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Li XL, Li F, Zhu XY, Wang XD, Kou ZZ, Liu SQ, Li H. Whole-brain mapping of monosynaptic afferent inputs to the CRH neurons in the medial prefrontal cortex of mice. J Anat 2024; 244:527-536. [PMID: 38009263 PMCID: PMC10862190 DOI: 10.1111/joa.13981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 11/28/2023] Open
Abstract
Corticotropin-releasing hormone (CRH) neurons are densely distributed in the medial prefrontal cortex (mPFC), which plays a crucial role in integrating and processing emotional and cognitive inputs from other brain regions. Therefore, it is important to know the neural afferent patterns of mPFCCRH neurons, which are still unclear. Here, we utilized a rabies virus-based monosynaptic retrograde tracing system to map the presynaptic afferents of the mPFCCRH neurons throughout the entire brain. The results show that the mPFCCRH neurons receive inputs from three main groups of brain regions: (1) the cortex, primarily the orbital cortex, somatomotor areas, and anterior cingulate cortex; (2) the thalamus, primarily the anteromedial nucleus, mediodorsal thalamic nucleus, and central medial thalamic nucleus; and (3) other brain regions, primarily the basolateral amygdala, hippocampus, and dorsal raphe nucleus. Taken together, our results are valuable for further investigations into the roles of the mPFCCRH neurons in normal and neurological disease states. These investigations can shed light on various aspects such as cognitive processing, emotional modulation, motivation, sociability, and pain.
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Affiliation(s)
- Xiao-Lan Li
- Institute of Basic Medicine and Forensic Medicine, North Sichuan Medical College, Nanchong, China
- Department of Human Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Military Medical University, Xi'an, China
| | - Fei Li
- Department of Human Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Military Medical University, Xi'an, China
| | - Xin-Yi Zhu
- Department of Human Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Military Medical University, Xi'an, China
| | - Xiao-Dong Wang
- Department of Emergency Medicine, Inner Mongolia Armed Police Corps Hospital, Hohhot, China
| | - Zhen-Zhen Kou
- Department of Human Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Military Medical University, Xi'an, China
| | - Shang-Qing Liu
- Institute of Basic Medicine and Forensic Medicine, North Sichuan Medical College, Nanchong, China
- School of International Education and Cooperation, North Sichuan Medical College, Nanchong, China
| | - Hui Li
- Department of Human Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Military Medical University, Xi'an, China
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2
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Fortin-Houde J, Henderson F, Dumas S, Ducharme G, Amilhon B. Parallel streams of raphe VGLUT3-positive inputs target the dorsal and ventral hippocampus in each hemisphere. J Comp Neurol 2023; 531:702-719. [PMID: 36855269 DOI: 10.1002/cne.25452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/23/2022] [Accepted: 12/13/2022] [Indexed: 03/02/2023]
Abstract
The hippocampus (HP) receives neurochemically diverse inputs from the raphe nuclei, including glutamatergic axons characterized by the expression of the vesicular glutamate transporter type 3 (VGLUT3). These raphe-HP VGLUT3 projections have been suggested to play a critical role in HP functions, yet a complete anatomical overview of raphe VGLUT3 projections to the forebrain, and in particular to the HP, is lacking. Using anterograde viral tracing, we describe largely nonoverlapping VGLUT3-positive projections from the dorsal raphe (DR) and median raphe (MnR) to the forebrain, with the HP receiving inputs from the MnR. A limited subset of forebrain regions such as the amygdaloid complex, claustrum, and hypothalamus receives projections from both the DR and MnR that remain largely segregated. This highly complementary anatomical pattern suggests contrasting roles for DR and MnR VGLUT3 neurons. To further analyze the topography of VGLUT3 raphe projections to the HP, we used retrograde tracing and found that HP-projecting VGLUT3-positive neurons (VGLUT3HP ) distribute over several raphe subregions (including the MnR, paramedian raphe, and B9 cell group) and lack co-expression of serotonergic markers. Strikingly, double retrograde tracing experiments unraveled two parallel streams of VGLUT3-positive projections targeting the dorsal and ventral poles of the HP. These results demonstrate highly organized and segregated VGLUT3-positive projections to the HP, suggesting independent modulation of HP functions such as spatial memory and emotion-related behavior.
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Affiliation(s)
- Justine Fortin-Houde
- Département de Neuroscience, Université de Montréal, Montréal, Québec, Canada
- CHU Sainte-Justine Research Center, Montréal, Québec, Canada
| | - Fiona Henderson
- Département de Neuroscience, Université de Montréal, Montréal, Québec, Canada
- CHU Sainte-Justine Research Center, Montréal, Québec, Canada
| | | | | | - Bénédicte Amilhon
- Département de Neuroscience, Université de Montréal, Montréal, Québec, Canada
- CHU Sainte-Justine Research Center, Montréal, Québec, Canada
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3
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Harkin EF, Lynn MB, Payeur A, Boucher JF, Caya-Bissonnette L, Cyr D, Stewart C, Longtin A, Naud R, Béïque JC. Temporal derivative computation in the dorsal raphe network revealed by an experimentally driven augmented integrate-and-fire modeling framework. eLife 2023; 12:72951. [PMID: 36655738 PMCID: PMC9977298 DOI: 10.7554/elife.72951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 12/19/2022] [Indexed: 01/20/2023] Open
Abstract
By means of an expansive innervation, the serotonin (5-HT) neurons of the dorsal raphe nucleus (DRN) are positioned to enact coordinated modulation of circuits distributed across the entire brain in order to adaptively regulate behavior. Yet the network computations that emerge from the excitability and connectivity features of the DRN are still poorly understood. To gain insight into these computations, we began by carrying out a detailed electrophysiological characterization of genetically identified mouse 5-HT and somatostatin (SOM) neurons. We next developed a single-neuron modeling framework that combines the realism of Hodgkin-Huxley models with the simplicity and predictive power of generalized integrate-and-fire models. We found that feedforward inhibition of 5-HT neurons by heterogeneous SOM neurons implemented divisive inhibition, while endocannabinoid-mediated modulation of excitatory drive to the DRN increased the gain of 5-HT output. Our most striking finding was that the output of the DRN encodes a mixture of the intensity and temporal derivative of its input, and that the temporal derivative component dominates this mixture precisely when the input is increasing rapidly. This network computation primarily emerged from prominent adaptation mechanisms found in 5-HT neurons, including a previously undescribed dynamic threshold. By applying a bottom-up neural network modeling approach, our results suggest that the DRN is particularly apt to encode input changes over short timescales, reflecting one of the salient emerging computations that dominate its output to regulate behavior.
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Affiliation(s)
- Emerson F Harkin
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - Michael B Lynn
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - Alexandre Payeur
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
- Department of Physics, University of OttawaOttawaCanada
| | - Jean-François Boucher
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - Léa Caya-Bissonnette
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - Dominic Cyr
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - Chloe Stewart
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
| | - André Longtin
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
- Department of Physics, University of OttawaOttawaCanada
| | - Richard Naud
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
- Department of Physics, University of OttawaOttawaCanada
| | - Jean-Claude Béïque
- Brain and Mind Research Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of OttawaOttawaCanada
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4
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Clinton SM, Shupe EA, Glover ME, Unroe KA, McCoy CR, Cohen JL, Kerman IA. Modeling heritability of temperamental differences, stress reactivity, and risk for anxiety and depression: Relevance to research domain criteria (RDoC). Eur J Neurosci 2021; 55:2076-2107. [PMID: 33629390 PMCID: PMC8382785 DOI: 10.1111/ejn.15158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/29/2021] [Accepted: 02/20/2021] [Indexed: 01/04/2023]
Abstract
Animal models provide important tools to study biological and environmental factors that shape brain function and behavior. These models can be effectively leveraged by drawing on concepts from the National Institute of Mental Health Research Domain Criteria (RDoC) Initiative, which aims to delineate molecular pathways and neural circuits that underpin behavioral anomalies that transcend psychiatric conditions. To study factors that contribute to individual differences in emotionality and stress reactivity, our laboratory utilized Sprague-Dawley rats that were selectively bred for differences in novelty exploration. Selective breeding for low versus high locomotor response to novelty produced rat lines that differ in behavioral domains relevant to anxiety and depression, particularly the RDoC Negative Valence domains, including acute threat, potential threat, and loss. Bred Low Novelty Responder (LR) rats, relative to their High Responder (HR) counterparts, display high levels of behavioral inhibition, conditioned and unconditioned fear, avoidance, passive stress coping, anhedonia, and psychomotor retardation. The HR/LR traits are heritable, emerge in the first weeks of life, and appear to be driven by alterations in the developing amygdala and hippocampus. Epigenomic and transcriptomic profiling in the developing and adult HR/LR brain suggest that DNA methylation and microRNAs, as well as differences in monoaminergic transmission (dopamine and serotonin in particular), contribute to their distinct behavioral phenotypes. This work exemplifies ways that animal models such as the HR/LR rats can be effectively used to study neural and molecular factors driving emotional behavior, which may pave the way toward improved understanding the neurobiological mechanisms involved in emotional disorders.
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Affiliation(s)
- Sarah M Clinton
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Elizabeth A Shupe
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Matthew E Glover
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Keaton A Unroe
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Chelsea R McCoy
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Joshua L Cohen
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
| | - Ilan A Kerman
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.,Behavioral Health Service Line, Veterans Affairs Pittsburgh Health System, Pittsburgh, PA, USA
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5
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Guajardo HM, Hatini PG, Commons KG. The mouse dorsal raphe nucleus as understood by temporal Fgf8 lineage analysis. J Comp Neurol 2020; 529:2042-2054. [PMID: 33219573 DOI: 10.1002/cne.25071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/23/2020] [Accepted: 11/10/2020] [Indexed: 11/09/2022]
Abstract
Fgf8 is expressed transiently during embryogenesis at the midbrain-hindbrain border, an area that gives rise to a variety of neuronal populations including the dorsal raphe (DR) nucleus. Using an inducible Fgf8-cre allele, we identified the populations of neurons defined by Fgf8 lineage at different stages of development. When Fgf8-cre expression is induced at embryonic day 7.5 (T-E7.5), in the adult the entire DR and part of the median raphe (MnR) have Fgf8 lineage. When induced at later timepoints, Fgf8 lineage progressively ebbs from the caudal and ventral aspect of this domain, particularly on the midline. Successively excluded from Fgf8- lineage at T-E9.5 are serotonin neurons in the MnR and caudal-intrafascicular DR, followed at T-E11.5 by ventral-middle and caudal-dorsal DR. The last to show Fgf8 lineage are those serotonin neurons in the lateral wings and those at the rostral-dorsal pole of DR nucleus. Thus, the temporal succession of Fgf8 lineage correlates with organizational features of serotonin neurons in these nuclei.
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Affiliation(s)
- Herminio M Guajardo
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Paul G Hatini
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Kathryn G Commons
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
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6
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Okaty BW, Sturrock N, Escobedo Lozoya Y, Chang Y, Senft RA, Lyon KA, Alekseyenko OV, Dymecki SM. A single-cell transcriptomic and anatomic atlas of mouse dorsal raphe Pet1 neurons. eLife 2020; 9:e55523. [PMID: 32568072 PMCID: PMC7308082 DOI: 10.7554/elife.55523] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
Among the brainstem raphe nuclei, the dorsal raphe nucleus (DR) contains the greatest number of Pet1-lineage neurons, a predominantly serotonergic group distributed throughout DR subdomains. These neurons collectively regulate diverse physiology and behavior and are often therapeutically targeted to treat affective disorders. Characterizing Pet1 neuron molecular heterogeneity and relating it to anatomy is vital for understanding DR functional organization, with potential to inform therapeutic separability. Here we use high-throughput and DR subdomain-targeted single-cell transcriptomics and intersectional genetic tools to map molecular and anatomical diversity of DR-Pet1 neurons. We describe up to fourteen neuron subtypes, many showing biased cell body distributions across the DR. We further show that P2ry1-Pet1 DR neurons - the most molecularly distinct subtype - possess unique efferent projections and electrophysiological properties. These data complement and extend previous DR characterizations, combining intersectional genetics with multiple transcriptomic modalities to achieve fine-scale molecular and anatomic identification of Pet1 neuron subtypes.
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Affiliation(s)
- Benjamin W Okaty
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Nikita Sturrock
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | | | - YoonJeung Chang
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Rebecca A Senft
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Krissy A Lyon
- Department of Genetics, Harvard Medical SchoolBostonUnited States
| | | | - Susan M Dymecki
- Department of Genetics, Harvard Medical SchoolBostonUnited States
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7
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Serotonergic innervation of the auditory midbrain: dorsal raphe subregions differentially project to the auditory midbrain in male and female mice. Brain Struct Funct 2020; 225:1855-1871. [DOI: 10.1007/s00429-020-02098-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 06/06/2020] [Indexed: 01/12/2023]
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8
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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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9
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Fazio P, Ferreira D, Svenningsson P, Halldin C, Farde L, Westman E, Varrone A. High-resolution PET imaging reveals subtle impairment of the serotonin transporter in an early non-depressed Parkinson's disease cohort. Eur J Nucl Med Mol Imaging 2020; 47:2407-2416. [PMID: 32020370 PMCID: PMC7396398 DOI: 10.1007/s00259-020-04683-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE The serotonin transporter (SERT) is a biochemical marker for monoaminergic signaling in brain and has been suggested to be involved inthe pathophysiology of Parkinson's disease (PD). The aim of this PET study was to examine SERT availability in relevant brain regions in early stages ofnon-depressed PD patients. METHODS In a cross-sectional study, 18 PD patients (13 M/5F, 64 ± 7 years, range 46-74 years, disease duration 2.9 ± 2.6 years; UPDRS motor 21.9 ± 5.2) and 20 age- and gender-matched healthy control (HC) subjects (15 M/5F, 61 ± 7 years, range 50-72 years) were included. In a subsequent longitudinal phase, ten of the PD patients (7 M/3F, UPDRS motor 20.6 ± 6.9) underwent a second PET measurement after 18-24 months. After a 3-T MRI acquisition, baseline PET measurements were performed with [11C]MADAM using a high-resolution research tomograph. The non-displaceablebinding potential (BPND) was chosen as the outcome measure and was estimated at voxel level on wavelet-aided parametric images, by using the Logan graphical analysis and the cerebellum as reference region. A molecular template was generated to visualize and define different subdivisions of the raphe nuclei in the brainstem. Subortical and cortical regions of interest were segmented using FreeSurfer. Univariate analyses and multivariate network analyses were performed on the PET data. RESULTS The univariate region-based analysis showed no differences in SERT levels when the PD patients were compared with the HC neither at baseline or after 2 years of follow-up. The multivariate network analysis also showed no differences at baseline. However, prominent changes in integration and segregation measures were observed at follow-up, indicating a disconnection of the cortical and subcortical regions from the three nuclei of the raphe. CONCLUSION We conclude that the serotoninergic system in PD patients seems to become involved with a network dysregulation as the disease progresses, suggesting a disturbed serotonergic signaling from raphe nuclei to target subcortical and cortical regions.
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Affiliation(s)
- Patrik Fazio
- Center for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, RegionStockholm, Karolinska University Hospital, SE-17176, R5:02, Visionsgatan 70A, Stockholm, Sweden. .,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
| | - Daniel Ferreira
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden
| | - Per Svenningsson
- Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.,Section of Neurology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Christer Halldin
- Center for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, RegionStockholm, Karolinska University Hospital, SE-17176, R5:02, Visionsgatan 70A, Stockholm, Sweden
| | - Lars Farde
- Center for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, RegionStockholm, Karolinska University Hospital, SE-17176, R5:02, Visionsgatan 70A, Stockholm, Sweden
| | - Eric Westman
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 8AF, UK
| | - Andrea Varrone
- Center for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, RegionStockholm, Karolinska University Hospital, SE-17176, R5:02, Visionsgatan 70A, Stockholm, Sweden
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10
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Effects of plus-maze experience and chlordiazepoxide on anxiety-like behavior and serotonin neural activity in the dorsal raphe nucleus in rats. Behav Pharmacol 2020; 30:208-219. [PMID: 30169377 DOI: 10.1097/fbp.0000000000000423] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The extent to which rats express anxiety-like behavior on the elevated plus-maze (EPM) depends on their previous maze experience. Open-arm avoidance develops in maze-experienced rats, and is often accompanied by a diminished anxiolytic response to benzodiazepines. Regions of the dorsal raphe nucleus (DRN) were examined in male Sprague-Dawley rats using c-Fos and serotonin immunohistochemistry following a single exposure, a second exposure or no exposure to the EPM. We then examined the effect of the benzodiazepine anxiolytic chlordiazepoxide (CDP, 5 mg/kg) on EPM behavior and DRN neural activity. Enhanced open-arm avoidance was evident on the second EPM trial in both experiments. The observed pattern of c-Fos expression suggests that the first exposure to the maze activates serotonin cells in the rostral and dorsal regions of the DRN and that only the dorsal subregion is activated by a second exposure. CDP increased open-arm exploration during the first trial, which corresponded to decreased 5-hydroxytryptamine (5-HT) activity in the rostral and ventral subregions of the DRN. However, 5-HT activity in the DRN was reduced in rats on the second maze trial compared with the first trial, when CDP had no effect on open-arm exploration. These results suggest that open-arm avoidance in maze-experienced rats can be characterized as a coping response that is mediated by specific populations of 5-HT neurons in the DRN.
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11
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Metzger M, Souza R, Lima LB, Bueno D, Gonçalves L, Sego C, Donato J, Shammah-Lagnado SJ. Habenular connections with the dopaminergic and serotonergic system and their role in stress-related psychiatric disorders. Eur J Neurosci 2019; 53:65-88. [PMID: 31833616 DOI: 10.1111/ejn.14647] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/28/2019] [Accepted: 12/09/2019] [Indexed: 12/19/2022]
Abstract
The habenula (Hb) is a phylogenetically old epithalamic structure differentiated into two nuclear complexes, the medial (MHb) and lateral habenula (LHb). After decades of search for a great unifying function, interest in the Hb resurged when it was demonstrated that LHb plays a major role in the encoding of aversive stimuli ranging from noxious stimuli to the loss of predicted rewards. Consistent with a role as an anti-reward center, aberrant LHb activity has now been identified as a key factor in the pathogenesis of major depressive disorder. Moreover, both MHb and LHb emerged as new players in the reward circuitry by primarily mediating the aversive properties of distinct drugs of abuse. Anatomically, the Hb serves as a bridge that links basal forebrain structures with monoaminergic nuclei in the mid- and hindbrain. So far, research on Hb has focused on the role of the LHb in regulating midbrain dopamine release. However, LHb/MHb are also interconnected with the dorsal (DR) and median (MnR) raphe nucleus. Hence, it is conceivable that some of the habenular functions are at least partly mediated by the complex network that links MHb/LHb with pontomesencephalic monoaminergic nuclei. Here, we summarize research about the topography and transmitter phenotype of the reciprocal connections between the LHb and ventral tegmental area-nigra complex, as well as those between the LHb and DR/MnR. Indirect MHb outputs via interpeduncular nucleus to state-setting neuromodulatory networks will also be commented. Finally, we discuss the role of specific LHb-VTA and LHb/MHb-raphe circuits in anxiety and depression.
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Affiliation(s)
- Martin Metzger
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rudieri Souza
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Leandro B Lima
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Debora Bueno
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luciano Gonçalves
- Department of Human Anatomy, Federal University of the Triângulo Mineiro, Uberaba, Brazil
| | - Chemutai Sego
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Jose Donato
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sara J Shammah-Lagnado
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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12
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Ren J, Isakova A, Friedmann D, Zeng J, Grutzner SM, Pun A, Zhao GQ, Kolluru SS, Wang R, Lin R, Li P, Li A, Raymond JL, Luo Q, Luo M, Quake SR, Luo L. Single-cell transcriptomes and whole-brain projections of serotonin neurons in the mouse dorsal and median raphe nuclei. eLife 2019; 8:e49424. [PMID: 31647409 PMCID: PMC6812963 DOI: 10.7554/elife.49424] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/12/2019] [Indexed: 12/11/2022] Open
Abstract
Serotonin neurons of the dorsal and median raphe nuclei (DR, MR) collectively innervate the entire forebrain and midbrain, modulating diverse physiology and behavior. To gain a fundamental understanding of their molecular heterogeneity, we used plate-based single-cell RNA-sequencing to generate a comprehensive dataset comprising eleven transcriptomically distinct serotonin neuron clusters. Systematic in situ hybridization mapped specific clusters to the principal DR, caudal DR, or MR. These transcriptomic clusters differentially express a rich repertoire of neuropeptides, receptors, ion channels, and transcription factors. We generated novel intersectional viral-genetic tools to access specific subpopulations. Whole-brain axonal projection mapping revealed that DR serotonin neurons co-expressing vesicular glutamate transporter-3 preferentially innervate the cortex, whereas those co-expressing thyrotropin-releasing hormone innervate subcortical regions in particular the hypothalamus. Reconstruction of 50 individual DR serotonin neurons revealed diverse and segregated axonal projection patterns at the single-cell level. Together, these results provide a molecular foundation of the heterogenous serotonin neuronal phenotypes.
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Affiliation(s)
- Jing Ren
- Department of Biology and Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
| | - Alina Isakova
- Department of BioengineeringStanford UniversityStanfordUnited States
- Department of Applied PhysicsStanford UniversityStanfordUnited States
| | - Drew Friedmann
- Department of Biology and Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
| | - Jiawei Zeng
- National Institute of Biological ScienceBeijingChina
| | - Sophie M Grutzner
- Department of Biology and Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
| | - Albert Pun
- Department of Biology and Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
| | - Grace Q Zhao
- Department of NeurobiologyStanford University School of MedicineStanfordUnited States
| | - Sai Saroja Kolluru
- Department of BioengineeringStanford UniversityStanfordUnited States
- Department of Applied PhysicsStanford UniversityStanfordUnited States
| | - Ruiyu Wang
- National Institute of Biological ScienceBeijingChina
| | - Rui Lin
- National Institute of Biological ScienceBeijingChina
| | - Pengcheng Li
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (HUST)WuhanChina
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for BrainsmaticsSuzhouChina
| | - Anan Li
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (HUST)WuhanChina
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for BrainsmaticsSuzhouChina
| | - Jennifer L Raymond
- Department of NeurobiologyStanford University School of MedicineStanfordUnited States
| | - Qingming Luo
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (HUST)WuhanChina
| | - Minmin Luo
- National Institute of Biological ScienceBeijingChina
- School of Life ScienceTsinghua UniversityBeijingChina
| | - Stephen R Quake
- Department of BioengineeringStanford UniversityStanfordUnited States
- Department of Applied PhysicsStanford UniversityStanfordUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
| | - Liqun Luo
- Department of Biology and Howard Hughes Medical InstituteStanford UniversityStanfordUnited States
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13
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Chleilat E, Mallmann R, Spanagel R, Klugbauer N, Krieglstein K, Roussa E. Spatiotemporal Role of Transforming Growth Factor Beta 2 in Developing and Mature Mouse Hindbrain Serotonergic Neurons. Front Cell Neurosci 2019; 13:427. [PMID: 31619968 PMCID: PMC6763588 DOI: 10.3389/fncel.2019.00427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/06/2019] [Indexed: 12/31/2022] Open
Abstract
Transforming growth factor betas are integral molecular components of the signalling cascades defining development and survival of several neuronal groups. Among TGF-β ligands, TGF-β2 has been considered as relatively more important during development. We have generated a conditional knockout mouse of the Tgf-β2 gene with knock-in of an EGFP reporter and subsequently a mouse line with cell-type specific deletion of TGF-β2 ligand from Krox20 expressing cells (i.e., in cells from rhombomeres r3 and r5). We performed a phenotypic analysis of the hindbrain serotonergic system during development and in adulthood, determined the neurochemical profile in hindbrain and forebrain, and assessed behavioural performance of wild type and mutant mice. Mutant mice revealed significantly decreased number of caudal 5-HT neurons at embryonic day (E) 14, and impaired development of caudal dorsal raphe, median raphe, raphe magnus, and raphe obscurus neurons at E18, a phenotype that was largely restored and even overshot in dorsal raphe of mutant adult mice. Serotonin levels were decreased in hindbrain but significantly increased in cortex of adult mutant mice, though without any behavioural consequences. These results highlight differential and temporal dependency of developing and adult neurons on TGF-β2. The results also indicate TGF-β2 being directly or indirectly potent to modulate neurotransmitter synthesis and metabolism. The novel floxed TGF-β2 mouse model is a suitable tool for analysing the in vivo functions of TGF-β2 during development and in adulthood in many organs.
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Affiliation(s)
- Enaam Chleilat
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Robert Mallmann
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health (ZI), Heidelberg University, Mannheim, Germany
| | - Norbert Klugbauer
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Kerstin Krieglstein
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Eleni Roussa
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
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14
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Huang KW, Ochandarena NE, Philson AC, Hyun M, Birnbaum JE, Cicconet M, Sabatini BL. Molecular and anatomical organization of the dorsal raphe nucleus. eLife 2019; 8:e46464. [PMID: 31411560 PMCID: PMC6726424 DOI: 10.7554/elife.46464] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/13/2019] [Indexed: 12/20/2022] Open
Abstract
The dorsal raphe nucleus (DRN) is an important source of neuromodulators and has been implicated in a wide variety of behavioral and neurological disorders. The DRN is subdivided into distinct anatomical subregions comprised of multiple cell types, and its complex cellular organization has impeded efforts to investigate the distinct circuit and behavioral functions of its subdomains. Here we used single-cell RNA sequencing, in situ hybridization, anatomical tracing, and spatial correlation analysis to map the transcriptional and spatial profiles of cells from the mouse DRN. Our analysis of 39,411 single-cell transcriptomes revealed at least 18 distinct neuron subtypes and 5 serotonergic neuron subtypes with distinct molecular and anatomical properties, including a serotonergic neuron subtype that preferentially innervates the basal ganglia. Our study lays out the molecular organization of distinct serotonergic and non-serotonergic subsystems, and will facilitate the design of strategies for further dissection of the DRN and its diverse functions.
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Affiliation(s)
- Kee Wui Huang
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
| | - Nicole E Ochandarena
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
| | - Adrienne C Philson
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
| | - Minsuk Hyun
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
| | - Jaclyn E Birnbaum
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
| | - Marcelo Cicconet
- Image and Data Analysis CoreHarvard Medical SchoolBostonUnited States
| | - Bernardo L Sabatini
- Department of NeurobiologyHoward Hughes Medical Institute, Harvard Medical SchoolBostonUnited States
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15
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Ren J, Friedmann D, Xiong J, Liu CD, Ferguson BR, Weerakkody T, DeLoach KE, Ran C, Pun A, Sun Y, Weissbourd B, Neve RL, Huguenard J, Horowitz MA, Luo L. Anatomically Defined and Functionally Distinct Dorsal Raphe Serotonin Sub-systems. Cell 2018; 175:472-487.e20. [PMID: 30146164 PMCID: PMC6173627 DOI: 10.1016/j.cell.2018.07.043] [Citation(s) in RCA: 248] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 07/01/2018] [Accepted: 07/25/2018] [Indexed: 01/21/2023]
Abstract
The dorsal raphe (DR) constitutes a major serotonergic input to the forebrain and modulates diverse functions and brain states, including mood, anxiety, and sensory and motor functions. Most functional studies to date have treated DR serotonin neurons as a single population. Using viral-genetic methods, we found that subcortical- and cortical-projecting serotonin neurons have distinct cell-body distributions within the DR and differentially co-express a vesicular glutamate transporter. Further, amygdala- and frontal-cortex-projecting DR serotonin neurons have largely complementary whole-brain collateralization patterns, receive biased inputs from presynaptic partners, and exhibit opposite responses to aversive stimuli. Gain- and loss-of-function experiments suggest that amygdala-projecting DR serotonin neurons promote anxiety-like behavior, whereas frontal-cortex-projecting neurons promote active coping in the face of challenge. These results provide compelling evidence that the DR serotonin system contains parallel sub-systems that differ in input and output connectivity, physiological response properties, and behavioral functions.
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Affiliation(s)
- Jing Ren
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Drew Friedmann
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Jing Xiong
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Cindy D Liu
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Brielle R Ferguson
- Department of Neurology and Neurological Sciences, Stanford, CA 94305, USA
| | - Tanya Weerakkody
- Department of Neurology and Neurological Sciences, Stanford, CA 94305, USA
| | - Katherine E DeLoach
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Chen Ran
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Albert Pun
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Yanwen Sun
- Department of Physics, Stanford University, Stanford, CA 94305, USA
| | - Brandon Weissbourd
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Rachael L Neve
- Delivery Technology Core, Massachusetts General Hospital, Cambridge, MA 02139, USA
| | - John Huguenard
- Department of Neurology and Neurological Sciences, Stanford, CA 94305, USA
| | - Mark A Horowitz
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Liqun Luo
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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16
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Ehlinger DG, Commons KG. Cav1.2 L-type calcium channels regulate stress coping behavior via serotonin neurons. Neuropharmacology 2018; 144:282-290. [PMID: 30176250 DOI: 10.1016/j.neuropharm.2018.08.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/23/2018] [Accepted: 08/25/2018] [Indexed: 01/15/2023]
Abstract
Human genetic variation in the gene CACNA1C, which codes for the alpha-1c subunit of Cav1.2 L-type calcium channels (LTCCs), has been broadly associated with enhanced risk for neuropsychiatric disorders including major depression, bipolar and schizophrenia. Little is known about the specific neural circuits through which CACNA1C and Cav1.2 LTCCs impact disease etiology. However, serotonin (5-HT) neurotransmission has been consistently implicated in these neuropsychiatric disorders and Cav1.2 LTCCs may influence 5-HT neuron activity during relevant behavioral states such as stress. We utilized a temporally controlled and 5-HT neuron specific Cacna1c knockout mouse model to assess stress-coping behavior using the forced swim test and dorsal raphe (DR) 5-HT neuron Fos activation. Furthermore, we assessed 5-HT1A receptor function and feedback inhibition of the DR following administration of the 5-HT1A antagonist WAY-100635. We find that 5-HT neuron Cacna1c knockout disrupts active-coping behavior in the forced swim test and that this behavioral effect is rescued by blocking 5-HT1A receptors. Moreover, Cacna1c knockout mice display enhanced Fos expression in caudal DR 5-HT neurons and an enhanced response to a 5-HT1A receptor antagonist in rostral DR 5-HT neurons, indicating that loss of Cacna1c disrupts both 5-HT neuron activation and 5-HT1A dependent feedback inhibition across the caudal to rostral DR. Collectively, these results reveal an important role for 5-HT neuron Cav1.2 LTCCs in stress-coping behavior and 5-HT1A receptor function. This suggests that alterations in CACNA1C function or expression could influence the development or treatment of neuropsychiatric disorder through serotonergic mechanisms.
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Affiliation(s)
- Daniel G Ehlinger
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, USA; Department of Anesthesia, Harvard Medical School, Boston, MA, USA.
| | - Kathryn G Commons
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, USA; Department of Anesthesia, Harvard Medical School, Boston, MA, USA
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17
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Russo AM, Lawther AJ, Prior BM, Isbel L, Somers WG, Lesku JA, Richdale AL, Dissanayake C, Kent S, Lowry CA, Hale MW. Social approach, anxiety, and altered tryptophan hydroxylase 2 activity in juvenile BALB/c and C57BL/6J mice. Behav Brain Res 2018; 359:918-926. [PMID: 29935278 DOI: 10.1016/j.bbr.2018.06.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/24/2018] [Accepted: 06/19/2018] [Indexed: 12/28/2022]
Abstract
Autism spectrum disorder (ASD) is a heterogeneous and highly heritable condition with multiple aetiologies. Although the biological mechanisms underlying ASD are not fully understood, evidence suggests that dysregulation of serotonergic systems play an important role in ASD psychopathology. Preclinical models using mice with altered serotonergic neurotransmission may provide insight into the role of serotonin in behaviours relevant to clinical features of ASD. For example, BALB/c mice carry a loss-of-function single nucleotide polymorphism (SNP; C1473 G) in tryptophan hydroxylase 2 (Tph2), which encodes the brain-specific isoform of the rate-limiting enzyme for serotonin synthesis, and these mice frequently have been used to model symptoms of ASD. In this study, juvenile male BALB/c (G/G; loss-of-function variant) and C57BL/6 J (C/C; wild type variant) mice, were exposed to the three-chamber sociability test, and one week later to the elevated plus-maze (EPM). Tryptophan hydroxylase 2 (TPH2) activity was measured following injection of the aromatic amino acid decarboxylase (AADC)-inhibitor, NSD-1015, and subsequent HPLC detection of 5-hydroxytryptophan (5-HTP) within subregions of the dorsal raphe nucleus (DR) and median raphe nucleus (MnR). The BALB/c mice showed reduced social behaviour and increased anxious behaviour, as well as decreased 5-HTP accumulation in the rostral and mid-rostrocaudal DR. In the full cohort of mice, TPH2 activity in the mid-rostrocaudal DR was correlated with anxious behaviour in the EPM, however these correlations were not statistically significant within each strain, suggesting that TPH2 activity was not directly associated with either anxiety or sociability. Further research is therefore required to more fully understand how serotonergic systems are involved in mouse behaviours that resemble some of the clinical features of ASD.
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Affiliation(s)
- Adrian M Russo
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Adam J Lawther
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Benjamin M Prior
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Luke Isbel
- School of Molecular Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - W Gregory Somers
- Olga Tennison Autism Research Centre, La Trobe University, Melbourne, VIC, 3086, Australia
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Amanda L Richdale
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia; Olga Tennison Autism Research Centre, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Cheryl Dissanayake
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia; Olga Tennison Autism Research Centre, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Stephen Kent
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Matthew W Hale
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia.
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18
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Prouty EW, Chandler DJ, Waterhouse BD. Neurochemical differences between target-specific populations of rat dorsal raphe projection neurons. Brain Res 2017; 1675:28-40. [PMID: 28867482 PMCID: PMC5822427 DOI: 10.1016/j.brainres.2017.08.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/18/2017] [Accepted: 08/28/2017] [Indexed: 11/22/2022]
Abstract
Serotonin (5-HT)-containing neurons in the dorsal raphe (DR) nucleus project throughout the forebrain and are implicated in many physiological processes and neuropsychiatric disorders. Diversity among these neurons has been characterized in terms of their neurochemistry and anatomical organization, but a clear sense of whether these attributes align with specific brain functions or terminal fields is lacking. DR 5-HT neurons can co-express additional neuroactive substances, increasing the potential for individualized regulation of target circuits. The goal of this study was to link DR neurons to a specific functional role by characterizing cells according to both their neurotransmitter expression and efferent connectivity; specifically, cells projecting to the medial prefrontal cortex (mPFC), a region implicated in cognition, emotion, and responses to stress. Following retrograde tracer injection, brainstem sections from Sprague-Dawley rats were immunohistochemically stained for markers of serotonin, glutamate, GABA, and nitric oxide (NO). 98% of the mPFC-projecting serotonergic neurons co-expressed the marker for glutamate, while the markers for NO and GABA were observed in 60% and less than 1% of those neurons, respectively. To identify potential target-specific differences in co-transmitter expression, we also characterized DR neurons projecting to a visual sensory structure, the lateral geniculate nucleus (LGN). The proportion of serotonergic neurons co-expressing NO was greater amongst cells targeting the mPFC vs LGN (60% vs 22%). The established role of 5-HT in affective disorders and the emerging role of NO in stress signaling suggest that the impact of 5-HT/NO co-localization in DR neurons that regulate mPFC circuit function may be clinically relevant.
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Affiliation(s)
- Eric W Prouty
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Daniel J Chandler
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Barry D Waterhouse
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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19
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The lateral habenula and the serotonergic system. Pharmacol Biochem Behav 2017; 162:22-28. [PMID: 28528079 DOI: 10.1016/j.pbb.2017.05.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/10/2017] [Accepted: 05/16/2017] [Indexed: 12/15/2022]
Abstract
The habenula (Hb) is an epithalamic structure differentiated into two nuclear complexes, medial (MHb) and lateral habenula (LHb). After decades of relative neglect, interest in the Hb resurged when it was demonstrated that LHb neurons play a key role in encoding disappointments and expectation of punishments. Consistent with such a role, the LHb has been implicated in a broad array of functions and pathologic conditions, notably in mechanisms of stress and pain, as well as in the pathophysiology of mood disorders. So far, the vast majority of research involving the LHb has focused on its role in regulating midbrain dopamine release. However, the LHb is also robustly interconnected in a reciprocal manner with a set of rostral serotonin (5-HT) nuclei. Thus, there is increasing evidence that the LHb is amply linked to the dorsal (DR) and median raphe nucleus (MnR) by a complex network of parallel topographically organized direct and indirect pathways. Here, we summarize research about the interconnections of the LHb with different subregions of the DR and MnR, as well as findings about 5-HT-dependent modulation of LHb neurons. Finally, we discuss the contribution of distinct LHb-raphe loops to stress and stress-related psychiatric disorders including anxiety and depression.
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20
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Hartline JT, Smith AN, Kabelik D. Serotonergic activation during courtship and aggression in the brown anole, Anolis sagrei. PeerJ 2017; 5:e3331. [PMID: 28533977 PMCID: PMC5436558 DOI: 10.7717/peerj.3331] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 04/19/2017] [Indexed: 11/20/2022] Open
Abstract
The role of serotonin (5-hydroxytryptamine, 5-HT) in social behavior regulation is not fully understood. While 5-HT release in nuclei of the social behavior network has generally been associated with inhibition of aggressive behavior across multiple classes of vertebrates, less is known about its effects on sexual, especially non-copulatory courtship display behaviors. Furthermore, most research has examined effects at 5-HT release sites, while studies examining the behavioral relevance of source cell populations have generated contradictory findings. This study utilized immunohistochemistry to examine the colocalization of 5-HT with Fos, an immediate early gene product and marker of neural activity, in the raphe and superior reticular nuclei of male brown anoles (Anolis sagrei) exposed to either aggression, courtship, or control social interactions. Supporting previous research, copulation was associated with a decrease in 5-HT activity, while a novel link between 5-HT activity and latency to non-copulatory courtship was also found. Within the aggression group, intensity and frequency of behavior were both associated with decreased 5-HT activity. An effect of social context was also seen, with anoles exposed to either courtship or aggression encounters showing decreased 5-HT activity in certain raphe and superior reticular nuclei populations compared to controls. Interestingly, context effects and behavioral effects were seen at separate brain nuclei, suggesting the presence of separate systems with distinct functional roles.
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Affiliation(s)
- Jacob T Hartline
- Department of Biology, Rhodes College, Memphis, TN, United States of America.,Program in Neuroscience, Rhodes College, Memphis, TN, United States of America
| | - Alexandra N Smith
- Department of Biology, Rhodes College, Memphis, TN, United States of America.,Program in Neuroscience, Rhodes College, Memphis, TN, United States of America
| | - David Kabelik
- Department of Biology, Rhodes College, Memphis, TN, United States of America.,Program in Neuroscience, Rhodes College, Memphis, TN, United States of America
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21
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Lima LB, Bueno D, Leite F, Souza S, Gonçalves L, Furigo IC, Donato J, Metzger M. Afferent and efferent connections of the interpeduncular nucleus with special reference to circuits involving the habenula and raphe nuclei. J Comp Neurol 2017; 525:2411-2442. [DOI: 10.1002/cne.24217] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Leandro B. Lima
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Debora Bueno
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Fernanda Leite
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Stefani Souza
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Luciano Gonçalves
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Isadora C. Furigo
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Jose Donato
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
| | - Martin Metzger
- Department of Physiology & Biophysics; Institute of Biomedical Sciences, University of São Paulo; São Paulo Brazil
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22
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Cohen JL, Ata AE, Jackson NL, Rahn EJ, Ramaker RC, Cooper S, Kerman IA, Clinton SM. Differential stress induced c-Fos expression and identification of region-specific miRNA-mRNA networks in the dorsal raphe and amygdala of high-responder/low-responder rats. Behav Brain Res 2017; 319:110-123. [PMID: 27865919 PMCID: PMC5183530 DOI: 10.1016/j.bbr.2016.11.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/19/2016] [Accepted: 11/08/2016] [Indexed: 01/03/2023]
Abstract
Chronic stress triggers a variety of physical and mental health problems, and how individuals cope with stress influences risk for emotional disorders. To investigate molecular mechanisms underlying distinct stress coping styles, we utilized rats that were selectively-bred for differences in emotionality and stress reactivity. We show that high novelty responding (HR) rats readily bury a shock probe in the defensive burying test, a measure of proactive stress coping behavior, while low novelty responding (LR) rats exhibit enhanced immobility, a measure of reactive coping. Shock exposure in the defensive burying test elicited greater activation of HR rats' caudal dorsal raphe serotonergic cells compared to LRs, but lead to more pronounced activation throughout LRs' amygdala (lateral, basolateral, central, and basomedial nuclei) compared to HRs. RNA-sequencing revealed 271 mRNA transcripts and 33 microRNA species that were differentially expressed in HR/LR raphe and amygdala. We mapped potential microRNA-mRNA networks by correlating and clustering mRNA and microRNA expression and identified networks that differed in either the HR/LR dorsal raphe or amygdala. A dorsal raphe network linked three microRNAs which were down-regulated in LRs (miR-206-3p, miR-3559-5p, and miR-378a-3p) to repression of genes related to microglia and immune response (Cd74, Cyth4, Nckap1l, and Rac2), the genes themselves were up-regulated in LR dorsal raphe. In the amygdala, another network linked miR-124-5p, miR-146a-5p, miR-3068-3p, miR-380-5p, miR-539-3p, and miR-7a-1-3p with repression of chromatin remodeling-related genes (Cenpk, Cenpq, Itgb3bp, and Mis18a). Overall this work highlights potential drivers of gene-networks and downstream molecular pathways within the raphe and amygdala that contribute to individual differences in stress coping styles and stress vulnerabilities.
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Affiliation(s)
- Joshua L Cohen
- Medical Scientist Training Program, University of Alabama-Birmingham, USA
| | - Anooshah E Ata
- University of Alabama-Birmingham School of Medicine, USA
| | - Nateka L Jackson
- Department of Neurobiology, University of Alabama-Birmingham, USA
| | - Elizabeth J Rahn
- Department of Neurobiology, University of Alabama-Birmingham, USA
| | - Ryne C Ramaker
- Medical Scientist Training Program, University of Alabama-Birmingham, USA; HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Sara Cooper
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Ilan A Kerman
- School of Neuroscience, Virginia Tech University, USA; Department of Psychiatry & Behavioral Medicine, Carilion Clinic, Virginia Tech Carilion School of Medicine, USA
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23
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EphrinA5 Signaling Is Required for the Distinctive Targeting of Raphe Serotonin Neurons in the Forebrain. eNeuro 2017; 4:eN-NWR-0327-16. [PMID: 28197551 PMCID: PMC5292598 DOI: 10.1523/eneuro.0327-16.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/06/2017] [Indexed: 12/13/2022] Open
Abstract
Serotonin (5-HT) neurotransmission in the brain relies on a widespread axon terminal network originating from the hindbrain raphe nuclei. These projections are topographically organized such that the dorsal (DR), and median raphe (MnR) nuclei have different brain targets. However, the guidance molecules involved in this selective targeting in development are unknown. Here, we show the implication of ephrinA5 signaling in this process. We find that the EphA5 gene is selectively expressed in a subset of 5-HT neurons during embryonic and postnatal development. Highest coexpression of EphA5 and the 5-HT marker Tph2 is found in the DR, with lower coexpression in the MnR, and hardly any colocalization of the caudal raphe in the medulla. Accordingly, ephrinA induced a dose-dependent collapse response of 5-HT growth cones cultured from rostral but not caudal raphe. Ectopic expression of ephrinA3, after in utero electroporation in the amygdala and piriform cortex, repelled 5-HT raphe fiber ingrowth. Conversely, misplaced DR 5-HT axons were found in ephrin A5 knockout mice in brain regions that are normally only targeted by MnR 5-HT axons. This causes an overall increase in the density of 5-HT innervation in the ventromedial hypothalamus, the suprachiasmatic nucleus, and the olfactory bulb. All these brain areas have high expression of ephrinAs at the time of 5-HT fiber ingrowth. Present results show for the first time the role of a guidance molecule for the region-specific targeting of raphe neurons. This has important implications to understand how functional parsing of central 5-HT neurons is established during development.
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24
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Wang P, Li H, Barde S, Zhang MD, Sun J, Wang T, Zhang P, Luo H, Wang Y, Yang Y, Wang C, Svenningsson P, Theodorsson E, Hökfelt TGM, Xu ZQD. Depression-like behavior in rat: Involvement of galanin receptor subtype 1 in the ventral periaqueductal gray. Proc Natl Acad Sci U S A 2016; 113:E4726-35. [PMID: 27457954 PMCID: PMC4987783 DOI: 10.1073/pnas.1609198113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The neuropeptide galanin coexists in rat brain with serotonin in the dorsal raphe nucleus and with noradrenaline in the locus coeruleus (LC), and it has been suggested to be involved in depression. We studied rats exposed to chronic mild stress (CMS), a rodent model of depression. As expected, these rats showed several endophenotypes relevant to depression-like behavior compared with controls. All these endophenotypes were normalized after administration of a selective serotonin reuptake inhibitor. The transcripts for galanin and two of its receptors, galanin receptor 1 (GALR1) and GALR2, were analyzed with quantitative real-time PCR using laser capture microdissection in the following brain regions: the hippocampal formation, LC, and ventral periaqueductal gray (vPAG). Only Galr1 mRNA levels were significantly increased, and only in the latter region. After knocking down Galr1 in the vPAG with an siRNA technique, all parameters of the depressive behavioral phenotype were similar to controls. Thus, the depression-like behavior in rats exposed to CMS is likely related to an elevated expression of Galr1 in the vPAG, suggesting that a GALR1 antagonist could have antidepressant effects.
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Affiliation(s)
- Peng Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hui Li
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Ming-Dong Zhang
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden; Division of Molecular Neurobiology, Department of Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Jing Sun
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Tong Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Pan Zhang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hanjiang Luo
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Yongjun Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Yutao Yang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Chuanyue Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Per Svenningsson
- Center for Molecular Medicine, Department of Neurology and Clinical Neuroscience, Karolinska Institutet and Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linkoping University, SE-58183 Linkoping, Sweden
| | - Tomas G M Hökfelt
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden;
| | - Zhi-Qing David Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China;
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Mlinar B, Montalbano A, Piszczek L, Gross C, Corradetti R. Firing Properties of Genetically Identified Dorsal Raphe Serotonergic Neurons in Brain Slices. Front Cell Neurosci 2016; 10:195. [PMID: 27536220 PMCID: PMC4971071 DOI: 10.3389/fncel.2016.00195] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 07/22/2016] [Indexed: 11/13/2022] Open
Abstract
Tonic spiking of serotonergic neurons establishes serotonin levels in the brain. Since the first observations, slow regular spiking has been considered as a defining feature of serotonergic neurons. Recent studies, however, have revealed the heterogeneity of serotonergic neurons at multiple levels, comprising their electrophysiological properties, suggesting the existence of functionally distinct cellular subpopulations. In order to examine in an unbiased manner whether serotonergic neurons of the dorsal raphe nucleus (DRN) are heterogeneous, we used a non-invasive loose-seal cell-attached method to record α1 adrenergic receptor-stimulated spiking of a large sample of neurons in brain slices obtained from transgenic mice lines that express fluorescent marker proteins under the control of serotonergic system-specific Tph2 and Pet-1 promoters. We found wide homogeneous distribution of firing rates, well fitted by a single Gaussian function (r (2) = 0.93) and independent of anatomical location (P = 0.45), suggesting that in terms of intrinsic firing properties, serotonergic neurons in the DRN represent a single cellular population. Characterization of the population in terms of spiking regularity was hindered by its dependence on the firing rate. For instance, the coefficient of variation of the interspike intervals (ISI), a common measure of spiking irregularity, is of limited usefulness since it correlates negatively with the firing rate (r = -0.33, P < 0.0001). Nevertheless, the majority of neurons exhibited regular, pacemaker-like activity, with coefficient of variance of the ISI lower than 0.5 in ~97% of cases. Unexpectedly, a small percentage of neurons (~1%) exhibited a particular spiking pattern, characterized by low frequency (~0.02-0.1 Hz) oscillations in the firing rate. Transitions between regular and oscillatory firing were observed, suggesting that the oscillatory firing is an alternative firing pattern of serotonergic neurons.
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Affiliation(s)
- Boris Mlinar
- Department of Neuroscience, Psychology, Drug Research and Children's Health, University of Florence Florence, Italy
| | - Alberto Montalbano
- Department of Neuroscience, Psychology, Drug Research and Children's Health, University of Florence Florence, Italy
| | - Lukasz Piszczek
- Mouse Biology Unit, European Molecular Biology Laboratory Monterotondo, Italy
| | - Cornelius Gross
- Mouse Biology Unit, European Molecular Biology Laboratory Monterotondo, Italy
| | - Renato Corradetti
- Department of Neuroscience, Psychology, Drug Research and Children's Health, University of Florence Florence, Italy
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26
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Affiliation(s)
- Albert Adell
- Institute of Biomedicine and Biotechnology of Cantabria, IBBTEC (CSIC, Universidad de Cantabria), 39011 Santander, Spain
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27
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Urbanavicius J, Lagos P, Torterolo P, Abin-Carriquiry JA, Scorza C. Melanin-concentrating hormone projections to the dorsal raphe nucleus: An immunofluorescence and in vivo microdialysis study. J Chem Neuroanat 2016; 72:16-24. [DOI: 10.1016/j.jchemneu.2015.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/12/2015] [Accepted: 11/14/2015] [Indexed: 10/22/2022]
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28
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Commons KG. Ascending serotonin neuron diversity under two umbrellas. Brain Struct Funct 2016; 221:3347-60. [PMID: 26740230 DOI: 10.1007/s00429-015-1176-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 12/19/2015] [Indexed: 12/30/2022]
Abstract
Forebrain serotonin relevant for many psychological disorders arises in the hindbrain, primarily within the dorsal and median raphe nuclei (DR and MR). These nuclei are heterogeneous, containing several distinct groups of serotonin neurons. Here, new insight into the afferent and efferent connectivity of these areas is reviewed in correlation with their developmental origin. These data suggest that the caudal third of the DR, the area originally designated B6, may be misidentified as part of the DR as it shares many features of connectivity with the MR. By considering the rostral DR independently and affiliating the B6 to the MR, the diverse subgroups of serotonin neurons can be arranged with more coherence into two umbrella groups, each with distinctive domains of influence. Serotonin neurons within the rostral DR are uniquely interconnected with brain areas associated with emotion and motivation such as the amygdala, accumbens and ventral pallidum. In contrast serotonin neurons in the B6 and MR are characterized by their dominion over the septum and hippocampus. This distinction between the DR and B6/MR parallels their developmental origin and likely impacts their role in both behavior and psychopathology. Implications and further subdivisions within these areas are discussed.
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Affiliation(s)
- Kathryn G Commons
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA. .,Department of Anaesthesia, Harvard Medical School, Boston, USA.
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29
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Fernandez SP, Cauli B, Cabezas C, Muzerelle A, Poncer JC, Gaspar P. Multiscale single-cell analysis reveals unique phenotypes of raphe 5-HT neurons projecting to the forebrain. Brain Struct Funct 2015; 221:4007-4025. [PMID: 26608830 DOI: 10.1007/s00429-015-1142-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/02/2015] [Indexed: 11/28/2022]
Abstract
Serotonergic neurons of the raphe nuclei exhibit anatomical, neurochemical and elecrophysiological heterogeneity that likely underpins their specific role in multiple behaviors. However, the precise organization of serotonin (5-HT) neurons to orchestrate 5-HT release patterns throughout the brain is not well understood. We compared the electrophysiological and neurochemical properties of dorsal and median raphe 5-HT neurons projecting to the medial prefrontal cortex (mPFC), amygdala (BLA) and dorsal hippocampus (dHP), combining retrograde tract tracing with brain slice electrophysiology and single-cell RT-PCR in Pet1-EGFP mice. Our results show that 5-HT neurons projecting to the dHP and the mPFC and the BLA form largely non-overlapping populations and that BLA-projecting neurons have characteristic excitability and membrane properties. In addition, using an unbiased clustering method that correlates anatomical, molecular and electrophysiological phenotypes, we find that 5-HT neurons with projections to the mPFC and the dHP segregate from those projecting to the BLA. Single-cell gene profiling showed a restricted expression of the peptide galanin in the population of 5-HT neurons projecting to the mPFC. Finally, cluster analysis allowed identifying an atypical subtype of 5-HT neuron with low excitability, long firing delays and preferential expression of the vesicular glutamate transporter type 3. Overall, these findings allow to define correlated anatomical and physiological identities of serotonin raphe neurons that help understanding how discrete raphe cells subpopulations account for the heterogeneous activities of the midbrain serotonergic system.
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Affiliation(s)
- Sebastian Pablo Fernandez
- Institut du Fer à Moulin, INSERM U839, 17 rue du Fer à Moulin, 75005, Paris, France. .,Université Pierre et Marie Curie, Paris, France. .,Institut du Fer a Moulin, Paris, France.
| | - Bruno Cauli
- Université Pierre et Marie Curie, Paris, France.,CNRS, UMR 8246, Neuroscience Paris Seine, 75005, Paris, France.,Inserm UMR-S 1130, Neuroscience Paris Seine, 75005, Paris, France
| | - Carolina Cabezas
- Institut du Fer à Moulin, INSERM U839, 17 rue du Fer à Moulin, 75005, Paris, France.,Université Pierre et Marie Curie, Paris, France.,Institut du Fer a Moulin, Paris, France
| | - Aude Muzerelle
- Institut du Fer à Moulin, INSERM U839, 17 rue du Fer à Moulin, 75005, Paris, France.,Université Pierre et Marie Curie, Paris, France.,Institut du Fer a Moulin, Paris, France
| | - Jean-Christophe Poncer
- Institut du Fer à Moulin, INSERM U839, 17 rue du Fer à Moulin, 75005, Paris, France.,Université Pierre et Marie Curie, Paris, France.,Institut du Fer a Moulin, Paris, France
| | - Patricia Gaspar
- Institut du Fer à Moulin, INSERM U839, 17 rue du Fer à Moulin, 75005, Paris, France. .,Université Pierre et Marie Curie, Paris, France. .,Institut du Fer a Moulin, Paris, France.
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30
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Anxiogenic drug administration and elevated plus-maze exposure in rats activate populations of relaxin-3 neurons in the nucleus incertus and serotonergic neurons in the dorsal raphe nucleus. Neuroscience 2015; 303:270-84. [DOI: 10.1016/j.neuroscience.2015.06.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/24/2015] [Accepted: 06/24/2015] [Indexed: 12/20/2022]
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31
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Kusek M, Sowa J, Kamińska K, Gołembiowska K, Tokarski K, Hess G. 5-HT7 receptor modulates GABAergic transmission in the rat dorsal raphe nucleus and controls cortical release of serotonin. Front Cell Neurosci 2015; 9:324. [PMID: 26347612 PMCID: PMC4539517 DOI: 10.3389/fncel.2015.00324] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/05/2015] [Indexed: 01/17/2023] Open
Abstract
The 5-HT7 receptor is one of the several serotonin (5-HT) receptor subtypes that are expressed in the dorsal raphe nucleus (DRN). Some earlier findings suggested that 5-HT7 receptors in the DRN were localized on GABAergic interneurons modulating the activity of 5-HT projection neurons. The aim of the present study was to find out how the 5-HT7 receptor modulates the GABAergic synaptic input to putative 5-HT DRN neurons, and whether blockade of the 5-HT7 receptor would affect the release of 5-HT in the target structure. Male Wistar rats with microdialysis probes implanted in the prefrontal cortex (PFC) received injections of the 5-HT7 receptor antagonist (2R)-1-[(3-hydroxyphenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrrolidine hydrochloride (SB 269970), which induced an increase in the levels of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in the PFC. In another set of experiments whole-cell recordings from presumed projection neurons were carried out using DRN slices. SB 269970 application resulted in depolarization and in an increase in the firing frequency of the cells. In order to activate 5-HT7 receptors, 5-carboxamidotryptamine (5-CT) was applied in the presence of N-[2-[4-(2-methoxyphenyl)-1piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635). Hyperpolarization of cells and a decrease in the firing frequency were observed after activation of the 5-HT7 receptor. Blockade of 5-HT7 receptors caused a decrease in the mean frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), while its activation induced an increase. The mechanism of these effects appears to involve tonically-active 5-HT7 receptors modulating firing and/or GABA release from inhibitory interneurons which regulate the activity of DRN serotonergic projection neurons.
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Affiliation(s)
- Magdalena Kusek
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Joanna Sowa
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Katarzyna Kamińska
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Krystyna Gołembiowska
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Grzegorz Hess
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland ; Institute of Zoology, Jagiellonian University Krakow, Poland
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