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Soto NN, Gaspar P, Bacci A. Not Just a Mood Disorder─Is Depression a Neurodevelopmental, Cognitive Disorder? Focus on Prefronto-Thalamic Circuits. ACS Chem Neurosci 2024; 15:1611-1618. [PMID: 38580316 PMCID: PMC11027097 DOI: 10.1021/acschemneuro.3c00828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 04/07/2024] Open
Abstract
Depression is one of the most burdensome psychiatric disorders, affecting hundreds of millions of people worldwide. The disease is characterized not only by severe emotional and affective impairments, but also by disturbed vegetative and cognitive functions. Although many candidate mechanisms have been proposed to cause the disease, the pathophysiology of cognitive impairments in depression remains unclear. In this article, we aim to assess the link between cognitive alterations in depression and possible developmental changes in neuronal circuit wiring during critical periods of susceptibility. We review the existing literature and propose a role of serotonin signaling during development in shaping the functional states of prefrontal neuronal circuits and prefronto-thalamic loops. We discuss how early life insults affecting the serotonergic system could be important in the alterations of these local and long-range circuits, thus favoring the emergence of neurodevelopmental disorders, such as depression.
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Affiliation(s)
- Nina Nitzan Soto
- ICM−Paris
Brain Institute, CNRS, INSERM, Sorbonne
Université, 47 Boulevard de l’Hopital, 75013 Paris, France
| | - Patricia Gaspar
- ICM−Paris
Brain Institute, CNRS, INSERM, Sorbonne
Université, 47 Boulevard de l’Hopital, 75013 Paris, France
| | - Alberto Bacci
- ICM−Paris
Brain Institute, CNRS, INSERM, Sorbonne
Université, 47 Boulevard de l’Hopital, 75013 Paris, France
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2
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Janowitz HN, Linden DJ. Chronic Treatment with Serotonin Selective Reuptake Inhibitors Does Not Affect Regrowth of Serotonin Axons Following Amphetamine Injury in the Mouse Forebrain. eNeuro 2024; 11:ENEURO.0444-22.2023. [PMID: 38355299 PMCID: PMC10867722 DOI: 10.1523/eneuro.0444-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 08/01/2023] [Accepted: 08/12/2023] [Indexed: 02/16/2024] Open
Abstract
A current hypothesis to explain the limited recovery following brain and spinal cord trauma stems from the dogma that neurons in the mammalian central nervous system lack the ability to regenerate their axons after injury. Serotonin (5-HT) neurons in the adult brain are a notable exception in that they can slowly regrow their axons following chemical or mechanical lesions. This process of regrowth occurs without intervention over several months and results in anatomical recovery that approximates the preinjured state. During development, serotonin is a trophic factor, playing a role in both cell survival and axon growth. Additionally, some studies have shown that stroke patients treated after injury with serotonin selective reuptake inhibitors (SSRIs) appeared to have improved recovery. To test the hypothesis that serotonin can influence the regrowth of 5-HT axons, mice received a high dose of para-chloroamphetamine (PCA) to induce widespread retrograde degeneration of 5-HT axons. Then, after a short rest period to avoid any interaction with the acute injury phase, SSRIs were administered daily for 6 or 10 weeks. Using immunohistochemistry in 5-HT transporter-GFP BAC transgenic mice, we determined that while PCA led to a rapid initial decrease in total 5-HT axon length in the somatosensory cortex, visual cortex, or area CA1 of the hippocampus, treatment with either fluoxetine or sertraline (two different SSRIs) did not affect the recovery of axon length. These results suggest that chronic SSRI treatment does not affect the regrowth of 5-HT axons and argue against SSRIs as a potential therapy following brain injury.
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Affiliation(s)
- Haley N Janowitz
- Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - David J Linden
- Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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3
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Erzurumlu RS. Serotonin, birth, and thalamocortical wiring. Proc Natl Acad Sci U S A 2023; 120:e2312515120. [PMID: 37651446 PMCID: PMC10500185 DOI: 10.1073/pnas.2312515120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Affiliation(s)
- Reha S. Erzurumlu
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD21201
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4
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Sinclair-Wilson A, Lawrence A, Ferezou I, Cartonnet H, Mailhes C, Garel S, Lokmane L. Plasticity of thalamocortical axons is regulated by serotonin levels modulated by preterm birth. Proc Natl Acad Sci U S A 2023; 120:e2301644120. [PMID: 37549297 PMCID: PMC10438379 DOI: 10.1073/pnas.2301644120] [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: 01/31/2023] [Accepted: 07/09/2023] [Indexed: 08/09/2023] Open
Abstract
Sensory inputs are conveyed to distinct primary areas of the neocortex through specific thalamocortical axons (TCA). While TCA have the ability to reorient postnatally to rescue embryonic mistargeting and target proper modality-specific areas, how this remarkable adaptive process is regulated remains largely unknown. Here, using a mutant mouse model with a shifted TCA trajectory during embryogenesis, we demonstrated that TCA rewiring occurs during a short postnatal time window, preceded by a prenatal apoptosis of thalamic neurons-two processes that together lead to the formation of properly innervated albeit reduced primary sensory areas. We furthermore showed that preterm birth, through serotonin modulation, impairs early postnatal TCA plasticity, as well as the subsequent delineation of cortical area boundary. Our study defines a birth and serotonin-sensitive period that enables concerted adaptations of TCA to primary cortical areas with major implications for our understanding of brain wiring in physiological and preterm conditions.
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Affiliation(s)
- Alexander Sinclair-Wilson
- Team Brain Development and Plasticity, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
| | - Akindé Lawrence
- Team Brain Development and Plasticity, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
| | - Isabelle Ferezou
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400Saclay, France
| | - Hugues Cartonnet
- Team Brain Development and Plasticity, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
| | - Caroline Mailhes
- Acute Transgenesis Facility, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
| | - Sonia Garel
- Team Brain Development and Plasticity, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
- Collège de France, PSL Research University, 75005Paris, France
| | - Ludmilla Lokmane
- Team Brain Development and Plasticity, Institut de Biologie de l’ENS, École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005Paris, France
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5
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Vicenzi S, Foa L, Gasperini RJ. Serotonin functions as a bidirectional guidance molecule regulating growth cone motility. Cell Mol Life Sci 2021; 78:2247-2262. [PMID: 32939562 PMCID: PMC11072016 DOI: 10.1007/s00018-020-03628-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/14/2020] [Accepted: 08/21/2020] [Indexed: 02/02/2023]
Abstract
The neurotransmitter serotonin has been implicated in a range of complex neurological disorders linked to alterations of neuronal circuitry. Serotonin is synthesized in the developing brain before most neuronal circuits become fully functional, suggesting that serotonin might play a distinct regulatory role in shaping circuits prior to its function as a classical neurotransmitter. In this study, we asked if serotonin acts as a guidance cue by examining how serotonin alters growth cone motility of rodent sensory neurons in vitro. Using a growth cone motility assay, we found that serotonin acted as both an attractive and repulsive guidance cue through a narrow concentration range. Extracellular gradients of 50 µM serotonin elicited attraction, mediated by the serotonin 5-HT2a receptor while 100 µM serotonin elicited repulsion mediated by the 5-HT1b receptor. Importantly, high resolution imaging of growth cones indicated that these receptors signalled through their canonical pathways of endoplasmic reticulum-mediated calcium release and cAMP depletion, respectively. This novel characterisation of growth cone motility in response to serotonin gradients provides compelling evidence that secreted serotonin acts at the molecular level as an axon guidance cue to shape neuronal circuit formation during development.
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Affiliation(s)
- Silvia Vicenzi
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Lisa Foa
- School of Psychological Sciences, University of Tasmania, Hobart, Australia
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6
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Fuchs C, Gennaccaro L, Ren E, Galvani G, Trazzi S, Medici G, Loi M, Conway E, Devinsky O, Rimondini R, Ciani E. Pharmacotherapy with sertraline rescues brain development and behavior in a mouse model of CDKL5 deficiency disorder. Neuropharmacology 2019; 167:107746. [PMID: 31469994 DOI: 10.1016/j.neuropharm.2019.107746] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/27/2019] [Accepted: 08/21/2019] [Indexed: 12/15/2022]
Abstract
Mutations in the X-linked cyclin-dependent kinase-like 5 (CDKL5) gene cause a severe neurodevelopmental disorder, CDKL5 deficiency disorder (CDD). CDKL5 is fundamental for correct brain development and function, but the molecular mechanisms underlying aberrant neurologic dysfunction in CDD are incompletely understood. Here we show a dysregulation of hippocampal and cortical serotonergic (5-HT) receptor expression in heterozygous Cdkl5 knockout (KO) female mice, suggesting that impaired 5-HT neurotransmission contributes to CDD. We demonstrate that targeting impaired 5-HT signaling via the selective serotonin reuptake inhibitor (SSRI) sertraline rescues CDD-related neurodevelopmental and behavioral defects in heterozygous Cdkl5 KO female mice. In particular, chronic treatment with sertraline normalized locomotion, stereotypic and autistic-like features, and spatial memory in Cdkl5 KO mice. These positive behavioral effects were accompanied by restored neuronal survival, dendritic development and synaptic connectivity. At a molecular level, sertraline increased brain-derived neurotrophic factor (BDNF) expression and restored abnormal phosphorylation levels of tyrosine kinase B (TrkB) and its downstream target the extracellular signal-regulated kinase (ERK1/2). Since sertraline is an FDA-approved drug with an extensive safety and tolerability data package, even for children, our findings suggest that sertraline may improve neurodevelopment in children with CDD. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.
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Affiliation(s)
- Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy.
| | - Laura Gennaccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Elisa Ren
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Giuseppe Galvani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Stefania Trazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Giorgio Medici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Manuela Loi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| | - Erin Conway
- Department of Neurology, NYU Langone Health, New York, USA
| | - Orrin Devinsky
- Department of Neurology, NYU Langone Health, New York, USA
| | - Roberto Rimondini
- Department of Medical and Clinical Sciences, University of Bologna, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy.
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7
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Kott J, Brummelte S. Trick or treat? Evaluating contributing factors and sex-differences for developmental effects of maternal depression and its treatment. Horm Behav 2019; 111:31-45. [PMID: 30658054 DOI: 10.1016/j.yhbeh.2019.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 12/14/2018] [Accepted: 01/11/2019] [Indexed: 11/29/2022]
Abstract
Maternal depression and treatment with selective serotonin reuptake inhibitors (SSRIs), the most common form of pharmaceutical intervention, can both have an impact on infant development. As such, it is difficult for healthcare providers to recommend a course of treatment to expectant mothers suffering from depression, or to women on antidepressant medication prior to pregnancy. This review will discuss the existing research on the developmental impacts of maternal depression and its treatment with SSRIs, with a particular focus on contributing factors that complicate our attempt to disentangle the consequences of maternal depression and its treatment such as the timing or severity of the depression. We will explore avenues for translational animal models to help address the question of "Trick or Treat", i.e.: which is worse for offspring development: exposure to maternal depression, or the SSRI treatment? Further, we will explore sex-dependent outcomes for the offspring in human and animal studies as male and female offspring may react differently to the presence of maternal depression or antidepressant treatment. Without more clinical and preclinical data, it remains difficult for women to make an informed decision regarding their depression treatment before, during, and after their pregnancy.
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Affiliation(s)
- Jennifer Kott
- Department of Psychology, Wayne State University, Detroit, MI, USA
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8
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Developmental outcomes after gestational antidepressant treatment with sertraline and its discontinuation in an animal model of maternal depression. Behav Brain Res 2019; 366:1-12. [PMID: 30836156 DOI: 10.1016/j.bbr.2019.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/04/2019] [Accepted: 03/01/2019] [Indexed: 01/21/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed to women before or during pregnancy to manage their depressive symptoms. However, there is still little knowledge regarding the long-term development effects of SSRI exposure for the fetus or the effects of discontinuing SSRI treatment during pregnancy. This study utilized a translational animal model of maternal depression (based on giving high levels of corticosterone (CORT, 40 mg/kg, s.c.) or vehicle (Oil) for 21 days prior to conception) to investigate the effects of sertraline (a frequently prescribed SSRI; 20 mg/kg p.o., treatment started ∼7 days prior to conception) and its discontinuation during pregnancy (on gestational day 16) compared to vehicle (water) treatment on the development of the offspring. Our results revealed that both corticosterone exposure prior to pregnancy and sertraline administration and its discontinuation during gestation had sex-specific effects on behavior in the adult offspring. In particular, pre-conceptional maternal corticosterone treatment impacted the stress response, anxiety-like behavior and cognitive performance in adult female offspring, while gestational SSRI exposure and its discontinuation compared to full-term exposure affected impulsivity in females, and exploratory behavior in males. More research is needed on the effects of exposure to antidepressant medication and its discontinuation compared to depression during pregnancy and how each impacts development to better help women make informed decisions about their medication use during pregnancy.
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9
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Murthi P, Vaillancourt C. RETRACTED: Placental serotonin systems in pregnancy metabolic complications associated with maternal obesity and gestational diabetes mellitus. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165391. [PMID: 30738809 DOI: 10.1016/j.bbadis.2019.01.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 12/12/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
The publication was retracted by request of the authors following an investigation by Monash University performed following its Procedures for Investigating Code Breaches and in accordance with the Australian Code for the Responsible Conduct of Research.
The University concluded on the balance of probability that a significant part of the text in the paper was included without knowledge, without consent and without correct attribution of the original author who, at the time, was a student at the University. The results discussed in the review article are still scientifically valid.
☆
This article is part of a Special Issue entitled: Membrane Transporters and Receptors in Pregnancy Metabolic Complications edited by Luis Sobrevia.
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Affiliation(s)
- Padma Murthi
- Department of Medicine, School of Clinical Sciences, Department of Physiology, Monash University, Clayton, Victoria, Australia; Hudson Institute of Medical Research, The Ritchie Centre, Clayton, Victoria, Australia; Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, Victoria, Australia.
| | - Cathy Vaillancourt
- INRS-Institut Armand-Frappier, Université du Québec and Biomed Research Center, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada; Center for Interdisciplinary Research on Well-Being, Health, Society and Environment, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
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10
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Bonkowsky JL, Son JH. Hypoxia and connectivity in the developing vertebrate nervous system. Dis Model Mech 2018; 11:11/12/dmm037127. [PMID: 30541748 PMCID: PMC6307895 DOI: 10.1242/dmm.037127] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The developing nervous system depends upon precise regulation of oxygen levels. Hypoxia, the condition of low oxygen concentration, can interrupt developmental sequences and cause a range of molecular, cellular and neuronal changes and injuries. The roles and effects of hypoxia on the central nervous system (CNS) are poorly characterized, even though hypoxia is simultaneously a normal component of development, a potentially abnormal environmental stressor in some settings, and a clinically important complication, for example of prematurity. Work over the past decade has revealed that hypoxia causes specific disruptions in the development of CNS connectivity, altering axon pathfinding and synapse development. The goals of this article are to review hypoxia's effects on the development of CNS connectivity, including its genetic and molecular mediators, and the changes it causes in CNS circuitry and function due to regulated as well as unintended mechanisms. The transcription factor HIF1α is the central mediator of the CNS response to hypoxia (as it is elsewhere in the body), but hypoxia also causes a dysregulation of gene expression. Animals appear to have evolved genetic and molecular responses to hypoxia that result in functional behavioral alterations to adapt to the changes in oxygen concentration during CNS development. Understanding the molecular pathways underlying both the normal and abnormal effects of hypoxia on CNS connectivity may reveal novel insights into common neurodevelopmental disorders. In addition, this Review explores the current gaps in knowledge, and suggests important areas for future studies. Summary: The nervous system's exposure to hypoxia has developmental and clinical relevance. In this Review, the authors discuss the effects of hypoxia on the development of the CNS, and its long-term behavioral and neurodevelopmental consequences.
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Affiliation(s)
- Joshua L Bonkowsky
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84108, USA
| | - Jong-Hyun Son
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84108, USA.,Department of Biology, University of Scranton, Scranton, PA 18510, USA
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11
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Garcia LP, Witteveen JS, Middelman A, van Hulten JA, Martens GJM, Homberg JR, Kolk SM. Perturbed Developmental Serotonin Signaling Affects Prefrontal Catecholaminergic Innervation and Cortical Integrity. Mol Neurobiol 2018; 56:1405-1420. [PMID: 29948943 PMCID: PMC6400880 DOI: 10.1007/s12035-018-1105-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 05/03/2018] [Indexed: 11/26/2022]
Abstract
Proper development of the medial prefrontal cortex (mPFC), crucial for correct cognitive functioning, requires projections from, among others, the serotonergic (5-HT) and catecholaminergic systems, but it is unclear how these systems influence each other during development. Here, we describe the parallel development of the 5-HT and catecholaminergic prefrontal projection systems in rat and demonstrate a close engagement of both systems in the proximity of Cajal-Retzius cells. We further show that in the absence of the 5-HT transporter (5-HTT), not only the developing 5-HT but also the catecholaminergic system, including their projections towards the mPFC, are affected. In addition, the layer identity of the mPFC neurons and reelin-positive interneuron number and integration are altered in the absence of the 5-HTT. Together, our data demonstrate a functional interplay between the developing mPFC 5-HT and catecholaminergic systems, and call for a holistic approach in studying neurotransmitter systems-specific developmental consequences for adult behavior, to eventually allow the design of better treatment strategies for neuropsychiatric disorders.
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Affiliation(s)
- Lidiane P Garcia
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Josefine S Witteveen
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Anthonieke Middelman
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Cognitive Neuroscience, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Josephus A van Hulten
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Gerard J M Martens
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Judith R Homberg
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Cognitive Neuroscience, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Sharon M Kolk
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands.
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12
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Ellegood J, Yee Y, Kerr TM, Muller CL, Blakely RD, Henkelman RM, Veenstra-VanderWeele J, Lerch JP. Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging. Mol Autism 2018; 9:24. [PMID: 29651330 PMCID: PMC5894125 DOI: 10.1186/s13229-018-0210-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/21/2018] [Indexed: 02/03/2023] Open
Abstract
Background The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4, has been extensively studied. Methods Using a 7-T MRI and deformation-based morphometry, we assessed neuroanatomical differences in an Slc6a4 knockout mouse on a C57BL/6 genetic background, along with an Slc6a4 Ala56 knockin mouse on two different genetic backgrounds (129S and C57BL/6). Results Individually (same sex, same background, same genotype), the only differences found were in the female Slc6a4 knockout mouse; all the others had no significant differences. However, an analysis of variance across the whole study sample revealed a significant effect of Slc6a4 on the amygdala, thalamus, dorsal raphe nucleus, and lateral and frontal cortices. Conclusions This work shows that an increase or decrease in SERT function has a significant effect on the neuroanatomy in 5-HT relevant regions, particularly the raphe nuclei. Notably, the Slc6a4 Ala56 knockin alone appears to have an insignificant, but suggestive, effect compared to the KO, which is consistent with Slc6a4 function. Despite the small number of 5-HT neurons and their localization to the brainstem, it is clear that 5-HT plays an important role in neuroanatomical organization. Electronic supplementary material The online version of this article (10.1186/s13229-018-0210-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jacob Ellegood
- 1Mouse Imaging Centre (MICe), Hospital for Sick Children, 25 Orde Street, Toronto, Ontario M5T 3H7 Canada
| | - Yohan Yee
- 1Mouse Imaging Centre (MICe), Hospital for Sick Children, 25 Orde Street, Toronto, Ontario M5T 3H7 Canada.,4Department of Medical Biophysics, University of Toronto, Toronto, ON M5S Canada
| | - Travis M Kerr
- 3Department of Psychiatry, Vanderbilt University, Nashville, TN 37235 USA
| | | | - Randy D Blakely
- 2Department of Pharmacology, Vanderbilt University, Nashville, TN 37235 USA.,3Department of Psychiatry, Vanderbilt University, Nashville, TN 37235 USA.,5Department of Biomedical Science and Brain Institute, Florida Atlantic University, Jupiter, FL 33431 USA
| | - R Mark Henkelman
- 1Mouse Imaging Centre (MICe), Hospital for Sick Children, 25 Orde Street, Toronto, Ontario M5T 3H7 Canada.,4Department of Medical Biophysics, University of Toronto, Toronto, ON M5S Canada
| | - Jeremy Veenstra-VanderWeele
- 2Department of Pharmacology, Vanderbilt University, Nashville, TN 37235 USA.,6Department of Psychiatry, Columbia University, New York, NY 10027 USA
| | - Jason P Lerch
- 1Mouse Imaging Centre (MICe), Hospital for Sick Children, 25 Orde Street, Toronto, Ontario M5T 3H7 Canada.,4Department of Medical Biophysics, University of Toronto, Toronto, ON M5S Canada
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13
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Khazipov R, Milh M. Early patterns of activity in the developing cortex: Focus on the sensorimotor system. Semin Cell Dev Biol 2018; 76:120-129. [DOI: 10.1016/j.semcdb.2017.09.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 02/08/2023]
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14
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Wang B, Iyengar R, Li-Harms X, Joo JH, Wright C, Lavado A, Horner L, Yang M, Guan JL, Frase S, Green DR, Cao X, Kundu M. The autophagy-inducing kinases, ULK1 and ULK2, regulate axon guidance in the developing mouse forebrain via a noncanonical pathway. Autophagy 2017; 14:796-811. [PMID: 29099309 DOI: 10.1080/15548627.2017.1386820] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mammalian ULK1 (unc-51 like kinase 1) and ULK2, Caenorhabditis elegans UNC-51, and Drosophila melanogaster Atg1 are serine/threonine kinases that regulate flux through the autophagy pathway in response to various types of cellular stress. C. elegans UNC-51 and D. melanogaster Atg1 also promote axonal growth and defasciculation; disruption of these genes results in defective axon guidance in invertebrates. Although disrupting ULK1/2 function impairs normal neurite outgrowth in vitro, the role of ULK1 and ULK2 in the developing brain remains poorly characterized. Here, we show that ULK1 and ULK2 are required for proper projection of axons in the forebrain. Mice lacking Ulk1 and Ulk2 in their central nervous systems showed defects in axonal pathfinding and defasciculation affecting the corpus callosum, anterior commissure, corticothalamic axons and thalamocortical axons. These defects impaired the midline crossing of callosal axons and caused hypoplasia of the anterior commissure and disorganization of the somatosensory cortex. The axon guidance defects observed in ulk1/2 double-knockout mice and central nervous system-specific (Nes-Cre) Ulk1/2-conditional double-knockout mice were not recapitulated in mice lacking other autophagy genes (i.e., Atg7 or Rb1cc1 [RB1-inducible coiled-coil 1]). The brains of Ulk1/2-deficient mice did not show stem cell defects previously attributed to defective autophagy in ambra1 (autophagy/Beclin 1 regulator 1)- and Rb1cc1-deficient mice or accumulation of SQSTM1 (sequestosome 1)+ or ubiquitin+ deposits. Together, these data demonstrate that ULK1 and ULK2 regulate axon guidance during mammalian brain development via a noncanonical (i.e., autophagy-independent) pathway.
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Affiliation(s)
- Bo Wang
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA.,f Integrated Biomedical Sciences Program , the University of Tennessee Health Science Center , Memphis , TN , USA
| | - Rekha Iyengar
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Xiujie Li-Harms
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Joung Hyuck Joo
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Christopher Wright
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Alfonso Lavado
- b Department of Developmental Neurobiology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Linda Horner
- d Cell and Tissue Imaging Center , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Mao Yang
- c Department of Immunology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Jun-Lin Guan
- e Department of Cancer Biology , University of Cincinnati College of Medicine , Cincinnati , OH , USA
| | - Sharon Frase
- d Cell and Tissue Imaging Center , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Douglas R Green
- c Department of Immunology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Xinwei Cao
- b Department of Developmental Neurobiology , St. Jude Children's Research Hospital , Memphis , TN , USA
| | - Mondira Kundu
- a Department of Pathology , St. Jude Children's Research Hospital , Memphis , TN , USA
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15
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Maternal Inflammation Disrupts Fetal Neurodevelopment via Increased Placental Output of Serotonin to the Fetal Brain. J Neurosci 2017; 36:6041-9. [PMID: 27251625 DOI: 10.1523/jneurosci.2534-15.2016] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 04/13/2016] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Maternal inflammation during pregnancy affects placental function and is associated with increased risk of neurodevelopmental disorders in the offspring. The molecular mechanisms linking placental dysfunction to abnormal fetal neurodevelopment remain unclear. During typical development, serotonin (5-HT) synthesized in the placenta from maternal l-tryptophan (TRP) reaches the fetal brain. There, 5-HT modulates critical neurodevelopmental processes. We investigated the effects of maternal inflammation triggered in midpregnancy in mice by the immunostimulant polyriboinosinic-polyribocytidylic acid [poly(I:C)] on TRP metabolism in the placenta and its impact on fetal neurodevelopment. We show that a moderate maternal immune challenge upregulates placental TRP conversion rapidly to 5-HT through successively transient increases in substrate availability and TRP hydroxylase (TPH) enzymatic activity, leading to accumulation of exogenous 5-HT and blunting of endogenous 5-HT axonal outgrowth specifically within the fetal forebrain. The pharmacological inhibition of TPH activity blocked these effects. These results establish altered placental TRP conversion to 5-HT as a new mechanism by which maternal inflammation disrupts 5-HT-dependent neurogenic processes during fetal neurodevelopment. SIGNIFICANCE STATEMENT The mechanisms linking maternal inflammation during pregnancy with increased risk of neurodevelopmental disorders in the offspring are poorly understood. In this study, we show that maternal inflammation in midpregnancy results in an upregulation of tryptophan conversion to serotonin (5-HT) within the placenta. Remarkably, this leads to exposure of the fetal forebrain to increased concentrations of this biogenic amine and to specific alterations of crucially important 5-HT-dependent neurogenic processes. More specifically, we found altered serotonergic axon growth resulting from increased 5-HT in the fetal forebrain. The data provide a new understanding of placental function playing a key role in fetal brain development and how this process is altered by adverse prenatal events such as maternal inflammation. The results uncover important future directions for understanding the early developmental origins of mental disorders.
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16
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Nakai N, Nagano M, Saitow F, Watanabe Y, Kawamura Y, Kawamoto A, Tamada K, Mizuma H, Onoe H, Watanabe Y, Monai H, Hirase H, Nakatani J, Inagaki H, Kawada T, Miyazaki T, Watanabe M, Sato Y, Okabe S, Kitamura K, Kano M, Hashimoto K, Suzuki H, Takumi T. Serotonin rebalances cortical tuning and behavior linked to autism symptoms in 15q11-13 CNV mice. SCIENCE ADVANCES 2017; 3:e1603001. [PMID: 28691086 PMCID: PMC5479676 DOI: 10.1126/sciadv.1603001] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 04/26/2017] [Indexed: 05/21/2023]
Abstract
Serotonin is a critical modulator of cortical function, and its metabolism is defective in autism spectrum disorder (ASD) brain. How serotonin metabolism regulates cortical physiology and contributes to the pathological and behavioral symptoms of ASD remains unknown. We show that normal serotonin levels are essential for the maintenance of neocortical excitation/inhibition balance, correct sensory stimulus tuning, and social behavior. Conversely, low serotonin levels in 15q dup mice (a model for ASD with the human 15q11-13 duplication) result in impairment of the same phenotypes. Restoration of normal serotonin levels in 15q dup mice revealed the reversibility of a subset of ASD-related symptoms in the adult. These findings suggest that serotonin may have therapeutic potential for discrete ASD symptoms.
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Affiliation(s)
- Nobuhiro Nakai
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Masatoshi Nagano
- Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan
| | - Fumihito Saitow
- Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan
| | - Yasuhito Watanabe
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
- Department of Clinical Neurobiology, University Hospital and German Cancer Research Center, Heidelberg 69120, Germany
- Corresponding author. (T.T.); (H.S.); (Yasuhito Watanabe)
| | - Yoshinobu Kawamura
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Akiko Kawamoto
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Kota Tamada
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Hiroshi Mizuma
- RIKEN Center for Life Science Technologies, Chuo, Kobe 650-0047, Japan
| | - Hirotaka Onoe
- RIKEN Center for Life Science Technologies, Chuo, Kobe 650-0047, Japan
| | | | - Hiromu Monai
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Hajime Hirase
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Jin Nakatani
- Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan
| | - Hirofumi Inagaki
- Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan
| | - Tomoyuki Kawada
- Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan
| | - Taisuke Miyazaki
- Department of Anatomy and Embryology, Hokkaido University Graduate School of Medicine, Kita, Sapporo 060-8638, Japan
| | - Masahiko Watanabe
- Department of Anatomy and Embryology, Hokkaido University Graduate School of Medicine, Kita, Sapporo 060-8638, Japan
| | - Yuka Sato
- Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo 113-8654, Japan
| | - Shigeo Okabe
- Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo 113-8654, Japan
| | - Kazuo Kitamura
- Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo 113-8654, Japan
| | - Masanobu Kano
- Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo 113-8654, Japan
| | - Kouichi Hashimoto
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Hidenori Suzuki
- Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo, Japan
- Corresponding author. (T.T.); (H.S.); (Yasuhito Watanabe)
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo, Japan
- Corresponding author. (T.T.); (H.S.); (Yasuhito Watanabe)
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17
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Vinokurova D, Zakharov A, Akhmetshina D, Nasretdinov A, Valeeva G, Khazipov R. The Effects of Fluoxetine on Sensory-Evoked Responses in the Neonatal Rat Barrel Cortex. BIONANOSCIENCE 2017. [DOI: 10.1007/s12668-016-0370-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Teissier A, Soiza-Reilly M, Gaspar P. Refining the Role of 5-HT in Postnatal Development of Brain Circuits. Front Cell Neurosci 2017; 11:139. [PMID: 28588453 PMCID: PMC5440475 DOI: 10.3389/fncel.2017.00139] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/26/2017] [Indexed: 11/30/2022] Open
Abstract
Changing serotonin (5-hydroxytryptamine, 5-HT) brain levels during critical periods in development has long-lasting effects on brain function, particularly on later anxiety/depression-related behaviors in adulthood. A large part of the known developmental effects of 5-HT occur during critical periods of postnatal life, when activity-dependent mechanisms remodel neural circuits. This was first demonstrated for the maturation of sensory brain maps in the barrel cortex and the visual system. More recently this has been extended to the 5-HT raphe circuits themselves and to limbic circuits. Recent studies overviewed here used new genetic models in mice and rats and combined physiological and structural approaches to provide new insights on the cellular and molecular mechanisms controlled by 5-HT during late stages of neural circuit maturation in the raphe projections, the somatosensory cortex and the visual system. Similar mechanisms appear to be also involved in the maturation of limbic circuits such as prefrontal circuits. The latter are of particular relevance to understand the impact of transient 5-HT dysfunction during postnatal life on psychiatric illnesses and emotional disorders in adult life.
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Affiliation(s)
- Anne Teissier
- Institut du Fer à Moulin, Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S839Paris, France.,Université Pierre et Marie CurieParis, France.,Institut du Fer à MoulinParis, France
| | - Mariano Soiza-Reilly
- Institut du Fer à Moulin, Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S839Paris, France.,Université Pierre et Marie CurieParis, France.,Institut du Fer à MoulinParis, France
| | - Patricia Gaspar
- Institut du Fer à Moulin, Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S839Paris, France.,Université Pierre et Marie CurieParis, France.,Institut du Fer à MoulinParis, France
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19
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King JR, Velasquez JC, Torii M, Bonnin A. Effect of Maternal ±Citalopram Exposure on P11 Expression and Neurogenesis in the Mouse Fetal Brain. ACS Chem Neurosci 2017; 8:1019-1025. [PMID: 28076682 DOI: 10.1021/acschemneuro.6b00339] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Fetal exposure to selective serotonin reuptake inhibitors (SSRI) has been associated with increased risk of adverse neurodevelopmental outcomes. In the adult brain, SSRI therapy regulates p11 (s100a10) expression and alters neurogenesis. The protein p11 indirectly regulates 5-HT signaling through 5-HT1B/D receptors. In the fetal brain, signaling through these receptors modulates axonal circuit formation. We determined whether p11 is expressed in the fetal mouse brain, and whether maternal SSRI exposure affects fetal p11 expression and neurogenesis. The SSRI ± citalopram was administered to pregnant mice from gestational day 8 to 17. Results show that p11 is expressed in fetal thalamic neurons and thalamocortical axons. Furthermore, p11 protein expression is significantly decreased in the fetal thalamus after in utero ±citalopram exposure compared to untreated controls, and neurogenesis is significantly decreased in specific fetal brain regions. These findings reveal differential regulation of p11 expression and altered neurogenesis in the fetal brain as a result of maternal SSRI exposure.
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Affiliation(s)
- Jennifer R. King
- Department
of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine,
Keck School of Medicine, University of Southern California, Los Angeles, California 90089, United States
| | - Juan C. Velasquez
- Zilkha
Neurogenetic Institute and Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, California 90089, United States
| | - Masaaki Torii
- Center
for Neuroscience Research, Children’s National Medical Center, Washington,
D.C. 20010, United States
- Department
of Pediatrics, Pharmacology and Physiology, The George Washington University, Washington, D.C. 20052, United States
| | - Alexandre Bonnin
- Zilkha
Neurogenetic Institute and Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, California 90089, United States
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20
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Siemann JK, Muller CL, Forsberg CG, Blakely RD, Veenstra-VanderWeele J, Wallace MT. An autism-associated serotonin transporter variant disrupts multisensory processing. Transl Psychiatry 2017; 7:e1067. [PMID: 28323282 PMCID: PMC5416665 DOI: 10.1038/tp.2017.17] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/29/2016] [Accepted: 01/09/2017] [Indexed: 01/29/2023] Open
Abstract
Altered sensory processing is observed in many children with autism spectrum disorder (ASD), with growing evidence that these impairments extend to the integration of information across the different senses (that is, multisensory function). The serotonin system has an important role in sensory development and function, and alterations of serotonergic signaling have been suggested to have a role in ASD. A gain-of-function coding variant in the serotonin transporter (SERT) associates with sensory aversion in humans, and when expressed in mice produces traits associated with ASD, including disruptions in social and communicative function and repetitive behaviors. The current study set out to test whether these mice also exhibit changes in multisensory function when compared with wild-type (WT) animals on the same genetic background. Mice were trained to respond to auditory and visual stimuli independently before being tested under visual, auditory and paired audiovisual (multisensory) conditions. WT mice exhibited significant gains in response accuracy under audiovisual conditions. In contrast, although the SERT mutant animals learned the auditory and visual tasks comparably to WT littermates, they failed to show behavioral gains under multisensory conditions. We believe these results provide the first behavioral evidence of multisensory deficits in a genetic mouse model related to ASD and implicate the serotonin system in multisensory processing and in the multisensory changes seen in ASD.
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Affiliation(s)
- J K Siemann
- Neuroscience Program, Vanderbilt University, Nashville, TN, USA
| | - C L Muller
- Neuroscience Program, Vanderbilt University, Nashville, TN, USA
| | - C G Forsberg
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA
| | - R D Blakely
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA
- Silvio O. Conte Center for Neuroscience Research, Vanderbilt University, Nashville, TN, USA
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Jupiter, FL, USA
- Florida Atlantic University Brain Institute, Florida Atlantic University, Jupiter, FL, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - J Veenstra-VanderWeele
- Silvio O. Conte Center for Neuroscience Research, Vanderbilt University, Nashville, TN, USA
- Department of Psychiatry, Sackler Institute for Developmental Psychobiology, Columbia University, New York, NY, USA
- Center for Autism and The Developing Brain, New York Presbyterian Hospital, New York, NY, USA
- New York State Psychiatric Institute, New York, NY, USA
| | - M T Wallace
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA
- Silvio O. Conte Center for Neuroscience Research, Vanderbilt University, Nashville, TN, USA
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
- Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, TN, USA
- Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN, USA
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21
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Miceli S, Nadif Kasri N, Joosten J, Huang C, Kepser L, Proville R, Selten MM, van Eijs F, Azarfar A, Homberg JR, Celikel T, Schubert D. Reduced Inhibition within Layer IV of Sert Knockout Rat Barrel Cortex is Associated with Faster Sensory Integration. Cereb Cortex 2017; 27:933-949. [PMID: 28158484 PMCID: PMC5390402 DOI: 10.1093/cercor/bhx016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/07/2016] [Accepted: 01/11/2017] [Indexed: 12/19/2022] Open
Abstract
Neural activity is essential for the maturation of sensory systems. In the rodent primary somatosensory cortex (S1), high extracellular serotonin (5-HT) levels during development impair neural transmission between the thalamus and cortical input layer IV (LIV). Rodent models of impaired 5-HT transporter (SERT) function show disruption in their topological organization of S1 and in the expression of activity-regulated genes essential for inhibitory cortical network formation. It remains unclear how such alterations affect the sensory information processing within cortical LIV. Using serotonin transporter knockout (Sert-/-) rats, we demonstrate that high extracellular serotonin levels are associated with impaired feedforward inhibition (FFI), fewer perisomatic inhibitory synapses, a depolarized GABA reversal potential and reduced expression of KCC2 transporters in juvenile animals. At the neural population level, reduced FFI increases the excitatory drive originating from LIV, facilitating evoked representations in the supragranular layers II/III. The behavioral consequence of these changes in network excitability is faster integration of the sensory information during whisker-based tactile navigation, as Sert-/- rats require fewer whisker contacts with tactile targets and perform object localization with faster reaction times. These results highlight the association of serotonergic homeostasis with formation and excitability of sensory cortical networks, and consequently with sensory perception.
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Affiliation(s)
- Stéphanie Miceli
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Neural Networks, Center of Advanced European Studies and Research (caesar), Max Planck Society, Germany
| | - Nael Nadif Kasri
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Joep Joosten
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Chao Huang
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Lara Kepser
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Rémi Proville
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Martijn M. Selten
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Fenneke van Eijs
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Alireza Azarfar
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Judith R. Homberg
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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22
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Mosser CA, Baptista S, Arnoux I, Audinat E. Microglia in CNS development: Shaping the brain for the future. Prog Neurobiol 2017; 149-150:1-20. [DOI: 10.1016/j.pneurobio.2017.01.002] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/22/2022]
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23
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Gezelius H, López-Bendito G. Thalamic neuronal specification and early circuit formation. Dev Neurobiol 2016; 77:830-843. [PMID: 27739248 DOI: 10.1002/dneu.22460] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/16/2016] [Accepted: 10/10/2016] [Indexed: 12/12/2022]
Abstract
The thalamus is a central structure of the brain, primarily recognized for the relay of incoming sensory and motor information to the cerebral cortex but also key in high order intracortical communication. It consists of glutamatergic projection neurons organized in several distinct nuclei, each having a stereotype connectivity pattern and functional roles. In the adult, these nuclei can be appreciated by architectural boundaries, although their developmental origin and specification is only recently beginning to be revealed. Here, we summarize the current knowledge on the specification of the distinct thalamic neurons and nuclei, starting from early embryonic patterning until the postnatal days when active sensory experience is initiated and the overall system connectivity is already established. We also include an overview of the guidance processes important for establishing thalamocortical connections, with emphasis on the early topographical specification. The extensively studied thalamocortical axon branching in the cortex is briefly mentioned; however, the maturation and plasticity of this connection are beyond the scope of this review. In separate chapters, additional mechanisms and/or features that influence the specification and development of thalamic neurons and their circuits are also discussed. Finally, an outlook of future directions is given. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 830-843, 2017.
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Affiliation(s)
- Henrik Gezelius
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Avenida Ramón y Cajal, s/n, Sant Joan d'Alacant, Spain
| | - Guillermina López-Bendito
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Avenida Ramón y Cajal, s/n, Sant Joan d'Alacant, Spain
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24
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Wu HH, Choi S, Levitt P. Differential patterning of genes involved in serotonin metabolism and transport in extra-embryonic tissues of the mouse. Placenta 2016; 42:74-83. [PMID: 27238716 PMCID: PMC4886340 DOI: 10.1016/j.placenta.2016.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/10/2016] [Accepted: 03/26/2016] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Serotonin (5-HT) is an important neuromodulator, but recently has been shown to be involved in neurodevelopment. Although previous studies have demonstrated that the placenta is a major source of forebrain 5-HT during early forebrain development, the processes of how 5-HT production, metabolism, and transport from placenta to fetus are regulated are unknown. As an initial step in determining the mechanisms involved, we investigated the expression patterns of genes critical for 5-HT system function in mouse extraembryonic tissues. METHODS Mid-through late gestation expression of 5-HT system-related enzymes, Tph1, Ddc, Maoa, and 5-HT transporters, Sert/Slc6a4, Oct3/Slc22a3, Vmat2/Slc18a2, and 5-HT in placenta and yolk sac were examined, with cell type-specific resolution, using multiplex fluorescent in situ hybridization to co-localize transcripts and immunocytochemistry to co-localize the corresponding proteins and neurotransmitter. RESULTS Tph1 and Ddc are found in the syncytiotrophoblast I (SynT-I) and sinusoidal trophoblast giant cells (S-TGC), whereas Maoa is expressed in SynT-I, syncytiotrophoblast II (SynT-II) and S-TGC. Oct3 expression is observed in the SynT-II only, while Vmat2 is mainly expressed in S-TGC. Surprisingly, there were comparatively high expression of Tph1, Ddc, and Maoa in the yolk sac visceral endoderm. DISCUSSION In addition to trophoblast cells, visceral endoderm cells in the yolk sac may contribute to fetal 5-HT production. The findings raise the possibility of a more complex regulation of 5-HT access to the fetus through the differential roles of trophoblasts that surround maternal and fetal blood space and of yolk sac endoderm prior to normal degeneration.
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Affiliation(s)
- Hsiao-Huei Wu
- Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sera Choi
- Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Pat Levitt
- Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Institute for the Developing Mind, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Muller CL, Anacker AMJ, Veenstra-VanderWeele J. The serotonin system in autism spectrum disorder: From biomarker to animal models. Neuroscience 2016; 321:24-41. [PMID: 26577932 PMCID: PMC4824539 DOI: 10.1016/j.neuroscience.2015.11.010] [Citation(s) in RCA: 319] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/26/2015] [Accepted: 11/04/2015] [Indexed: 02/02/2023]
Abstract
Elevated whole blood serotonin, or hyperserotonemia, was the first biomarker identified in autism spectrum disorder (ASD) and is present in more than 25% of affected children. The serotonin system is a logical candidate for involvement in ASD due to its pleiotropic role across multiple brain systems both dynamically and across development. Tantalizing clues connect this peripheral biomarker with changes in brain and behavior in ASD, but the contribution of the serotonin system to ASD pathophysiology remains incompletely understood. Studies of whole blood serotonin levels in ASD and in a large founder population indicate greater heritability than for the disorder itself and suggest an association with recurrence risk. Emerging data from both neuroimaging and postmortem samples also indicate changes in the brain serotonin system in ASD. Genetic linkage and association studies of both whole blood serotonin levels and of ASD risk point to the chromosomal region containing the serotonin transporter (SERT) gene in males but not in females. In ASD families with evidence of linkage to this region, multiple rare SERT amino acid variants lead to a convergent increase in serotonin uptake in cell models. A knock-in mouse model of one of these variants, SERT Gly56Ala, recapitulates the hyperserotonemia biomarker and shows increased brain serotonin clearance, increased serotonin receptor sensitivity, and altered social, communication, and repetitive behaviors. Data from other rodent models also suggest an important role for the serotonin system in social behavior, in cognitive flexibility, and in sensory development. Recent work indicates that reciprocal interactions between serotonin and other systems, such as oxytocin, may be particularly important for social behavior. Collectively, these data point to the serotonin system as a prime candidate for treatment development in a subgroup of children defined by a robust, heritable biomarker.
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Affiliation(s)
- C L Muller
- Vanderbilt Brain Institute, Vanderbilt University, 465 21st Avenue South, Nashville, TN 37232, USA.
| | - A M J Anacker
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, Mail Unit 78, New York, NY 10032, USA.
| | - J Veenstra-VanderWeele
- Sackler Institute for Developmental Psychobiology, Department of Psychiatry, Columbia University; Center for Autism and the Developing Brain, New York Presbyterian Hospital; New York State Psychiatric Institute, 1051 Riverside Drive, Mail Unit 78, New York, NY 10032, USA.
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Akhmetshina D, Zakharov A, Vinokurova D, Nasretdinov A, Valeeva G, Khazipov R. The serotonin reuptake inhibitor citalopram suppresses activity in the neonatal rat barrel cortex in vivo. Brain Res Bull 2016; 124:48-54. [PMID: 27016034 DOI: 10.1016/j.brainresbull.2016.03.011] [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] [Received: 11/07/2015] [Revised: 02/10/2016] [Accepted: 03/21/2016] [Indexed: 02/02/2023]
Abstract
Inhibition of serotonin uptake, which causes an increase in extracellular serotonin levels, disrupts the development of thalamocortical barrel maps in neonatal rodents. Previous in vitro studies have suggested that the disruptive effect of excessive serotonin on barrel map formation involves a depression at thalamocortical synapses. However, the effects of serotonin uptake inhibitors on the early thalamocortical activity patterns in the developing barrel cortex in vivo remain largely unknown. Here, using extracellular recordings of the local field potentials and multiple unit activity (MUA) we explored the effects of the selective serotonin reuptake inhibitor (SSRI) citalopram (10-20mg/kg, intraperitoneally) on sensory evoked activity in the barrel cortex of neonatal (postnatal days P2-5) rats in vivo. We show that administration of citalopram suppresses the amplitude and prolongs the delay of the sensory evoked potentials, reduces the power and frequency of the early gamma oscillations, and suppresses sensory evoked and spontaneous neuronal firing. In the adolescent P21-29 animals, citalopram affected neither sensory evoked nor spontaneous activity in barrel cortex. We suggest that suppression of the early thalamocortical activity patterns contributes to the disruption of the barrel map development caused by SSRIs and other conditions elevating extracellular serotonin levels.
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Affiliation(s)
| | - Andrei Zakharov
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia; Department of Physiology, Kazan State Medical University, Kazan, Russia
| | - Daria Vinokurova
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| | - Azat Nasretdinov
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| | - Guzel Valeeva
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.
| | - Roustem Khazipov
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia; INMED-INSERM U901, Marseille, France; University Aix-Marseille II, Marseille, France
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Naumann RK, Ray S, Prokop S, Las L, Heppner FL, Brecht M. Conserved size and periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex. J Comp Neurol 2016; 524:783-806. [PMID: 26223342 PMCID: PMC5014138 DOI: 10.1002/cne.23865] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 11/29/2022]
Abstract
To understand the structural basis of grid cell activity, we compare medial entorhinal cortex architecture in layer 2 across five mammalian species (Etruscan shrews, mice, rats, Egyptian fruit bats, and humans), bridging ∼100 million years of evolutionary diversity. Principal neurons in layer 2 are divided into two distinct cell types, pyramidal and stellate, based on morphology, immunoreactivity, and functional properties. We confirm the existence of patches of calbindin-positive pyramidal cells across these species, arranged periodically according to analyses techniques like spatial autocorrelation, grid scores, and modifiable areal unit analysis. In rodents, which show sustained theta oscillations in entorhinal cortex, cholinergic innervation targeted calbindin patches. In bats and humans, which only show intermittent entorhinal theta activity, cholinergic innervation avoided calbindin patches. The organization of calbindin-negative and calbindin-positive cells showed marked differences in entorhinal subregions of the human brain. Layer 2 of the rodent medial and the human caudal entorhinal cortex were structurally similar in that in both species patches of calbindin-positive pyramidal cells were superimposed on scattered stellate cells. The number of calbindin-positive neurons in a patch increased from ∼80 in Etruscan shrews to ∼800 in humans, only an ∼10-fold over a 20,000-fold difference in brain size. The relatively constant size of calbindin patches differs from cortical modules such as barrels, which scale with brain size. Thus, selective pressure appears to conserve the distribution of stellate and pyramidal cells, periodic arrangement of calbindin patches, and relatively constant neuron number in calbindin patches in medial/caudal entorhinal cortex.
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Affiliation(s)
- Robert K. Naumann
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
- Max‐Planck‐Institute for Brain ResearchMax‐von‐Laue‐Str. 460438Frankfurt am MainGermany
| | - Saikat Ray
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
| | - Stefan Prokop
- Neuropathology Institute, Charité Medical School10117BerlinGermany
| | - Liora Las
- Department of NeurobiologyWeizmann Institute of ScienceRehovot76100Israel
| | - Frank L. Heppner
- Neuropathology Institute, Charité Medical School10117BerlinGermany
| | - Michael Brecht
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
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Brummelte S, Mc Glanaghy E, Bonnin A, Oberlander TF. Developmental changes in serotonin signaling: Implications for early brain function, behavior and adaptation. Neuroscience 2016; 342:212-231. [PMID: 26905950 DOI: 10.1016/j.neuroscience.2016.02.037] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 02/07/2023]
Abstract
The neurotransmitter serotonin (5-HT) plays a central role in brain development, regulation of mood, stress reactivity and risk of psychiatric disorders, and thus alterations in 5-HT signaling early in life have critical implications for behavior and mental health across the life span. Drawing on preclinical and emerging human evidence this narrative review paper will examine three key aspects when considering the consequences of early life changes in 5-HT: (1) developmental origins of variations of 5-HT signaling; (2) influence of genetic and epigenetic factors; and (3) preclinical and clinical consequences of 5-HT-related changes associated with antidepressant exposure (SSRIs). The developmental consequences of altered prenatal 5-HT signaling varies greatly and outcomes depend on an ongoing interplay between biological (genetic/epigenetic variations) and environmental factors, both pre and postnatally. Emerging evidence suggests that variations in 5-HT signaling may increase sensitivity to risky home environments, but may also amplify a positive response to a nurturing environment. In this sense, factors that change central 5-HT levels may act as 'plasticity' rather than 'risk' factors associated with developmental vulnerability. Understanding the impact of early changes in 5-HT levels offers critical insights that might explain the variations in early typical brain development that underlies behavioral risk.
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Affiliation(s)
- S Brummelte
- Department of Psychology, Wayne State University, 5057 Woodward Avenue, Detroit, MI 48202, USA.
| | - E Mc Glanaghy
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - A Bonnin
- Zilkha Neurogenetic Institute and Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - T F Oberlander
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
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A Serotonin Circuit Acts as an Environmental Sensor to Mediate Midline Axon Crossing through EphrinB2. J Neurosci 2016; 35:14794-808. [PMID: 26538650 DOI: 10.1523/jneurosci.1295-15.2015] [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] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Modulation of connectivity formation in the developing brain in response to external stimuli is poorly understood. Here, we show that the raphe nucleus and its serotonergic projections regulate pathfinding of commissural axons in zebrafish. We found that the raphe neurons extend projections toward midline-crossing axons and that when serotonergic signaling is blocked by pharmacological inhibition or by raphe neuron ablation, commissural pathfinding is disrupted. We demonstrate that the serotonin receptor htr2a is expressed on these commissural axons and that genetic knock-down of htr2a disrupts crossing. We further show that knock-down of htr2a or ablation of the raphe neurons increases ephrinB2a protein levels in commissural axons. An ephrinB2a mutant can rescue midline crossing when serotonergic signaling is blocked. Furthermore, we found that regulation of serotonin expression in the raphe neurons is modulated in response to the developmental environment. Hypoxia causes the raphe to decrease serotonin levels, leading to a reduction in midline crossing. Increasing serotonin in the setting of hypoxia restored midline crossing. Our findings demonstrate an instructive role for serotonin in axon guidance acting through ephrinB2a and reveal a novel mechanism for developmental interpretation of the environmental milieu in the generation of mature neural circuitry. SIGNIFICANCE STATEMENT We show here that serotonin has a novel role in regulating connectivity in response to the developmental environment. We demonstrate that serotonergic projections from raphe neurons regulate pathfinding of crossing axons. The neurons modulate their serotonin levels, and thus alter crossing, in response to the developmental environment including hypoxia. The findings suggest that modification of the serotonergic system by early exposures may contribute to permanent CNS connectivity alterations. This has important ramifications because of the association between premature birth and accompanying hypoxia, and increased risk of autism and evidence associating in utero exposure to some antidepressants and neurodevelopmental disorders. Finally, this work demonstrates that the vertebrate CNS can modulate its connectivity in response to the external environment.
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Benítez-Burraco A, Boeckx C. Possible functional links among brain- and skull-related genes selected in modern humans. Front Psychol 2015; 6:794. [PMID: 26136701 PMCID: PMC4468360 DOI: 10.3389/fpsyg.2015.00794] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 05/26/2015] [Indexed: 12/12/2022] Open
Abstract
The sequencing of the genomes from extinct hominins has revealed that changes in some brain-related genes have been selected after the split between anatomically-modern humans and Neanderthals/Denisovans. To date, no coherent view of these changes has been provided. Following a line of research we initiated in Boeckx and Benítez-Burraco (2014a), we hypothesize functional links among most of these genes and their products, based on the existing literature for each of the gene discussed. The genes we focus on are found mutated in different cognitive disorders affecting modern populations and their products are involved in skull and brain morphology, and neural connectivity. If our hypothesis turns out to be on the right track, it means that the changes affecting most of these proteins resulted in a more globular brain and ultimately brought about modern cognition, with its characteristic generativity and capacity to form and exploit cross-modular concepts, properties most clearly manifested in language.
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Affiliation(s)
| | - Cedric Boeckx
- Catalan Institute for Research and Advanced Studies , Barcelona, Spain ; Department of Linguistics, Universitat de Barcelona , Barcelona, Spain
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31
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Chen X, Ye R, Gargus JJ, Blakely RD, Dobrenis K, Sze JY. Disruption of Transient Serotonin Accumulation by Non-Serotonin-Producing Neurons Impairs Cortical Map Development. Cell Rep 2015; 10:346-358. [PMID: 25600870 PMCID: PMC4824665 DOI: 10.1016/j.celrep.2014.12.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 11/10/2014] [Accepted: 12/15/2014] [Indexed: 01/24/2023] Open
Abstract
Polymorphisms that alter serotonin transporter SERT expression and functionality increase the risks for autism and psychiatric traits. Here, we investigate how SERT controls serotonin signaling in developing CNS in mice. SERT is transiently expressed in specific sets of glutamatergic neurons and uptakes extrasynaptic serotonin during perinatal CNS development. We show that SERT expression in glutamatergic thalamocortical axons (TCAs) dictates sensory map architecture. Knockout of SERT in TCAs causes lasting alterations in TCA patterning, spatial organizations of cortical neurons, and dendritic arborization in sensory cortex. Pharmacological reduction of serotonin synthesis during the first postnatal week rescues sensory maps in SERTGluΔ mice. Furthermore, knockdown of SERT expression in serotonin-producing neurons does not impair barrel maps. We propose that spatiotemporal SERT expression in non-serotonin-producing neurons represents a determinant in early life genetic programming of cortical circuits. Perturbing this SERT function could be involved in the origin of sensory and cognitive deficits associated with neurodevelopmental disorders.
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Affiliation(s)
- Xiaoning Chen
- Department of Molecular Pharmacology and Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ran Ye
- Departments of Pharmacology & Psychiatry, Silvio O. Conte Center for Neuroscience Research, Vanderbilt University, Nashville, TN 37232, USA
| | - J Jay Gargus
- Center for Autism Research and Translation and Department of Physiology & Biophysics and Section of Human Genetics in Pediatrics, University of California, Irvine, Irvine, CA 92697, USA
| | - Randy D Blakely
- Departments of Pharmacology & Psychiatry, Silvio O. Conte Center for Neuroscience Research, Vanderbilt University, Nashville, TN 37232, USA
| | - Kostantin Dobrenis
- Dominick P. Purpura Department of Neuroscience and Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ji Ying Sze
- Department of Molecular Pharmacology and Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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32
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Monoamine-sensitive developmental periods impacting adult emotional and cognitive behaviors. Neuropsychopharmacology 2015; 40:88-112. [PMID: 25178408 PMCID: PMC4262911 DOI: 10.1038/npp.2014.231] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/30/2014] [Accepted: 08/20/2014] [Indexed: 02/07/2023]
Abstract
Development passes through sensitive periods, during which plasticity allows for genetic and environmental factors to exert indelible influence on the maturation of the organism. In the context of central nervous system development, such sensitive periods shape the formation of neurocircuits that mediate, regulate, and control behavior. This general mechanism allows for development to be guided by both the genetic blueprint as well as the environmental context. While allowing for adaptation, such sensitive periods are also vulnerability windows during which external and internal factors can confer risk to disorders by derailing otherwise resilient developmental programs. Here we review developmental periods that are sensitive to monoamine signaling and impact adult behaviors of relevance to psychiatry. Specifically, we review (1) a serotonin-sensitive period that impacts sensory system development, (2) a serotonin-sensitive period that impacts cognition, anxiety- and depression-related behaviors, and (3) a dopamine- and serotonin-sensitive period affecting aggression, impulsivity and behavioral response to psychostimulants. We discuss preclinical data to provide mechanistic insight, as well as epidemiological and clinical data to point out translational relevance. The field of translational developmental neuroscience has progressed exponentially providing solid conceptual advances and unprecedented mechanistic insight. With such knowledge at hand and important methodological innovation ongoing, the field is poised for breakthroughs elucidating the developmental origins of neuropsychiatric disorders, and thus understanding pathophysiology. Such knowledge of sensitive periods that determine the developmental trajectory of complex behaviors is a necessary step towards improving prevention and treatment approaches for neuropsychiatric disorders.
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33
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Blackiston DJ, Anderson GM, Rahman N, Bieck C, Levin M. A novel method for inducing nerve growth via modulation of host resting potential: gap junction-mediated and serotonergic signaling mechanisms. Neurotherapeutics 2015; 12:170-84. [PMID: 25449797 PMCID: PMC4322068 DOI: 10.1007/s13311-014-0317-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A major goal of regenerative medicine is to restore the function of damaged or missing organs through the implantation of bioengineered or donor-derived components. It is necessary to understand the signals and cues necessary for implanted structures to innervate the host, as organs devoid of neural connections provide little benefit to the patient. While developmental studies have identified neuronal pathfinding molecules required for proper patterning during embryogenesis, strategies to initiate innervation in structures transplanted at later times or alternate locations remain limited. Recent work has identified membrane resting potential of nerves as a key regulator of growth cone extension or arrest. Here, we identify a novel role of bioelectricity in the generation of axon guidance cues, showing that neurons read the electric topography of surrounding cells, and demonstrate these cues can be leveraged to initiate sensory organ transplant innervation. Grafts of fluorescently labeled embryological eye primordia were used to produce ectopic eyes in Xenopus laevis tadpoles. Depolarization of host tissues through anion channel activation or other means led to a striking hyperinnervation of the body by these ectopic eyes. A screen of possible transduction mechanisms identified serotonergic signaling to be essential for hyperinnervation to occur, and our molecular data suggest a possible model of bioelectrical control of the distribution of neurotransmitters that guides nerve growth. Together, these results identify the molecular components of bioelectrical signaling among cells that regulates axon guidance, and suggest novel biomedical and bioengineering strategies for triggering neuronal outgrowth using ion channel drugs already approved for human use.
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Affiliation(s)
- Douglas J. Blackiston
- Center for Regenerative and Developmental Biology and Department of Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155 USA
| | - George M. Anderson
- Yale Child Study Center and Department of Laboratory Medicine, Yale University School of Medicine, 230 S. Frontage Rd., New Haven, CT 06519 USA
| | - Nikita Rahman
- Center for Regenerative and Developmental Biology and Department of Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155 USA
| | - Clara Bieck
- Center for Regenerative and Developmental Biology and Department of Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155 USA
| | - Michael Levin
- Center for Regenerative and Developmental Biology and Department of Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155 USA
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Lokmane L, Garel S. Map transfer from the thalamus to the neocortex: inputs from the barrel field. Semin Cell Dev Biol 2014; 35:147-55. [PMID: 25020201 DOI: 10.1016/j.semcdb.2014.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/03/2014] [Accepted: 07/04/2014] [Indexed: 01/05/2023]
Abstract
Sensory perception relies on the formation of stereotyped maps inside the brain. This feature is particularly well illustrated in the mammalian neocortex, which is subdivided into distinct cortical sensory areas that comprise topological maps, such as the somatosensory homunculus in humans or the barrel field of the large whiskers in rodents. How somatosensory maps are formed and relayed into the neocortex remain essential questions in developmental neuroscience. Here, we will present our current knowledge on whisker map transfer in the mouse model, with the goal of linking embryonic and postnatal studies into a comprehensive framework.
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Affiliation(s)
- Ludmilla Lokmane
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, 46 rue d'Ulm, Paris F-75005, France; Inserm, U1024, Paris F-75005, France; CNRS, UMR 8197, Paris F-75005, France.
| | - Sonia Garel
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, 46 rue d'Ulm, Paris F-75005, France; Inserm, U1024, Paris F-75005, France; CNRS, UMR 8197, Paris F-75005, France.
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35
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Huo Y, Fang Q, Shi YL, Zhang YH, Zhang JX. Chronic exposure to a predator or its scent does not inhibit male-male competition in male mice lacking brain serotonin. Front Behav Neurosci 2014; 8:116. [PMID: 24782727 PMCID: PMC3986541 DOI: 10.3389/fnbeh.2014.00116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 03/19/2014] [Indexed: 12/01/2022] Open
Abstract
Although it is well-known that defective signaling of the 5-HT system in the brain and stressful stimuli can cause psychological disorders, their combined effects on male–male aggression and sexual attractiveness remain unknown. Our research aimed at examining such effects using tryptophan hydroxylase 2 (Tph2) knockout male mice vs. a rat- or rat scent-based chronic stress model. Tph2+/+ and Tph2−/− male mice were placed individually into the rat home cage (rat), a cage containing soiled rat bedding (rat scent) or a cage containing fresh bedding (control) for 5 h every other day for 56 consecutive days. In Tph2+/+ male mice, rat-exposure decreased male–male aggression and sexual attractiveness of urine odor relative to either rat scent-exposure or control; and rat scent-exposure decreased aggression rather than sexual attractiveness of urine odor compared with control. However, such dose-dependent and long-lasting behavioral inhibitory effects vanished in Tph2−/− male mice. RT-PCR assay further revealed that putative regulatory genes, such as AR, ERα and GluR4 in the prefrontal cortex, and TrkB-Tc and 5-HTR1A in the hippocampus, were down-regulated at the mRNA level in either rat- or rat scent-exposed Tph2+/+ male mice, but partially in the Tph2−/− ones. Hence, we suggest that the dose-dependent and long-lasting inhibitory effects of chronic predator exposure on male–male aggression, sexual attractiveness of urine odor, and mRNA expression of central regulatory genes might be mediated through the 5-HT system in the brain of male mice.
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Affiliation(s)
- Ying Huo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences Beijing, China ; Department of College of Life Sciences, University of Chinese Academy of Sciences Beijing, China
| | - Qi Fang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences Beijing, China ; Department of College of Life Sciences, University of Chinese Academy of Sciences Beijing, China
| | - Yao-Long Shi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences Beijing, China ; Department of College of Life Sciences, University of Chinese Academy of Sciences Beijing, China
| | - Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences Beijing, China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences Beijing, China
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36
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Nicol X, Gaspar P. Routes to cAMP: shaping neuronal connectivity with distinct adenylate cyclases. Eur J Neurosci 2014; 39:1742-51. [PMID: 24628976 DOI: 10.1111/ejn.12543] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/03/2014] [Accepted: 02/04/2014] [Indexed: 01/22/2023]
Abstract
cAMP signaling affects a large number of the developmental processes needed for the construction of the CNS, including cell differentiation, axon outgrowth, response to guidance molecules or modulation of synaptic connections. This points to a key role of adenylate cyclases (ACs), the synthetic enzymes of cAMP, for neural development. ACs exist as 10 different isoforms, which are activated by distinct signaling pathways. The implication of specific AC isoforms in neural wiring was only recently demonstrated in mouse mutants, knockout (KO) for different AC isoforms, AC1, AC3, AC5, AC8 and soluble (s)AC/AC10. These studies stressed the importance of three of these isoforms, as sensors of neural activity that could modify the survival of neurons (sAC), axon outgrowth (sAC), or the response of axons to guidance molecules such as ephrins (AC1) or semaphorins (AC3). We summarize here the current knowledge on the role of these ACs for the development of sensory maps, in the somatosensory, visual and olfactory systems, which have been the most extensively studied. In these systems, AC1/AC3 KO revealed targeting mistakes due to the defective pruning and lack of discrimination of incoming axons to signals present in target structures. In contrast, no changes in cell differentiation, survival or axon outgrowth were noted in these mutants, suggesting a specificity of cAMP production routes for individual cellular processes within a given neuron. Further studies indicate that the subcellular localization of ACs could be key to their specific role in axon targeting and may explain their selective roles in neuronal wiring.
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Affiliation(s)
- Xavier Nicol
- Inserm UMR-S 968, Institut de la Vision, 75012, Paris, France; CNRS UMR 7210, 75012, Paris, France; Université Pierre et Marie Curie, Paris, France
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Garcia-Garcia A, Tancredi AN, Leonardo ED. 5-HT(1A) [corrected] receptors in mood and anxiety: recent insights into autoreceptor versus heteroreceptor function. Psychopharmacology (Berl) 2014; 231:623-36. [PMID: 24337875 PMCID: PMC3927969 DOI: 10.1007/s00213-013-3389-x] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 11/26/2013] [Indexed: 11/26/2022]
Abstract
RATIONALE Serotonin (5-HT) neurotransmission is intimately linked to anxiety and depression and a diverse body of evidence supports the involvement of the main inhibitory serotonergic receptor, the serotonin-1A (5-HT(1A)) subtype, in both disorders. OBJECTIVES In this review, we examine the function of 5-HT(1A) receptor subpopulations and re-interpret our understanding of their role in mental illness in light of new data, separating both spatial (autoreceptor versus heteroreceptor) and the temporal (developmental versus adult) roles of the endogenous 5-HT(1A) receptors, emphasizing their distinct actions in mediating anxiety and depression-like behaviors. RESULTS It is difficult to unambiguously distinguish the effects of different populations of the 5-HT(1A) receptors with traditional genetic animal models and pharmacological approaches. However, with the advent of novel genetic systems and subpopulation-selective pharmacological agents, direct evidence for the distinct roles of these populations in governing emotion-related behavior is emerging. CONCLUSIONS There is strong and growing evidence for a functional dissociation between auto- and heteroreceptor populations in mediating anxiety and depressive-like behaviors, respectively. Furthermore, while it is well established that 5-HT(1A) receptors act developmentally to establish normal anxiety-like behaviors, the developmental role of 5-HT(1A) heteroreceptors is less clear, and the specific mechanisms underlying the developmental role of each subpopulation are likely to be key elements determining mood control in adult subjects.
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Affiliation(s)
- Alvaro Garcia-Garcia
- Department of Psychiatry, Division of Integrative Neuroscience, Columbia University and the New York State Psychiatric Institute, 1051 Riverside Dr. Box 87, New York, NY 10032
- Correspondence should be addressed to either AGG at or EDL at , Telephone: (001) 212-543-5266, Fax: (001) 212-543-5129
| | | | - E. David Leonardo
- Department of Psychiatry, Division of Integrative Neuroscience, Columbia University and the New York State Psychiatric Institute, 1051 Riverside Dr. Box 87, New York, NY 10032
- Correspondence should be addressed to either AGG at or EDL at , Telephone: (001) 212-543-5266, Fax: (001) 212-543-5129
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The birth of the barrels. Dev Cell 2013; 27:3-4. [PMID: 24135227 DOI: 10.1016/j.devcel.2013.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Refinement of sensory maps follows a highly reproducible tempo dictated largely by peripheral sensory receptors and neural activity. In this issue of Developmental Cell, Toda et al. (2013) add a new twist by showing that the timing of birth plays a decisive role in setting the clock for pattern emergence.
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Moroto M, Nishimura A, Morimoto M, Isoda K, Morita T, Yoshida M, Morioka S, Tozawa T, Hasegawa T, Chiyonobu T, Yoshimoto K, Hosoi H. Altered somatosensory barrel cortex refinement in the developing brain of Mecp2-null mice. Brain Res 2013; 1537:319-26. [DOI: 10.1016/j.brainres.2013.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/13/2013] [Accepted: 09/16/2013] [Indexed: 12/13/2022]
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Witteveen JS, Middelman A, van Hulten JA, Martens GJM, Homberg JR, Kolk SM. Lack of serotonin reuptake during brain development alters rostral raphe-prefrontal network formation. Front Cell Neurosci 2013; 7:143. [PMID: 24109430 PMCID: PMC3790074 DOI: 10.3389/fncel.2013.00143] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/15/2013] [Indexed: 11/13/2022] Open
Abstract
Besides its "classical" neurotransmitter function, serotonin (5-HT) has been found to also act as a neurodevelopmental signal. During development, the 5-HT projection system, besides an external placental source, represents one of the earliest neurotransmitter systems to innervate the brain. One of the targets of the 5-HT projection system, originating in the brainstem raphe nuclei, is the medial prefrontal cortex (mPFC), an area involved in higher cognitive functions and important in the etiology of many neurodevelopmental disorders. Little is known, however, about the exact role of 5-HT and its signaling molecules in the formation of the raphe-prefrontal network. Using explant essays, we here studied the role of the 5-HT transporter (5-HTT), an important modulator of the 5-HT signal, in rostral raphe-prefrontal network formation. We found that the chemotrophic nature of the interaction between the origin (rostral raphe cluster) and a target (mPFC) of the 5-HT projection system was affected in rats lacking the 5-HTT (5-HTT(-/-)). While 5-HTT deficiency did not affect the dorsal raphe 5-HT-positive outgrowing neurites, the median raphe 5-HT neurites switched from a strong repulsive to an attractive interaction when co-cultured with the mPFC. Furthermore, the fasciculation of the mPFC outgrowing neurites was dependent on the amount of 5-HTT. In the mPFC of 5-HTT(-/-) pups, we observed clear differences in 5-HT innervation and the identity of a class of projection neurons of the mPFC. In the absence of the 5-HTT, the 5-HT innervation in all subareas of the early postnatal mPFC increased dramatically and the number of Satb2-positive callosal projection neurons was decreased. Together, these results suggest a 5-HTT dependency during early development of these brain areas and in the formation of the raphe-prefrontal network. The tremendous complexity of the 5-HT projection system and its role in several neurodevelopmental disorders highlights the need for further research in this largely unexplored area.
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Affiliation(s)
- Josefine S Witteveen
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Nijmegen, Netherlands
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41
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Vitalis T, Ansorge MS, Dayer AG. Serotonin homeostasis and serotonin receptors as actors of cortical construction: special attention to the 5-HT3A and 5-HT6 receptor subtypes. Front Cell Neurosci 2013; 7:93. [PMID: 23801939 PMCID: PMC3686152 DOI: 10.3389/fncel.2013.00093] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/27/2013] [Indexed: 12/15/2022] Open
Abstract
Cortical circuits control higher-order cognitive processes and their function is highly dependent on their structure that emerges during development. The construction of cortical circuits involves the coordinated interplay between different types of cellular processes such as proliferation, migration, and differentiation of neural and glial cell subtypes. Among the multiple factors that regulate the assembly of cortical circuits, 5-HT is an important developmental signal that impacts on a broad diversity of cellular processes. 5-HT is detected at the onset of embryonic telencephalic formation and a variety of serotonergic receptors are dynamically expressed in the embryonic developing cortex in a region and cell-type specific manner. Among these receptors, the ionotropic 5-HT3A receptor and the metabotropic 5-HT6 receptor have recently been identified as novel serotonergic targets regulating different aspects of cortical construction including neuronal migration and dendritic differentiation. In this review, we focus on the developmental impact of serotonergic systems on the construction of cortical circuits and discuss their potential role in programming risk for human psychiatric disorders.
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Affiliation(s)
- Tania Vitalis
- Laboratoire de Neurobiologie, ESPCI ParisTech, Centre National de la Recherche Scientifique-UMR 7637 Paris, France
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Miceli S, Negwer M, van Eijs F, Kalkhoven C, van Lierop I, Homberg J, Schubert D. High serotonin levels during brain development alter the structural input-output connectivity of neural networks in the rat somatosensory layer IV. Front Cell Neurosci 2013; 7:88. [PMID: 23761736 PMCID: PMC3675331 DOI: 10.3389/fncel.2013.00088] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/22/2013] [Indexed: 02/01/2023] Open
Abstract
Homeostatic regulation of serotonin (5-HT) concentration is critical for “normal” topographical organization and development of thalamocortical (TC) afferent circuits. Down-regulation of the serotonin transporter (SERT) and the consequent impaired reuptake of 5-HT at the synapse, results in a reduced terminal branching of developing TC afferents within the primary somatosensory cortex (S1). Despite the presence of multiple genetic models, the effect of high extracellular 5-HT levels on the structure and function of developing intracortical neural networks is far from being understood. Here, using juvenile SERT knockout (SERT−/−) rats we investigated, in vitro, the effect of increased 5-HT levels on the structural organization of (i) the TC projections of the ventroposteromedial thalamic nucleus toward S1, (ii) the general barrel-field pattern, and (iii) the electrophysiological and morphological properties of the excitatory cell population in layer IV of S1 [spiny stellate (SpSt) and pyramidal cells]. Our results confirmed previous findings that high levels of 5-HT during development lead to a reduction of the topographical precision of TCA projections toward the barrel cortex. Also, the barrel pattern was altered but not abolished in SERT−/− rats. In layer IV, both excitatory SpSt and pyramidal cells showed a significantly reduced intracolumnar organization of their axonal projections. In addition, the layer IV SpSt cells gave rise to a prominent projection toward the infragranular layer Vb. Our findings point to a structural and functional reorganization of TCAs, as well as early stage intracortical microcircuitry, following the disruption of 5-HT reuptake during critical developmental periods. The increased projection pattern of the layer IV neurons suggests that the intracortical network changes are not limited to the main entry layer IV but may also affect the subsequent stages of the canonical circuits of the barrel cortex.
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Affiliation(s)
- Stéphanie Miceli
- Department of Cognitive Neuroscience, Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen Medical Centre Nijmegen, Netherlands
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Velasquez JC, Goeden N, Bonnin A. Placental serotonin: implications for the developmental effects of SSRIs and maternal depression. Front Cell Neurosci 2013; 7:47. [PMID: 23630464 PMCID: PMC3632750 DOI: 10.3389/fncel.2013.00047] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 04/03/2013] [Indexed: 01/15/2023] Open
Abstract
In addition to its role in the pathophysiology of numerous psychiatric disorders, increasing evidence points to serotonin (5-HT) as a crucial molecule for the modulation of neurodevelopmental processes. Recent evidence indicates that the placenta is involved in the synthesis of 5-HT from maternally derived tryptophan (TRP). This gives rise to the possibility that genetic and environmental perturbations directly affecting placental TRP metabolism may lead to abnormal brain circuit wiring in the developing embryo, and therefore contribute to the developmental origin of psychiatric disorders. In this review, we discuss how perturbations of the placental TRP metabolic pathway may lead to abnormal brain development and function throughout life. Of particular interest is prenatal exposure to maternal depression and antidepressants, both known to alter fetal development. We review existing evidence on how antidepressants can alter placental physiology in its key function of maintaining fetal homeostasis and have long-term effects on fetal forebrain development.
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Affiliation(s)
- Juan C Velasquez
- Department of Cell and Neurobiology, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California Los Angeles, CA, USA
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Narboux-Nême N, Angenard G, Mosienko V, Klempin F, Pitychoutis PM, Deneris E, Bader M, Giros B, Alenina N, Gaspar P. Postnatal growth defects in mice with constitutive depletion of central serotonin. ACS Chem Neurosci 2013; 4:171-81. [PMID: 23336056 DOI: 10.1021/cn300165x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 12/14/2012] [Indexed: 12/31/2022] Open
Abstract
Although the trophic actions of serotonin (5-HT) are well established, only few developmental defects have been reported in mouse strains with constitutive hyposerotonergia. We analyzed postnatal growth and cortical development in three different mutant mouse strains with constitutive reductions in central 5-HT levels. We compared two previously published mouse strains with severe (-95%) depletions of 5-HT, the tryptophan hydroxylase (Tph) 2(-/-) mouse line and VMAT2(sert-cre) mice, with a new strain, in which VMAT2 deletion is driven by Pet1 (VMAT2(pet1-cre)) in 5-HT raphe neurons leading to partial (-75%) reduction in brain 5-HT levels. We find that normal embryonic growth and postnatal growth retardation are common features of all these mouse strains. Postnatal growth retardation varied from mild to severe according to the extent of the brain 5-HT reduction and gender. Normal growth was reinstated in VMAT2(sert-cre) mice by reconstituting central 5-HT stores. Growth abnormalities could not be linked to altered food intake or temperature control. Morphological study of the cerebral cortex over postnatal development showed a delayed maturation of the upper cortical layers in the VMAT2(sert-cre) and Tph2(-/-) mice, but not in the VMAT2(pet1-cre) mice. No changes in layer-specific gene expression or morphological alterations of barrel cortex development were found. Overall, these observations sustain the notion that central 5-HT signaling is required for the preweaning growth spurt of mouse pups. Brain development appeared to be immune to severe central 5-HT depletion for its overall growth during prenatal life, whereas reduced brain growth and delayed cortical maturation development occurred during postnatal life. Reduced developmental 5-HT signaling during postnatal development might modulate the function and fine structure of neural circuits in ways that affect adult behavior.
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Affiliation(s)
- Nicolas Narboux-Nême
- INSERM, UMR-S 839, Institut du Fer à
Moulin, 17, rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie (UPMC), Paris 06, Paris, France
| | - Gaelle Angenard
- INSERM, UMR-S 839, Institut du Fer à
Moulin, 17, rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie (UPMC), Paris 06, Paris, France
| | | | | | - Pothitos M. Pitychoutis
- INSERM, UMR-S 839, Institut du Fer à
Moulin, 17, rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie (UPMC), Paris 06, Paris, France
| | - Evan Deneris
- Case Western Reserve University, Cleveland, Ohio 44101, United States
| | - Michael Bader
- Max-Delbrueck-Center for Molecular Medicine, 13125 Berlin-Buch, Germany
| | - Bruno Giros
- Université Pierre et Marie Curie (UPMC), Paris 06, Paris, France
- CNRS UMR 7224, 9 Quai St Bernard, 75005 Paris, France
- Douglas Hospital, Department of Psychiatry, McGill University, Montreal, Canada
| | - Natalia Alenina
- Max-Delbrueck-Center for Molecular Medicine, 13125 Berlin-Buch, Germany
| | - Patricia Gaspar
- INSERM, UMR-S 839, Institut du Fer à
Moulin, 17, rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie (UPMC), Paris 06, Paris, France
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Altieri SC, Garcia-Garcia AL, Leonardo ED, Andrews AM. Rethinking 5-HT1A receptors: emerging modes of inhibitory feedback of relevance to emotion-related behavior. ACS Chem Neurosci 2013; 4:72-83. [PMID: 23336046 DOI: 10.1021/cn3002174] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 12/20/2012] [Indexed: 11/27/2022] Open
Abstract
The complexities of the involvement of the serotonin transmitter system in numerous biological processes and psychiatric disorders is, to a substantial degree, attributable to the large number of serotonin receptor families and subtypes that have been identified and characterized for over four decades. Of these, the 5-HT(1A) receptor subtype, which was the first to be cloned and characterized, has received considerable attention based on its purported role in the etiology and treatment of mood and anxiety disorders. 5-HT(1A) receptors function both at presynaptic (autoreceptor) and postsynaptic (heteroreceptor) sites. Recent research has implicated distinct roles for these two populations of receptors in mediating emotion-related behavior. New concepts as to how 5-HT(1A) receptors function to control serotonergic tone throughout life were highlights of the proceedings of the 2012 Serotonin Club Meeting in Montpellier, France. Here, we review recent findings and current perspectives on functional aspects of 5-HT(1A) auto- and heteroreceptors with particular regard to their involvement in altered anxiety and mood states.
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Affiliation(s)
| | - Alvaro L. Garcia-Garcia
- Department of Psychiatry, Division of Integrative Neuroscience, Columbia University and New York State Psychiatric Institute, New York, New York 10032, United States
| | - E. David Leonardo
- Department of Psychiatry, Division of Integrative Neuroscience, Columbia University and New York State Psychiatric Institute, New York, New York 10032, United States
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Abstract
In primary sensory neocortical areas of mammals, the distribution of sensory receptors is mapped with topographic precision and amplification in proportion to the peripheral receptor density. The visual, somatosensory and auditory cortical maps are established during a critical period in development. Throughout this window in time, the developing cortical maps are vulnerable to deleterious effects of sense organ damage or sensory deprivation. The rodent barrel cortex offers an invaluable model system with which to investigate the mechanisms underlying the formation of topographic maps and their plasticity during development. Five rows of mystacial vibrissa (whisker) follicles on the snout and an array of sinus hairs are represented by layer IV neural modules ('barrels') and thalamocortical axon terminals in the primary somatosensory cortex. Perinatal damage to the whiskers or the sensory nerve innervating them irreversibly alters the structural organization of the barrels. Earlier studies emphasized the role of the sensory periphery in dictating whisker-specific brain maps and patterns. Recent advances in molecular genetics and analyses of genetically altered mice allow new insights into neural pattern formation in the neocortex and the mechanisms underlying critical period plasticity. Here, we review the development and patterning of the barrel cortex and the critical period plasticity.
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Affiliation(s)
- Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201-1075, USA.
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