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Cheng J, Chen L, Zheng YN, Liu J, Zhang L, Zhang XM, Huang L, Yuan QL. Disfunction of dorsal raphe nucleus-hippocampus serotonergic-HTR3 transmission results in anxiety phenotype of Neuroplastin 65-deficient mice. Acta Pharmacol Sin 2024; 45:1393-1405. [PMID: 38528118 PMCID: PMC11192762 DOI: 10.1038/s41401-024-01252-5] [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: 11/10/2023] [Accepted: 02/26/2024] [Indexed: 03/27/2024] Open
Abstract
Anxiety disorders are the most common psychiatric condition, but the etiology of anxiety disorders remains largely unclear. Our previous studies have shown that neuroplastin 65 deficiency (NP65-/-) mice exhibit abnormal social and mental behaviors and decreased expression of tryptophan hydroxylase 2 (TPH2) protein. However, whether a causal relationship between TPH2 reduction and anxiety disorders exists needs to be determined. In present study, we found that replenishment of TPH2 in dorsal raphe nucleus (DRN) enhanced 5-HT level in the hippocampus and alleviated anxiety-like behaviors. In addition, injection of AAV-NP65 in DRN significantly increased TPH2 expression in DRN and hippocampus, and reduced anxiety-like behaviors. Acute administration of exogenous 5-HT or HTR3 agonist SR57227A in hippocampus mitigated anxiety-like behaviors in NP65-/- mice. Moreover, replenishment of TPH2 in DRN partly repaired the impairment of long-term potentiation (LTP) maintenance in hippocampus of NP65-/- mice. Finally, we found that loss of NP65 lowered transcription factors Lmx1b expression in postnatal stage and replenishment of NP65 in DRN reversed the decrease in Lmx1b expression of NP65-/- mice. Together, our findings reveal that NP65 deficiency induces anxiety phenotype by downregulating DRN-hippocampus serotonergic-HTR3 transmission. These studies provide a novel and insightful view about NP65 function, suggesting an attractive potential target for treatment of anxiety disorders.
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Affiliation(s)
- Jie Cheng
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Ling Chen
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Ya-Ni Zheng
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Juan Liu
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Lei Zhang
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Xiao-Ming Zhang
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Liang Huang
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Qiong-Lan Yuan
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China.
- Department of Human Anatomy, Histology and Embryology, Tongji University School of Medicine, Shanghai, 200092, China.
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2
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Li Y, Duan J, Li Y, Zhang M, Wu J, Wang G, Li S, Hu Z, Qu Y, Li Y, Hu X, Guo F, Cao L, Lu J. Transcriptomic profiling across human serotonin neuron differentiation via the FEV reporter system. Stem Cell Res Ther 2024; 15:107. [PMID: 38637896 PMCID: PMC11027224 DOI: 10.1186/s13287-024-03728-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: 12/29/2023] [Accepted: 04/10/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND The detailed transcriptomic profiles during human serotonin neuron (SN) differentiation remain elusive. The establishment of a reporter system based on SN terminal selector holds promise to produce highly-purified cells with an early serotonergic fate and help elucidate the molecular events during human SN development process. METHODS A fifth Ewing variant (FEV)-EGFP reporter system was established by CRISPR/Cas9 technology to indicate SN since postmitotic stage. FACS was performed to purify SN from the heterogeneous cell populations. RNA-sequencing analysis was performed for cells at four key stages of differentiation (pluripotent stem cells, serotonergic neural progenitors, purified postmitotic SN and purifed mature SN) to explore the transcriptomic dynamics during SN differentiation. RESULTS We found that human serotonergic fate specification may commence as early as day 21 of differentiation from human pluripotent stem cells. Furthermore, the transcriptional factors ZIC1, HOXA2 and MSX2 were identified as the hub genes responsible for orchestrating serotonergic fate determination. CONCLUSIONS For the first time, we exposed the developmental transcriptomic profiles of human SN via FEV reporter system, which will further our understanding for the development process of human SN.
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Affiliation(s)
- 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, China
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 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, 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, China
| | - Meihui Zhang
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jiaan Wu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, 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, 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, China
| | - Zhangsen Hu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yi Qu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yunhe 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, China
| | - Xiran Hu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, 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, 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, China.
- Suzhou Institute of Tongji University, Suzhou, China.
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3
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Smith J, Richerson G, Kouchi H, Duprat F, Mantegazza M, Bezin L, Rheims S. Are we there yet? A critical evaluation of sudden and unexpected death in epilepsy models. Epilepsia 2024; 65:9-25. [PMID: 37914406 DOI: 10.1111/epi.17812] [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: 08/04/2023] [Revised: 10/11/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023]
Abstract
Although animal models have helped to elaborate meaningful hypotheses about the pathophysiology of sudden and unexpected death in epilepsy (SUDEP), specific prevention strategies are still lacking, potentially reflecting the limitations of these models and the intrinsic difficulties of investigating SUDEP. The interpretation of preclinical data and their translation to diagnostic and therapeutic developments in patients thus require a high level of confidence in their relevance to model the human situation. Preclinical models of SUDEP are heterogeneous and include rodent and nonrodent species. A critical aspect is whether the animals have isolated seizures exclusively induced by a specific trigger, such as models where seizures are elicited by electrical stimulation, pharmacological intervention, or DBA mouse strains, or whether they suffer from epilepsy with spontaneous seizures, with or without spontaneous SUDEP, either of nongenetic epilepsy etiology or from genetically based developmental and epileptic encephalopathies. All these models have advantages and potential disadvantages, but it is important to be aware of these limitations to interpret data appropriately in a translational perspective. The majority of models with spontaneous seizures are of a genetic basis, whereas SUDEP cases with a genetic basis represent only a small proportion of the total number. In almost all models, cardiorespiratory arrest occurs during the course of the seizure, contrary to that in patients observed at the time of death, potentially raising the issue of whether we are studying models of SUDEP or models of periseizure death. However, some of these limitations are impossible to avoid and can in part be dependent on specific features of SUDEP, which may be difficult to model. Several preclinical tools are available to address certain gaps in SUDEP pathophysiology, which can be used to further validate current preclinical models.
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Affiliation(s)
- Jonathon Smith
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - George Richerson
- Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Hayet Kouchi
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - Fabrice Duprat
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Massimo Mantegazza
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Laurent Bezin
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
| | - Sylvain Rheims
- Lyon Neuroscience Research Center (CRNL, INSERM U1028/CNRS UMR 5292, Lyon 1 University), Lyon, France
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon and Lyon 1 University, Lyon, France
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4
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Koutsioumpa C, Santiago C, Jacobs K, Lehnert BP, Barrera V, Hutchinson JN, Schmelyun D, Lehoczky JA, Paul DL, Ginty DD. Skin-type-dependent development of murine mechanosensory neurons. Dev Cell 2023; 58:2032-2047.e6. [PMID: 37607547 PMCID: PMC10615785 DOI: 10.1016/j.devcel.2023.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/26/2023] [Accepted: 07/27/2023] [Indexed: 08/24/2023]
Abstract
Mechanosensory neurons innervating the skin underlie our sense of touch. Fast-conducting, rapidly adapting mechanoreceptors innervating glabrous (non-hairy) skin form Meissner corpuscles, while in hairy skin, they associate with hair follicles, forming longitudinal lanceolate endings. How mechanoreceptors develop axonal endings appropriate for their skin targets is unknown. We report that mechanoreceptor morphologies across different skin regions are indistinguishable during early development but diverge post-natally, in parallel with skin maturation. Neurons terminating along the glabrous and hairy skin border exhibit hybrid morphologies, forming both Meissner corpuscles and lanceolate endings. Additionally, molecular profiles of neonatal glabrous and hairy skin-innervating neurons largely overlap. In mouse mutants with ectopic glabrous skin, mechanosensory neurons form end-organs appropriate for the altered skin type. Finally, BMP5 and BMP7 are enriched in glabrous skin, and signaling through type I bone morphogenetic protein (BMP) receptors in neurons is critical for Meissner corpuscle morphology. Thus, mechanoreceptor morphogenesis is flexibly instructed by target tissues.
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Affiliation(s)
- Charalampia Koutsioumpa
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Celine Santiago
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Kiani Jacobs
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Brendan P Lehnert
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Victor Barrera
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - John N Hutchinson
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Dhane Schmelyun
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Jessica A Lehoczky
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - David L Paul
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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5
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Abstract
PURPOSE OF REVIEW Sudden unexpected death in epilepsy (SUDEP) is a leading cause of death in patients with epilepsy. This review highlights the recent literature regarding epidemiology on a global scale, putative mechanisms and thoughts towards intervention and prevention. RECENT FINDINGS Recently, numerous population-based studies have examined the incidence of SUDEP in many countries. Remarkably, incidence is quite consistent across these studies, and is commensurate with the recent estimates of about 1.2 per 1000 patient years. These studies further continue to support that incidence is similar across the ages and that comparable factors portend heightened risk for SUDEP. Fervent research in patients and animal studies continues to hone the understanding of potential mechanisms for SUDEP, especially those regarding seizure-induced respiratory dysregulation. Many of these studies and others have begun to lay out a path towards identification of improved treatment and prevention means. However, continued efforts are needed to educate medical professionals about SUDEP risk and the need to disclose this to patients. SUMMARY SUDEP is a devastating potential outcome of epilepsy. More is continually learned about risk and mechanisms from clinical and preclinical studies. This knowledge can hopefully be leveraged into preventive measures in the near future.
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Affiliation(s)
- Gordon F Buchanan
- Department of Neurology
- Neuroscience Graduate Program
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Ana T Novella Maciel
- Department of Neurology
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Universidad Nacional Autónoma de México, Mexico City, México
| | - Matthew J Summerfield
- Neuroscience Graduate Program
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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6
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Johnson GL, Glasser MB, Charles JF, Duryea J, Lehoczky JA. En1 and Lmx1b do not recapitulate embryonic dorsal-ventral limb patterning functions during mouse digit tip regeneration. Cell Rep 2022; 41:111701. [PMID: 36417876 PMCID: PMC9727699 DOI: 10.1016/j.celrep.2022.111701] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 09/09/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022] Open
Abstract
The mouse digit tip regenerates following amputation. How the regenerate is patterned is unknown, but a long-standing hypothesis proposes developmental patterning mechanisms are re-used during regeneration. The digit tip bone exhibits dorsal-ventral (DV) polarity, so we focus on En1 and Lmx1b, two factors necessary for DV patterning during limb development. We investigate whether they are re-expressed during regeneration in a developmental-like pattern and whether they direct DV morphology of the regenerate. We find that both En1 and Lmx1b are expressed in the regenerating digit tip epithelium and mesenchyme, respectively, but without DV polarity. Conditional genetics and quantitative analysis of digit tip bone morphology determine that genetic deletion of En1 or Lmx1b in adult digit tip regeneration modestly reduces bone regeneration but does not affect DV patterning. Collectively, our data suggest that, while En1 and Lmx1b are re-expressed during mouse digit tip regeneration, they do not define the DV axis during regeneration.
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Affiliation(s)
- Gemma L. Johnson
- Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston, MA 02115, USA,Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Morgan B. Glasser
- Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Julia F. Charles
- Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston, MA 02115, USA,Department of Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Jeffrey Duryea
- Department of Radiology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Jessica A. Lehoczky
- Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston, MA 02115, USA,Lead contact,Correspondence:
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7
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Feng W, Destain H, Smith JJ, Kratsios P. Maintenance of neurotransmitter identity by Hox proteins through a homeostatic mechanism. Nat Commun 2022; 13:6097. [PMID: 36243871 PMCID: PMC9569373 DOI: 10.1038/s41467-022-33781-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
Hox transcription factors play fundamental roles during early patterning, but they are also expressed continuously, from embryonic stages through adulthood, in the nervous system. However, the functional significance of their sustained expression remains unclear. In C. elegans motor neurons (MNs), we find that LIN-39 (Scr/Dfd/Hox4-5) is continuously required during post-embryonic life to maintain neurotransmitter identity, a core element of neuronal function. LIN-39 acts directly to co-regulate genes that define cholinergic identity (e.g., unc-17/VAChT, cho-1/ChT). We further show that LIN-39, MAB-5 (Antp/Hox6-8) and the transcription factor UNC-3 (Collier/Ebf) operate in a positive feedforward loop to ensure continuous and robust expression of cholinergic identity genes. Finally, we identify a two-component design principle for homeostatic control of Hox gene expression in adult MNs: Hox transcriptional autoregulation is counterbalanced by negative UNC-3 feedback. These findings uncover a noncanonical role for Hox proteins during post-embryonic life, critically broadening their functional repertoire from early patterning to the control of neurotransmitter identity.
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Affiliation(s)
- Weidong Feng
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA
| | - Honorine Destain
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA
| | - Jayson J Smith
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL, USA.
- University of Chicago Neuroscience Institute, Chicago, IL, USA.
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA.
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8
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Zhang XL, Spencer WC, Tabuchi N, Kitt MM, Deneris ES. Reorganization of postmitotic neuronal chromatin accessibility for maturation of serotonergic identity. eLife 2022; 11:e75970. [PMID: 35471146 PMCID: PMC9098219 DOI: 10.7554/elife.75970] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/12/2022] [Indexed: 12/02/2022] Open
Abstract
Assembly of transcriptomes encoding unique neuronal identities requires selective accessibility of transcription factors to cis-regulatory sequences in nucleosome-embedded postmitotic chromatin. Yet, the mechanisms controlling postmitotic neuronal chromatin accessibility are poorly understood. Here, we show that unique distal enhancers define the Pet1 neuron lineage that generates serotonin (5-HT) neurons in mice. Heterogeneous single-cell chromatin landscapes are established early in postmitotic Pet1 neurons and reveal the putative regulatory programs driving Pet1 neuron subtype identities. Distal enhancer accessibility is highly dynamic as Pet1 neurons mature, suggesting the existence of regulatory factors that reorganize postmitotic neuronal chromatin. We find that Pet1 and Lmx1b control chromatin accessibility to select Pet1-lineage-specific enhancers for 5-HT neurotransmission. Additionally, these factors are required to maintain chromatin accessibility during early maturation suggesting that postmitotic neuronal open chromatin is unstable and requires continuous regulatory input. Together, our findings reveal postmitotic transcription factors that reorganize accessible chromatin for neuron specialization.
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Affiliation(s)
- Xinrui L Zhang
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - William C Spencer
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Nobuko Tabuchi
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Meagan M Kitt
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Evan S Deneris
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
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9
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Kitt MM, Tabuchi N, Spencer WC, Robinson HL, Zhang XL, Eastman BA, Lobur KJ, Silver J, Mei L, Deneris ES. An adult-stage transcriptional program for survival of serotonergic connectivity. Cell Rep 2022; 39:110711. [PMID: 35443166 PMCID: PMC9109281 DOI: 10.1016/j.celrep.2022.110711] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/23/2022] [Accepted: 03/30/2022] [Indexed: 12/23/2022] Open
Abstract
Neurons must function for decades of life, but how these non-dividing cells are preserved is poorly understood. Using mouse serotonin (5-HT) neurons as a model, we report an adult-stage transcriptional program specialized to ensure the preservation of neuronal connectivity. We uncover a switch in Lmx1b and Pet1 transcription factor function from controlling embryonic axonal growth to sustaining a transcriptomic signature of 5-HT connectivity comprising functionally diverse synaptic and axonal genes. Adult-stage deficiency of Lmx1b and Pet1 causes slowly progressing degeneration of 5-HT synapses and axons, increased susceptibility of 5-HT axons to neurotoxic injury, and abnormal stress responses. Axon degeneration occurs in a die back pattern and is accompanied by accumulation of α-synuclein and amyloid precursor protein in spheroids and mitochondrial fragmentation without cell body loss. Our findings suggest that neuronal connectivity is transcriptionally protected by maintenance of connectivity transcriptomes; progressive decay of such transcriptomes may contribute to age-related diseases of brain circuitry.
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Affiliation(s)
- Meagan M Kitt
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Nobuko Tabuchi
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - W Clay Spencer
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Heath L Robinson
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Xinrui L Zhang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Brent A Eastman
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Katherine J Lobur
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jerry Silver
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Evan S Deneris
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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10
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Karthik S, Huang D, Delgado Y, Laing JJ, Peltekian L, Iverson GN, Grady F, Miller RL, McCann CM, Fritzsch B, Iskusnykh IY, Chizhikov VV, Geerling JC. Molecular ontology of the parabrachial nucleus. J Comp Neurol 2022; 530:1658-1699. [PMID: 35134251 PMCID: PMC9119955 DOI: 10.1002/cne.25307] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/22/2022] [Accepted: 01/25/2022] [Indexed: 11/07/2022]
Abstract
This article has been removed because of a technical problem in the rendering of the PDF. 11 February 2022.
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Affiliation(s)
| | - Dake Huang
- Department of NeurologyUniversity of IowaIowa CityIowaUSA
| | | | | | - Lila Peltekian
- Department of NeurologyUniversity of IowaIowa CityIowaUSA
| | | | - Fillan Grady
- Department of NeurologyUniversity of IowaIowa CityIowaUSA
| | - Rebecca L. Miller
- Department of Anatomy and NeurobiologyWashington University School of MedicineSaint LouisMissouriUSA
| | - Corey M. McCann
- Department of Anatomy and NeurobiologyWashington University School of MedicineSaint LouisMissouriUSA
| | - Bernd Fritzsch
- Iowa Neuroscience InstituteIowa CityIowaUSA
- Department of BiologyUniversity of IowaIowa CityIowaUSA
| | - Igor Y. Iskusnykh
- Department of Anatomy and NeurobiologyUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Victor V. Chizhikov
- Department of Anatomy and NeurobiologyUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Joel C. Geerling
- Department of NeurologyUniversity of IowaIowa CityIowaUSA
- Iowa Neuroscience InstituteIowa CityIowaUSA
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11
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Teran FA, Bravo E, Richerson GB. Sudden unexpected death in epilepsy: Respiratory mechanisms. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:153-176. [PMID: 36031303 PMCID: PMC10191258 DOI: 10.1016/b978-0-323-91532-8.00012-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Epilepsy is one of the most common chronic neurologic diseases, with a prevalence of 1% in the US population. Many people with epilepsy live normal lives, but are at risk of sudden unexpected death in epilepsy (SUDEP). This mysterious comorbidity of epilepsy causes premature death in 17%-50% of those with epilepsy. Most SUDEP occurs after a generalized seizure, and patients are typically found in bed in the prone position. Until recently, it was thought that SUDEP was due to cardiovascular failure, but patients who died while being monitored in hospital epilepsy units revealed that most SUDEP is due to postictal central apnea. Some cases may occur when seizures invade the amygdala and activate projections to the brainstem. Evidence suggests that the pathophysiology is linked to defects in the serotonin system and central CO2 chemoreception, and that there is considerable overlap with mechanisms thought to be involved in sudden infant death syndrome (SIDS). Future work is needed to identify biomarkers for patients at highest risk, improve ascertainment, develop methods to alert caregivers when SUDEP is imminent, and find effective approaches to prevent these fatal events.
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Affiliation(s)
- Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States.
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA, United States
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12
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Grady FS, Boes AD, Geerling JC. A Century Searching for the Neurons Necessary for Wakefulness. Front Neurosci 2022; 16:930514. [PMID: 35928009 PMCID: PMC9344068 DOI: 10.3389/fnins.2022.930514] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/15/2022] [Indexed: 11/25/2022] Open
Abstract
Wakefulness is necessary for consciousness, and impaired wakefulness is a symptom of many diseases. The neural circuits that maintain wakefulness remain incompletely understood, as do the mechanisms of impaired consciousness in many patients. In contrast to the influential concept of a diffuse "reticular activating system," the past century of neuroscience research has identified a focal region of the upper brainstem that, when damaged, causes coma. This region contains diverse neuronal populations with different axonal projections, neurotransmitters, and genetic identities. Activating some of these populations promotes wakefulness, but it remains unclear which specific neurons are necessary for sustaining consciousness. In parallel, pharmacological evidence has indicated a role for special neurotransmitters, including hypocretin/orexin, histamine, norepinephrine, serotonin, dopamine, adenosine and acetylcholine. However, genetically targeted experiments have indicated that none of these neurotransmitters or the neurons producing them are individually necessary for maintaining wakefulness. In this review, we emphasize the need to determine the specific subset of brainstem neurons necessary for maintaining arousal. Accomplishing this will enable more precise mapping of wakefulness circuitry, which will be useful in developing therapies for patients with coma and other disorders of arousal.
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Affiliation(s)
- Fillan S Grady
- Geerling Laboratory, Department of Neurology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, United States
| | - Aaron D Boes
- Boes Laboratory, Departments of Pediatrics, Neurology, and Psychiatry, The University of Iowa, Iowa City, IA, United States
| | - Joel C Geerling
- Geerling Laboratory, Department of Neurology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, United States
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Abstract
PURPOSE OF REVIEW The serotonergic system is implicated in multiple aspects of epilepsy, including seizure susceptibility, sudden unexpected death in epilepsy (SUDEP), and comorbid depression. Despite the complexity of serotonin's effects on various neuronal networks, ongoing research provides considerable insight into the role of serotonin in human epilepsy. This review explores the potential roles of serotonergic therapies to improve clinical outcomes in epilepsy. RECENT FINDINGS In recent decades, research has markedly increased our knowledge of the diverse effects of serotonin on brain function. Animal models of epilepsy have identified the influence of serotonin on seizure threshold in specific brain regions, serotoninergic augmentation's protective effects on terminal apnea and mortality in SUDEP, and mechanisms underlying behavioral improvement in some models of comorbid depression. Human clinical studies are largely consistent with animal data but the translation into definitive treatment decisions has moved less rapidly. SUMMARY Evidence for serotonergic therapy is promising for improvement in seizure control and prevention of SUDEP. For some epilepsies, such as Dravet syndrome, basic research on serotonin receptor agonists has translated into a positive clinical trial for fenfluramine. The cumulative results of safety and efficacy studies support the routine use of SSRIs for comorbid depression in epilepsy.
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Affiliation(s)
| | | | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry, University of Kentucky
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14
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Salesse C, Charest J, Doucet-Beaupré H, Castonguay AM, Labrecque S, De Koninck P, Lévesque M. Opposite Control of Excitatory and Inhibitory Synapse Formation by Slitrk2 and Slitrk5 on Dopamine Neurons Modulates Hyperactivity Behavior. Cell Rep 2021; 30:2374-2386.e5. [PMID: 32075770 DOI: 10.1016/j.celrep.2020.01.084] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 12/03/2019] [Accepted: 01/24/2020] [Indexed: 11/26/2022] Open
Abstract
The neurodevelopmental origin of hyperactivity disorder has been suggested to involve the dopaminergic system, but the underlying mechanisms are still unknown. Here, transcription factors Lmx1a and Lmx1b are shown to be essential for midbrain dopaminergic (mDA) neuron excitatory synaptic inputs and dendritic development. Strikingly, conditional knockout (cKO) of Lmx1a/b in postmitotic mDA neurons results in marked hyperactivity. In seeking Lmx1a/b target genes, we identify positively regulated Slitrk2 and negatively regulated Slitrk5. These two synaptic adhesion proteins promote excitatory and inhibitory synapses on mDA neurons, respectively. Knocking down Slitrk2 reproduces some of the Lmx1a/b cKO cellular and behavioral phenotypes, whereas Slitrk5 knockdown has opposite effects. The hyperactivity caused by this imbalance in excitatory/inhibitory synaptic inputs on dopamine neurons is reproduced by chronically inhibiting the ventral tegmental area during development using pharmacogenetics. Our study shows that alterations in developing dopaminergic circuits strongly impact locomotor activity, shedding light on mechanisms causing hyperactivity behaviors.
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Affiliation(s)
- Charleen Salesse
- CERVO Brain Research Centre, 2601 de la Canardière, Québec, QC G1J 2G3, Canada
| | - Julien Charest
- CERVO Brain Research Centre, 2601 de la Canardière, Québec, QC G1J 2G3, Canada
| | | | | | - Simon Labrecque
- CERVO Brain Research Centre, 2601 de la Canardière, Québec, QC G1J 2G3, Canada
| | - Paul De Koninck
- CERVO Brain Research Centre, 2601 de la Canardière, Québec, QC G1J 2G3, Canada; Department of Biochemistry, Microbiology and Bioinformatics, Faculty of Science and Engineering, Université Laval, Québec, QC G1V 0A6, Canada
| | - Martin Lévesque
- CERVO Brain Research Centre, 2601 de la Canardière, Québec, QC G1J 2G3, Canada; Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada.
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15
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Laureano-Melo R, Dos-Santos RC, da Conceição RR, de Souza JS, da Silva Lau R, da Silva Souza Silva S, Marinho BG, Giannocco G, Ahmed RG, da Silva Côrtes W. Perinatal fluoxetine treatment promotes long-term behavioral changes in adult mice. Metab Brain Dis 2020; 35:1341-1351. [PMID: 32827287 DOI: 10.1007/s11011-020-00606-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/04/2020] [Indexed: 01/19/2023]
Abstract
Serotonin exerts a significant role in the mammalian central nervous system embryogenesis and brain ontogeny. Therefore, we investigate the effect of perinatal fluoxetine (FLX), a selective serotonin reuptake inhibitor, administration on the behavioral expression of adult male Swiss mice. For this purpose, two groups (n = 6 each, and ~ 35 g) of pregnant female Swiss mice were mated. Their offspring were treated with FLX (10 mg/Kg, s.c.) from postnatal day (PND) 5 to 15. At PND 16, one male puppy of each litter was euthanized, and the hippocampus was dissected for RNA analysis. At 70 days of life, the male offspring underwent a behavioral assessment in the open field, object recognition task, light-dark box, tail suspension and rotarod test. According to our results, the programmed animals had a decrease in TPH2, 5HT1a, SERT, BDNF, and LMX1B expression. Also, it was observed less time of immobility in tail suspension test and higher grooming time in the open field test. In the light-dark box test, the FLX-treated offspring had less time in the light side than control. We also observed a low cognitive performance in the object recognition task and poor motor skill learning in the rotarod test. These findings suggest that programming with FLX during the neonatal period alters a hippocampal serotonergic system, promoting anxiety and antidepressant behavior in adults, as well as a low mnemonic capacity.
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Affiliation(s)
- Roberto Laureano-Melo
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil.
- Department of Veterinary Medicine, Barra Mansa University Center, Rio de Janeiro, Brazil.
| | - Raoni Conceição Dos-Santos
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil
| | - Rodrigo Rodrigues da Conceição
- Molecular and Translational Endocrinology Laboratory, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Janaina Sena de Souza
- Molecular and Translational Endocrinology Laboratory, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Raphael da Silva Lau
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil
| | - Samantha da Silva Souza Silva
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil
| | - Bruno Guimarães Marinho
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil
| | - Gisele Giannocco
- Molecular and Translational Endocrinology Laboratory, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - R G Ahmed
- Division of Anatomy and Embryology, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - Wellington da Silva Côrtes
- Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Health and Biological Sciences, Universidade Federal Rural do Rio de Janeiro, Seropedica, Brazil
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16
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Flaive A, Fougère M, van der Zouwen CI, Ryczko D. Serotonergic Modulation of Locomotor Activity From Basal Vertebrates to Mammals. Front Neural Circuits 2020; 14:590299. [PMID: 33224027 PMCID: PMC7674590 DOI: 10.3389/fncir.2020.590299] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
During the last 50 years, the serotonergic (5-HT) system was reported to exert a complex modulation of locomotor activity. Here, we focus on two key factors that likely contribute to such complexity. First, locomotion is modulated directly and indirectly by 5-HT neurons. The locomotor circuitry is directly innervated by 5-HT neurons in the caudal brainstem and spinal cord. Also, indirect control of locomotor activity results from ascending projections of 5-HT cells in the rostral brainstem that innervate multiple brain centers involved in motor action planning. Second, each approach used to manipulate the 5-HT system likely engages different 5-HT-dependent mechanisms. This includes the recruitment of different 5-HT receptors, which can have excitatory or inhibitory effects on cell activity. These receptors can be located far or close to the 5-HT release sites, making their activation dependent on the level of 5-HT released. Here we review the activity of different 5-HT nuclei during locomotor activity, and the locomotor effects of 5-HT precursors, exogenous 5-HT, selective 5-HT reuptake inhibitors (SSRI), electrical or chemical stimulation of 5-HT neurons, genetic deletions, optogenetic and chemogenetic manipulations. We highlight both the coherent and controversial aspects of 5-HT modulation of locomotor activity from basal vertebrates to mammals. This mini review may hopefully inspire future studies aiming at dissecting the complex effects of 5-HT on locomotor function.
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Affiliation(s)
- Aurélie Flaive
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Maxime Fougère
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Cornelis Immanuel van der Zouwen
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC, Canada.,Centre des Neurosciences de Sherbrooke, Sherbrooke, QC, Canada
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17
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Inactivation of the GATA Cofactor ZFPM1 Results in Abnormal Development of Dorsal Raphe Serotonergic Neuron Subtypes and Increased Anxiety-Like Behavior. J Neurosci 2020; 40:8669-8682. [PMID: 33046550 DOI: 10.1523/jneurosci.2252-19.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 12/14/2022] Open
Abstract
Serotonergic neurons in the dorsal raphe (DR) nucleus are associated with several psychiatric disorders including depression and anxiety disorders, which often have a neurodevelopmental component. During embryonic development, GATA transcription factors GATA2 and GATA3 operate as serotonergic neuron fate selectors and regulate the differentiation of serotonergic neuron subtypes of DR. Here, we analyzed the requirement of GATA cofactor ZFPM1 in the development of serotonergic neurons using Zfpm1 conditional mouse mutants. Our results demonstrated that, unlike the GATA factors, ZFPM1 is not essential for the early differentiation of serotonergic precursors in the embryonic rhombomere 1. In contrast, in perinatal and adult male and female Zfpm1 mutants, a lateral subpopulation of DR neurons (ventrolateral part of the DR) was lost, whereas the number of serotonergic neurons in a medial subpopulation (dorsal region of the medial DR) had increased. Additionally, adult male and female Zfpm1 mutants had reduced serotonin concentration in rostral brain areas and displayed increased anxiety-like behavior. Interestingly, female Zfpm1 mutant mice showed elevated contextual fear memory that was abolished with chronic fluoxetine treatment. Altogether, these results demonstrate the importance of ZFPM1 for the development of DR serotonergic neuron subtypes involved in mood regulation. It also suggests that the neuronal fate selector function of GATAs is modulated by their cofactors to refine the differentiation of neuronal subtypes.SIGNIFICANCE STATEMENT Predisposition to anxiety disorders has both a neurodevelopmental and a genetic basis. One of the brainstem nuclei involved in the regulation of anxiety is the dorsal raphe, which contains different subtypes of serotonergic neurons. We show that inactivation of a transcriptional cofactor ZFPM1 in mice results in a developmental failure of laterally located dorsal raphe serotonergic neurons and changes in serotonergic innervation of rostral brain regions. This leads to elevated anxiety-like behavior and contextual fear memory, alleviated by chronic fluoxetine treatment. Our work contributes to understanding the neurodevelopmental mechanisms that may be disturbed in the anxiety disorder.
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18
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Hernández A, Olvera-Hernández S, Fernández-Guasti A. Lack of interaction between prenatal stress and prenatal letrozole to induce same-sex preference in male rats. Physiol Behav 2020; 224:113042. [PMID: 32619527 DOI: 10.1016/j.physbeh.2020.113042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/12/2020] [Accepted: 06/28/2020] [Indexed: 12/29/2022]
Abstract
Same-sex partner preference between males has been observed in all species in which this behavior has been studied. Disruption of brain estradiol synthesis during development has been proposed as one of the biological causes underlying this behavior in some mammals. In support of this possibility, perinatal administration of aromatase inhibitors (such as letrozole) to male rat pups, induces around half of them to have same-sex preference and female sexual behavior in adulthood. Another putative factor that modifies sex preference is prenatal stress. Several stress protocols, applied to the pregnant dam, cause some of the adult male progeny to have an increased male preference, a decreased preference for the female, and lordosis behavior. Interestingly, these effects of stress might be mediated by its inhibitory action on brain aromatase. The aim of the present study was to analyze a possible interaction between these two factors in male rats. Pregnant dams were exposed to one of the four treatments across gestation days 10-22 (G10-G22): 1) vehicle-treated non-stressed controls; 2) letrozole (0.56 µg/kg); 3) 30 min immobilization stress); 4) both letrozole and stress combined. The male offspring were tested in adulthood for partner preference in a three-chambered arena, where we also recorded the masculine and feminine sexual behaviors. One week later males were tested for masculine and feminine sexual behavior in cylindrical arenas where they interacted for 30 min with a receptive female and thereafter with a sexually active male for another 30 min. Letrozole, stress and their combination resulted in same-sex preference in 40, 31 and 50% of males, respectively, compared to 5% in the control group. In the sexual behavior tests, prenatal stress reduced the percentage of males displaying intromissions and ejaculation (impaired masculinization), while letrozole mainly increased lordosis (impaired defeminization). The males prenatally submitted to stress and treated with letrozole presented these behavioral features but did not differ from both treatments given independently. The results indicate that the changes induced by stress or the aromatase inhibition produced by letrozole only accounts for a shift in partner preference in around half of the males and that there was no interaction between these two factors.
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Affiliation(s)
- Alejandra Hernández
- Pharmacobiology Department. Center of Research and Advanced Studies of IPN (CINVESTAV), México
| | - Sandra Olvera-Hernández
- Medical and Psychology School, Autonomous University of Baja California, Tijuana, B.C., México
| | - Alonso Fernández-Guasti
- Pharmacobiology Department. Center of Research and Advanced Studies of IPN (CINVESTAV), México..
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19
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Kinney HC, Haynes RL. The Serotonin Brainstem Hypothesis for the Sudden Infant Death Syndrome. J Neuropathol Exp Neurol 2020; 78:765-779. [PMID: 31397480 DOI: 10.1093/jnen/nlz062] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/28/2019] [Accepted: 06/25/2019] [Indexed: 01/04/2023] Open
Abstract
The sudden infant death syndrome (SIDS) is the leading cause of postneonatal infant mortality in the United States today, with an overall rate of 0.39/1000 live births. It is defined as the sudden and unexpected death of an infant <12 months of age that remains unexplained after a complete autopsy, death scene investigation, and review of the clinical history. The serotonin brainstem hypothesis has been a leading hypothesis for SIDS over the last 2 decades. Our laboratory has studied this hypothesis over time with a variety of tissue techniques, including tissue receptor autoradiography, high performance liquid chromatography, Western blot analysis, immunocytochemistry, and proteomics. The purpose of this article is to review the progress in our laboratory toward supporting this hypothesis. We conclude that an important subset of SIDS infants has serotonergic abnormalities resulting from a "core lesion" in the medullary reticular formation comprised of nuclei that contain serotonin neurons. This lesion could lead to a failure of protective brainstem responses to homeostatic challenges during sleep in a critical developmental period which cause sleep-related sudden death.
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Affiliation(s)
- Hannah C Kinney
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Robin L Haynes
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
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20
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Abstract
Neurons that synthesize and release 5-hydroxytryptamine (5-HT; serotonin) express a core set of genes that establish and maintain this neurotransmitter phenotype and distinguish these neurons from other brain cells. Beyond a shared 5-HTergic phenotype, these neurons display divergent cellular properties in relation to anatomy, morphology, hodology, electrophysiology and gene expression, including differential expression of molecules supporting co-transmission of additional neurotransmitters. This diversity suggests that functionally heterogeneous subtypes of 5-HT neurons exist, but linking subsets of these neurons to particular functions has been technically challenging. We discuss recent data from molecular genetic, genomic and functional methods that, when coupled with classical findings, yield a reframing of the 5-HT neuronal system as a conglomeration of diverse subsystems with potential to inspire novel, more targeted therapies for clinically distinct 5-HT-related disorders.
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21
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Petrucci AN, Joyal KG, Purnell BS, Buchanan GF. Serotonin and sudden unexpected death in epilepsy. Exp Neurol 2020; 325:113145. [PMID: 31866464 PMCID: PMC7029792 DOI: 10.1016/j.expneurol.2019.113145] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/12/2019] [Accepted: 12/10/2019] [Indexed: 12/20/2022]
Abstract
Epilepsy is a highly prevalent disease characterized by recurrent, spontaneous seizures. Approximately one-third of epilepsy patients will not achieve seizure freedom with medical management and become refractory to conventional treatments. These patients are at greatest risk for sudden unexpected death in epilepsy (SUDEP). The exact etiology of SUDEP is unknown, but a combination of respiratory, cardiac, neuronal electrographic dysfunction, and arousal impairment is thought to underlie SUDEP. Serotonin (5-HT) is involved in regulation of breathing, sleep/wake states, arousal, and seizure modulation and has been implicated in the pathophysiology of SUDEP. This review explores the current state of understanding of the relationship between 5-HT, epilepsy, and respiratory and autonomic control processes relevant to SUDEP in epilepsy patients and in animal models.
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Affiliation(s)
- Alexandra N Petrucci
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, United States of America; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, United States of America
| | - Katelyn G Joyal
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, United States of America; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, United States of America
| | - Benton S Purnell
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, United States of America; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, United States of America
| | - Gordon F Buchanan
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, United States of America; Department of Neurology, University of Iowa, Iowa City, IA 52242, United States of America; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, United States of America.
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22
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5-HT neurons and central CO2 chemoreception. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/b978-0-444-64125-0.00021-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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23
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Petitjean H, Bourojeni FB, Tsao D, Davidova A, Sotocinal SG, Mogil JS, Kania A, Sharif-Naeini R. Recruitment of Spinoparabrachial Neurons by Dorsal Horn Calretinin Neurons. Cell Rep 2019; 28:1429-1438.e4. [DOI: 10.1016/j.celrep.2019.07.048] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 06/13/2019] [Accepted: 07/15/2019] [Indexed: 01/11/2023] Open
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24
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Donovan LJ, Spencer WC, Kitt MM, Eastman BA, Lobur KJ, Jiao K, Silver J, Deneris ES. Lmx1b is required at multiple stages to build expansive serotonergic axon architectures. eLife 2019; 8:e48788. [PMID: 31355748 PMCID: PMC6685705 DOI: 10.7554/elife.48788] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/27/2019] [Indexed: 01/18/2023] Open
Abstract
Formation of long-range axons occurs over multiple stages of morphological maturation. However, the intrinsic transcriptional mechanisms that temporally control different stages of axon projection development are unknown. Here, we addressed this question by studying the formation of mouse serotonin (5-HT) axons, the exemplar of long-range profusely arborized axon architectures. We report that LIM homeodomain factor 1b (Lmx1b)-deficient 5-HT neurons fail to generate axonal projections to the forebrain and spinal cord. Stage-specific targeting demonstrates that Lmx1b is required at successive stages to control 5-HT axon primary outgrowth, selective routing, and terminal arborization. We show a Lmx1b→Pet1 regulatory cascade is temporally required for 5-HT arborization and upregulation of the 5-HT axon arborization gene, Protocadherin-alphac2, during postnatal development of forebrain 5-HT axons. Our findings identify a temporal regulatory mechanism in which a single continuously expressed transcription factor functions at successive stages to orchestrate the progressive development of long-range axon architectures enabling expansive neuromodulation.
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Affiliation(s)
- Lauren J Donovan
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - William C Spencer
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Meagan M Kitt
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Brent A Eastman
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Katherine J Lobur
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Kexin Jiao
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Jerry Silver
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Evan S Deneris
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
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25
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Cummings KJ, Hodges MR. The serotonergic system and the control of breathing during development. Respir Physiol Neurobiol 2019; 270:103255. [PMID: 31362064 DOI: 10.1016/j.resp.2019.103255] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/28/2019] [Accepted: 07/12/2019] [Indexed: 01/26/2023]
Abstract
Serotonin (5-hydroxytryptamine 5-HT) was first discovered in the late 1940's as an endogenous bioactive amine capable of inducing vasoconstriction, and in the mid-1950's was found in the brain. It was in these early years that some of the first demonstrations were made regarding a role for brain 5-HT in neurological function and behavior, including data implicating reduced brain levels of 5-HT in clinical depression. Since that time, advances in molecular biology and physiological approaches in basic science research have intensely focused on 5-HT in the brain, and the many facets of its role during embryonic development, post-natal maturation, and neural function in adulthood continues to be established. This review focuses on what is known about the developmental roles for the 5-HT system, which we define as the neurons producing 5-HT along with pre-and post-synaptic receptors, in a vital homeostatic motor behavior - the control of breathing. We will cover what is known about the embryonic origins and fate specification of 5-HT neurons, and how the 5-HT system influences pre- and post-natal maturation of the ventilatory control system. In addition, we will focus on the role of the 5-HT system in specific respiratory behaviors during fetal, neonatal and postnatal development, and the relevance of dysfunction in this system in respiratory-related human pathologies including Sudden Infant Death Syndrome (SIDS).
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211, USA.
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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26
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Matthes S, Mosienko V, Popova E, Rivalan M, Bader M, Alenina N. Targeted Manipulation of Brain Serotonin: RNAi-Mediated Knockdown of Tryptophan Hydroxylase 2 in Rats. ACS Chem Neurosci 2019; 10:3207-3217. [PMID: 30977636 DOI: 10.1021/acschemneuro.8b00635] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of the biogenic monoamine serotonin (5-hydroxytryptamine, 5-HT). Two existing TPH isoforms are responsible for the generation of two distinct serotonergic systems in vertebrates. TPH1, predominantly expressed in the gastrointestinal tract and pineal gland, mediates 5-HT biosynthesis in non-neuronal tissues, while TPH2, mainly found in the raphe nuclei of the brain stem, is accountable for the production of 5-HT in the brain. Neuronal 5-HT is a key regulator of mood and behavior and its deficiency has been implicated in a variety of neuropsychiatric disorders, e.g., depression and anxiety. To gain further insights into the complexity of central 5-HT modulations of physiological and pathophysiological processes, a new transgenic rat model, allowing an inducible gene knockdown of Tph2, was established based on doxycycline-inducible shRNA-expression. Biochemical phenotyping revealed a functional knockdown of Tph2 mRNA expression following oral doxycycline administration, with subsequent reductions in the corresponding levels of TPH2 enzyme expression and activity. Transgenic rats showed also significantly decreased tissue levels of 5-HT and its degradation product 5-Hydroxyindoleacetic acid (5-HIAA) in the raphe nuclei, hippocampus, hypothalamus, and cortex, while peripheral 5-HT concentrations in the blood remained unchanged. In summary, this novel transgenic rat model allows inducible manipulation of 5-HT biosynthesis specifically in the brain and may help to elucidate the role of 5-HT in the pathophysiology of affective disorders.
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Affiliation(s)
- Susann Matthes
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Straße 10, 13125 Berlin-Buch, Germany
- Institute for Biology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Valentina Mosienko
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Straße 10, 13125 Berlin-Buch, Germany
- College of Medicine and Health, Institute of Biomedical and Clinical Sciences, University of Exeter, Hatherly Building, Prince of Wales Rd., EX4 4PS Exeter, United Kingdom
| | - Elena Popova
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Straße 10, 13125 Berlin-Buch, Germany
| | - Marion Rivalan
- Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Michael Bader
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Straße 10, 13125 Berlin-Buch, Germany
- Institute for Biology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
- Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Straße 2, 10178 Berlin, Germany
| | - Natalia Alenina
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Straße 10, 13125 Berlin-Buch, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, 13316 Berlin, Germany
- Institute of Translational Biomedicine, St. Petersburg State University, Saint Petersburg 199034, Russia
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Liu Y, Sun Y, Zhao X, Kim JY, Luo L, Wang Q, Meng X, Li Y, Sui N, Chen ZF, Pan C, Li L, Zhang Y. Enhancement of Aggression Induced by Isolation Rearing is Associated with a Lack of Central Serotonin. Neurosci Bull 2019; 35:841-852. [PMID: 30977041 DOI: 10.1007/s12264-019-00373-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/13/2019] [Indexed: 01/06/2023] Open
Abstract
Isolation rearing (IR) enhances aggressive behavior, and the central serotonin (5-hydroxytryptamine, 5-HT) system has been linked to IR-induced aggression. However, whether the alteration of central serotonin is the cause or consequence of enhanced aggression is still unknown. In the present study, using mice deficient in central serotonin Tph2-/- and Lmx1b-/-, we examined the association between central serotonin and aggression with or without social isolation. We demonstrated that central serotonergic neurons are critical for the enhanced aggression after IR. 5-HT depletion in wild-type mice increased aggression. On the other hand, application of 5-HT in Lmx1b-/- mice inhibited the enhancement of aggression under social isolation conditions. Dopamine was downregulated in Lmx1b-/- mice. Similar to 5-HT, L-DOPA decreased aggression in Lmx1b-/- mice. Our results link the serotoninergic system directly to aggression and this may have clinical implications for aggression-related human conditions.
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Affiliation(s)
- Yiqiong Liu
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, 100871, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, 100871, China
| | | | - Xiaoyan Zhao
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100005, China
| | - Ji-Young Kim
- Department of Anesthesiology, Department of Psychiatry, Department of Developmental Biology, Center for the Study of Itch, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Lu Luo
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Qian Wang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Xiaolu Meng
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yonghui Li
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Nan Sui
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhou-Feng Chen
- Department of Anesthesiology, Department of Psychiatry, Department of Developmental Biology, Center for the Study of Itch, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Chuxiong Pan
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100005, China
| | - Liang Li
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China. .,Beijing Institute for Brain Disorders, Beijing, 100069, China.
| | - Yan Zhang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, 100871, China. .,PKU-IDG/McGovern Institute for Brain Research, Beijing, 100871, China.
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28
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Kruse SW, Dayton KG, Purnell BS, Rosner JI, Buchanan GF. Effect of monoamine reuptake inhibition and α 1 blockade on respiratory arrest and death following electroshock-induced seizures in mice. Epilepsia 2019; 60:495-507. [PMID: 30723893 PMCID: PMC6467066 DOI: 10.1111/epi.14652] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 12/26/2018] [Accepted: 01/03/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. Although the mechanisms for SUDEP are incompletely understood, seizure-induced respiratory arrest (S-IRA) has been strongly and consistently implicated. A body of evidence indicates that serotonin (5-HT), a modulator of breathing, plays a critical role in SUDEP. Because the 5-HT and norepinephrine (NE) systems interact in many biologic processes and NE is known to modulate breathing and seizures, we hypothesized that NE may play a role in S-IRA and SUDEP. METHODS We examined the effects of pharmacologic manipulation of 5-HT and NE on S-IRA and death following maximal electroshock (MES)-induced seizures in adult wild-type (WT) mice, genetically 5-HT neuron-deficient (Lmx1bf/f/p ) mice, and chemically NE neuron-deficient mice. Mice were treated with pharmacologic agents targeting the serotonergic and noradrenergic systems and subjected to seizure induction via MES while breathing was measured via whole-body plethysmography. RESULTS S-IRA and death was reduced in WT mice with NE reuptake inhibitors (NRIs), reboxetine and atomoxetine, selective serotonin reuptake inhibitors (SSRIs), fluoxetine and citalopram, and the dual 5-HT/NE reuptake inhibitor (SNRI), duloxetine. S-IRA and death was also reduced in Lmx1bf/f/p mice with reboxetine and fluoxetine. The protective effects of the reuptake inhibitors were prevented by the α1 antagonist, prazosin. Citalopram did not reduce S-IRA and death in NE neuron-deficient mice. SIGNIFICANCE These data suggest that 5-HT and NE critically interact in the modulation of breathing following a seizure and potentially inform preventive strategies for SUDEP.
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Affiliation(s)
- Stephen W. Kruse
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242
| | - Kyle G. Dayton
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242
| | - Benton S. Purnell
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242
| | - Jared I. Rosner
- Secondary Student Training Program, University of Iowa, Iowa City, IA 52242
| | - Gordon F. Buchanan
- Department of Neurology, University of Iowa, Iowa City, IA 52242
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242
- Carver College of Medicine, University of Iowa, Iowa City, IA 52242
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29
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Cesario JM, Landin Malt A, Chung JU, Khairallah MP, Dasgupta K, Asam K, Deacon LJ, Choi V, Almaidhan AA, Darwiche NA, Kim J, Johnson RL, Jeong J. Anti-osteogenic function of a LIM-homeodomain transcription factor LMX1B is essential to early patterning of the calvaria. Dev Biol 2018; 443:103-116. [PMID: 29852132 DOI: 10.1016/j.ydbio.2018.05.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/15/2018] [Accepted: 05/26/2018] [Indexed: 12/22/2022]
Abstract
The calvaria (upper part of the skull) is made of plates of bone and fibrous joints (sutures and fontanelles), and the proper balance and organization of these components are crucial to normal development of the calvaria. In a mouse embryo, the calvaria develops from a layer of head mesenchyme that surrounds the brain from shortly after mid-gestation. The mesenchyme just above the eye (supra-orbital mesenchyme, SOM) generates ossification centers for the bones, which then grow toward the apex gradually. In contrast, the mesenchyme apical to SOM (early migrating mesenchyme, EMM), including the area at the vertex, does not generate an ossification center. As a result, the dorsal midline of the head is occupied by sutures and fontanelles at birth. To date, the molecular basis for this regional difference in developmental programs is unknown. The current study provides vital insights into the genetic regulation of calvarial patterning. First, we showed that osteogenic signals were active in both EMM and SOM during normal development, which suggested the presence of an anti-osteogenic factor in EMM to counter the effect of these signals. Subsequently, we identified Lmx1b as an anti-osteogenic gene that was expressed in EMM but not in SOM. Furthermore, head mesenchyme-specific deletion of Lmx1b resulted in heterotopic ossification from EMM at the vertex, and craniosynostosis affecting multiple sutures. Conversely, forced expression of Lmx1b in SOM was sufficient to inhibit osteogenic specification. Therefore, we conclude that Lmx1b plays a key role as an anti-osteogenic factor in patterning the head mesenchyme into areas with different osteogenic competence. In turn, this patterning event is crucial to generating the proper organization of the bones and soft tissue joints of the calvaria.
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Affiliation(s)
- Jeffry M Cesario
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - André Landin Malt
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Jong Uk Chung
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Michael P Khairallah
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Krishnakali Dasgupta
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Kesava Asam
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Lindsay J Deacon
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Veronica Choi
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Asma A Almaidhan
- Department of Orthodontics, New York University College of Dentistry, New York, NY, United States
| | - Nadine A Darwiche
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Jimin Kim
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States
| | - Randy L Johnson
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Juhee Jeong
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States.
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30
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Male rats with same-sex preference show higher immobility in the forced swim test, but similar effects of fluoxetine and desipramine than males that prefer females. Pharmacol Biochem Behav 2018; 171:39-45. [PMID: 29807066 DOI: 10.1016/j.pbb.2018.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 12/13/2022]
Abstract
Sex preference in male rats is partly determined by the organizational action of estradiol. Thus, several paradigms have used aromatase inhibitors to manipulate sex preference. We recently showed that a subpopulation of male rats prenatally treated with letrozole (0.56 μg/kg, G10-G22), a non-steroidal third generation aromatase inhibitor, had same-sex preference, female sexual behavior (including lordosis and proceptivity) and penile erections when exposed to other males. These males, in addition, displayed high levels of experimental anxiety in the plus maze test and were insensitive to the anxiogenic-like acute effect of FLX (10 mg/kg). The two main purposes of the present work were: a) to study the behavioral profile of males displaying same-sex preference in the forced swim test (FST), and b) to analyze if the antidepressant-like effect of the subchronic treatment with FLX (10 mg/kg, 3 times) or desipramine (DMI, 10 mg/kg, 3 times) vary according to sex preference. Males treated prenatally with letrozole with same-sex preference showed more immobility and less active behaviors (swimming and climbing) in the FST than males with female preference. Subchronic treatment with FLX and DMI reduced immobility when compared to saline controls, while FLX increased swimming and DMI increased climbing behavior. Treatments were equally effective in males with preference for other males and those that preferred females. These results indicate that an association exists between prenatal letrozole treatment, same-sex preference and immobility in the FST.
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31
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Zhang X, Yan H, Luo Y, Huang Z, Rao Y. Thermoregulation-Independent Regulation of Sleep by Serotonin Revealed in Mice Defective in Serotonin Synthesis. Mol Pharmacol 2018; 93:657-664. [DOI: 10.1124/mol.117.111229] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 04/03/2018] [Indexed: 11/22/2022] Open
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32
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Dorsal Raphe Serotonin Neurons Mediate CO 2-Induced Arousal from Sleep. J Neurosci 2018; 38:1915-1925. [PMID: 29378860 DOI: 10.1523/jneurosci.2182-17.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/07/2018] [Accepted: 01/10/2018] [Indexed: 01/10/2023] Open
Abstract
Arousal from sleep in response to CO2 is a critical protective phenomenon. Dysregulation of CO2-induced arousal contributes to morbidity and mortality from prevalent diseases, such as obstructive sleep apnea and sudden infant death syndrome. Despite the critical nature of this protective reflex, the precise mechanism for CO2-induced arousal is unknown. Because CO2 is a major regulator of breathing, prevailing theories suggest that activation of respiratory chemo- and mechano-sensors is required for CO2-induced arousal. However, populations of neurons that are not involved in the regulation of breathing are also chemosensitive. Among these are serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) that comprise a component of the ascending arousal system. We hypothesized that direct stimulation of these neurons with CO2 could cause arousal from sleep independently of enhancing breathing. Dialysis of CO2-rich acidified solution into DRN, but not medullary raphe responsible for modulating breathing, caused arousal from sleep. Arousal was lost in mice with a genetic absence of 5-HT neurons, and with acute pharmacological or optogenetic inactivation of DRN 5-HT neurons. Here we demonstrate that CO2 can cause arousal from sleep directly, without requiring enhancement of breathing, and that chemosensitive 5-HT neurons in the DRN critically mediate this arousal. Better understanding mechanisms underlying this protective reflex may lead to interventions to reduce disease-associated morbidity and mortality.SIGNIFICANCE STATEMENT Although CO2-induced arousal is critical to a number of diseases, the specific mechanism is not well understood. We previously demonstrated that serotonin (5-HT) neurons are important for CO2-induced arousal, as mice without 5-HT neurons do not arouse to CO2 Many have interpreted this to mean that medullary 5-HT neurons that regulate breathing are important in this arousal mechanism. Here we found that direct application of CO2-rich aCSF to the dorsal raphe nucleus, but not the medullary raphe, causes arousal from sleep, and that this arousal was lost with genetic ablation or acute inhibition of 5-HT neurons. We propose that 5-HT neurons in the dorsal raphe nucleus can be activated directly by CO2 to cause arousal independently of respiratory activation.
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33
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Deneris E, Gaspar P. Serotonin neuron development: shaping molecular and structural identities. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2018; 7:10.1002/wdev.301. [PMID: 29072810 PMCID: PMC5746461 DOI: 10.1002/wdev.301] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/03/2017] [Accepted: 08/24/2017] [Indexed: 02/03/2023]
Abstract
The continuing fascination with serotonin (5-hydroxytryptamine, 5-HT) as a nervous system chemical messenger began with its discovery in the brains of mammals in 1953. Among the many reasons for this decades-long interest is that the small numbers of neurons that make 5-HT influence the excitability of neural circuits in nearly every region of the brain and spinal cord. A further reason is that 5-HT dysfunction has been linked to a range of psychiatric and neurological disorders many of which have a neurodevelopmental component. This has led to intense interest in understanding 5-HT neuron development with the aim of determining whether early alterations in their generation lead to brain disease susceptibility. Here, we present an overview of the neuroanatomical organization of vertebrate 5-HT neurons, their neurogenesis, and prodigious axonal architectures, which enables the expansive reach of 5-HT neuromodulation in the central nervous system. We review recent findings that have revealed the molecular basis for the tremendous diversity of 5-HT neuron subtypes, the impact of environmental factors on 5-HT neuron development, and how 5-HT axons are topographically organized through disparate signaling pathways. We summarize studies of the gene regulatory networks that control the differentiation, maturation, and maintenance of 5-HT neurons. These studies show that the regulatory factors controlling acquisition of 5-HT-type transmitter identity continue to play critical roles in the functional maturation and the maintenance of 5-HT neurons. New insights are presented into how continuously expressed 5-HT regulatory factors control 5-HT neurons at different stages of life and how the regulatory networks themselves are maintained. WIREs Dev Biol 2018, 7:e301. doi: 10.1002/wdev.301 This article is categorized under: Nervous System Development > Vertebrates: General Principles Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics Gene Expression and Transcriptional Hierarchies > Cellular Differentiation Nervous System Development > Secondary: Vertebrates: Regional Development.
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Affiliation(s)
- Evan Deneris
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Patricia Gaspar
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S839, Paris, France
- Sorbonne Université, Paris, France
- Institut du Fer à Moulin, Campus Jussieu, Paris, France
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34
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Bourguignon C, Storch KF. Control of Rest:Activity by a Dopaminergic Ultradian Oscillator and the Circadian Clock. Front Neurol 2017; 8:614. [PMID: 29230188 PMCID: PMC5711773 DOI: 10.3389/fneur.2017.00614] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 11/03/2017] [Indexed: 11/23/2022] Open
Abstract
There is long-standing evidence for rhythms in locomotor activity, as well as various other aspects of physiology, with periods substantially shorter than 24 h in organisms ranging from fruit flies to humans. These ultradian oscillations, whose periods frequently fall between 2 and 6 h, are normally well integrated with circadian rhythms; however, they often lack the period stability and expression robustness of the latter. An adaptive advantage of ultradian rhythms has been clearly demonstrated for the common vole, suggesting that they may have evolved to confer social synchrony. The cellular substrate and mechanism of ultradian rhythm generation have remained elusive so far, however recent findings—the subject of this review—now indicate that ultradian locomotor rhythms rely on an oscillator based on dopamine, dubbed the dopaminergic ultradian oscillator (DUO). These findings also reveal that the DUO period can be lengthened from <4 to >48 h by methamphetamine treatment, suggesting that the previously described methamphetamine-sensitive (circadian) oscillator represents a long-period manifestation of the DUO.
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Affiliation(s)
- Clément Bourguignon
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Kai-Florian Storch
- Douglas Mental Health University Institute, Montreal, QC, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
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35
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Purnell BS, Hajek MA, Buchanan GF. Time-of-day influences on respiratory sequelae following maximal electroshock-induced seizures in mice. J Neurophysiol 2017; 118:2592-2600. [PMID: 28794189 PMCID: PMC5668461 DOI: 10.1152/jn.00039.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 11/22/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in refractory epilepsy patients. Although specific mechanisms underlying SUDEP are not well understood, evidence suggests most SUDEP occurs due to seizure-induced respiratory arrest. SUDEP also tends to happen at night. Although this may be due to circumstances in which humans find themselves at night, such as being alone without supervision or sleeping prone, or to independent influences of sleep state, there are a number of reasons why the night (i.e., circadian influences) could be an independent risk factor for SUDEP. We explored this possibility. Adult male WT mice were instrumented for EEG, EMG, and EKG recording and subjected to maximal electroshock (MES) seizures during wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep during the nighttime/dark phase. These data were compared with data collected following seizures induced during the daytime/light phase. Seizures induced during the nighttime were similar in severity and duration to those induced during the daytime; however, seizures induced during the nighttime were associated with a lesser degree of respiratory dysregulation and postictal EEG suppression. Seizures induced during REM sleep during the nighttime were universally fatal, as is seen when seizures are induced during REM during the daytime. Taken together, these data implicate a role for time of day in influencing the physiological consequences of seizures that may contribute to seizure-induced death.NEW & NOTEWORTHY Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. SUDEP frequently occurs during the night, which has been attributed to an effect of sleep. We have shown that sleep state does indeed influence survival following a seizure. That SUDEP occurs during the night could also implicate a circadian influence. In this study we found that time of day independently affects the physiological consequences of seizures.
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Affiliation(s)
- Benton S Purnell
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Michael A Hajek
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut
| | - Gordon F Buchanan
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa Carver College of Medicine, Iowa City, Iowa;
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, Iowa; and
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut
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36
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Chabrat A, Brisson G, Doucet-Beaupré H, Salesse C, Schaan Profes M, Dovonou A, Akitegetse C, Charest J, Lemstra S, Côté D, Pasterkamp RJ, Abrudan MI, Metzakopian E, Ang SL, Lévesque M. Transcriptional repression of Plxnc1 by Lmx1a and Lmx1b directs topographic dopaminergic circuit formation. Nat Commun 2017; 8:933. [PMID: 29038581 PMCID: PMC5643336 DOI: 10.1038/s41467-017-01042-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 08/15/2017] [Indexed: 12/27/2022] Open
Abstract
Mesodiencephalic dopamine neurons play central roles in the regulation of a wide range of brain functions, including voluntary movement and behavioral processes. These functions are served by distinct subtypes of mesodiencephalic dopamine neurons located in the substantia nigra pars compacta and the ventral tegmental area, which form the nigrostriatal, mesolimbic, and mesocortical pathways. Until now, mechanisms involved in dopaminergic circuit formation remained largely unknown. Here, we show that Lmx1a, Lmx1b, and Otx2 transcription factors control subtype-specific mesodiencephalic dopamine neurons and their appropriate axon innervation. Our results revealed that the expression of Plxnc1, an axon guidance receptor, is repressed by Lmx1a/b and enhanced by Otx2. We also found that Sema7a/Plxnc1 interactions are responsible for the segregation of nigrostriatal and mesolimbic dopaminergic pathways. These findings identify Lmx1a/b, Otx2, and Plxnc1 as determinants of dopaminergic circuit formation and should assist in engineering mesodiencephalic dopamine neurons capable of regenerating appropriate connections for cell therapy.Midbrain dopaminergic neurons (mDAs) in the VTA and SNpc project to different regions and form distinct circuits. Here the authors show that transcription factors Lmx1a, Lmx1b, and Otx2 control the axon guidance of mDAs and the segregation of mesolimbic and nigrostriatal dopaminergic pathways.
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Affiliation(s)
- Audrey Chabrat
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Guillaume Brisson
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Hélène Doucet-Beaupré
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Charleen Salesse
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Marcos Schaan Profes
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Axelle Dovonou
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Cléophace Akitegetse
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Julien Charest
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
| | - Suzanne Lemstra
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands
| | - Daniel Côté
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3
- Département de Physique, Genie Physique et Optique, Université Laval, Québec, Quebec, G1V 0A6, Canada
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands
| | - Monica I Abrudan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
- Faculty of Medicine, School of Public Health, Imperial College, London, W2 1PG, UK
| | - Emmanouil Metzakopian
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Siew-Lan Ang
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Martin Lévesque
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Québec, Quebec, G1V 0A6, Canada.
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Québec, Quebec, Canada, G1J 2G3.
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Adult Brain Serotonin Deficiency Causes Hyperactivity, Circadian Disruption, and Elimination of Siestas. J Neurosci 2017; 36:9828-42. [PMID: 27656022 DOI: 10.1523/jneurosci.1469-16.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/03/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Serotonin (5-HT) is a crucial neuromodulator linked to many psychiatric disorders. However, after more than 60 years of study, its role in behavior remains poorly understood, in part because of a lack of methods to target 5-HT synthesis specifically in the adult brain. Here, we have developed a genetic approach that reproducibly achieves near-complete elimination of 5-HT synthesis from the adult ascending 5-HT system by stereotaxic injection of an adeno-associated virus expressing Cre recombinase (AAV-Cre) into the midbrain/pons of mice carrying a loxP-conditional tryptophan hydroxylase 2 (Tph2) allele. We investigated the behavioral effects of deficient brain 5-HT synthesis and discovered a unique composite phenotype. Surprisingly, adult 5-HT deficiency did not affect anxiety-like behavior, but resulted in a robust hyperactivity phenotype in novel and home cage environments. Moreover, loss of 5-HT led to an altered pattern of circadian behavior characterized by an advance in the onset and a delay in the offset of daily activity, thus revealing a requirement for adult 5-HT in the control of daily activity patterns. Notably, after normalizing for hyperactivity, we found that the normal prolonged break in nocturnal activity (siesta), a period of rapid eye movement (REM) and non-REM sleep, was absent in all animals in which 5-HT deficiency was verified. Our findings identify adult 5-HT as a requirement for siestas, implicate adult 5-HT in sleep-wake homeostasis, and highlight the importance of our adult-specific 5-HT-synthesis-targeting approach in understanding 5-HT's role in controlling behavior. SIGNIFICANCE STATEMENT Serotonin (5-HT) is a crucial neuromodulator, yet its role in behavior remains poorly understood, in part because of a lack of methods to target specifically adult brain 5-HT synthesis. We developed an approach that reproducibly achieves near-complete elimination of 5-HT synthesis from the adult ascending 5-HT system. Using this technique, we discovered that adult 5-HT deficiency led to a novel compound phenotype consisting of hyperactivity, disrupted circadian behavior patterns, and elimination of siestas, a period of increased sleep during the active phase. These findings highlight the importance of our approach in understanding 5-HT's role in behavior, especially in controlling activity levels, circadian behavior, and sleep-wake homeostasis, behaviors that are disrupted in many psychiatric disorders such as attention deficit hyperactivity disorder.
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Spencer WC, Deneris ES. Regulatory Mechanisms Controlling Maturation of Serotonin Neuron Identity and Function. Front Cell Neurosci 2017; 11:215. [PMID: 28769770 PMCID: PMC5515867 DOI: 10.3389/fncel.2017.00215] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/05/2017] [Indexed: 11/29/2022] Open
Abstract
The brain serotonin (5-hydroxytryptamine; 5-HT) system has been extensively studied for its role in normal physiology and behavior, as well as, neuropsychiatric disorders. The broad influence of 5-HT on brain function, is in part due to the vast connectivity pattern of 5-HT-producing neurons throughout the CNS. 5-HT neurons are born and terminally specified midway through embryogenesis, then enter a protracted period of maturation, where they functionally integrate into CNS circuitry and then are maintained throughout life. The transcriptional regulatory networks controlling progenitor cell generation and terminal specification of 5-HT neurons are relatively well-understood, yet the factors controlling 5-HT neuron maturation are only recently coming to light. In this review, we first provide an update on the regulatory network controlling 5-HT neuron development, then delve deeper into the properties and regulatory strategies governing 5-HT neuron maturation. In particular, we discuss the role of the 5-HT neuron terminal selector transcription factor (TF) Pet-1 as a key regulator of 5-HT neuron maturation. Pet-1 was originally shown to positively regulate genes needed for 5-HT synthesis, reuptake and vesicular transport, hence 5-HT neuron-type transmitter identity. It has now been shown to regulate, both positively and negatively, many other categories of genes in 5-HT neurons including ion channels, GPCRs, transporters, neuropeptides, and other transcription factors. Its function as a terminal selector results in the maturation of 5-HT neuron excitability, firing characteristics, and synaptic modulation by several neurotransmitters. Furthermore, there is a temporal requirement for Pet-1 in the control of postmitotic gene expression trajectories thus indicating a direct role in 5-HT neuron maturation. Proper regulation of the maturation of cellular identity is critical for normal neuronal functioning and perturbations in the gene regulatory networks controlling these processes may result in long-lasting changes in brain function in adulthood. Further study of 5-HT neuron gene regulatory networks is likely to provide additional insight into how neurons acquire their mature identities and how terminal selector-type TFs function in postmitotic vertebrate neurons.
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Affiliation(s)
- William C Spencer
- Department of Neurosciences, Case Western Reserve UniversityCleveland, OH, United States
| | - Evan S Deneris
- Department of Neurosciences, Case Western Reserve UniversityCleveland, OH, United States
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Song NN, Huang Y, Yu X, Lang B, Ding YQ, Zhang L. Divergent Roles of Central Serotonin in Adult Hippocampal Neurogenesis. Front Cell Neurosci 2017; 11:185. [PMID: 28713247 PMCID: PMC5492328 DOI: 10.3389/fncel.2017.00185] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/16/2017] [Indexed: 11/13/2022] Open
Abstract
The central serotonin (5-HT) system is the main target of selective serotonin reuptake inhibitors (SSRIs), the first-line antidepressants widely used in current general practice. One of the prominent features of chronic SSRI treatment in rodents is the enhanced adult neurogenesis in the hippocampus, which has been proposed to contribute to antidepressant effects. Therefore, tremendous effort has been made to decipher how central 5-HT regulates adult hippocampal neurogenesis. In this paper, we review how changes in the central serotonergic system alter adult hippocampal neurogenesis. We focus on data obtained from three categories of genetically engineered mouse models: (1) mice with altered central 5-HT levels from embryonic stages, (2) mice with deletion of 5-HT receptors from embryonic stages, and (3) mice with altered central 5-HT system exclusively in adulthood. These recent findings provide unique insights to interpret the multifaceted roles of central 5-HT on adult hippocampal neurogenesis and its associated effects on depression.
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Affiliation(s)
- Ning-Ning Song
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China
| | - Ying Huang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China
| | - Xin Yu
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China
| | - Bing Lang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China.,Mental Health Institute of the Second Xiangya Hospital, National Clinical Research Center on Mental Disorders, National Technology Institute on Mental Disorders, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South UniversityChangsha, China
| | - Yu-Qiang Ding
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China
| | - Lei Zhang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of MedicineShanghai, China.,Department of Anatomy and Neurobiology, Tongji University School of MedicineShanghai, China
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40
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Oliveira MAP, Balling R, Smidt MP, Fleming RMT. Embryonic development of selectively vulnerable neurons in Parkinson's disease. NPJ Parkinsons Dis 2017; 3:21. [PMID: 28685157 PMCID: PMC5484687 DOI: 10.1038/s41531-017-0022-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 05/24/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023] Open
Abstract
A specific set of brainstem nuclei are susceptible to degeneration in Parkinson's disease. We hypothesise that neuronal vulnerability reflects shared phenotypic characteristics that confer selective vulnerability to degeneration. Neuronal phenotypic specification is mainly the cumulative result of a transcriptional regulatory program that is active during the development. By manual curation of the developmental biology literature, we comprehensively reconstructed an anatomically resolved cellular developmental lineage for the adult neurons in five brainstem regions that are selectively vulnerable to degeneration in prodromal or early Parkinson's disease. We synthesised the literature on transcription factors that are required to be active, or required to be inactive, in the development of each of these five brainstem regions, and at least two differentially vulnerable nuclei within each region. Certain transcription factors, e.g., Ascl1 and Lmx1b, seem to be required for specification of many brainstem regions that are susceptible to degeneration in early Parkinson's disease. Some transcription factors can even distinguish between differentially vulnerable nuclei within the same brain region, e.g., Pitx3 is required for specification of the substantia nigra pars compacta, but not the ventral tegmental area. We do not suggest that Parkinson's disease is a developmental disorder. In contrast, we consider identification of shared developmental trajectories as part of a broader effort to identify the molecular mechanisms that underlie the phenotypic features that are shared by selectively vulnerable neurons. Systematic in vivo assessment of fate determining transcription factors should be completed for all neuronal populations vulnerable to degeneration in early Parkinson's disease.
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Affiliation(s)
- Miguel A. P. Oliveira
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
| | - Marten P. Smidt
- Department of Molecular Neuroscience, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands
| | - Ronan M. T. Fleming
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
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Feng HJ, Faingold CL. Abnormalities of serotonergic neurotransmission in animal models of SUDEP. Epilepsy Behav 2017; 71:174-180. [PMID: 26272185 PMCID: PMC4749463 DOI: 10.1016/j.yebeh.2015.06.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/05/2015] [Accepted: 06/06/2015] [Indexed: 12/25/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a devastating event, and both DBA/1 and DBA/2 mice have been shown to be relevant animal models for studying SUDEP. DBA mice exhibit seizure-induced respiratory arrest (S-IRA), leading to cardiac arrest and subsequent sudden death after generalized audiogenic seizures (AGSs). This sequence of terminal events is also observed in the majority of witnessed human SUDEP cases. Several pathophysiological mechanisms, including respiratory/cardiac dysfunction, have been proposed to contribute to human SUDEP. Several (but not all) selective serotonin (5-HT) reuptake inhibitors (SSRIs), including fluoxetine, can reversibly block S-IRA, and abnormal expression of 5-HT receptors is found in the brainstem of DBA mice. DBA mice, which do not initially show S-IRA, exhibit S-IRA after treatment with a nonselective 5-HT antagonist. These studies suggest that abnormalities of 5-HT neurotransmission are involved in the pathogenesis of S-IRA in DBA mice. Serotonergic (5-HT) transmission plays an important role in normal respiration, and DBA mice exhibiting S-IRA can be resuscitated using a rodent ventilator. It is important and interesting to know if fluoxetine blocks S-IRA in DBA mice by enhancing respiratory ventilation. To test this, the effects of breathing stimulants, doxapram, and 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (PK-THPP) were compared with the effects of fluoxetine on S-IRA in DBA/1 mice. Although fluoxetine reduces the incidence of S-IRA in DBA/1 mice, as reported previously, the same dose of fluoxetine fails to enhance baseline respiratory ventilation in the absence of AGSs. Doxapram and PK-THPP augment the baseline ventilation in DBA/1 mice. However, these breathing stimulants are ineffective in preventing S-IRA in DBA/1 mice. These data suggest that fluoxetine blocks S-IRA in DBA/1 mice by cellular/molecular mechanisms other than enhancement of basal ventilation. Future research directions are also discussed. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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Affiliation(s)
- Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Carl L. Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, Illinois 62794, U.S.A
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Diacylglycerol kinase ε localizes to subsurface cisterns of cerebellar Purkinje cells. Cell Tissue Res 2017; 368:441-458. [PMID: 28191598 DOI: 10.1007/s00441-017-2579-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/16/2017] [Indexed: 10/20/2022]
Abstract
Following activation of Gq protein-coupled receptors, phospholipase C yields a pair of second messengers: diacylglycerol (DG) and inositol 1,4,5-trisphosphate. Diacylglycerol kinase (DGK) phosphorylates DG to produce phosphatidic acid, another second messenger. Of the DGK family, DGKε is the only DGK isoform that exhibits substrate specificity for DG with an arachidonoyl acyl chain at the sn-2 position. Recently, we demonstrated that hydrophobic residues in the N-terminus of DGKε play an important role in targeting the endoplasmic reticulum in transfected cells. However, its cellular expression and subcellular localization in the brain remain elusive. In the present study, we investigate this issue using specific DGKε antibody. DGKε was richly expressed in principal neurons of higher brain regions, including pyramidal cells in the hippocampus and neocortex, medium spiny neurons in the striatum and Purkinje cells in the cerebellum. In Purkinje cells, DGKε was localized to the subsurface cisterns and colocalized with inositol 1,4,5-trisphosphate receptor-1 in dendrites and axons. In dendrites of Purkinje cells, DGKε was also distributed in close apposition to DG lipase-α, which catalyzes arachidonoyl-DG to produce 2-arachidonoyl glycerol, a major endocannabinoid in the brain. Behaviorally, DGKε-knockout mice exhibited hyper-locomotive activities and impaired motor coordination and learning. These findings suggest that DGKε plays an important role in neuronal and brain functions through its distinct neuronal expression and subcellular localization and also through coordinated arrangement with other molecules involving the phosphoinositide signaling pathway.
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Beltrán-Castillo S, Morgado-Valle C, Eugenín J. The Onset of the Fetal Respiratory Rhythm: An Emergent Property Triggered by Chemosensory Drive? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:163-192. [PMID: 29080027 DOI: 10.1007/978-3-319-62817-2_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The mechanisms responsible for the onset of respiratory activity during fetal life are unknown. The onset of respiratory rhythm may be a consequence of the genetic program of each of the constituents of the respiratory network, so they start to interact and generate respiratory cycles when reaching a certain degree of maturation. Alternatively, generation of cycles might require the contribution of recently formed sensory inputs that will trigger oscillatory activity in the nascent respiratory neural network. If this hypothesis is true, then sensory input to the respiratory generator must be already formed and become functional before the onset of fetal respiration. In this review, we evaluate the timing of the onset of the respiratory rhythm in comparison to the appearance of receptors, neurotransmitter machinery, and afferent projections provided by two central chemoreceptive nuclei, the raphe and locus coeruleus nuclei.
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Affiliation(s)
- Sebastián Beltrán-Castillo
- Laboratorio de Sistemas Neurales, Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile
| | - Consuelo Morgado-Valle
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Campus Xalapa, Berlin 7, Fracc., Monte Magno Animas, C.P. 91190, Xalapa, Veracruz, Mexico.
| | - Jaime Eugenín
- Laboratorio de Sistemas Neurales, Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile.
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Vadodaria KC, Marchetto MC, Mertens J, Gage FH. Generating human serotonergic neurons in vitro: Methodological advances. Bioessays 2016; 38:1123-1129. [PMID: 27716980 DOI: 10.1002/bies.201600127] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Technologies for deriving human neurons in vitro have transformed our ability to study cellular and molecular components of human neurotransmission. Three groups, including our own, have recently published methods for efficiently generating human serotonergic neurons in vitro. Remarkably, serotonergic neurons derived from each method robustly produce serotonin, express raphe genes, are electrically active, and respond to selective serotonin reuptake inhibitors in vitro. Two of the methods utilize transdifferentiation technology by overexpressing key serotonergic transcription factors. The third and most recent method involves differentiating induced pluripotent stem cells (iPSCs) to serotonergic neurons using developmental patterning cues. In this mini-review, we briefly describe the developmental programs governing serotonergic specification in vivo and how they have been harnessed to achieve serotonergic differentiation in vitro. We discuss the distinct and overlapping features of the recently published methodologies and their value in the context of in vitro disease modeling. Also see the video abstract here.
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Affiliation(s)
- Krishna C Vadodaria
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Maria C Marchetto
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Jerome Mertens
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA.
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Cerpa VJ, Wu Y, Bravo E, Teran FA, Flynn RS, Richerson GB. Medullary 5-HT neurons: Switch from tonic respiratory drive to chemoreception during postnatal development. Neuroscience 2016; 344:1-14. [PMID: 27619736 DOI: 10.1016/j.neuroscience.2016.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 01/27/2023]
Abstract
Serotonin (5-HT) neurons contribute to respiratory chemoreception in adult mice, but it is unclear whether they play a similar role in neonatal mice. We studied breathing during development in Lmx1bf/f/p mice, which lack 5-HT neurons. From postnatal days 1-7 (P1-P7), ventilation of Lmx1bf/f/p mice breathing room air was 50% of WT mice (p<0.001). By P12, baseline ventilation increased to a level equal to WT mice. In contrast, the hypercapnic ventilatory response (HCVR) of neonatal Lmx1bf/f/p and WT mice was equal to each other, but were both much less than adult WT mice. By P21 the HCVR of WT mice increased to near adult levels, but the HCVR of Lmx1bf/f/p mice had not changed, and was 42% less than WT mice. Primary cell cultures were prepared from the ventromedial medulla of neonatal mice, and patch-clamp recordings were made from neurons identified as serotonergic by expression of a reporter gene. In parallel with developmental changes of the HCVR in vivo, 5-HT neurons had little chemosensitivity to acidosis until 12days in vitro (DIV), after which their response increased to reach a plateau around 25 DIV. Neonatal Lmx1bf/f/p mice displayed high mortality and decreased growth rate, and this worsened in hypoxia. Mortality was decreased in hyperoxia. These results indicate that maturation of 5-HT neurons contributes to development of respiratory CO2/pH chemoreception during the first few weeks of life in mice in vivo. A defect in the 5-HT system in early postnatal life decreases survival due in part to hypoxia.
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Affiliation(s)
- Veronica J Cerpa
- Department of Neurology, Yale University, New Haven, CT 06510, United States; Department of Neurology, University of Iowa, Iowa City, IA 52242, United States
| | - Yuanming Wu
- Department of Neurology, Yale University, New Haven, CT 06510, United States; Department of Neurology, University of Iowa, Iowa City, IA 52242, United States
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States.
| | - Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA 52242, United States
| | - Rachel S Flynn
- Department of Neurology, Yale University, New Haven, CT 06510, United States
| | - George B Richerson
- Department of Neurology, Yale University, New Haven, CT 06510, United States; Department of Neurology, University of Iowa, Iowa City, IA 52242, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA 52242, United States; Veterans Affairs Medical Center, Iowa City, IA 52242, United States
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46
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Hilinski WC, Bostrom JR, England SJ, Juárez-Morales JL, de Jager S, Armant O, Legradi J, Strähle U, Link BA, Lewis KE. Lmx1b is required for the glutamatergic fates of a subset of spinal cord neurons. Neural Dev 2016; 11:16. [PMID: 27553035 PMCID: PMC4995821 DOI: 10.1186/s13064-016-0070-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/08/2016] [Indexed: 01/27/2023] Open
Abstract
Background Alterations in neurotransmitter phenotypes of specific neurons can cause imbalances in excitation and inhibition in the central nervous system (CNS), leading to diseases. Therefore, the correct specification and maintenance of neurotransmitter phenotypes is vital. As with other neuronal properties, neurotransmitter phenotypes are often specified and maintained by particular transcription factors. However, the specific molecular mechanisms and transcription factors that regulate neurotransmitter phenotypes remain largely unknown. Methods In this paper we use single mutant, double mutant and transgenic zebrafish embryos to elucidate the functions of Lmx1ba and Lmx1bb in the regulation of spinal cord interneuron neurotransmitter phenotypes. Results We demonstrate that lmx1ba and lmx1bb are both expressed in zebrafish spinal cord and that lmx1bb is expressed by both V0v cells and dI5 cells. Our functional analyses demonstrate that these transcription factors are not required for neurotransmitter fate specification at early stages of development, but that in embryos with at least two lmx1ba and/or lmx1bb mutant alleles there is a reduced number of excitatory (glutamatergic) spinal interneurons at later stages of development. In contrast, there is no change in the numbers of V0v or dI5 cells. These data suggest that lmx1b-expressing spinal neurons still form normally, but at least a subset of them lose, or do not form, their normal excitatory fates. As the reduction in glutamatergic cells is only seen at later stages of development, Lmx1b is probably required either for the maintenance of glutamatergic fates or to specify glutamatergic phenotypes of a subset of later forming neurons. Using double labeling experiments, we also show that at least some of the cells that lose their normal glutamatergic phenotype are V0v cells. Finally, we also establish that Evx1 and Evx2, two transcription factors that are required for V0v cells to acquire their excitatory neurotransmitter phenotype, are also required for lmx1ba and lmx1bb expression in these cells, suggesting that Lmx1ba and Lmx1bb act downstream of Evx1 and Evx2 in V0v cells. Conclusions Lmx1ba and Lmx1bb function at least partially redundantly in the spinal cord and three functional lmx1b alleles are required in zebrafish for correct numbers of excitatory spinal interneurons at later developmental stages. Taken together, our data significantly enhance our understanding of how spinal cord neurotransmitter fates are regulated.
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Affiliation(s)
- William C Hilinski
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.,Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA
| | - Jonathan R Bostrom
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI, 53226, USA
| | - Samantha J England
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - José L Juárez-Morales
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - Sarah de Jager
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Olivier Armant
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021, Karlsruhe, Germany
| | - Jessica Legradi
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021, Karlsruhe, Germany
| | - Uwe Strähle
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021, Karlsruhe, Germany
| | - Brian A Link
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI, 53226, USA
| | - Katharine E Lewis
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
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Doucet-Beaupré H, Gilbert C, Profes MS, Chabrat A, Pacelli C, Giguère N, Rioux V, Charest J, Deng Q, Laguna A, Ericson J, Perlmann T, Ang SL, Cicchetti F, Parent M, Trudeau LE, Lévesque M. Lmx1a and Lmx1b regulate mitochondrial functions and survival of adult midbrain dopaminergic neurons. Proc Natl Acad Sci U S A 2016; 113:E4387-96. [PMID: 27407143 PMCID: PMC4968767 DOI: 10.1073/pnas.1520387113] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The LIM-homeodomain transcription factors Lmx1a and Lmx1b play critical roles during the development of midbrain dopaminergic progenitors, but their functions in the adult brain remain poorly understood. We show here that sustained expression of Lmx1a and Lmx1b is required for the survival of adult midbrain dopaminergic neurons. Strikingly, inactivation of Lmx1a and Lmx1b recreates cellular features observed in Parkinson's disease. We found that Lmx1a/b control the expression of key genes involved in mitochondrial functions, and their ablation results in impaired respiratory chain activity, increased oxidative stress, and mitochondrial DNA damage. Lmx1a/b deficiency caused axonal pathology characterized by α-synuclein(+) inclusions, followed by a progressive loss of dopaminergic neurons. These results reveal the key role of these transcription factors beyond the early developmental stages and provide mechanistic links between mitochondrial dysfunctions, α-synuclein aggregation, and the survival of dopaminergic neurons.
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Affiliation(s)
- Hélène Doucet-Beaupré
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Catherine Gilbert
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Marcos Schaan Profes
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Audrey Chabrat
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Consiglia Pacelli
- Department of Pharmacology, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Neurosciences, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Nicolas Giguère
- Department of Pharmacology, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Neurosciences, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Véronique Rioux
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Julien Charest
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Qiaolin Deng
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Ariadna Laguna
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; The Ludwig Institute for Cancer Research, 171 77 Stockholm, Sweden
| | - Johan Ericson
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Thomas Perlmann
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; The Ludwig Institute for Cancer Research, 171 77 Stockholm, Sweden
| | - Siew-Lan Ang
- The Francis Crick Institute, London, NW1 2BE, United Kingdom
| | - Francesca Cicchetti
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de recherche du Centre Hospitalier Universitaire de Québec, Quebec, QC G1V 4G2, Canada
| | - Martin Parent
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada
| | - Louis-Eric Trudeau
- Department of Pharmacology, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Neurosciences, Central Nervous System Research Group, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Martin Lévesque
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Quebec QC G1V 0A6, Canada; Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC G1J 2G3, Canada;
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Kim S, Barry DM, Liu XY, Yin S, Munanairi A, Meng QT, Cheng W, Mo P, Wan L, Liu SB, Ratnayake K, Zhao ZQ, Gautam N, Zheng J, Karunarathne WKA, Chen ZF. Facilitation of TRPV4 by TRPV1 is required for itch transmission in some sensory neuron populations. Sci Signal 2016; 9:ra71. [PMID: 27436359 DOI: 10.1126/scisignal.aaf1047] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The transient receptor potential channels (TRPs) respond to chemical irritants and temperature. TRPV1 responds to the itch-inducing endogenous signal histamine, and TRPA1 responds to the itch-inducing chemical chloroquine. We showed that, in sensory neurons, TRPV4 is important for both chloroquine- and histamine-induced itch and that TRPV1 has a role in chloroquine-induced itch. Chloroquine-induced scratching was reduced in mice in which TRPV1 was knocked down or pharmacologically inhibited. Both TRPV4 and TRPV1 were present in some sensory neurons. Pharmacological blockade of either TRPV4 or TRPV1 significantly attenuated the Ca(2+) response of sensory neurons exposed to histamine or chloroquine. Knockout of Trpv1 impaired Ca(2+) responses and reduced scratching behavior evoked by a TRPV4 agonist, whereas knockout of Trpv4 did not alter TRPV1-mediated capsaicin responses. Electrophysiological analysis of human embryonic kidney (HEK) 293 cells coexpressing TRPV4 and TRPV1 revealed that the presence of both channels enhanced the activation kinetics of TRPV4 but not of TRPV1. Biochemical and biophysical studies suggested a close proximity between TRPV4 and TRPV1 in dorsal root ganglion neurons and in cultured cells. Thus, our studies identified TRPV4 as a channel that contributes to both histamine- and chloroquine-induced itch and indicated that the function of TRPV4 in itch signaling involves TRPV1-mediated facilitation. TRP facilitation through the formation of heteromeric complexes could be a prevalent mechanism by which the vast array of somatosensory information is encoded in sensory neurons.
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Affiliation(s)
- Seungil Kim
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Devin M Barry
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xian-Yu Liu
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shijin Yin
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Admire Munanairi
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Qing-Tao Meng
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Wei Cheng
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian 116044, P.R. China
| | - Ping Mo
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Nanhai Hospital of Southern Medical University, Foshan 528000, P.R. China
| | - Li Wan
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shen-Bin Liu
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA
| | - Zhong-Qiu Zhao
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Narasimhan Gautam
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jie Zheng
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA 95616, USA
| | | | - Zhou-Feng Chen
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA. Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Pet-1 Switches Transcriptional Targets Postnatally to Regulate Maturation of Serotonin Neuron Excitability. J Neurosci 2016; 36:1758-74. [PMID: 26843655 DOI: 10.1523/jneurosci.3798-15.2016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
UNLABELLED Newborn neurons enter an extended maturation stage, during which they acquire excitability characteristics crucial for development of presynaptic and postsynaptic connectivity. In contrast to earlier specification programs, little is known about the regulatory mechanisms that control neuronal maturation. The Pet-1 ETS (E26 transformation-specific) factor is continuously expressed in serotonin (5-HT) neurons and initially acts in postmitotic precursors to control acquisition of 5-HT transmitter identity. Using a combination of RNA sequencing, electrophysiology, and conditional targeting approaches, we determined gene expression patterns in maturing flow-sorted 5-HT neurons and the temporal requirements for Pet-1 in shaping these patterns for functional maturation of mouse 5-HT neurons. We report a profound disruption of postmitotic expression trajectories in Pet-1(-/-) neurons, which prevented postnatal maturation of 5-HT neuron passive and active intrinsic membrane properties, G-protein signaling, and synaptic responses to glutamatergic, lysophosphatidic, and adrenergic agonists. Unexpectedly, conditional targeting revealed a postnatal stage-specific switch in Pet-1 targets from 5-HT synthesis genes to transmitter receptor genes required for afferent modulation of 5-HT neuron excitability. Five-HT1a autoreceptor expression depended transiently on Pet-1, thus revealing an early postnatal sensitive period for control of 5-HT excitability genes. Chromatin immunoprecipitation followed by sequencing revealed that Pet-1 regulates 5-HT neuron maturation through direct gene activation and repression. Moreover, Pet-1 directly regulates the 5-HT neuron maturation factor Engrailed 1, which suggests Pet-1 orchestrates maturation through secondary postmitotic regulatory factors. The early postnatal switch in Pet-1 targets uncovers a distinct neonatal stage-specific function for Pet-1, during which it promotes maturation of 5-HT neuron excitability. SIGNIFICANCE STATEMENT The regulatory mechanisms that control functional maturation of neurons are poorly understood. We show that in addition to inducing brain serotonin (5-HT) synthesis and reuptake, the Pet-1 ETS (E26 transformation-specific) factor subsequently globally coordinates postmitotic expression trajectories of genes necessary for maturation of 5-HT neuron excitability. Further, Pet-1 switches its transcriptional targets as 5-HT neurons mature from 5-HT synthesis genes to G-protein-coupled receptors, which are necessary for afferent synaptic modulation of 5-HT neuron excitability. Our findings uncover gene-specific switching of downstream targets as a previously unrecognized regulatory strategy through which continuously expressed transcription factors control acquisition of neuronal identity at different stages of development.
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Hajek MA, Buchanan GF. Influence of vigilance state on physiological consequences of seizures and seizure-induced death in mice. J Neurophysiol 2016; 115:2286-93. [PMID: 26888097 DOI: 10.1152/jn.00011.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/13/2016] [Indexed: 12/31/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. SUDEP occurs more commonly during nighttime sleep. The details of why SUDEP occurs at night are not well understood. Understanding why SUDEP occurs at night during sleep might help to better understand why SUDEP occurs at all and hasten development of preventive strategies. Here we aimed to understand circumstances causing seizures that occur during sleep to result in death. Groups of 12 adult male mice were instrumented for EEG, EMG, and EKG recording and subjected to seizure induction via maximal electroshock (MES) during wakefulness, nonrapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep. Seizure inductions were performed with concomitant EEG, EMG, and EKG recording and breathing assessment via whole body plethysmography. Seizures induced via MES during sleep were associated with more profound respiratory suppression and were more likely to result in death. Despite REM sleep being a time when seizures do not typically occur spontaneously, when seizures were forced to occur during REM sleep, they were invariably fatal in this model. An examination of baseline breathing revealed that mice that died following a seizure had increased baseline respiratory rate variability compared with those that did not die. These data demonstrate that sleep, especially REM sleep, can be a dangerous time for a seizure to occur. These data also demonstrate that there may be baseline respiratory abnormalities that can predict which individuals have higher risk for seizure-induced death.
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Affiliation(s)
- Michael A Hajek
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut
| | - Gordon F Buchanan
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut; Veterans Affairs Medical Center, West Haven, Connecticut; and Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, Iowa
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