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Tsuboi D, Nagai T, Yoshimoto J, Kaibuchi K. Neuromodulator regulation and emotions: insights from the crosstalk of cell signaling. Front Mol Neurosci 2024; 17:1376762. [PMID: 38516040 PMCID: PMC10954900 DOI: 10.3389/fnmol.2024.1376762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 02/26/2024] [Indexed: 03/23/2024] Open
Abstract
The unraveling of the regulatory mechanisms that govern neuronal excitability is a major challenge for neuroscientists worldwide. Neurotransmitters play a critical role in maintaining the balance between excitatory and inhibitory activity in the brain. The balance controls cognitive functions and emotional responses. Glutamate and γ-aminobutyric acid (GABA) are the primary excitatory and inhibitory neurotransmitters of the brain, respectively. Disruptions in the balance between excitatory and inhibitory transmission are implicated in several psychiatric disorders, including anxiety disorders, depression, and schizophrenia. Neuromodulators such as dopamine and acetylcholine control cognition and emotion by regulating the excitatory/inhibitory balance initiated by glutamate and GABA. Dopamine is closely associated with reward-related behaviors, while acetylcholine plays a role in aversive and attentional behaviors. Although the physiological roles of neuromodulators have been extensively studied neuroanatomically and electrophysiologically, few researchers have explored the interplay between neuronal excitability and cell signaling and the resulting impact on emotion regulation. This review provides an in-depth understanding of "cell signaling crosstalk" in the context of neuronal excitability and emotion regulation. It also anticipates that the next generation of neurochemical analyses, facilitated by integrated phosphorylation studies, will shed more light on this topic.
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Affiliation(s)
- Daisuke Tsuboi
- Division of Cell Biology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Taku Nagai
- Division of Behavioral Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Junichiro Yoshimoto
- Department of Biomedical Data Science, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Kozo Kaibuchi
- Division of Cell Biology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, Japan
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KASAI H. Unraveling the mysteries of dendritic spine dynamics: Five key principles shaping memory and cognition. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2023; 99:254-305. [PMID: 37821392 PMCID: PMC10749395 DOI: 10.2183/pjab.99.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 07/11/2023] [Indexed: 10/13/2023]
Abstract
Recent research extends our understanding of brain processes beyond just action potentials and chemical transmissions within neural circuits, emphasizing the mechanical forces generated by excitatory synapses on dendritic spines to modulate presynaptic function. From in vivo and in vitro studies, we outline five central principles of synaptic mechanics in brain function: P1: Stability - Underpinning the integral relationship between the structure and function of the spine synapses. P2: Extrinsic dynamics - Highlighting synapse-selective structural plasticity which plays a crucial role in Hebbian associative learning, distinct from pathway-selective long-term potentiation (LTP) and depression (LTD). P3: Neuromodulation - Analyzing the role of G-protein-coupled receptors, particularly dopamine receptors, in time-sensitive modulation of associative learning frameworks such as Pavlovian classical conditioning and Thorndike's reinforcement learning (RL). P4: Instability - Addressing the intrinsic dynamics crucial to memory management during continual learning, spotlighting their role in "spine dysgenesis" associated with mental disorders. P5: Mechanics - Exploring how synaptic mechanics influence both sides of synapses to establish structural traces of short- and long-term memory, thereby aiding the integration of mental functions. We also delve into the historical background and foresee impending challenges.
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Affiliation(s)
- Haruo KASAI
- International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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3
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Longhena F, Faustini G, Brembati V, Pizzi M, Benfenati F, Bellucci A. An updated reappraisal of synapsins: structure, function and role in neurological and psychiatric disorders. Neurosci Biobehav Rev 2021; 130:33-60. [PMID: 34407457 DOI: 10.1016/j.neubiorev.2021.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023]
Abstract
Synapsins (Syns) are phosphoproteins strongly involved in neuronal development and neurotransmitter release. Three distinct genes SYN1, SYN2 and SYN3, with elevated evolutionary conservation, have been described to encode for Synapsin I, Synapsin II and Synapsin III, respectively. Syns display a series of common features, but also exhibit distinctive localization, expression pattern, post-translational modifications (PTM). These characteristics enable their interaction with other synaptic proteins, membranes and cytoskeletal components, which is essential for the proper execution of their multiple functions in neuronal cells. These include the control of synapse formation and growth, neuron maturation and renewal, as well as synaptic vesicle mobilization, docking, fusion, recycling. Perturbations in the balanced expression of Syns, alterations of their PTM, mutations and polymorphisms of their encoding genes induce severe dysregulations in brain networks functions leading to the onset of psychiatric or neurological disorders. This review presents what we have learned since the discovery of Syn I in 1977, providing the state of the art on Syns structure, function, physiology and involvement in central nervous system disorders.
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Affiliation(s)
- Francesca Longhena
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Viviana Brembati
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Marina Pizzi
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Fabio Benfenati
- Italian Institute of Technology, Via Morego 30, Genova, Italy; IRCSS Policlinico San Martino Hospital, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Laboratory for Preventive and Personalized Medicine, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
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Dysfunction of the serotonergic system in the brain of synapsin triple knockout mice is associated with behavioral abnormalities resembling synapsin-related human pathologies. Prog Neuropsychopharmacol Biol Psychiatry 2021; 105:110135. [PMID: 33058959 DOI: 10.1016/j.pnpbp.2020.110135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/31/2020] [Accepted: 10/06/2020] [Indexed: 11/23/2022]
Abstract
Synapsins (Syns) are a family of phosphoproteins associated with synaptic vesicles (SVs). Their main function is to regulate neurotransmitter release by maintaining a reserve pool of SVs at the presynaptic terminal. Previous studies reported that the deletion of one or more Syn genes in mice results in an epileptic phenotype and autism-related behavioral abnormalities. Here we aimed at characterizing the behavioral phenotype and neurobiological correlates of the deletion of Syns in a Syn triple knockout (TKO) mouse model. Wild type (WT) and TKO mice were tested in the open field, novelty suppressed feeding, light-dark box, forced swim, tail suspension and three-chamber sociability tests. Using in vivo electrophysiology, we recorded the spontaneous activity of dorsal raphe nucleus (DRN) serotonin (5-HT) and ventral tegmental area (VTA) dopamine (DA) neurons. Levels of 5-HT and DA in the frontal cortex and hippocampus of WT and TKO mice were also assessed using a High-Performance Liquid Chromatography. TKO mice displayed hyperactivity and impaired social and anxiety-like behavior. Behavioral dysfunctions were accompanied by reduced firing activity of DRN 5-HT, but not VTA DA, neurons. TKO mice also showed increased responsiveness of DRN 5-HT-1A autoreceptors, measured as a reduced dose of the 5-HT-1A agonist 8-OH-DPAT necessary to inhibit DRN 5-HT firing activity by 50%. Finally, hippocampal 5-HT levels were lower in TKO than in WT mice. Overall, Syns deletion in mice leads to a reduction in DRN 5-HT firing activity and hippocampal 5-HT levels along with behavioral alterations reminiscent of human neuropsychiatric conditions associated with Syn dysfunction.
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Naderi M, Kwong RWM. A comprehensive review of the neurobehavioral effects of bisphenol S and the mechanisms of action: New insights from in vitro and in vivo models. ENVIRONMENT INTERNATIONAL 2020; 145:106078. [PMID: 32911243 DOI: 10.1016/j.envint.2020.106078] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
The normal brain development and function are delicately driven by an ever-changing milieu of steroid hormones arising from fetal, placental, and maternal origins. This reliance on the neuroendocrine system sets the stage for the exquisite sensitivity of the central nervous system to the adverse effects of endocrine-disrupting chemicals (EDCs). Bisphenol A (BPA) is one of the most common EDCs which has been a particular focus of environmental concern for decades due to its widespread nature and formidable threat to human and animal health. The heightened regulatory actions and the scientific and public concern over the adverse health effects of BPA have led to its replacement with a suite of structurally similar but less known alternative chemicals. Bisphenol S (BPS) is the main substitute for BPA that is increasingly being used in a wide array of consumer and industrial products. Although it was considered to be a safe BPA alternative, mounting evidence points to the deleterious effects of BPS on a wide range of neuroendocrine functions in animals. In addition to its reproductive toxicity, recent experimental efforts indicate that BPS has a considerable potential to induce neurotoxicity and behavioral dysfunction. This review analyzes the current state of knowledge regarding the neurobehavioral effects of BPS and discusses its potential mode of actions on several aspects of the neuroendocrine system. We summarize the role of certain hormones and their signaling pathways in the regulation of brain and behavior and discuss how BPS induces neurotoxicity through interactions with these pathways. Finally, we review potential links between BPS exposure and aberrant neurobehavioral functions in animals and identify key knowledge gaps and hypotheses for future research.
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Affiliation(s)
- Mohammad Naderi
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Raymond W M Kwong
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
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Mossa A, Manzini MC. Molecular causes of sex-specific deficits in rodent models of neurodevelopmental disorders. J Neurosci Res 2019; 99:37-56. [PMID: 31872500 PMCID: PMC7754327 DOI: 10.1002/jnr.24577] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/02/2019] [Accepted: 12/09/2019] [Indexed: 12/12/2022]
Abstract
Neurodevelopmental disorders (NDDs) such as intellectual disability and autism spectrum disorder consistently show a male bias in prevalence, but it remains unclear why males and females are affected with different frequency. While many behavioral studies of transgenic NDD models have focused only on males, the requirement by the National Institutes of Health to consider sex as a biological variable has promoted the comparison of male and female performance in wild-type and mutant animals. Here, we review examples of rodent models of NDDs in which sex-specific deficits were identified in molecular, physiological, and/or behavioral responses, showing sex differences in susceptibility to disruption of genes mutated in NDDs. Haploinsufficiency in genes involved in mechanisms such as synaptic function (GABRB3 and NRXN1), chromatin remodeling (CHD8, EMHT1, and ADNP), and intracellular signaling (CC2D1A and ERK1) lead to more severe behavioral outcomes in males. However, in the absence of behavioral deficits, females can still present with cellular and electrophysiological changes that could be due to compensatory mechanisms or differential allocation of molecular and cellular functions in the two sexes. By contrasting these findings with mouse models where females are more severely affected (MTHFR and AMBRA1), we propose a framework to approach the study of sex-specific deficits possibly leading to sex bias in NDDs.
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Affiliation(s)
- Adele Mossa
- Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - M Chiara Manzini
- Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.,Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
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Pogorelov VM, Kao HT, Augustine GJ, Wetsel WC. Postsynaptic Mechanisms Render Syn I/II/III Mice Highly Responsive to Psychostimulants. Int J Neuropsychopharmacol 2019; 22:453-465. [PMID: 31188434 PMCID: PMC6600466 DOI: 10.1093/ijnp/pyz019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/11/2019] [Accepted: 04/23/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Synapsins are encoded by SYN I, SYN II, and SYN III, and they regulate neurotransmitter release by maintaining a reserve pool of synaptic vesicles. METHODS Presynaptic dopamine responses to cocaine were examined by microdialysis, and postsynaptic responses were evaluated to various dopamine receptor agonists in the open field with SynI/SynII/SynIII triple knockout mice. RESULTS Triple knockout mice showed enhanced spontaneous locomotion in a novel environment and were hyper-responsive to indirect and direct D1 and D2 dopamine agonists. Triple knockout animals appeared sensitized to cocaine upon first open field exposure; sensitization developed across days in wild-type controls. When mutants were preexposed to a novel environment before injection, cocaine-stimulated locomotion was reduced and behavioral sensitization retarded. Baseline dopamine turnover was enhanced in mutants and novel open field exposure increased their striatal dopamine synthesis rates. As KCl-depolarization stimulated comparable dopamine release in both genotypes, their readily releasable pools appeared indistinguishable. Similarly, cocaine-induced hyperlocomotion was indifferent to blockade of newly synthesized dopamine and depletion of releasable dopamine pools. Extracellular dopamine release was similar in wild-type and triple knockout mice preexposed to the open field and given cocaine or placed immediately into the arena following injection. Since motor effects to novelty and psychostimulants depend upon frontocortical-striatal inputs, we inhibited triple knockout medial frontal cortex with GABA agonists. Locomotion was transiently increased in cocaine-injected mutants, while their supersensitive cocaine response to novelty was lost. CONCLUSIONS These results reveal presynaptic dopamine release is not indicative of agonist-induced triple knockout hyperlocomotion. Instead, their novelty response occurs primarily through postsynaptic mechanisms and network effects.
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Affiliation(s)
- Vladimir M Pogorelov
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina
| | - Hung-Teh Kao
- Department of Psychiatry and Human Behavior, Brown University, BioMedical Center, Providence, Rhode Island
| | - George J Augustine
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore and the Institute of Molecular and Cellular Biology, Singapore, Singapore
| | - William C Wetsel
- Departments of Cell Biology and Neurobiology, Duke University Medical Center, Durham, North Carolina,Correspondence: William C. Wetsel, PhD, Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, 354 Sands Building, P.O. Box 103203, 333 Research Drive, Durham, NC 27710 ()
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8
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Torres-Lista V, Giménez-Llort L. Vibrating Tail, Digging, Body/Face Interaction, and Lack of Barbering: Sex-Dependent Behavioral Signatures of Social Dysfunction in 3xTg-AD Mice as Compared to Mice with Normal Aging. J Alzheimers Dis 2019; 69:969-977. [PMID: 31156176 PMCID: PMC6598105 DOI: 10.3233/jad-190253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2019] [Indexed: 12/29/2022]
Abstract
Modeling of Alzheimer's disease (AD), classically focused on the subject-environment interaction, foresees current social neuroscience efforts as improving the predictive validity of new strategies. Here we studied social functioning among congeners in 13-14-month-old mice with normal aging in naturalistic and experimental conditions and depicted behavioral signatures of dysfunction in age-matched 3xTg-AD mice. The most sensitive variables were vibrating tail, digging, body/face and self-grooming, that can be easily used in housing routines and the assessment of strategies. Sex-specific signatures (vibrating tail, digging, and grooming) defined female 3xTg-AD mice ethogram. All animals sleep huddled while barbering was only found in females with normal aging.
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Affiliation(s)
- Virginia Torres-Lista
- Department of Psychiatry and Forensic Medicine, Faculty of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Lydia Giménez-Llort
- Department of Psychiatry and Forensic Medicine, Faculty of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
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Michetti C, Caruso A, Pagani M, Sabbioni M, Medrihan L, David G, Galbusera A, Morini M, Gozzi A, Benfenati F, Scattoni ML. The Knockout of Synapsin II in Mice Impairs Social Behavior and Functional Connectivity Generating an ASD-like Phenotype. Cereb Cortex 2018; 27:5014-5023. [PMID: 28922833 DOI: 10.1093/cercor/bhx207] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Indexed: 12/28/2022] Open
Abstract
Autism spectrum disorders (ASD) and epilepsy are neurodevelopmental conditions that appear with high rate of co-occurrence, suggesting the possibility of a common genetic basis. Mutations in Synapsin (SYN) genes, particularly SYN1 and SYN2, have been recently associated with ASD and epilepsy in humans. Accordingly, mice lacking Syn1 or Syn2, but not Syn3, experience epileptic seizures and display autistic-like traits that precede the onset of seizures. Here, we analyzed social behavior and ultrasonic vocalizations emitted in 2 social contexts by SynI, SynII, or SynIII mutants and show that SynII mutants display the most severe ASD-like phenotype. We also show that the behavioral SynII phenotype correlates with a significant decrease in auditory and hippocampal functional connectivity as measured with resting state functional magnetic resonance imaging (rsfMRI). Taken together, our results reveal a permissive contribution of Syn2 to the expression of normal socio-communicative behavior, and suggest that Syn2-mediated synaptic dysfunction can lead to ASD-like behavior through dysregulation of cortical connectivity.
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Affiliation(s)
- Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Angela Caruso
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Marco Pagani
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy.,Center for Mind and Brain Sciences, University of Trento, Rovereto 38068, Italy
| | - Mara Sabbioni
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Lucian Medrihan
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Gergely David
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Alberto Galbusera
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Monica Morini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Alessandro Gozzi
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Maria Luisa Scattoni
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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Ginsenoside Rg1 Ameliorates Behavioral Abnormalities and Modulates the Hippocampal Proteomic Change in Triple Transgenic Mice of Alzheimer's Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6473506. [PMID: 29204248 PMCID: PMC5674513 DOI: 10.1155/2017/6473506] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/07/2017] [Accepted: 08/24/2017] [Indexed: 01/19/2023]
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases, so far, there are no effective measures to prevent and cure this deadly condition. Ginsenoside Rg1 (Rg1) was shown to improve behavioral abnormalities in AD; however, the potential mechanisms remain unclear. In this study, we pretreated 7-month-old 3xTg-AD mice for 6 weeks with Rg1 and evaluated the effects of Rg1 on the behaviors and the protein expression of hippocampal tissues. The behavioral tests showed that Rg1 could improve the memory impairment and ameliorate the depression-like behaviors of 3xTg-AD mice. Proteomic results revealed a total of 28 differentially expressed hippocampal proteins between Rg1-treated and nontreated 3xTg-AD mice. Among these proteins, complexin-2 (CPLX2), synapsin-2 (SYN2), and synaptosomal-associated protein 25 (SNP25) were significantly downregulated in the hippocampus of 3xTg-AD mice compared with the WT mice, and the treatment of Rg1 modulated the expression of CPLX2 and SNP25 in the hippocampus of 3xTg-AD mice. The expression of CPLX2, SYN2, and SNP25 was further validated by Western blot analysis. Taken together, we concluded that Rg1 could be a potential candidate drug to improve the behavioral deficits in AD via modulating the expression of the proteins (i.e., CPLX2, SYN2, and SNP25).
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Li YC, Kavalali ET. Synaptic Vesicle-Recycling Machinery Components as Potential Therapeutic Targets. Pharmacol Rev 2017; 69:141-160. [PMID: 28265000 DOI: 10.1124/pr.116.013342] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Presynaptic nerve terminals are highly specialized vesicle-trafficking machines. Neurotransmitter release from these terminals is sustained by constant local recycling of synaptic vesicles independent from the neuronal cell body. This independence places significant constraints on maintenance of synaptic protein complexes and scaffolds. Key events during the synaptic vesicle cycle-such as exocytosis and endocytosis-require formation and disassembly of protein complexes. This extremely dynamic environment poses unique challenges for proteostasis at synaptic terminals. Therefore, it is not surprising that subtle alterations in synaptic vesicle cycle-associated proteins directly or indirectly contribute to pathophysiology seen in several neurologic and psychiatric diseases. In contrast to the increasing number of examples in which presynaptic dysfunction causes neurologic symptoms or cognitive deficits associated with multiple brain disorders, synaptic vesicle-recycling machinery remains an underexplored drug target. In addition, irrespective of the involvement of presynaptic function in the disease process, presynaptic machinery may also prove to be a viable therapeutic target because subtle alterations in the neurotransmitter release may counter disease mechanisms, correct, or compensate for synaptic communication deficits without the need to interfere with postsynaptic receptor signaling. In this article, we will overview critical properties of presynaptic release machinery to help elucidate novel presynaptic avenues for the development of therapeutic strategies against neurologic and neuropsychiatric disorders.
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Affiliation(s)
- Ying C Li
- Departments of Neuroscience (Y.C.L., E.T.K.) and Physiology (E.T.K.), University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ege T Kavalali
- Departments of Neuroscience (Y.C.L., E.T.K.) and Physiology (E.T.K.), University of Texas Southwestern Medical Center, Dallas, Texas
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12
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Emerging Synaptic Molecules as Candidates in the Etiology of Neurological Disorders. Neural Plast 2017; 2017:8081758. [PMID: 28331639 PMCID: PMC5346360 DOI: 10.1155/2017/8081758] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 02/06/2017] [Indexed: 01/06/2023] Open
Abstract
Synapses are complex structures that allow communication between neurons in the central nervous system. Studies conducted in vertebrate and invertebrate models have contributed to the knowledge of the function of synaptic proteins. The functional synapse requires numerous protein complexes with specialized functions that are regulated in space and time to allow synaptic plasticity. However, their interplay during neuronal development, learning, and memory is poorly understood. Accumulating evidence links synapse proteins to neurodevelopmental, neuropsychiatric, and neurodegenerative diseases. In this review, we describe the way in which several proteins that participate in cell adhesion, scaffolding, exocytosis, and neurotransmitter reception from presynaptic and postsynaptic compartments, mainly from excitatory synapses, have been associated with several synaptopathies, and we relate their functions to the disease phenotype.
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13
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Mulligan KA, Cheyette BNR. Neurodevelopmental Perspectives on Wnt Signaling in Psychiatry. MOLECULAR NEUROPSYCHIATRY 2017; 2:219-246. [PMID: 28277568 DOI: 10.1159/000453266] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mounting evidence indicates that Wnt signaling is relevant to pathophysiology of diverse mental illnesses including schizophrenia, bipolar disorder, and autism spectrum disorder. In the 35 years since Wnt ligands were first described, animal studies have richly explored how downstream Wnt signaling pathways affect an array of neurodevelopmental processes and how their disruption can lead to both neurological and behavioral phenotypes. Recently, human induced pluripotent stem cell (hiPSC) models have begun to contribute to this literature while pushing it in increasingly translational directions. Simultaneously, large-scale human genomic studies are providing evidence that sequence variation in Wnt signal pathway genes contributes to pathogenesis in several psychiatric disorders. This article reviews neurodevelopmental and postneurodevelopmental functions of Wnt signaling, highlighting mechanisms, whereby its disruption might contribute to psychiatric illness, and then reviews the most reliable recent genetic evidence supporting that mutations in Wnt pathway genes contribute to psychiatric illness. We are proponents of the notion that studies in animal and hiPSC models informed by the human genetic data combined with the deep knowledge base and tool kits generated over the last several decades of basic neurodevelopmental research will yield near-term tangible advances in neuropsychiatry.
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Affiliation(s)
- Kimberly A Mulligan
- Department of Biological Sciences, California State University, Sacramento, CA, USA
| | - Benjamin N R Cheyette
- Department of Psychiatry, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
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14
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Molinaro L, Hui P, Tan M, Mishra RK. Role of presynaptic phosphoprotein synapsin II in schizophrenia. World J Psychiatry 2015; 5:260-272. [PMID: 26425441 PMCID: PMC4582303 DOI: 10.5498/wjp.v5.i3.260] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 04/30/2015] [Accepted: 06/11/2015] [Indexed: 02/05/2023] Open
Abstract
Synapsin II is a member of the neuronal phosphoprotein family. These phosphoproteins are evolutionarily conserved across many organisms and are important in a variety of synaptic functions, including synaptogenesis and the regulation of neurotransmitter release. A number of genome-wide scans, meta-analyses, and genetic susceptibility studies have implicated the synapsin II gene (3p25) in the etiology of schizophrenia (SZ) and other psychiatric disorders. Further studies have found a reduction of synapsin II mRNA and protein in the prefrontal cortex in post-mortem samples from schizophrenic patients. Disruptions in the expression of this gene may cause synaptic dysfunction, which can result in neurotransmitter imbalances, likely contributing to the pathogenesis of SZ. SZ is a costly, debilitating psychiatric illness affecting approximately 1.1% of the world’s population, amounting to 51 million people today. The disorder is characterized by positive (hallucinations, paranoia), negative (social withdrawal, lack of motivation), and cognitive (memory impairments, attention deficits) symptoms. This review provides a comprehensive summary of the structure, function, and involvement of the synapsin family, specifically synapsin II, in the pathophysiology of SZ and possible target for therapeutic intervention/implications.
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Carrel D, Hernandez K, Kwon M, Mau C, Trivedi MP, Brzustowicz LM, Firestein BL. Nitric oxide synthase 1 adaptor protein, a protein implicated in schizophrenia, controls radial migration of cortical neurons. Biol Psychiatry 2015; 77:969-78. [PMID: 25542305 PMCID: PMC4416077 DOI: 10.1016/j.biopsych.2014.10.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 10/08/2014] [Accepted: 10/22/2014] [Indexed: 12/22/2022]
Abstract
BACKGROUND Where a neuron is positioned in the brain during development determines neuronal circuitry and information processing needed for normal brain function. When aberrations in this process occur, cognitive disorders may result. Patients diagnosed with schizophrenia have been reported to show altered neuronal connectivity and heterotopias. To elucidate pathways by which this process occurs and become aberrant, we have chosen to study the long isoform of nitric oxide synthase 1 adaptor protein (NOS1AP), a protein encoded by a susceptibility gene for schizophrenia. METHODS To determine whether NOS1AP plays a role in cortical patterning, we knocked down or co-overexpressed NOS1AP and a green fluorescent protein or red fluorescent protein (TagRFP) reporter in neuronal progenitor cells of the embryonic rat neocortex using in utero electroporation. We analyzed sections of cortex (ventricular zone, intermediate zone, and cortical plate [CP]) containing green fluorescent protein or red fluorescent protein TagRFP positive cells and counted the percentage of positive cells that migrated to each region from at least three rats for each condition. RESULTS NOS1AP overexpression disrupts neuronal migration, resulting in increased cells in intermediate zone and less cells in CP, and decreases dendritogenesis. Knockdown results in increased migration, with more cells reaching the CP. The phosphotyrosine binding region, but not the PDZ-binding motif, is necessary for NOS1AP function. Amino acids 181 to 307, which are sufficient for NOS1AP-mediated decreases in dendrite number, have no effect on migration. CONCLUSIONS Our studies show for the first time a critical role for the schizophrenia-associated gene NOS1AP in cortical patterning, which may contribute to underlying pathophysiology seen in schizophrenia.
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Affiliation(s)
- Damien Carrel
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey; Neurophotonics Laboratory, Paris Descartes University, Paris, France
| | - Kristina Hernandez
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey; Molecular Biosciences Graduate Program Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Munjin Kwon
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey; Molecular Biosciences Graduate Program Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Christine Mau
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Meera P Trivedi
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Linda M Brzustowicz
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey.
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Basu D, Tian Y, Hui P, Bhandari J, Johnson RL, Mishra RK. Change in expression of vesicular protein synapsin II by chronic treatment with D2 allosteric modulator PAOPA. Peptides 2015; 66:58-62. [PMID: 25703303 DOI: 10.1016/j.peptides.2015.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 12/21/2022]
Abstract
The hallmark symptoms of schizophrenia include profound disturbances in thought, perception, cognition etc., which negatively impacts an individual's quality of life. Current antipsychotic drugs are not effective in treating all symptoms of this disorder, and often cause severe movement and metabolic side effects. Consequently, there remains a strong impetus to develop safer and more efficacious therapeutics for patients, as well as elucidating the etiology of schizophrenia. Previous work in our lab has introduced a novel candidate for the treatment of this disease: the dopamine D2 receptor (D2R) allosteric modulator, 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA). We have previously shown that PAOPA, by selectively modulating D2R, can ameliorate schizophrenia-like symptoms in animal models, although the precise mechanism is presently not understood. Synapsin II is a presynaptic vesicular protein which has been strongly implicated in schizophrenia, as it is reduced in the prefrontal cortex of patients, and knockdown of this protein elicits schizophrenia-like phenotypes in animal models. Given the therapeutic effects of PAOPA and the role of synapsin II in schizophrenia, the objective of this study was to investigate the effect of chronic administration of PAOPA (45 days) on neuronal synapsin II protein expression in rodents. Immunoblot results revealed that the synapsin IIa, but not the IIb isoform, was increased in the dopaminergic regions of the striatum, nucleus accumbens, and medial prefrontal cortex. The results of this study implicate a role for modulation of synapsin II as a possible therapeutic mechanism of action for potential antipsychotic drug PAOPA.
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Affiliation(s)
- Dipannita Basu
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Yuxin Tian
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Patricia Hui
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Jayant Bhandari
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Rodney L Johnson
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Ram K Mishra
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5.
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McCullumsmith RE, Hammond JH, Shan D, Meador-Woodruff JH. Postmortem brain: an underutilized substrate for studying severe mental illness. Neuropsychopharmacology 2014; 39:65-87. [PMID: 24091486 PMCID: PMC3857666 DOI: 10.1038/npp.2013.239] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
We propose that postmortem tissue is an underutilized substrate that may be used to translate genetic and/or preclinical studies, particularly for neuropsychiatric illnesses with complex etiologies. Postmortem brain tissues from subjects with schizophrenia have been extensively studied, and thus serve as a useful vehicle for illustrating the challenges associated with this biological substrate. Schizophrenia is likely caused by a combination of genetic risk and environmental factors that combine to create a disease phenotype that is typically not apparent until late adolescence. The complexity of this illness creates challenges for hypothesis testing aimed at understanding the pathophysiology of the illness, as postmortem brain tissues collected from individuals with schizophrenia reflect neuroplastic changes from a lifetime of severe mental illness, as well as treatment with antipsychotic medications. While there are significant challenges with studying postmortem brain, such as the postmortem interval, it confers a translational element that is difficult to recapitulate in animal models. On the other hand, data derived from animal models typically provide specific mechanistic and behavioral measures that cannot be generated using human subjects. Convergence of these two approaches has led to important insights for understanding molecular deficits and their causes in this illness. In this review, we discuss the problem of schizophrenia, review the common challenges related to postmortem studies, discuss the application of biochemical approaches to this substrate, and present examples of postmortem schizophrenia studies that illustrate the role of the postmortem approach for generating important new leads for understanding the pathophysiology of severe mental illness.
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Affiliation(s)
| | - John H Hammond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - Dan Shan
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
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Corradi A, Fadda M, Piton A, Patry L, Marte A, Rossi P, Cadieux-Dion M, Gauthier J, Lapointe L, Mottron L, Valtorta F, Rouleau GA, Fassio A, Benfenati F, Cossette P. SYN2 is an autism predisposing gene: loss-of-function mutations alter synaptic vesicle cycling and axon outgrowth. Hum Mol Genet 2013; 23:90-103. [PMID: 23956174 PMCID: PMC3857945 DOI: 10.1093/hmg/ddt401] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
An increasing number of genes predisposing to autism spectrum disorders (ASDs) has been identified, many of which are implicated in synaptic function. This 'synaptic autism pathway' notably includes disruption of SYN1 that is associated with epilepsy, autism and abnormal behavior in both human and mice models. Synapsins constitute a multigene family of neuron-specific phosphoproteins (SYN1-3) present in the majority of synapses where they are implicated in the regulation of neurotransmitter release and synaptogenesis. Synapsins I and II, the major Syn isoforms in the adult brain, display partially overlapping functions and defects in both isoforms are associated with epilepsy and autistic-like behavior in mice. In this study, we show that nonsense (A94fs199X) and missense (Y236S and G464R) mutations in SYN2 are associated with ASD in humans. The phenotype is apparent in males. Female carriers of SYN2 mutations are unaffected, suggesting that SYN2 is another example of autosomal sex-limited expression in ASD. When expressed in SYN2 knockout neurons, wild-type human Syn II fully rescues the SYN2 knockout phenotype, whereas the nonsense mutant is not expressed and the missense mutants are virtually unable to modify the SYN2 knockout phenotype. These results identify for the first time SYN2 as a novel predisposing gene for ASD and strengthen the hypothesis that a disturbance of synaptic homeostasis underlies ASD.
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Affiliation(s)
- Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova 16132, Italy
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Krimsky S. Genetic causation: a cross disciplinary inquiry. ADVANCES IN CHILD DEVELOPMENT AND BEHAVIOR 2013; 44:307-23. [PMID: 23834010 DOI: 10.1016/b978-0-12-397947-6.00011-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The growth of genome-wide and Candidate Gene Association Studies have elevated genetic causality in medicine and behavioral science. This chapter explores the concept of causality as it has been applied in genetic explanations and distinguishes the varieties of methods used to establish genetic causation. The essay ends with a cautionary note on applying genetic causation to complex human behaviors and neurocognitive abnormalities.
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Affiliation(s)
- Sheldon Krimsky
- Department of Urban and Environmental Policy and Planning, Tufts University, Medford, MA, USA.
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Lavi A, Sheinin A, Shapira R, Zelmanoff D, Ashery U. DOC2B and Munc13-1 differentially regulate neuronal network activity. ACTA ACUST UNITED AC 2013; 24:2309-23. [PMID: 23537531 DOI: 10.1093/cercor/bht081] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Alterations in the levels of synaptic proteins affect synaptic transmission and synaptic plasticity. However, the precise effects on neuronal network activity are still enigmatic. Here, we utilized microelectrode array (MEA) to elucidate how manipulation of the presynaptic release process affects the activity of neuronal networks. By combining pharmacological tools and genetic manipulation of synaptic proteins, we show that overexpression of DOC2B and Munc13-1, proteins known to promote vesicular maturation and release, elicits opposite effects on the activity of the neuronal network. Although both cause an increase in the overall number of spikes, the distribution of spikes is different. While DOC2B enhances, Munc13-1 reduces the firing rate within bursts of spikes throughout the network; however, Munc13-1 increases the rate of network bursts. DOC2B's effects were mimicked by Strontium that elevates asynchronous release but not by a DOC2B mutant that enhances spontaneous release rate. This suggests for the first time that increased asynchronous release on the single-neuron level promotes bursting activity in the network level. This innovative study demonstrates the complementary role of the network level in explaining the physiological relevance of the cellular activity of presynaptic proteins and the transformation of synaptic release manipulation from the neuron to the network level.
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Affiliation(s)
- Ayal Lavi
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anton Sheinin
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ronit Shapira
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Daniel Zelmanoff
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Uri Ashery
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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21
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Synapsin II gene expression in the dorsolateral prefrontal cortex of brain specimens from patients with schizophrenia and bipolar disorder: effect of lifetime intake of antipsychotic drugs. THE PHARMACOGENOMICS JOURNAL 2013; 14:63-9. [PMID: 23529008 PMCID: PMC3970980 DOI: 10.1038/tpj.2013.6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/04/2013] [Accepted: 02/04/2013] [Indexed: 01/31/2023]
Abstract
Synapsins are neuronal phosphoproteins crucial to regulating the processes required for normal neurotransmitter release. Synapsin II, in particular, has been implied as a candidate gene for schizophrenia. This study investigated synapsin II mRNA expression, using Real Time RT-PCR, in coded dorsolateral prefrontal cortical samples provided by the Stanley Foundation Neuropathology Consortium. Synapsin IIa was decreased in patients with schizophrenia when compared to both healthy subjects and patients with bipolar disorder, whereas the synapsin IIb was only significantly reduced in patients with schizophrenia when compared to healthy subjects, but not patients with bipolar disorder. Furthermore, lifetime antipsychotic drug use was positively associated with synapsin IIa expression in patients with schizophrenia. Results suggest that impairment of synaptic transmission by synapsin II reduction may contribute to dysregulated convergent molecular mechanisms which result in aberrant neural circuits that characterize schizophrenia, while implicating involvement of synapsin II in therapeutic mechanisms of currently prescribed antipsychotic drugs.
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22
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Logan RW, Robledo RF, Recla JM, Philip VM, Bubier JA, Jay JJ, Harwood C, Wilcox T, Gatti DM, Bult CJ, Churchill GA, Chesler EJ. High-precision genetic mapping of behavioral traits in the diversity outbred mouse population. GENES BRAIN AND BEHAVIOR 2013; 12:424-37. [PMID: 23433259 PMCID: PMC3709837 DOI: 10.1111/gbb.12029] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 01/14/2013] [Accepted: 02/17/2013] [Indexed: 12/11/2022]
Abstract
Historically our ability to identify genetic variants underlying complex behavioral traits in mice has been limited by low mapping resolution of conventional mouse crosses. The newly developed Diversity Outbred (DO) population promises to deliver improved resolution that will circumvent costly fine-mapping studies. The DO is derived from the same founder strains as the Collaborative Cross (CC), including three wild-derived strains. Thus the DO provides more allelic diversity and greater potential for discovery compared to crosses involving standard mouse strains. We have characterized 283 male and female DO mice using open-field, light–dark box, tail-suspension and visual-cliff avoidance tests to generate 38 behavioral measures. We identified several quantitative trait loci (QTL) for these traits with support intervals ranging from 1 to 3 Mb in size. These intervals contain relatively few genes (ranging from 5 to 96). For a majority of QTL, using the founder allelic effects together with whole genome sequence data, we could further narrow the positional candidates. Several QTL replicate previously published loci. Novel loci were also identified for anxiety- and activity-related traits. Half of the QTLs are associated with wild-derived alleles, confirming the value to behavioral genetics of added genetic diversity in the DO. In the presence of wild-alleles we sometimes observe behaviors that are qualitatively different from the expected response. Our results demonstrate that high-precision mapping of behavioral traits can be achieved with moderate numbers of DO animals, representing a significant advance in our ability to leverage the mouse as a tool for behavioral genetics
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Affiliation(s)
- R W Logan
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
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23
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Greco B, Managò F, Tucci V, Kao HT, Valtorta F, Benfenati F. Autism-related behavioral abnormalities in synapsin knockout mice. Behav Brain Res 2012; 251:65-74. [PMID: 23280234 PMCID: PMC3730181 DOI: 10.1016/j.bbr.2012.12.015] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 11/19/2012] [Accepted: 12/10/2012] [Indexed: 02/08/2023]
Abstract
Several synaptic genes predisposing to autism-spectrum disorder (ASD) have been identified. Nonsense and missense mutations in the SYN1 gene encoding for Synapsin I have been identified in families segregating for idiopathic epilepsy and ASD and genetic mapping analyses have identified variations in the SYN2 gene as significantly contributing to epilepsy predisposition. Synapsins (Syn I/II/III) are a multigene family of synaptic vesicle-associated phosphoproteins playing multiple roles in synaptic development, transmission and plasticity. Lack of SynI and/or SynII triggers a strong epileptic phenotype in mice associated with mild cognitive impairments that are also present in the non-epileptic SynIII(-/-) mice. SynII(-/-) and SynIII(-/-) mice also display schizophrenia-like traits, suggesting that Syns could be involved in the regulation of social behavior. Here, we studied social interaction and novelty, social recognition and social dominance, social transmission of food preference and social memory in groups of male SynI(-/-), SynII(-/-) and SynIII(-/-) mice before and after the appearance of the epileptic phenotype and compared their performances with control mice. We found that deletion of Syn isoforms widely impairs social behaviors and repetitive behaviors, resulting in ASD-related phenotypes. SynI or SynIII deletion altered social behavior, whereas SynII deletion extensively impaired various aspects of social behavior and memory, altered exploration of a novel environment and increased self-grooming. Social impairments of SynI(-/-) and SynII(-/-) mice were evident also before the onset of seizures. The results demonstrate an involvement of Syns in generation of the behavioral traits of ASD and identify Syn knockout mice as a useful experimental model of ASD and epilepsy.
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Affiliation(s)
- Barbara Greco
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy
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24
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Ayalew M, Le-Niculescu H, Levey DF, Jain N, Changala B, Patel SD, Winiger E, Breier A, Shekhar A, Amdur R, Koller D, Nurnberger JI, Corvin A, Geyer M, Tsuang MT, Salomon D, Schork NJ, Fanous AH, O'Donovan MC, Niculescu AB. Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction. Mol Psychiatry 2012; 17:887-905. [PMID: 22584867 PMCID: PMC3427857 DOI: 10.1038/mp.2012.37] [Citation(s) in RCA: 322] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 02/28/2012] [Accepted: 03/05/2012] [Indexed: 02/07/2023]
Abstract
We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein-coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology.
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Affiliation(s)
- M Ayalew
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Indianapolis VA Medical Center, Indianapolis, IN, USA
| | - H Le-Niculescu
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - D F Levey
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - N Jain
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - B Changala
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - S D Patel
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - E Winiger
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Breier
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Shekhar
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - R Amdur
- Washington DC VA Medical Center, Washington, DC, USA
| | - D Koller
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - J I Nurnberger
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Corvin
- Department of Psychiatry, Trinity College, Dublin, Ireland
| | - M Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - M T Tsuang
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - D Salomon
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - N J Schork
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - A H Fanous
- Washington DC VA Medical Center, Washington, DC, USA
| | - M C O'Donovan
- Department of Psychological Medicine, School of Medicine, Cardiff University, Cardiff, UK
| | - A B Niculescu
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Indianapolis VA Medical Center, Indianapolis, IN, USA
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Dyck BA, Tan ML, Daya RP, Basu D, Sookram CDR, Thomas N, Mishra RK. Behavioral effects of non-viral mediated RNA interference of synapsin II in the medial prefrontal cortex of the rat. Schizophr Res 2012; 137:32-8. [PMID: 22341900 DOI: 10.1016/j.schres.2012.01.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/20/2012] [Accepted: 01/24/2012] [Indexed: 02/08/2023]
Abstract
Synapsin II is a synaptic vesicle-associated phosphoprotein that has been implicated in the pathophysiology of schizophrenia. Researchers have demonstrated reductions in synapsin II mRNA and protein in post-mortem prefrontal cortex and hippocampus samples from patients with schizophrenia. Synapsin II protein expression has been shown to be regulated by dopamine D(1) and D(2) receptor activation. Furthermore, behavioral testing of the synapsin II knockout mouse has revealed a schizophrenic-like behavioral phenotype in this mutant strain, suggesting a relationship between dysregulated and/or reduced synapsin II and schizophrenia. However, it remains unknown the specific regions of the brain of which perturbations in synapsin II play a role in the pathophysiology of this disease. The aim of this project was to evaluate animals with a selective knock-down of synapsin II in the medial prefrontal cortex through the use of siRNA technology. Two weeks after continuous infusion of synapsin II siRNAs, animals were examined for the presence of a schizophrenic-like behavioral phenotype. Our results reveal that rats with selective reductions in medial prefrontal cortical synapsin II demonstrate deficits in sensorimotor gating (prepulse inhibition), hyperlocomotion, and reduced social behavior. These results implicate a role for decreased medial prefrontal cortical synapsin II levels in the pathophysiology of schizophrenia and the mechanisms of aberrant prefrontal cortical circuitry, and suggest that increasing synapsin II levels in the medial prefrontal cortex may potentially serve as a novel therapeutic target for this devastating disorder.
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Affiliation(s)
- Bailey A Dyck
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
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Wynder C, Stalker L, Doughty ML. Role of H3K4 demethylases in complex neurodevelopmental diseases. Epigenomics 2012; 2:407-18. [PMID: 22121901 DOI: 10.2217/epi.10.12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Significant neurological disorders can result from subtle perturbations of gene regulation that are often linked to epigenetic regulation. Proteins that regulate the methylation of lysine 4 of histone H3 (H3K4) and play a central role in epigenetic regulation, and mutations in genes encoding these enzymes have been identified in both autism and Rett syndrome. The H3K4 demethylases remove methyl groups from lysine 4 leading to loss of RNA polymerase binding and transcriptional repression. When these proteins are mutated, brain development is altered. Currently, little is known regarding how these gene regulators function at the genomic level. In this article, we will discuss findings that link H3K4 demethylases to neurodevelopment and neurological disease.
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Affiliation(s)
- Christopher Wynder
- McMaster Stem Cell & Cancer Institute, McMaster University, Hamilton, Ontario L8N 3Z5 Canada.
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Powell SB, Weber M, Geyer MA. Genetic models of sensorimotor gating: relevance to neuropsychiatric disorders. Curr Top Behav Neurosci 2012; 12:251-318. [PMID: 22367921 PMCID: PMC3357439 DOI: 10.1007/7854_2011_195] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sensorimotor gating, or the ability of a sensory event to suppress a motor response, can be measured operationally via prepulse inhibition (PPI) of the startle response. PPI is deficient in schizophrenia patients as well as other neuropsychiatric disorders, can be measured across species, and has been used widely as a translational tool in preclinical neuropharmacological and genetic research. First developed to assess drug effects in pharmacological and developmental models, PPI has become one of the standard behavioral measures in genetic models of schizophrenia and other neuropsychiatric disorders that exhibit PPI deficits. In this chapter we review the literature on genetic models of sensorimotor gating and discuss the utility of PPI as a tool in phenotyping mutant mouse models. We highlight the approaches to genetic mouse models of neuropsychiatric disease, discuss some of the important caveats to these approaches, and provide a comprehensive table covering the more recent genetic models that have evaluated PPI.
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Affiliation(s)
- Susan B. Powell
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc, 1 DNA Way, South San Francisco, CA 94080-4990, USA
| | - Mark A. Geyer
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Evidence for disease and antipsychotic medication effects in post-mortem brain from schizophrenia patients. Mol Psychiatry 2011; 16:1189-202. [PMID: 20921955 DOI: 10.1038/mp.2010.100] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Extensive research has been conducted on post-mortem brain tissue in schizophrenia (SCZ), particularly the dorsolateral prefrontal cortex (DLPFC). However, to what extent the reported changes are due to the disorder itself, and which are the cumulative effects of lifetime medication remains to be determined. In this study, we employed label-free liquid chromatography-mass spectrometry-based proteomic and proton nuclear magnetic resonance-based metabonomic profiling approaches to investigate DLPFC tissue from two cohorts of SCZ patients grouped according to their lifetime antipsychotic dose, together with tissue from bipolar disorder (BPD) subjects, and normal controls (n=10 per group). Both techniques showed profound changes in tissue from low-cumulative-medication SCZ subjects, but few changes in tissue from medium-cumulative-medication subjects. Protein expression changes were validated by Western blot and investigated further in a third group of subjects who were subjected to high-cumulative-medication over the course of their lifetime. Furthermore, key protein expression and metabolite level changes correlated significantly with lifetime antipsychotic dose. This suggests that the detected changes are present before antipsychotic therapy and, moreover, may be normalized with treatment. Overall, our analyses revealed novel protein and metabolite changes in low-cumulative-medication subjects associated with synaptogenesis, neuritic dynamics, presynaptic vesicle cycling, amino acid and glutamine metabolism, and energy buffering systems. Most of these markers were altered specifically in SCZ as determined by analysis of the same brain region from BPD patients.
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Dyck BA, Beyaert MGR, Ferro MA, Mishra RK. Medial prefrontal cortical synapsin II knock-down induces behavioral abnormalities in the rat: examining synapsin II in the pathophysiology of schizophrenia. Schizophr Res 2011; 130:250-9. [PMID: 21689907 DOI: 10.1016/j.schres.2011.05.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/17/2011] [Accepted: 05/19/2011] [Indexed: 01/11/2023]
Abstract
Synapsin II is a synaptic vesicle-associated phosphoprotein that has been implicated in the pathophysiology of schizophrenia. Studies have demonstrated reductions in synapsin II mRNA and protein in medial prefrontal cortical post-mortem samples from patients with schizophrenia, genetic associations between synapsin II and schizophrenia, and synapsin II protein regulation by dopamine receptor activation. Collectively, this research indicates a relationship between synapsin II dysregulation and schizophrenia; however, it remains unknown whether perturbations in synapsin II play a role in the pathophysiology of this disease. The aim of this project was to evaluate animals with selective knock-down of synapsin II in the medial prefrontal cortex. After continuous infusion of synapsin II antisense sequences, animals were examined for the presence of schizophrenic-like behavioral phenotypes and assessed on the response to clinically relevant antipsychotic drugs. Our results indicate that rats with selective reductions in medial prefrontal cortical synapsin II demonstrate deficits in sensorimotor gating (prepulse inhibition), reduced social behavior, and hyperlocomotion, which are corrected by the atypical antipsychotic drug olanzapine. Additionally, synapsin II knock-down disrupts serial search efficiency. These behavioral changes are accompanied by reductions in vesicular neurotransmitter transporter protein concentrations for glutamate (VGLUT1 and VGLUT2) and GABA (VGAT), without affecting dopamine (VMAT2). These results implicate a causal role for decreased synapsin II in the medial prefrontal cortex in the pathophysiology of schizophrenia and the mechanisms of aberrant prefrontal cortical circuitry, and suggest that synapsin II may potentially serve as a novel therapeutic target for this disorder.
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Affiliation(s)
- Bailey A Dyck
- Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, ON, Canada, L8N 3Z5
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Abstract
The possible role of the CB(2) receptor (CB(2)r) in psychiatric disorders has been considered. Several animal models use knockout (KO) mice that display schizophrenia-like behaviors and this study evaluated the role of CB(2)r in the regulation of such behaviors. Mice lacking the CB(2)r (CB(2)KO) were challenged in open field, light-dark box, elevated plus-maze, tail suspension, step down inhibitory avoidance, and pre-pulse inhibition tests (PPI). Furthermore, the effects of treatment with cocaine and risperidone were evaluated using the OF and the PPI test. Gene expression of dopamine D(2) (D(2)r), adrenergic-α(2C) (α(2C)r), serotonergic 5-HT(2A) and 5-HT(2C) receptors (5-HT(2A)r and 5-HT(2C)r) were studied by RT-PCR in brain regions related to schizophrenia. Deletion of CB(2)r decreased motor activity in the OF test, but enhanced response to acute cocaine and produced mood-related alterations, PPI deficit, and cognitive impairment. Chronic treatment with risperidone tended to impair PPI in WT mice, whereas it 'normalized' the PPI deficit in CB(2)KO mice. CB(2)KO mice presented increased D(2)r and α(2C)r gene expressions in the prefrontal cortex (PFC) and locus coeruleus (LC), decreased 5-HT(2C)r gene expression in the dorsal raphe (DR), and 5-HT(2A)r gene expression in the PFC. Chronic risperidone treatment in WT mice left α(2C)r gene expression unchanged, decreased D(2)r gene expression (15 μg/kg), and decreased 5-HT(2C)r and 5-HT(2A)r in PFC and DR. In CB(2)KO, the gene expression of D(2)r in the PFC, of α(2C)r in the LC, and of 5-HT(2C)r and 5-HT(2A)r in PFC was reduced; 5-HT(2C)r and 5-HT(2A)r gene expressions in DR were increased after treatment with risperidone. These results suggest that deletion of CB(2)r has a relation with schizophrenia-like behaviors. Pharmacological manipulation of CB(2)r may merit further study as a potential therapeutic target for the treatment of schizophrenia-related disorders.
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31
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Waites CL, Garner CC. Presynaptic function in health and disease. Trends Neurosci 2011; 34:326-37. [PMID: 21596448 DOI: 10.1016/j.tins.2011.03.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/14/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
Abstract
Neurons communicate with one another at specialized contact sites called synapses, composed of pre- and postsynaptic compartments. Presynaptic compartments, or 'boutons', signal to the postsynaptic compartment by releasing chemical neurotransmitter in response to incoming electrical impulses. Recent studies link defects in the function of presynaptic boutons to the etiology of several neurodevelopmental and neurodegenerative diseases, including autism, schizophrenia and Alzheimer's disease. In this review, we describe five core functions of presynaptic boutons and the molecules that mediate these functions, focusing on a subset that are linked to human disease. We also discuss potential mechanisms through which the loss or alteration of these specific molecules could lead to defects in synaptic communication, neural circuit function and, ultimately, cognition and behavior.
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Affiliation(s)
- Clarissa L Waites
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University School of Medicine, 1201 Welch Rd. Palo Alto, CA 94304-5485, USA
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Etholm L, Lindén H, Eken T, Heggelund P. Electroencephalographic characterization of seizure activity in the synapsin I/II double knockout mouse. Brain Res 2011; 1383:270-88. [DOI: 10.1016/j.brainres.2011.01.070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/20/2011] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
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33
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Fassio A, Patry L, Congia S, Onofri F, Piton A, Gauthier J, Pozzi D, Messa M, Defranchi E, Fadda M, Corradi A, Baldelli P, Lapointe L, St-Onge J, Meloche C, Mottron L, Valtorta F, Khoa Nguyen D, Rouleau GA, Benfenati F, Cossette P. SYN1 loss-of-function mutations in autism and partial epilepsy cause impaired synaptic function. Hum Mol Genet 2011; 20:2297-307. [PMID: 21441247 DOI: 10.1093/hmg/ddr122] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Several genes predisposing to autism spectrum disorders (ASDs) with or without epilepsy have been identified, many of which are implicated in synaptic function. Here we report a Q555X mutation in synapsin 1 (SYN1), an X-linked gene encoding for a neuron-specific phosphoprotein implicated in the regulation of neurotransmitter release and synaptogenesis. This nonsense mutation was found in all affected individuals from a large French-Canadian family segregating epilepsy and ASDs. Additional mutations in SYN1 (A51G, A550T and T567A) were found in 1.0 and 3.5% of French-Canadian individuals with autism and epilepsy, respectively. The majority of these SYN1 mutations were clustered in the proline-rich D-domain which is substrate of multiple protein kinases. When expressed in synapsin I (SynI) knockout (KO) neurons, all the D-domain mutants failed in rescuing the impairment in the size and trafficking of synaptic vesicle pools, whereas the wild-type human SynI fully reverted the KO phenotype. Moreover, the nonsense Q555X mutation had a dramatic impact on phosphorylation by MAPK/Erk and neurite outgrowth, whereas the missense A550T and T567A mutants displayed impaired targeting to nerve terminals. These results demonstrate that SYN1 is a novel predisposing gene to ASDs, in addition to epilepsy, and strengthen the hypothesis that a disturbance of synaptic homeostasis underlies the pathogenesis of both diseases.
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Affiliation(s)
- Anna Fassio
- Department of Experimental Medicine, National Institute of Neuroscience, University of Genova, Viale Benedetto XV 3, 16132 Genova, Italy
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Gabriele N, Pontoriero GF, Thomas N, Shethwala SK, Pristupa ZB, Gabriele JP. Knockdown of mortalin within the medial prefrontal cortex impairs normal sensorimotor gating. Synapse 2011; 64:808-13. [PMID: 20340173 DOI: 10.1002/syn.20794] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The 70-kDa mitochondrial heat shock protein, mortalin, is a ubiquitously expressed, multifunctional protein that is capable of binding the neurotransmitter, dopamine, within the brain. Dopamine dysregulation has been implicated in many of the abnormal neurological behaviors. Although studies have indicated that mortalin is differentially regulated in response to dopaminergic modulation, research has yet to elucidate the role of mortalin in the regulation of dopaminergic activity. This study seeks to investigate the role of mortalin in the regulation of dopamine-dependent behavior, specifically as it pertains to schizophrenia (SCZ). Mortalin expression was knocked down through the infusion of antisense oligodeoxynucleotide molecules into the medial prefrontal cortex (mPFC). Rats infused with mortalin antisense oligodeoxynucleotide molecules exhibited significant prepulse inhibition deficits, suggestive of defects in normal sensorimotor gating. Furthermore, mortalin misexpression within the mPFC was coupled to a significant increase in mortalin protein expression within the nucleus accumbens at the molecular level. These findings demonstrate that mortalin plays an essential role in the regulation of dopamine-dependent behavior and plays an even greater role in the pathogenesis of SCZ.
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Affiliation(s)
- Nicole Gabriele
- Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, Ontario, Canada
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35
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Lopez de Lara C, Jaitovich-Groisman I, Cruceanu C, Mamdani F, Lebel V, Yerko V, Beck A, Young LT, Rouleau G, Grof P, Alda M, Turecki G. Implication of synapse-related genes in bipolar disorder by linkage and gene expression analyses. Int J Neuropsychopharmacol 2010; 13:1397-410. [PMID: 20667171 PMCID: PMC3525668 DOI: 10.1017/s1461145710000714] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Several chromosomal regions have been linked to bipolar disorder (BD). However, the search for specific genes has been hampered by inconsistent findings, partly due to genetic and phenotypic heterogeneity. We focused on lithium-responsive bipolar patients, a subgroup thought to be more homogeneous and conducted a multistage study including an initial linkage study followed up by fine mapping and gene expression. Our sample consisted of 36 families (275 genotyped individuals, 132 affected) recruited through probands who were responders to long-term lithium treatment. We conducted a genome-wide scan with 811 microsatellite markers followed by fine mapping. Gene expression studies of candidate regions were conducted on six post-mortem prefrontal brain regions of 20 individuals (8 BD and 12 controls). We identified regions 3p25, 3p14 and 14q11 as showing the highest genome-wide linkage signal (LOD 2.53, 2.04 and 3.19, respectively). Fine mapping provided further support for 3p25, while only modest support was found in the other two regions. We identified a group of synaptic, mitochondrial and apoptotic genes with altered expression patterns in BD. Analysis of an independent microarray dataset supported the implication of synapse-related and mitochondrial genes in BD. In conclusion, using two complementary strategies, we found evidence of linkage to lithium-responsive BD on 3p25, 3p14 and 14q11 as well as significantly dysregulated genes on these regions suggesting altered synaptic and mitochondrial function in BD. Further studies are warranted to demonstrate the functional role of these genes in BD.
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RIM1alpha and interacting proteins involved in presynaptic plasticity mediate prepulse inhibition and additional behaviors linked to schizophrenia. J Neurosci 2010; 30:5326-33. [PMID: 20392954 DOI: 10.1523/jneurosci.0328-10.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Several presynaptic proteins involved in neurotransmitter release in the CNS have been implicated in schizophrenia in human clinical genetic studies, in postmortem studies, and in studies of putative animal models of schizophrenia. The presynaptic protein RIM1alpha mediates presynaptic plasticity and cognitive function. We now demonstrate that mice deficient in RIM1alpha exhibit abnormalities in multiple schizophrenia-relevant behavioral tasks including prepulse inhibition, response to psychotomimetic drugs, and social interaction. These schizophrenia-relevant behavioral findings are relatively selective to RIM1alpha-deficient mice, as mice bearing mutations in the RIM1alpha binding partners Rab3A or synaptotagmin 1 only show decreased prepulse inhibition. In addition to RIM1alpha's involvement in multiple behavioral abnormalities, these data suggest that alterations in presynaptic forms of short-term plasticity are linked to alterations in prepulse inhibition, a measure of sensorimotor gating.
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Coleman WL, Bykhovskaia M. Cooperative regulation of neurotransmitter release by Rab3a and synapsin II. Mol Cell Neurosci 2010; 44:190-200. [PMID: 20338242 DOI: 10.1016/j.mcn.2010.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 03/09/2010] [Accepted: 03/12/2010] [Indexed: 11/16/2022] Open
Abstract
To understand how the presynaptic proteins synapsin and Rab3a may interact in the regulation of the synaptic vesicle cycle and the release process, we derived a double knockout (DKO) mouse lacking both synapsin II and Rab3a. We found that Rab3a deletion rescued epileptic-like seizures typical for synapsin II gene deleted animals (Syn II(-)). Furthermore, action potential evoked release was drastically reduced in DKO synapses, although spontaneous release remained normal. At low Ca2+ conditions, quantal content was equally reduced in Rab3a(-) and DKO synapses, but as Ca2+ concentration increased, the increase in quantal content was more prominent in Rab3a(-). Electron microscopy analysis revealed that DKO synapses have a combined phenotype, with docked vesicles being reduced similar to Rab3a(-), and intraterminal vesicles being depleted similar to Syn II(-). Consistently, both Syn II(-) and DKO terminals had increased synaptic depression and incomplete recovery. Taken together, our results suggest that synapsin II and Rab3a have separate roles in maintaining the total store of synaptic vesicles and cooperate in promoting the latest steps of neuronal secretion.
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Affiliation(s)
- William L Coleman
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, USA
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O'Tuathaigh CMP, Kirby BP, Moran PM, Waddington JL. Mutant mouse models: genotype-phenotype relationships to negative symptoms in schizophrenia. Schizophr Bull 2010; 36:271-88. [PMID: 19934211 PMCID: PMC2833123 DOI: 10.1093/schbul/sbp125] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Negative symptoms encompass diminution in emotional expression and motivation, some of which relate to human attributes that may not be accessible readily in animals. Additionally, their refractoriness to treatment precludes therapeutic validation of putative models. This review considers critically the application of mutant mouse models to the study of the pathobiology of negative symptoms. It focuses on 4 main approaches: genes related to the pathobiology of schizophrenia, genes associated with risk for schizophrenia, neurodevelopmental-synaptic genes, and variant approaches from other areas of neurobiology. Despite rapid advances over the past several years, it is clear that we continue to face substantive challenges in applying mutant models to better understand the pathobiology of negative symptoms: the majority of evidence relates to impairments in social behavior, with only limited data relating to anhedonia and negligible data concerning avolition and other features; even for the most widely examined feature, social behavior, studies have used diverse assessments thereof; modelling must proceed in cognizance of increasing evidence that genes and pathobiologies implicated in schizophrenia overlap with other psychotic disorders, particularly bipolar disorder. Despite the caveats and challenges, several mutant lines evidence a phenotype for at least one index of social behavior. Though this may suggest superficially some shared relationship to negative symptoms, it is not yet possible to specify either the scope or the pathobiology of that relationship for any given gene. The breadth and depth of ongoing studies in mutants hold the prospect of addressing these shortcomings.
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Affiliation(s)
- Colm M. P. O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland,To whom correspondence should be addressed; tel: +353-1-402-2377, fax: +353-1-402-2453, e-mail:
| | - Brian P. Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Paula M. Moran
- School of Psychology, University of Nottingham, Nottingham, UK
| | - John L. Waddington
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland
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Balemans MC, Huibers MM, Eikelenboom NW, Kuipers AJ, van Summeren RC, Pijpers MM, Tachibana M, Shinkai Y, van Bokhoven H, Van der Zee CE. Reduced exploration, increased anxiety, and altered social behavior: Autistic-like features of euchromatin histone methyltransferase 1 heterozygous knockout mice. Behav Brain Res 2010; 208:47-55. [DOI: 10.1016/j.bbr.2009.11.008] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 10/27/2009] [Accepted: 11/01/2009] [Indexed: 11/16/2022]
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Mignogna P, Viggiano D. Brain distribution of genes related to changes in locomotor activity. Physiol Behav 2010; 99:618-26. [PMID: 20138074 DOI: 10.1016/j.physbeh.2010.01.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2009] [Revised: 11/19/2009] [Accepted: 01/26/2010] [Indexed: 02/09/2023]
Abstract
The relationship between genes and behavior, and particularly the hyperactive behavior, is clearly not linear nor monotonic. To address this problem, a database of the locomotor behavior obtained from thousands of mutant mice has been previously retrieved from the literature. Data showed that the percent of genes in the genome related to locomotor hyperactivity is probably more than 1.56%. These genes do not belong to a single neurotransmitter system or biochemical pathway. Indeed, they are probably required for the correct development of a specific neuronal network necessary to decrease locomotor activity. The present paper analyzes the brain expression pattern of the genes whose deletion is accompanied by changes in locomotor behavior. Using literature data concerning knockout mice, 46 genes whose deletion was accompanied by increased locomotor behavior, 24 genes related to decreased locomotor behavior and 23 genes not involved in locomotor behavior (but important for other brain functions) have been identified. These three groups of genes belonged to overlapping neurotransmitter systems or cellular functions. Therefore, we postulated that a better predictor of the locomotor behavior resulting from gene deletion might be the brain expression pattern. To this aim we correlated the brain expression of the genes and the locomotor activity resulting from the deletion of the same genes, using two databases (Allen Brain Atlas and SymAtlas). The results showed that the deletion of genes with higher expression level in the brain had higher probability to be accompanied by increased behavioral activity. Moreover the genes that were accompanied by locomotor hyperactivity when deleted, were more expressed in the cerebral cortex, amygdala and hippocampus compared to the genes unrelated to locomotor activity. Therefore, the prediction of the behavioral effect of a gene should take into consideration its brain distribution. Moreover, data confirmed that genes highly expressed in the brain are more likely to induce hyperactivity when deleted. Finally, it is suggested that gene mutations linked to specific behavioral abnormalities (e.g. inattention) might probably be associated to hyperactivity if the same gene has elevated brain expression.
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Affiliation(s)
- Pasquale Mignogna
- Department of Health Sciences, University of Molise, Campobasso, 86100, Italy
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Role of AP-2alpha transcription factor in the regulation of synapsin II gene expression by dopamine D1 and D2 receptors. J Mol Neurosci 2009; 41:267-77. [PMID: 19842069 DOI: 10.1007/s12031-009-9299-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 10/02/2009] [Indexed: 01/11/2023]
Abstract
Synapsins are a family of neuron-specific phosphoproteins involved in synaptic vesicle docking, synaptogenesis, and synaptic plasticity. Previous studies have reported an increase in synapsin II protein by dopaminergic agents in the striatum, medial prefrontal cortex, and nucleus accumbens. This study investigated the mechanistic pathway involved in synapsin II regulation by dopaminergic drugs using primary midbrain neurons to determine which of several transcription factors regulates synapsin II expression. Protein kinase A (PKA) participation in the signaling pathway was examined using selective PKA inhibitors, which reduced synapsin II expression in cell cultures while dopaminergic agents were unable to increase synapsin II in the presence of the PKA inhibitor. Transcription factor involvement was further investigated using separate cultures treated with antisense deoxyoligonucleotides (ADONs) against the following transcription factors: activating protein 2 alpha (AP-2alpha), early growth response factor 1 (EGR-1), or polyoma enhancer activator-3 (PEA-3). Selective knockdown of AP-2alpha by ADONs reduced synapsin II levels, whereas treatment with EGR-1 and PEA-3 ADONs did not affect synapsin II expression. Furthermore, dopaminergic agents were no longer able to influence synapsin II concentrations following AP-2alpha knockdown. Collectively, these results indicate that a cyclic adenosine-3',5'-monophosphate/PKA-dependent mechanism involving the AP-2alpha transcription factor is likely responsible for the increase in neuronal synapsin II following dopamine D1 receptor stimulation or dopamine D2 receptor inhibition.
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