1
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Saraswathy VM, Zhou L, Mokalled MH. Single-cell analysis of innate spinal cord regeneration identifies intersecting modes of neuronal repair. Nat Commun 2024; 15:6808. [PMID: 39147780 PMCID: PMC11327264 DOI: 10.1038/s41467-024-50628-y] [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: 11/23/2023] [Accepted: 07/11/2024] [Indexed: 08/17/2024] Open
Abstract
Adult zebrafish have an innate ability to recover from severe spinal cord injury. Here, we report a comprehensive single nuclear RNA sequencing atlas that spans 6 weeks of regeneration. We identify cooperative roles for adult neurogenesis and neuronal plasticity during spinal cord repair. Neurogenesis of glutamatergic and GABAergic neurons restores the excitatory/inhibitory balance after injury. In addition, a transient population of injury-responsive neurons (iNeurons) show elevated plasticity 1 week post-injury. We found iNeurons are injury-surviving neurons that acquire a neuroblast-like gene expression signature after injury. CRISPR/Cas9 mutagenesis showed iNeurons are required for functional recovery and employ vesicular trafficking as an essential mechanism that underlies neuronal plasticity. This study provides a comprehensive resource of the cells and mechanisms that direct spinal cord regeneration and establishes zebrafish as a model of plasticity-driven neural repair.
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Affiliation(s)
- Vishnu Muraleedharan Saraswathy
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Lili Zhou
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Mayssa H Mokalled
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA.
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA.
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2
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Saied-Santiago K, Baxter M, Mathiaparanam J, Granato M. Serotonin neuromodulation directs optic nerve regeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.12.607648. [PMID: 39185204 PMCID: PMC11343150 DOI: 10.1101/2024.08.12.607648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Optic nerve (ON) regeneration in mammalian systems is limited by an overshadowing dominance of inhibitory factors. This has severely hampered the identification of pro- regenerative pathways. Here, we take advantage of the regenerative capacity of larval zebrafish to identify pathways that promote ON regeneration. From a small molecule screen, we identified modulators of serotonin (5-HT) signaling that inhibit ON regeneration. We find several serotonin type-1 receptor genes are expressed in RGC neurons during regeneration and that inhibiting 5- HT1 receptors or components of the 5-HT pathway selectively impedes ON regeneration. We show that 5-HT1 receptor signaling is dispensable during ON development yet is critical for regenerating axons to emerge from the injury site. Blocking 5-HT receptors once ON axons have crossed the chiasm does not inhibit regeneration, suggesting a selective role for 5-HT receptor signaling early during ON regeneration. Finally, we show that agonist-mediated activation of 5-HT1 receptors leads to enhanced and ectopic axonal regrowth. Combined, our results provide evidence for mechanisms through which serotonin-dependent neuromodulation directs ON regeneration in vivo. Summary Statement 5-HT1 receptors selectively promote early optic nerve regrowth in zebrafish but are dispensable during development. Serotonin receptor-dependent modulation instructs regenerating optic nerve axons toward the brain in vivo.
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3
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Zhang C, Bo R, Zhou T, Chen N, Yuan Y. The raphe nuclei are the early lesion site of gastric α-synuclein propagation to the substantia nigra. Acta Pharm Sin B 2024; 14:2057-2076. [PMID: 38799632 PMCID: PMC11119576 DOI: 10.1016/j.apsb.2024.01.015] [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] [Received: 09/23/2023] [Revised: 12/14/2023] [Accepted: 01/05/2024] [Indexed: 05/29/2024] Open
Abstract
Parkinson's disease (PD) is a neurodegeneration disease with α-synuclein accumulated in the substantia nigra pars compacta (SNpc) and most of the dopaminergic neurons are lost in SNpc while patients are diagnosed with PD. Exploring the pathology at an early stage contributes to the development of the disease-modifying strategy. Although the "gut-brain" hypothesis is proposed to explain the underlying mechanism, where the earlier lesioned site in the brain of gastric α-synuclein and how α-synuclein further spreads are not fully understood. Here we report that caudal raphe nuclei (CRN) are the early lesion site of gastric α-synuclein propagating through the spinal cord, while locus coeruleus (LC) and substantia nigra pars compacta (SNpc) were further affected over a time frame of 7 months. Pathological α-synuclein propagation via CRN leads to neuron loss and disordered neuron activity, accompanied by abnormal motor and non-motor behavior. Potential neuron circuits are observed among CRN, LC, and SNpc, which contribute to the venerability of dopaminergic neurons in SNpc. These results show that CRN is the key region for the gastric α-synuclein spread to the midbrain. Our study provides valuable details for the "gut-brain" hypothesis and proposes a valuable PD model for future research on early PD intervention.
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Affiliation(s)
| | | | - Tiantian Zhou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Materia Medica, Beijing 100050, China
| | - Naihong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Materia Medica, Beijing 100050, China
| | - Yuhe Yuan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Materia Medica, Beijing 100050, China
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4
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Finkel Z, Esteban F, Rodriguez B, Clifford T, Joseph A, Alostaz H, Dalmia M, Gutierrez J, Tamasi MJ, Zhang SM, Simone J, Petekci H, Nath S, Escott M, Garg SK, Gormley AJ, Kumar S, Gulati S, Cai L. AAV6 mediated Gsx1 expression in neural stem progenitor cells promotes neurogenesis and restores locomotor function after contusion spinal cord injury. Neurotherapeutics 2024; 21:e00362. [PMID: 38664194 DOI: 10.1016/j.neurot.2024.e00362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/29/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024] Open
Abstract
Genomic screened homeobox 1 (Gsx1 or Gsh1) is a neurogenic transcription factor required for the generation of excitatory and inhibitory interneurons during spinal cord development. In the adult, lentivirus (LV) mediated Gsx1 expression promotes neural regeneration and functional locomotor recovery in a mouse model of lateral hemisection spinal cord injury (SCI). The LV delivery method is clinically unsafe due to insertional mutations to the host DNA. In addition, the most common clinical case of SCI is contusion/compression. In this study, we identify that adeno-associated virus serotype 6 (AAV6) preferentially infects neural stem/progenitor cells (NSPCs) in the injured spinal cord. Using a rat model of contusion SCI, we demonstrate that AAV6 mediated Gsx1 expression promotes neurogenesis, increases the number of neuroblasts/immature neurons, restores excitatory/inhibitory neuron balance and serotonergic neuronal activity through the lesion core, and promotes locomotor functional recovery. Our findings support that AAV6 preferentially targets NSPCs for gene delivery and confirmed Gsx1 efficacy in clinically relevant rat model of contusion SCI.
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Affiliation(s)
- Zachary Finkel
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Fatima Esteban
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Brianna Rodriguez
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Tanner Clifford
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Adelina Joseph
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Hani Alostaz
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Mridul Dalmia
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Juan Gutierrez
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA; University of California, Santa Barbara, CA 93106, USA
| | - Matthew J Tamasi
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Samuel Ming Zhang
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Jonah Simone
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Hafize Petekci
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Susmita Nath
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Miriam Escott
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Shivam Kumar Garg
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Adam J Gormley
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Suneel Kumar
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA
| | - Sonia Gulati
- NeuroNovus Therapeutics Inc., 135 E 57th St., New York, NY 10022, USA
| | - Li Cai
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Rd, Piscataway, NJ 08854, USA; NeuroNovus Therapeutics Inc., 135 E 57th St., New York, NY 10022, USA.
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5
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Zhao Y, Huang CX, Gu Y, Zhao Y, Ren W, Wang Y, Chen J, Guan NN, Song J. Serotonergic modulation of vigilance states in zebrafish and mice. Nat Commun 2024; 15:2596. [PMID: 38519480 PMCID: PMC10959952 DOI: 10.1038/s41467-024-47021-0] [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: 10/22/2023] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
Vigilance refers to being alertly watchful or paying sustained attention to avoid potential threats. Animals in vigilance states reduce locomotion and have an enhanced sensitivity to aversive stimuli so as to react quickly to dangers. Here we report that an unconventional 5-HT driven mechanism operating at neural circuit level which shapes the internal state underlying vigilance behavior in zebrafish and male mice. The neural signature of internal vigilance state was characterized by persistent low-frequency high-amplitude neuronal synchrony in zebrafish dorsal pallium and mice prefrontal cortex. The neuronal synchronization underlying vigilance was dependent on intense release of 5-HT induced by persistent activation of either DRN 5-HT neuron or local 5-HT axon terminals in related brain regions via activation of 5-HTR7. Thus, we identify a mechanism of vigilance behavior across species that illustrates the interplay between neuromodulators and neural circuits necessary to shape behavior states.
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Affiliation(s)
- Yang Zhao
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Chun-Xiao Huang
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yiming Gu
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yacong Zhao
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Wenjie Ren
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yutong Wang
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Jinjin Chen
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Na N Guan
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China.
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China.
- Frontiers Science Center for Intelligent Autonomous Systems, Tongji University, Shanghai, China.
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Jianren Song
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China.
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China.
- Frontiers Science Center for Intelligent Autonomous Systems, Tongji University, Shanghai, China.
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
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6
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Shen Y, Chen X, Song Z, Yao H, Han A, Zhang Y, Cai Y, Hu B. MicroRNA-9 promotes axon regeneration of mauthner-cell in zebrafish via her6/ calcium activity pathway. Cell Mol Life Sci 2024; 81:104. [PMID: 38411738 PMCID: PMC10899279 DOI: 10.1007/s00018-024-05117-2] [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: 10/30/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 02/28/2024]
Abstract
MicroRNA (miRNA), functioning as a post-transcriptional regulatory element, plays a significant role in numerous regulatory mechanisms and serves as a crucial intrinsic factor influencing axon regeneration. Prior investigations have elucidated the involvement of miRNA-9 in various processes, however, its specific contribution to axon regeneration in the central nervous system (CNS) remains uncertain. Hence, the zebrafish Mauthner axon regeneration model was employed to manipulate the expression of miRNA-9 in single cells, revealing that upregulation of miRNA-9 facilitated axon regeneration. Additionally, her6, a downstream target gene of miRNA-9, was identified as a novel gene associated with axon regeneration. Suppression of her6 resulted in enhanced Mauthner axon regeneration, as evidenced by the significantly improved regenerative capacity observed in her6 knockout zebrafish. In addition, modulation of her6 expression affects intracellular calcium levels in neurons and promoting her6 expression leads to a decrease in calcium levels in vivo using the new NEMOf calcium indicator. Moreover, the administration of the neural activity activator, pentylenetetrazol (PTZ) partially compensated for the inhibitory effect of her6 overexpression on the calcium level and promoted axon regeneration. Taken together, our study revealed a role for miRNA-9 in the process of axon regeneration in the CNS, which improved intracellular calcium activity and promoted axon regeneration by inhibiting the expression of downstream target gene her6. In our study, miRNA-9 emerged as a novel and intriguing target in the intricate regulation of axon regeneration and offered compelling evidence for the intricate relationship between calcium activity and the facilitation of axon regeneration.
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Affiliation(s)
- Yueru Shen
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Xinghan Chen
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Zheng Song
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Huaitong Yao
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Along Han
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Yawen Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Yuan Cai
- First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Bing Hu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China.
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
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7
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Cucun G, Köhler M, Pfitsch S, Rastegar S. Insights into the mechanisms of neuron generation and specification in the zebrafish ventral spinal cord. FEBS J 2024; 291:646-662. [PMID: 37498183 DOI: 10.1111/febs.16913] [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: 05/02/2023] [Revised: 06/20/2023] [Accepted: 07/25/2023] [Indexed: 07/28/2023]
Abstract
The vertebrate nervous system is composed of a wide range of neurons and complex synaptic connections, raising the intriguing question of how neuronal diversity is generated. The spinal cord provides an excellent model for exploring the mechanisms governing neuronal diversity due to its simple neural network and the conserved molecular processes involved in neuron formation and specification during evolution. This review specifically examines two distinct progenitor domains present in the zebrafish ventral spinal cord: the lateral floor plate (LFP) and the p2 progenitor domain. The LFP is responsible for the production of GABAergic Kolmer-Agduhr neurons (KA″), glutamatergic V3 neurons, and intraspinal serotonergic neurons, while the p2 domain generates V2 precursors that subsequently differentiate into three unique subpopulations of V2 neurons, namely glutamatergic V2a, GABAergic V2b, and glycinergic V2s. Based on recent findings, we will examine the fundamental signaling pathways and transcription factors that play a key role in the specification of these diverse neurons and neuronal subtypes derived from the LFP and p2 progenitor domains.
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Affiliation(s)
- Gokhan Cucun
- Institute for Biological and Chemical Systems - Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
| | - Melina Köhler
- Institute for Biological and Chemical Systems - Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
| | - Sabrina Pfitsch
- Institute for Biological and Chemical Systems - Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
| | - Sepand Rastegar
- Institute for Biological and Chemical Systems - Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
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8
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Muraleedharan Saraswathy V, Zhou L, Mokalled MH. Single-cell analysis of innate spinal cord regeneration identifies intersecting modes of neuronal repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541505. [PMID: 37292638 PMCID: PMC10245778 DOI: 10.1101/2023.05.19.541505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Adult zebrafish have an innate ability to recover from severe spinal cord injury. Here, we report a comprehensive single nuclear RNA sequencing atlas that spans 6 weeks of regeneration. We identify cooperative roles for adult neurogenesis and neuronal plasticity during spinal cord repair. Neurogenesis of glutamatergic and GABAergic neurons restores the excitatory/inhibitory balance after injury. In addition, transient populations of injury-responsive neurons (iNeurons) show elevated plasticity between 1 and 3 weeks post-injury. Using cross-species transcriptomics and CRISPR/Cas9 mutagenesis, we found iNeurons are injury-surviving neurons that share transcriptional similarities with a rare population of spontaneously plastic mouse neurons. iNeurons are required for functional recovery and employ vesicular trafficking as an essential mechanism that underlies neuronal plasticity. This study provides a comprehensive resource of the cells and mechanisms that direct spinal cord regeneration and establishes zebrafish as a model of plasticity-driven neural repair.
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9
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Mays KC, Haiman JH, Janušonis S. An experimental platform for stochastic analyses of single serotonergic fibers in the mouse brain. Front Neurosci 2023; 17:1241919. [PMID: 37869509 PMCID: PMC10587471 DOI: 10.3389/fnins.2023.1241919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023] Open
Abstract
The self-organization of the serotonergic matrix, a massive axon meshwork in all vertebrate brains, is driven by the structural and dynamical properties of its constitutive elements. Each of these elements, a single serotonergic axon (fiber), has a unique trajectory and can be supported by a soma that executes one of the many available transcriptional programs. This "individuality" of serotonergic neurons necessitates the development of specialized methods for single-fiber analyses, both at the experimental and theoretical levels. We developed an integrated platform that facilitates experimental isolation of single serotonergic fibers in brain tissue, including regions with high fiber densities, and demonstrated the potential of their quantitative analyses based on stochastic modeling. Single fibers were visualized using two transgenic mouse models, one of which is the first implementation of the Brainbow toolbox in this system. The trajectories of serotonergic fibers were automatically traced in the three spatial dimensions with a novel algorithm, and their properties were captured with a single parameter associated with the directional von Mises-Fisher probability distribution. The system represents an end-to-end workflow that can be imported into various studies, including those investigating serotonergic dysfunction in brain disorders. It also supports new research directions inspired by single-fiber analyses in the serotonergic matrix, including supercomputing simulations and modeling in physics.
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Affiliation(s)
| | | | - Skirmantas Janušonis
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
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10
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Zeng CW, Tsai HJ. The Promising Role of a Zebrafish Model Employed in Neural Regeneration Following a Spinal Cord Injury. Int J Mol Sci 2023; 24:13938. [PMID: 37762240 PMCID: PMC10530783 DOI: 10.3390/ijms241813938] [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: 07/27/2023] [Revised: 09/07/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Spinal cord injury (SCI) is a devastating event that results in a wide range of physical impairments and disabilities. Despite the advances in our understanding of the biological response to injured tissue, no effective treatments are available for SCIs at present. Some studies have addressed this issue by exploring the potential of cell transplantation therapy. However, because of the abnormal microenvironment in injured tissue, the survival rate of transplanted cells is often low, thus limiting the efficacy of such treatments. Many studies have attempted to overcome these obstacles using a variety of cell types and animal models. Recent studies have shown the utility of zebrafish as a model of neural regeneration following SCIs, including the proliferation and migration of various cell types and the involvement of various progenitor cells. In this review, we discuss some of the current challenges in SCI research, including the accurate identification of cell types involved in neural regeneration, the adverse microenvironment created by SCIs, attenuated immune responses that inhibit nerve regeneration, and glial scar formation that prevents axonal regeneration. More in-depth studies are needed to fully understand the neural regeneration mechanisms, proteins, and signaling pathways involved in the complex interactions between the SCI microenvironment and transplanted cells in non-mammals, particularly in the zebrafish model, which could, in turn, lead to new therapeutic approaches to treat SCIs in humans and other mammals.
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Affiliation(s)
- Chih-Wei Zeng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA;
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Huai-Jen Tsai
- Department of Life Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
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11
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Takeda A, Fujita M, Funakoshi K. Distribution of 5HT receptors during the regeneration process after spinal cord transection in goldfish. J Chem Neuroanat 2023; 131:102281. [PMID: 37119932 DOI: 10.1016/j.jchemneu.2023.102281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/15/2023] [Accepted: 04/26/2023] [Indexed: 05/01/2023]
Abstract
Spinal cord injury in teleosts leads to a fibrous scar, but axons sometimes spontaneously regenerate beyond the scar. In goldfish, regenerating axons enter the scar through tubular structures and enlargement of the tubular diameter is proportional to the increase in the number of regenerating axons. During the regeneration process, mast cells containing 5-hydroxytryptamine (5HT) are recruited to the injury site, and 5HT neurons are newly generated. Here, we investigated the distribution of 5HT receptors during this process to determine their role in remodeling the fibrous scar and tubular structures. At 2 weeks after spinal cord transection (SCT) in goldfish, expression of the 5HT2A and 5HT2C receptor subtypes was observed in the ependymo-radial glial cells lining the central canal of the spinal cord. 5HT2A was expressed at the luminal surface, suggesting that it is receptive to 5HT in the cerebrospinal fluid. 5HT2C, on the other hand, was expressed around the nuclei and in the radial processes protruding from the basal surface, suggesting that it is receptive to 5HT released from nearby nerve endings. 5HT2C was also expressed in the fibrous scar where mast cells containing 5HT were abundant. 5HT1B expression was coincident with the basement membrane bordering the fibrous scar and the surrounding nervous tissue, and with the basement membrane of the tubular structure through which axons pass during regeneration. Our findings suggest that multiple 5HT receptors are involved in remodeling the injured site during the regenerative process following SCT. Ependymo-radial glial cells expressing 5HT2A and 5HT2C are involved in neurogenesis and gliogenesis, which might contribute to remodeling the fibrous scar in coordination with 5HT-containing mast cells. Coincident expression of 5HT1B with the basement membrane might be involved in remodeling the tubular structures, thereby promoting axonal regeneration.
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Affiliation(s)
- Akihito Takeda
- Department of Neuroanatomy, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama, Japan
| | - Mao Fujita
- Department of Neuroanatomy, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama, Japan
| | - Kengo Funakoshi
- Department of Neuroanatomy, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama, Japan.
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Chen F, Köhler M, Cucun G, Takamiya M, Kizil C, Cosacak MI, Rastegar S. sox1a:eGFP transgenic line and single-cell transcriptomics reveal the origin of zebrafish intraspinal serotonergic neurons. iScience 2023; 26:107342. [PMID: 37529101 PMCID: PMC10387610 DOI: 10.1016/j.isci.2023.107342] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/03/2023] [Accepted: 07/06/2023] [Indexed: 08/03/2023] Open
Abstract
Sox transcription factors are crucial for vertebrate nervous system development. In zebrafish embryo, sox1 genes are expressed in neural progenitor cells and neurons of ventral spinal cord. Our recent study revealed that the loss of sox1a and sox1b function results in a significant decline of V2 subtype neurons (V2s). Using single-cell RNA sequencing, we analyzed the transcriptome of sox1a lineage progenitors and neurons in the zebrafish spinal cord at four time points during embryonic development, employing the Tg(sox1a:eGFP) line. In addition to previously characterized sox1a-expressing neurons, we discovered the expression of sox1a in late-developing intraspinal serotonergic neurons (ISNs). Developmental trajectory analysis suggests that ISNs arise from lateral floor plate (LFP) progenitor cells. Pharmacological inhibition of the Notch signaling pathway revealed its role in negatively regulating LFP progenitor cell differentiation into ISNs. Our findings highlight the zebrafish LFP as a progenitor domain for ISNs, alongside known Kolmer-Agduhr (KA) and V3 interneurons.
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Affiliation(s)
- Fushun Chen
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Melina Köhler
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Gokhan Cucun
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Masanari Takamiya
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Caghan Kizil
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Helmholtz Association, Tatzberg 41, 01307 Dresden, Germany
- Department of Neurology and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY 10032, USA
| | - Mehmet Ilyas Cosacak
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Helmholtz Association, Tatzberg 41, 01307 Dresden, Germany
| | - Sepand Rastegar
- Institute of Biological and Chemical Systems-Biological Information Processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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Jensen NO, Burris B, Zhou L, Yamada H, Reyes C, Pincus Z, Mokalled MH. Functional trajectories during innate spinal cord repair. Front Mol Neurosci 2023; 16:1155754. [PMID: 37492522 PMCID: PMC10365889 DOI: 10.3389/fnmol.2023.1155754] [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: 01/31/2023] [Accepted: 05/26/2023] [Indexed: 07/27/2023] Open
Abstract
Adult zebrafish are capable of anatomical and functional recovery following severe spinal cord injury. Axon growth, glial bridging and adult neurogenesis are hallmarks of cellular regeneration during spinal cord repair. However, the correlation between these cellular regenerative processes and functional recovery remains to be elucidated. Whereas the majority of established functional regeneration metrics measure swim capacity, we hypothesize that gait quality is more directly related to neurological health. Here, we performed a longitudinal swim tracking study for 60 individual zebrafish spanning 8 weeks of spinal cord regeneration. Multiple swim parameters as well as axonal and glial bridging were integrated. We established rostral compensation as a new gait quality metric that highly correlates with functional recovery. Tensor component analysis of longitudinal data supports a correspondence between functional recovery trajectories and neurological outcomes. Moreover, our studies predicted and validated that a subset of functional regeneration parameters measured 1 to 2 weeks post-injury is sufficient to predict the regenerative outcomes of individual animals at 8 weeks post-injury. Our findings established new functional regeneration parameters and generated a comprehensive correlative database between various functional and cellular regeneration outputs.
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Affiliation(s)
- Nicholas O. Jensen
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Brooke Burris
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Lili Zhou
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Hunter Yamada
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Catrina Reyes
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Zachary Pincus
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Mayssa H. Mokalled
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
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14
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Xu L, Yang Y, Zhong W, Li W, Liu C, Guo Z, Yu X. Comparative efficacy of five most common traditional Chinese medicine monomers for promoting recovery of motor function in rats with blunt spinal cord injury: a network meta-analysis. Front Neurol 2023; 14:1165076. [PMID: 37465765 PMCID: PMC10351986 DOI: 10.3389/fneur.2023.1165076] [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: 02/13/2023] [Accepted: 06/15/2023] [Indexed: 07/20/2023] Open
Abstract
Objective This research employed a network meta-analysis (NMA) to examine the effectiveness of five traditional Chinese medicine (TCM) monomers for promoting motor function recovery in rats with blunt spinal cord injury (SCI). Methods Wangfang, China National Knowledge Infrastructure, Web of Science, Embase, Chinese Scientific Journal Database, PubMed, and the Chinese Biomedical Literature Databases were searched for retrieving relevant articles published from their inception to December 2022. Two reviewers performed screening of search results, data extraction, and literature quality assessment independently. Results For this meta-analysis, 59 publications were included. Based on the recovery of motor function at weeks 1, 2, 3, and 4 in NMA, almost all TCM groups had significantly increased positive effects than the negative control animals. In terms of cumulative probability, the tanshinone IIA (TIIA) group ranked first in restoring motor function in the first week after blunt SCI, and the resveratrol (RSV) group ranked first during the last 3 weeks. Conclusion The NMA revealed that TCM monomers could effectively restore motor function in the rat model of blunt SCI. In rats with blunt SCI, TIIA may be the most effective TCM monomer during the first week, whereas RSV may be the most effective TCM monomer during the last 3 weeks in promoting motor function recovery. For better evidence reliability in preclinical investigations and safer extrapolation of those findings into clinical settings, further research standardizing the implementation and reporting of animal experiments is required. Systematic Review Registration https://inplasy.com/, identifier INPLASY202310070.
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Underwood KL, Walker WJ, Garrett PI, Linch S, Rynes TP, Mruk K. Optimizing spinal cord injury in zebrafish larvae: effects of age on the injury response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.541337. [PMID: 37292959 PMCID: PMC10245662 DOI: 10.1101/2023.05.18.541337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Zebrafish are an increasingly popular model to study spinal cord injury (SCI) regeneration. The transparency of larval zebrafish makes them ideal to study cellular processes in real time. Standardized approaches, including age of injury, are not readily available making comparisons of the results with other models challenging. In this study, we systematically examined the response to spinal cord transection of larval zebrafish at three different ages (3-7 days post fertilization or dpf) to determine whether the developmental complexity of the central nervous system affects the overall response to SCI. We then used imaging and behavioral analysis to evaluate whether differences existed based on the age of injury. All ages of larval zebrafish upregulated the required genes for glial bridge formation, ctgfa and gfap, at the site of injury, consistent with studies from adult zebrafish. Though all larval ages upregulated factors required to promote glial bridging, young larval zebrafish (3 dpf) were better able to regenerate axons independent of the glial bridge, unlike older zebrafish (7 dpf). Consistent with this data, locomotor experiments demonstrated that some swimming behavior occurs independent of glial bridge formation, further highlighting the need for standardization of this model and recovery assays. Overall, we found subtle cellular differences based on the age of transection in zebrafish, underlining the importance of considering age when designing experiments aimed at understanding regeneration.
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Cheng J, Guan NN. A fresh look at propriospinal interneurons plasticity and intraspinal circuits remodeling after spinal cord injury. IBRO Neurosci Rep 2023. [DOI: 10.1016/j.ibneur.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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17
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Jensen NO, Burris B, Zhou L, Yamada H, Reyes C, Mokalled MH. Functional Trajectories during innate spinal cord repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.526502. [PMID: 36778427 PMCID: PMC9915574 DOI: 10.1101/2023.01.31.526502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Adult zebrafish are capable of anatomical and functional recovery following severe spinal cord injury. Axon growth, glial bridging and adult neurogenesis are hallmarks of cellular regeneration during spinal cord repair. However, the correlation between these cellular regenerative processes and functional recovery remains to be elucidated. Whereas the majority of established functional regeneration metrics measure swim capacity, we hypothesize that gait quality is more directly related to neurological health. Here, we performed a longitudinal swim tracking study for sixty individual zebrafish spanning eight weeks of spinal cord regeneration. Multiple swim parameters as well as axonal and glial bridging were integrated. We established rostral compensation as a new gait quality metric that highly correlates with functional recovery. Tensor component analysis of longitudinal data supports a correspondence between functional recovery trajectories and neurological outcomes. Moreover, our studies predicted and validated that a subset of functional regeneration parameters measured 1 to 2 weeks post-injury is sufficient to predict the regenerative outcomes of individual animals at 8 weeks post-injury. Our findings established new functional regeneration parameters and generated a comprehensive correlative database between various functional and cellular regeneration outputs.
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18
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Hingorani M, Viviani AML, Sanfilippo JE, Janušonis S. High-resolution spatiotemporal analysis of single serotonergic axons in an in vitro system. Front Neurosci 2022; 16:994735. [PMID: 36353595 PMCID: PMC9638127 DOI: 10.3389/fnins.2022.994735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/28/2022] [Indexed: 12/04/2022] Open
Abstract
Vertebrate brains have a dual structure, composed of (i) axons that can be well-captured with graph-theoretical methods and (ii) axons that form a dense matrix in which neurons with precise connections operate. A core part of this matrix is formed by axons (fibers) that store and release 5-hydroxytryptamine (5-HT, serotonin), an ancient neurotransmitter that supports neuroplasticity and has profound implications for mental health. The self-organization of the serotonergic matrix is not well understood, despite recent advances in experimental and theoretical approaches. In particular, individual serotonergic axons produce highly stochastic trajectories, fundamental to the construction of regional fiber densities, but further advances in predictive computer simulations require more accurate experimental information. This study examined single serotonergic axons in culture systems (co-cultures and monolayers), by using a set of complementary high-resolution methods: confocal microscopy, holotomography (refractive index-based live imaging), and super-resolution (STED) microscopy. It shows that serotonergic axon walks in neural tissue may strongly reflect the stochastic geometry of this tissue and it also provides new insights into the morphology and branching properties of serotonergic axons. The proposed experimental platform can support next-generation analyses of the serotonergic matrix, including seamless integration with supercomputing approaches.
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Huang CX, Wang Z, Cheng J, Zhu Z, Guan NN, Song J. De novo establishment of circuit modules restores locomotion after spinal cord injury in adult zebrafish. Cell Rep 2022; 41:111535. [DOI: 10.1016/j.celrep.2022.111535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/12/2022] [Accepted: 09/29/2022] [Indexed: 11/03/2022] Open
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20
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Xu T, Duan J, Li Y, Wang G, Li S, Li Y, Lu W, Yan X, Ren Y, Guo F, Cao L, Lu J. Generation of a TPH2-EGFP reporter cell line for purification and monitoring of human serotonin neurons in vitro and in vivo. Stem Cell Reports 2022; 17:2365-2379. [PMID: 36150384 PMCID: PMC9561537 DOI: 10.1016/j.stemcr.2022.08.012] [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] [Received: 01/28/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 10/25/2022] Open
Abstract
Generation of serotonin neurons (SNs) from human pluripotent stem cells (hPSCs) provides a promising platform to explore the mechanisms of serotonin-associated neuropsychiatric disorders. However, neural differentiation always yields heterogeneous cell populations, making it difficult to identify and purify SNs in vitro or track them in vivo following transplantation. Herein, we generated a TPH2-EGFP reporter hPSC line with insertion of EGFP into the endogenous tryptophan hydroxylase 2 (TPH2) locus using CRISPR-Cas9-mediated gene editing technology. This TPH2-reporter, which faithfully indicated TPH2 expression during differentiation, enabled us to obtain purified SNs for subsequent transcriptional analysis and study of pharmacological responses to antidepressants. In addition, the reporter system showed strong EGFP expression to indicate SNs, which enabled us to explore in vitro and ex vivo electrophysiological properties of SNs. In conclusion, this TPH2-EGFP reporter cell line might be of great significance for studies on human SN-related development and differentiation, drug screening, disease modeling, and cell replacement therapies.
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Affiliation(s)
- Ting Xu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jinjin Duan
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Yingqi Li
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Guanhao Wang
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Shuanqing Li
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - You Li
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Wenting Lu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Xinyi Yan
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Yixuan Ren
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Fei Guo
- Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Lining Cao
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
| | - Jianfeng Lu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; Suzhou Institute of Tongji University, Suzhou 215101, China.
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Liu J, Wang S, Chen Z, Wu R, Yu H, Yang S, Xu J, Guo Y, Ding Y, Li G, Zeng X, Ma Y, Gong Y, Wu C, Zhang L, Zeng Y, Lai B. Therapeutic mechanism of transcranial iTBS on nerve regeneration and functional recovery in rats with complete spinal cord transection.. [DOI: 10.21203/rs.3.rs-2026215/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abstract
Background: After spinal cord transection injury, the inflammatory microenvironment formed in the injury site and the cascade of secondary injury results in limited regeneration of injured axons and the apoptosis of neurons in the sensorimotor cortex (SMC). It is crucial to reverse these adverse processes for the recovery of voluntary movement. In this study, transcranial intermittent theta-burst stimulation (iTBS) was used for the treatment of complete spinal cord transection in rats. The mechanism of transcranial iTBS as a new non-invasive neural regulation paradigm in promoting axonal regeneration and motor function repair was explored.
Methods: Rats from the iTBS group were treated with transcranial iTBS 72h after spinal cord injury (SCI). Each rat was received behavioral testing. Inflammation, neuronal apoptosis, neuroprotective effect, regeneration and synaptic plasticity were measured by immunofluorescence staining, western blotting and mRNA sequencing 2 or 4w after SCI. Each rat was received anterograde tracings in the SMC or the long descending propriospinal neurons and tested for motor evoked potentials. Regeneration of corticospinal tract (CST) and 5-hydroxytryptamine (5-HT) nerve fibers were detected eight weeks after SCI.
Results: Compared with the control group and the sham iTBS group, rats of the iTBS group showed reduced inflammatory responses and neuronal apoptosis in the SMC two weeks after treatment. After four weeks, the neuroimmune microenvironment at the injury site was improved, and neuroprotective effects were seen to promote axonal regeneration and synaptic plasticity. Significantly, eight weeks after treatment, transcranial iTBS also increased the regeneration of CST, 5-HT nerve fibers, and the long descending propriospinal tract (LDPT). Moreover, motor evoked potentials and hindlimb motor function were significantly improved at eight weeks.
Conclusions: Collectively, our results verified that iTBS has the potential to provide neuroprotective effects at early injury stages and pro-regeneration effects related to the 1) CST–5-HT; 2) CST–LDPT; and 3) CST–5-HT–LDPT descending motor pathways and revealed the relationships among neural pathway activation, neuroimmune regulation, neuroprotection, and axonal regeneration, as well as the interaction network of key genes. The proposed non-invasive transcranial iTBS treatment is expected to provide a serviceable practical and theoretical support for spinal cord injury.
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Affiliation(s)
- Jialin Liu
- Shengjing Hospital affiliated to China Medical University
| | - Shuai Wang
- The First Affiliated Hospital of Sun Yat-sen University,Guangzhou
| | - Zhenghong Chen
- The First Affiliated Hospital of Sun Yat-sen University,Guangzhou
| | | | | | | | | | | | | | - Ge Li
- Guangdong Academy of Medical Science
| | | | - Yuanhuan Ma
- Guangzhou Institute of Clinical Medicine, South China University of Technology
| | - Yulai Gong
- Sichuan Provincial Rehabilitation Hospital
| | | | - Lixin Zhang
- Shengjing Hospital affiliated to China Medical University
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22
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Alper SR, Dorsky RI. Unique advantages of zebrafish larvae as a model for spinal cord regeneration. Front Mol Neurosci 2022; 15:983336. [PMID: 36157068 PMCID: PMC9489991 DOI: 10.3389/fnmol.2022.983336] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/18/2022] [Indexed: 11/30/2022] Open
Abstract
The regenerative capacity of the spinal cord in mammals ends at birth. In contrast, teleost fish and amphibians retain this capacity throughout life, leading to the use of the powerful zebrafish model system to identify novel mechanisms that promote spinal cord regeneration. While adult zebrafish offer an effective comparison with non-regenerating mammals, they lack the complete array of experimental approaches that have made this animal model so successful. In contrast, the optical transparency, simple anatomy and complex behavior of zebrafish larvae, combined with the known conservation of pro-regenerative signals and cell types between larval and adult stages, suggest that they may hold even more promise as a system for investigating spinal cord regeneration. In this review, we highlight characteristics and advantages of the larval model that underlie its potential to provide future therapeutic approaches for treating human spinal cord injury.
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Tamvacakis AN, Lillvis JL, Sakurai A, Katz PS. The Consistency of Gastropod Identified Neurons Distinguishes Intra-Individual Plasticity From Inter-Individual Variability in Neural Circuits. Front Behav Neurosci 2022; 16:855235. [PMID: 35309684 PMCID: PMC8928192 DOI: 10.3389/fnbeh.2022.855235] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Gastropod mollusks are known for their large, individually identifiable neurons, which are amenable to long-term intracellular recordings that can be repeated from animal to animal. The constancy of individual neurons can help distinguish state-dependent or temporal variation within an individual from actual variability between individual animals. Investigations into the circuitry underlying rhythmic swimming movements of the gastropod species, Tritonia exsulans and Pleurobranchaea californica have uncovered intra- and inter-individual variability in synaptic connectivity and serotonergic neuromodulation. Tritonia has a reliably evoked escape swim behavior that is produced by a central pattern generator (CPG) composed of a small number of identifiable neurons. There is apparent individual variability in some of the connections between neurons that is inconsequential for the production of the swim behavior under normal conditions, but determines whether that individual can swim following a neural lesion. Serotonergic neuromodulation of synaptic strength intrinsic to the CPG creates neural circuit plasticity within an individual and contributes to reorganization of the network during recovery from injury and during learning. In Pleurobranchaea, variability over time in the modulatory actions of serotonin and in expression of serotonin receptor genes in an identified neuron directly reflects variation in swimming behavior. Tracking behavior and electrophysiology over hours to days was necessary to identify the functional consequences of these intra-individual, time-dependent variations. This work demonstrates the importance of unambiguous neuron identification, properly assessing the animal and network states, and tracking behavior and physiology over time to distinguish plasticity within the same animal at different times from variability across individual animals.
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Affiliation(s)
| | | | - Akira Sakurai
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Paul S. Katz
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
- *Correspondence: Paul S. Katz,
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