaches the cortex via distinct anatomical pathways. The lemniscal pathway relays whisking and touch information from the ventral posteromedial thalamic nucleus to layer IV of the primary somatosensory “barrel” cortex. The disorganized neocortex of the reeler mouse is a model system that should severely compromise the ingrowth of thalamocortical axons (TCAs) into the cortex. Moreover, it could disrupt intracortical wiring. We found that neuronal intermingling within the reeler barrel cortex substantially exceeded previous descriptions, leading to the loss of layers. However, viral tracing revealed that TCAs still specifically targeted transgenically labeled spiny layer IV neurons. Slice electrophysiology and optogenetics proved that these connections represent functional synapses. In addition, we assessed intracortical activation via immediate-early-gene expression resulting from a behavioral exploration task. The cellular composition of activated neuronal ensembles suggests extensive similarities in intracolumnar information processing in the wild-type and reeler brains. We conclude that extensive ectopic positioning of neuronal partners can be compensated for by cell-autonomous mechanisms that allow for the establishment of proper connectivity. Thus, genetic neuronal fate seems to be of greater importance for correct cortical wiring than radial neuronal position.
Collapse
Affiliation(s)
- Robin J Wagener
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Mirko Witte
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Julien Guy
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Nieves Mingo-Moreno
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Sebastian Kügler
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany Department of Neurology, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| |
Collapse
|
28
|
Plexin-B3 suppresses excitatory and promotes inhibitory synapse formation in rat hippocampal neurons. Exp Cell Res 2015; 335:269-78. [PMID: 25989221 DOI: 10.1016/j.yexcr.2015.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/23/2015] [Accepted: 05/10/2015] [Indexed: 11/21/2022]
Abstract
Molecular mechanisms underlying synaptogenesis and synaptic plasticity have become one of the main topics in neurobiology. Increasing evidence suggests that axon guidance molecules including semaphorins and plexins participate in synapse formation and elimination. Although class B plexins are widely expressed in the brain, their role in the nervous system remains poorly characterized. We previously identified that B-plexins modulate microtubule dynamics and through this impact dendrite growth in rat hippocampal neurons. Here, we demonstrate that Plexin-B2 and Plexin-B3 are present in dendrites, but do not localize in synapses. We find that overexpression of all B-plexins leads to decreased volume of excitatory synapses, and at the same time Plexin-B1 and Plexin-B3 promote inhibitory synapse assembly. Plexin-B3 mutants revealed that these processes use different downstream pathways. While elimination of excitatory synapses is the result of Plexin-B3 binding to microtubule end binding proteins EB1 and EB3, the increase in inhibitory synapses is mediated by regulation of Ras and Rho GTPases. Overall, our findings demonstrate that Plexin-B3 contributes to regulating synapse formation.
Collapse
|
29
|
Giacobini P. Shaping the Reproductive System: Role of Semaphorins in Gonadotropin-Releasing Hormone Development and Function. Neuroendocrinology 2015; 102:200-15. [PMID: 25967979 DOI: 10.1159/000431021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/28/2015] [Indexed: 11/19/2022]
Abstract
The semaphorin proteins, which contribute to the morphogenesis and homeostasis of a wide range of systems, are among the best-studied families of guidance cues. Much recent research has focused on the role of semaphorins in the development and adult activity of hormone systems and, reciprocally, how circulating reproductive hormones regulate their expression and function. Specifically, several reports have focused on the molecular mechanisms underlying the effects of semaphorins on the migration, survival and structural and functional plasticity of neurons that secrete gonadotropin-releasing hormone (GnRH), essential for the acquisition and maintenance of reproductive competence in mammals. Alterations in the development of this neuroendocrine system lead to anomalous or absent GnRH secretion, resulting in heterogeneous reproductive disorders such as congenital hypogonadotropic hypogonadism (CHH) or other conditions characterized by infertility or subfertility. This review summarizes current knowledge of the role of semaphorins and their receptors on the development, differentiation and plasticity of the GnRH system. In addition, the involvement of genetic deficits in semaphorin signaling in some forms of CHH in humans is discussed.
Collapse
Affiliation(s)
- Paolo Giacobini
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, School of Medicine, University of Lille, and Institut de Médecine Prédictive et de Recherche Thérapeutique, IFR114, Lille, France
| |
Collapse
|