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Sun Y, Li M, Geng J, Meng S, Tu R, Zhuang Y, Sun M, Rui M, Ou M, Xing G, Johnson TK, Xie W. Neuroligin 2 governs synaptic morphology and function through RACK1-cofilin signaling in Drosophila. Commun Biol 2023; 6:1056. [PMID: 37853189 PMCID: PMC10584876 DOI: 10.1038/s42003-023-05428-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023] Open
Abstract
Neuroligins are transmembrane cell adhesion proteins well-known for their genetic links to autism spectrum disorders. Neuroligins can function by regulating the actin cytoskeleton, however the factors and mechanisms involved are still largely unknown. Here, using the Drosophila neuromuscular junction as a model, we reveal that F-Actin assembly at the Drosophila NMJ is controlled through Cofilin signaling mediated by an interaction between DNlg2 and RACK1, factors not previously known to work together. The deletion of DNlg2 displays disrupted RACK1-Cofilin signaling pathway with diminished actin cytoskeleton proteo-stasis at the terminal of the NMJ, aberrant NMJ structure, reduced synaptic transmission, and abnormal locomotion at the third-instar larval stage. Overexpression of wildtype and activated Cofilin in muscles are sufficient to rescue the morphological and physiological defects in dnlg2 mutants, while inactivated Cofilin is not. Since the DNlg2 paralog DNlg1 is known to regulate F-actin assembly mainly via a specific interaction with WAVE complex, our present work suggests that the orchestration of F-actin by Neuroligins is a diverse and complex process critical for neural connectivity.
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Affiliation(s)
- Yichen Sun
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Moyi Li
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
- Jiangsu Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
| | - Junhua Geng
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Sibie Meng
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Renjun Tu
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Yan Zhuang
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Mingkuan Sun
- The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, 211166, China
| | - Menglong Rui
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Mengzhu Ou
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Guangling Xing
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
- Department of Biochemistry and Chemistry, and La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Wei Xie
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
- Jiangsu Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
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2
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Sadigurschi N, Scrift G, Hirrlinger J, Golan HM. Genetic impairment of folate metabolism regulates cortical interneurons and social behavior. Front Neurosci 2023; 17:1203262. [PMID: 37449270 PMCID: PMC10338116 DOI: 10.3389/fnins.2023.1203262] [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: 04/10/2023] [Accepted: 06/06/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction The implications of folate deficiency in neuropsychiatric disorders were demonstrated in numerous studies. Genetic deficiency in a key folate metabolism enzyme, MTHFR, is an example of the interaction between genetic and environmental risk factors: the maternal MTHFR deficiency governs in-utero nutrient availability, and the embryo's Mthfr genotype influences its ability to metabolize folates. Here, we explore how the maternal and offspring Mthfr genotypes affect cortical interneuron densities and distributions, mouse social outcome, and the relation of the different interneuron patterns to cortical excitability. Methods Two experiments were conducted to examine the effects of maternal and offspring Mthfr-KO heterozygosity. Mice were tested for direct social interactions (DSIs), repetitive behavior and cortical laminar distribution of interneuron populations expressing glutamate-decarboxylase-65, parvalbumin and somatostatin. Susceptibility to seizure was tested by exposure to pentylenetetrazole (PTZ). Results Maternal Mthfr+/- genotype was associated with suppressed social activities and reduced interneuron densities in all layers of the retrosplenial cortex (RSC). Somatostatin density and the somatostatin/parvalbumin ratio in the RSC and frontal cortex positively correlated with social behavior in the mice. An interaction between maternal and offspring Mthfr genotypes resulted in higher susceptibility of wild-type offspring to PTZ induced seizure. Discussion Maternal folate metabolism was shown to be critical to interneuron ontogenesis. Our results demonstrate that interneurons have a specific susceptibility to folate deficiency that may mediate folate's involvement in neuropsychiatric disease. The relations between cortical somatostatin interneuron patterns and social behavior highlight this subpopulation of interneurons as a target for further research.
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Affiliation(s)
- Noa Sadigurschi
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Gilad Scrift
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
- Department of Neurogenetics, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hava M. Golan
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- Azrieli National Center for Autism and Neurodevelopment Research, Ben-Gurion University of the Negev, Beer Sheva, Israel
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3
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Muellerleile J, Vnencak M, Sethi MVA, Jungenitz T, Schwarzacher SW, Jedlicka P. Increased Network Inhibition in the Dentate Gyrus of Adult Neuroligin-4 Knock-Out Mice. eNeuro 2023; 10:10/4/ENEURO.0471-22.2023. [PMID: 37080762 PMCID: PMC10121080 DOI: 10.1523/eneuro.0471-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/01/2023] [Accepted: 03/12/2023] [Indexed: 04/22/2023] Open
Abstract
Loss-of-function mutations in neuroligin-4 (Nlgn4), a member of the neuroligin family of postsynaptic adhesion proteins, cause autism spectrum disorder in humans. Nlgn4 knockout (KO) in mice leads to social behavior deficits and complex alterations of synaptic inhibition or excitation, depending on the brain region. In the present work, we comprehensively analyzed synaptic function and plasticity at the cellular and network levels in hippocampal dentate gyrus of Nlgn4 KO mice. Compared with wild-type littermates, adult Nlgn4 KO mice exhibited increased paired-pulse inhibition of dentate granule cell population spikes, but no impairments in excitatory synaptic transmission or short-term and long-term plasticity in vivo In vitro patch-clamp recordings in neonatal organotypic entorhino-hippocampal slice cultures from Nlgn4 KO and wild-type littermates revealed no significant differences in excitatory or inhibitory synaptic transmission, homeostatic synaptic plasticity, and passive electrotonic properties in dentate granule cells, suggesting that the increased inhibition in vivo is the result of altered network activity in the adult Nlgn4 KO. A comparison with prior studies on Nlgn 1-3 knock-out mice reveals that each of the four neuroligins exerts a characteristic effect on both intrinsic cellular and network activity in the dentate gyrus in vivo.
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Affiliation(s)
- Julia Muellerleile
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Faculty of Biosciences, Goethe University Frankfurt, 60439 Frankfurt am Main, Germany
| | - Matej Vnencak
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Mohammad Valeed Ahmed Sethi
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Tassilo Jungenitz
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
- Faculty of Medicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
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4
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Groisman AI, Aguilar-Arredondo A, Giacomini D, Schinder AF. Neuroligin-2 controls the establishment of fast GABAergic transmission in adult-born granule cells. Hippocampus 2023; 33:424-441. [PMID: 36709408 DOI: 10.1002/hipo.23505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/19/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
GABAergic inhibition is critical for the precision of neuronal spiking and the homeostatic regulation of network activity in the brain. Adult neurogenesis challenges network homeostasis because new granule cells (GCs) integrate continuously in the functional dentate gyrus. While developing, adult-born GCs undergo a transient state of enhanced excitability due to the delayed maturation of perisomatic GABAergic inhibition by parvalbumin interneurons (PV-INs). The mechanisms underlying this delayed synaptic maturation remain unknown. We examined the morphology and function of synapses formed by PV-INs onto new GCs over a 2-month interval in young adult mice, and investigated the influence of the synaptic adhesion molecule neuroligin-2 (NL2). Perisomatic appositions of PV-IN terminals onto new GCs were conspicuous at 2 weeks and continued to grow in size to reach a plateau over the fourth week. Postsynaptic knockdown of NL2 by expression of a short-hairpin RNA (shNL2) in new GCs resulted in smaller size of synaptic contacts, reduced area of perisomatic appositions of the vesicular GABA transporter VGAT, and the number of presynaptic active sites. GCs expressing shNL2 displayed spontaneous GABAergic responses with decreased frequency and amplitude, as well as slower kinetics compared to control GCs. In addition, postsynaptic responses evoked by optogenetic stimulation of PV-INs exhibited slow kinetics, increased paired-pulse ratio and coefficient of variation in GCs with NL2 knockdown, suggesting a reduction in the number of active synapses as well as in the probability of neurotransmitter release (Pr ). Our results demonstrate that synapses formed by PV-INs on adult-born GCs continue to develop beyond the point of anatomical growth, and require NL2 for the structural and functional maturation that accompanies the conversion into fast GABAergic transmission.
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Affiliation(s)
- Ayelén I Groisman
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | | | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
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5
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Boxer EE, Aoto J. Neurexins and their ligands at inhibitory synapses. Front Synaptic Neurosci 2022; 14:1087238. [PMID: 36618530 PMCID: PMC9812575 DOI: 10.3389/fnsyn.2022.1087238] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Since the discovery of neurexins (Nrxns) as essential and evolutionarily conserved synaptic adhesion molecules, focus has largely centered on their functional contributions to glutamatergic synapses. Recently, significant advances to our understanding of neurexin function at GABAergic synapses have revealed that neurexins can play pleiotropic roles in regulating inhibitory synapse maintenance and function in a brain-region and synapse-specific manner. GABAergic neurons are incredibly diverse, exhibiting distinct synaptic properties, sites of innervation, neuromodulation, and plasticity. Different classes of GABAergic neurons often express distinct repertoires of Nrxn isoforms that exhibit differential alternative exon usage. Further, Nrxn ligands can be differentially expressed and can display synapse-specific localization patterns, which may contribute to the formation of a complex trans-synaptic molecular code that establishes the properties of inhibitory synapse function and properties of local circuitry. In this review, we will discuss how Nrxns and their ligands sculpt synaptic inhibition in a brain-region, cell-type and synapse-specific manner.
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Affiliation(s)
| | - Jason Aoto
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Denver, CO, United States
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Liu X, Hua F, Yang D, Lin Y, Zhang L, Ying J, Sheng H, Wang X. Roles of neuroligins in central nervous system development: focus on glial neuroligins and neuron neuroligins. Lab Invest 2022; 20:418. [PMID: 36088343 PMCID: PMC9463862 DOI: 10.1186/s12967-022-03625-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/01/2022] [Indexed: 11/10/2022]
Abstract
Neuroligins are postsynaptic cell adhesion molecules that are relevant to many neurodevelopmental disorders. They are differentially enriched at the postsynapse and interact with their presynaptic ligands, neurexins, whose differential binding to neuroligins has been shown to regulate synaptogenesis, transmission, and other synaptic properties. The proper functioning of functional networks in the brain depends on the proper connection between neuronal synapses. Impaired synaptogenesis or synaptic transmission results in synaptic dysfunction, and these synaptic pathologies are the basis for many neurodevelopmental disorders. Deletions or mutations in the neuroligins genes have been found in patients with both autism and schizophrenia. It is because of the important role of neuroligins in synaptic connectivity and synaptic dysfunction that studies on neuroligins in the past have mainly focused on their expression in neurons. As studies on the expression of genes specific to various cells of the central nervous system deepened, neuroligins were found to be expressed in non-neuronal cells as well. In the central nervous system, glial cells are the most representative non-neuronal cells, which can also express neuroligins in large amounts, especially astrocytes and oligodendrocytes, and they are involved in the regulation of synaptic function, as are neuronal neuroligins. This review examines the mechanisms of neuron neuroligins and non-neuronal neuroligins in the central nervous system and also discusses the important role of neuroligins in the development of the central nervous system and neurodevelopmental disorders from the perspective of neuronal neuroligins and glial neuroligins.
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7
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Neuroligin-3 Regulates Excitatory Synaptic Transmission and EPSP-Spike Coupling in the Dentate Gyrus In Vivo. Mol Neurobiol 2021; 59:1098-1111. [PMID: 34845591 PMCID: PMC8857112 DOI: 10.1007/s12035-021-02663-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/22/2021] [Indexed: 11/27/2022]
Abstract
Neuroligin-3 (Nlgn3), a neuronal adhesion protein implicated in autism spectrum disorder (ASD), is expressed at excitatory and inhibitory postsynapses and hence may regulate neuronal excitation/inhibition balance. To test this hypothesis, we recorded field excitatory postsynaptic potentials (fEPSPs) in the dentate gyrus of Nlgn3 knockout (KO) and wild-type mice. Synaptic transmission evoked by perforant path stimulation was reduced in KO mice, but coupling of the fEPSP to the population spike was increased, suggesting a compensatory change in granule cell excitability. These findings closely resemble those in neuroligin-1 (Nlgn1) KO mice and could be partially explained by the reduction in Nlgn1 levels we observed in hippocampal synaptosomes from Nlgn3 KO mice. However, unlike Nlgn1, Nlgn3 is not necessary for long-term potentiation. We conclude that while Nlgn1 and Nlgn3 have distinct functions, both are required for intact synaptic transmission in the mouse dentate gyrus. Our results indicate that interactions between neuroligins may play an important role in regulating synaptic transmission and that ASD-related neuroligin mutations may also affect the synaptic availability of other neuroligins.
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8
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Lenz M, Eichler A, Kruse P, Muellerleile J, Deller T, Jedlicka P, Vlachos A. All-trans retinoic acid induces synaptopodin-dependent metaplasticity in mouse dentate granule cells. eLife 2021; 10:71983. [PMID: 34723795 PMCID: PMC8560091 DOI: 10.7554/elife.71983] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/15/2021] [Indexed: 12/27/2022] Open
Abstract
Previously we showed that the vitamin A metabolite all-trans retinoic acid (atRA) induces synaptic plasticity in acute brain slices prepared from the mouse and human neocortex (Lenz et al., 2021). Depending on the brain region studied, distinct effects of atRA on excitatory and inhibitory neurotransmission have been reported. Here, we used intraperitoneal injections of atRA (10 mg/kg) in adult C57BL/6J mice to study the effects of atRA on excitatory and inhibitory neurotransmission in the mouse fascia dentata—a brain region implicated in memory acquisition. No major changes in synaptic transmission were observed in the ventral hippocampus while a significant increase in both spontaneous excitatory postsynaptic current frequencies and synapse numbers were evident in the dorsal hippocampus 6 hr after atRA administration. The intrinsic properties of hippocampal dentate granule cells were not significantly different and hippocampal transcriptome analysis revealed no essential neuronal changes upon atRA treatment. In light of these findings, we tested for the metaplastic effects of atRA, that is, for its ability to modulate synaptic plasticity expression in the absence of major changes in baseline synaptic strength. Indeed, in vivo long-term potentiation (LTP) experiments demonstrated that systemic atRA treatment improves the ability of dentate granule cells to express LTP. The plasticity-promoting effects of atRA were not observed in synaptopodin-deficient mice, therefore, extending our previous results regarding the relevance of synaptopodin in atRA-mediated synaptic strengthening in the mouse prefrontal cortex. Taken together, our data show that atRA mediates synaptopodin-dependent metaplasticity in mouse dentate granule cells.
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Affiliation(s)
- Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Amelie Eichler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pia Kruse
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia Muellerleile
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany.,ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Giessen, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center Brain Links Brain Tools, University of Freiburg, Freiburg, Germany
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9
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Cruces-Solis H, Babaev O, Ali H, Piletti Chatain C, Mykytiuk V, Balekoglu N, Wenger S, Krueger-Burg D. Altered theta and beta oscillatory synchrony in a genetic mouse model of pathological anxiety. FASEB J 2021; 35:e21585. [PMID: 33960026 DOI: 10.1096/fj.202002028rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 11/11/2022]
Abstract
While the neural circuits mediating normal, adaptive defensive behaviors have been extensively studied, substantially less is currently known about the network mechanisms by which aberrant, pathological anxiety is encoded in the brain. Here we investigate in mice how deletion of Neuroligin-2 (Nlgn2), an inhibitory synapse-specific adhesion protein that has been associated with pathological anxiety and other psychiatric disorders, alters the communication between key brain regions involved in mediating defensive behaviors. To this end, we performed multi-site simultaneous local field potential (LFP) recordings from the basolateral amygdala (BLA), centromedial amygdala (CeM), bed nucleus of the stria terminalis (BNST), prefrontal cortex (mPFC) and ventral hippocampus (vHPC) in an open field paradigm. We found that LFP power in the vHPC was profoundly increased and was accompanied by an abnormal modulation of the synchrony of theta frequency oscillations particularly in the vHPC-mPFC-BLA circuit. Moreover, deletion of Nlgn2 increased beta and gamma frequency synchrony across the network, and this increase was associated with increased center avoidance. Local deletion of Nlgn2 in the vHPC and BLA revealed that they encode distinct aspects of this avoidance phenotype, with vHPC linked to immobility and BLA linked to a reduction in exploratory activity. Together, our data demonstrate that alterations in long-range functional connectivity link synaptic inhibition to abnormal defensive behaviors, and that both exaggerated activation of normal defensive circuits and recruitment of fundamentally distinct mechanisms contribute to this phenotype. Nlgn2 knockout mice therefore represent a highly relevant model to study the role of inhibitory synaptic transmission in the circuits underlying anxiety disorders.
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Affiliation(s)
- Hugo Cruces-Solis
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Olga Babaev
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Heba Ali
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Carolina Piletti Chatain
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Vasyl Mykytiuk
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Nursen Balekoglu
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Sally Wenger
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
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10
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Luo B, Liu Z, Lin D, Chen W, Ren D, Yu Z, Xiong M, Zhao C, Fei E, Li B. ErbB4 promotes inhibitory synapse formation by cell adhesion, independent of its kinase activity. Transl Psychiatry 2021; 11:361. [PMID: 34226493 PMCID: PMC8257755 DOI: 10.1038/s41398-021-01485-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 06/04/2021] [Accepted: 06/10/2021] [Indexed: 12/12/2022] Open
Abstract
The precise control of the nervous system function under the vitality of synapses is extremely critical. Efforts have been taken to explore the underlying cellular and molecular mechanisms for synapse formation. Cell adhesion molecules have been found important for synapse assembly in the brain. Many trans-adhesion complexes have been identified to modulate excitatory synapse formation. However, little is known about the synaptogenic mechanisms for inhibitory synapses. ErbB4 is a receptor tyrosine kinase enriched in interneurons. Here, we showed that overexpressing ErbB4 in HEK293T cells induced gephyrin or GABAAR α1 puncta in co-cultured primary hippocampal neurons. This induction of ErbB4 was independent of its kinase activity. K751M, a kinase-dead mutant of ErbB4, can also induce gephyrin or GABAAR α1 puncta in the co-culture system. We further constructed K751M knock-in mice and found that the homozygous were viable at birth and fertile without changes in gross brain structure. The number of interneurons and inhibitory synapses onto pyramidal neurons (PyNs) were comparable between K751M and wild-type mice but decreased in ErbB4-Null mice. Moreover, ErbB4 can interact in trans with Slitrk3, a transmembrane postsynaptic protein at inhibitory synapses, through the extracellular RLD domain of ErbB4. The deletion of RLD diminished the induction of gephyrin or GABAAR α1 puncta by ErbB4. Finally, disruption of ErbB4-Slitrk3 interaction through neutralization of Slitrk3 by secretable RLD decreased inhibitory synapses onto PyNs and impaired GABAergic transmission. These results identify that ErbB4, as a cell adhesion molecule, promotes inhibitory synapse formation onto PyNs by interacting with Slitrk3 and in a kinase-independent manner, providing an unexpected mechanism of ErbB4 in inhibitory synapse formation.
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Affiliation(s)
- Bin Luo
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Ziyang Liu
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Dong Lin
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Wenbing Chen
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Dongyan Ren
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Zheng Yu
- grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Mingtao Xiong
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Changqin Zhao
- grid.260463.50000 0001 2182 8825School of Life Sciences, Nanchang University, Nanchang, China ,grid.260463.50000 0001 2182 8825Institute of Life Science, Nanchang University, Nanchang, China
| | - Erkang Fei
- School of Life Sciences, Nanchang University, Nanchang, China. .,Institute of Life Science, Nanchang University, Nanchang, China.
| | - Baoming Li
- School of Life Sciences, Nanchang University, Nanchang, China. .,Institute of Life Science, Nanchang University, Nanchang, China. .,Department of Psychology and Institute of Brain Science, School of Education, Hangzhou Normal University, Hangzhou, China.
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11
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Cassel JC, Ferraris M, Quilichini P, Cholvin T, Boch L, Stephan A, Pereira de Vasconcelos A. The reuniens and rhomboid nuclei of the thalamus: A crossroads for cognition-relevant information processing? Neurosci Biobehav Rev 2021; 126:338-360. [PMID: 33766671 DOI: 10.1016/j.neubiorev.2021.03.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 01/29/2023]
Abstract
Over the past twenty years, the reuniens and rhomboid (ReRh) nuclei, which constitute the ventral midline thalamus, have received constantly growing attention. Since our first review article about the functional contributions of ReRh nuclei (Cassel et al., 2013), numerous (>80) important papers have extended anatomical knowledge, including at a developmental level, introduced new and very original electrophysiological insights on ReRh functions, and brought novel results on cognitive and non-cognitive implications of the ReRh. The current review will cover these recent articles, more on Re than on Rh, and their contribution will be approached according to their affiliation with work before 2013. These neuroanatomical, electrophysiological or behavioral findings appear coherent and point to the ReRh nuclei as two major components of a multistructural system supporting numerous cognitive (and non-cognitive) functions. They gate the flow of information, perhaps especially from the medial prefrontal cortex to the hippocampus and back, and coordinate activity and processing across these two (and possibly other) brain regions of major cognitive relevance.
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Affiliation(s)
- Jean-Christophe Cassel
- Laboratoire de Neurosciences Cognitives et Adaptatives, Université de Strasbourg, F-67000 Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000 Strasbourg, France.
| | - Maëva Ferraris
- Aix Marseille Université, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Pascale Quilichini
- Aix Marseille Université, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Thibault Cholvin
- Institute for Physiology I, University Clinics Freiburg, 79104 Freiburg, Germany
| | - Laurine Boch
- Laboratoire de Neurosciences Cognitives et Adaptatives, Université de Strasbourg, F-67000 Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000 Strasbourg, France
| | - Aline Stephan
- Laboratoire de Neurosciences Cognitives et Adaptatives, Université de Strasbourg, F-67000 Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000 Strasbourg, France
| | - Anne Pereira de Vasconcelos
- Laboratoire de Neurosciences Cognitives et Adaptatives, Université de Strasbourg, F-67000 Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000 Strasbourg, France
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12
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Albrecht A, Ben-Yishay E, Richter-Levin G. Behavioral profiling reveals an enhancement of dentate gyrus paired pulse inhibition in a rat model of PTSD. Mol Cell Neurosci 2021; 111:103601. [PMID: 33545324 DOI: 10.1016/j.mcn.2021.103601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 12/02/2020] [Accepted: 01/28/2021] [Indexed: 11/27/2022] Open
Abstract
We recently introduced behavioral profiling as a translational approach to increase the validity of animal models of posttraumatic stress disorder (PTSD). Behavioral profiling utilizes the response of a 'normal population' of control animals and compares the performance of animals with a history of traumatic stress in different behavioral tests that can capture PTSD-like symptoms. Thus, affected, PTSD-like individuals can be subdivided from resilient trauma-exposed animals. While in our recent study we focused mainly on tests for activity and anxiety, we now expand the behavioral tests battery and include also fear memory and extinction tasks as well as a spatial object recognition test in our behavioral profiling approach. Utilizing underwater trauma as the traumatic event, we found that only a small subset of animals exposed to underwater trauma showed lasting increases in anxiety-like behavior and heightened emotional memory formation. Adding juvenile stress as a model for childhood adversity increased the prevalence of such affected animals and furthermore and induced additional cognitive deficits in a subgroup of such emotionally affected individuals. In addition, multiple affected individual rats displayed increased local circuit activity in the dorsal dentate gyrus, as measured in vivo with paired pulse protocols in anesthetized animals. Together, our findings highlight behavioral profiling, refined by including multiple behavioral tests, as a valid tool to identify PTSD-like vs. resilient individual animals and further suggest that enhanced local inhibition in specific circuits of the dorsal dentate gyrus may be associated with the observed symptoms.
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Affiliation(s)
- Anne Albrecht
- Sagol Department of Neurobiology, University of Haifa, 199 Aba-Hushi Avenue, 3498838 Haifa, Israel; The Integrated Brain and Behavior Research Center (IBBRC), 199 Aba-Hushi Avenue, 3498838 Haifa, Israel; Institute of Anatomy, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany.
| | - Elhanan Ben-Yishay
- Sagol Department of Neurobiology, University of Haifa, 199 Aba-Hushi Avenue, 3498838 Haifa, Israel; The Integrated Brain and Behavior Research Center (IBBRC), 199 Aba-Hushi Avenue, 3498838 Haifa, Israel
| | - Gal Richter-Levin
- Sagol Department of Neurobiology, University of Haifa, 199 Aba-Hushi Avenue, 3498838 Haifa, Israel; The Integrated Brain and Behavior Research Center (IBBRC), 199 Aba-Hushi Avenue, 3498838 Haifa, Israel; Department of Psychology, University of Haifa, 199 Aba-Hushi Avenue, 3498838 Haifa, Israel
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13
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Ali H, Marth L, Krueger-Burg D. Neuroligin-2 as a central organizer of inhibitory synapses in health and disease. Sci Signal 2020; 13:13/663/eabd8379. [DOI: 10.1126/scisignal.abd8379] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Postsynaptic organizational protein complexes play central roles both in orchestrating synapse formation and in defining the functional properties of synaptic transmission that together shape the flow of information through neuronal networks. A key component of these organizational protein complexes is the family of synaptic adhesion proteins called neuroligins. Neuroligins form transsynaptic bridges with presynaptic neurexins to regulate various aspects of excitatory and inhibitory synaptic transmission. Neuroligin-2 (NLGN2) is the only member that acts exclusively at GABAergic inhibitory synapses. Altered expression and mutations in NLGN2 and several of its interacting partners are linked to cognitive and psychiatric disorders, including schizophrenia, autism, and anxiety. Research on NLGN2 has fundamentally shaped our understanding of the molecular architecture of inhibitory synapses. Here, we discuss the current knowledge on the molecular and cellular functions of mammalian NLGN2 and its role in the neuronal circuitry that regulates behavior in rodents and humans.
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Affiliation(s)
- Heba Ali
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Lena Marth
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075 Göttingen, Germany
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14
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Trobiani L, Meringolo M, Diamanti T, Bourne Y, Marchot P, Martella G, Dini L, Pisani A, De Jaco A, Bonsi P. The neuroligins and the synaptic pathway in Autism Spectrum Disorder. Neurosci Biobehav Rev 2020; 119:37-51. [PMID: 32991906 DOI: 10.1016/j.neubiorev.2020.09.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 12/13/2022]
Abstract
The genetics underlying autism spectrum disorder (ASD) is complex and heterogeneous, and de novo variants are found in genes converging in functional biological processes. Neuronal communication, including trans-synaptic signaling involving two families of cell-adhesion proteins, the presynaptic neurexins and the postsynaptic neuroligins, is one of the most recurrently affected pathways in ASD. Given the role of these proteins in determining synaptic function, abnormal synaptic plasticity and failure to establish proper synaptic contacts might represent mechanisms underlying risk of ASD. More than 30 mutations have been found in the neuroligin genes. Most of the resulting residue substitutions map in the extracellular, cholinesterase-like domain of the protein, and impair protein folding and trafficking. Conversely, the stalk and intracellular domains are less affected. Accordingly, several genetic animal models of ASD have been generated, showing behavioral and synaptic alterations. The aim of this review is to discuss the current knowledge on ASD-linked mutations in the neuroligin proteins and their effect on synaptic function, in various brain areas and circuits.
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Affiliation(s)
- Laura Trobiani
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Maria Meringolo
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Tamara Diamanti
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Yves Bourne
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Pascale Marchot
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Giuseppina Martella
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Luciana Dini
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Antonio Pisani
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Antonella De Jaco
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
| | - Paola Bonsi
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy.
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15
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Neuroligin 2 regulates absence seizures and behavioral arrests through GABAergic transmission within the thalamocortical circuitry. Nat Commun 2020; 11:3744. [PMID: 32719346 PMCID: PMC7385104 DOI: 10.1038/s41467-020-17560-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 07/08/2020] [Indexed: 12/20/2022] Open
Abstract
Epilepsy and autism spectrum disorders (ASD) are two distinct brain disorders but have a high rate of co-occurrence, suggesting shared pathogenic mechanisms. Neuroligins are cell adhesion molecules important in synaptic function and ASD, but their role in epilepsy remains unknown. In this study, we show that Neuroligin 2 (NLG2) knockout mice exhibit abnormal spike and wave discharges (SWDs) and behavioral arrests characteristic of absence seizures. The anti-absence seizure drug ethosuximide blocks SWDs and rescues behavioral arrests and social memory impairment in the knockout mice. Restoring GABAergic transmission either by optogenetic activation of the thalamic reticular nucleus (nRT) presynaptic terminals or postsynaptic NLG2 expression in the thalamic neurons reduces the SWDs and behavioral arrests in the knockout mice. These results indicate that NLG2-mediated GABAergic transmission at the nRT-thalamic circuit represents a common mechanism underlying both epileptic seizures and ASD. Neuroligins are postsynaptic cell adhesion molecules that are involved in synapse function and autism spectrum disorder. The authors show that NLG2-mediated GABAergic transmission at the thalamic reticular nucleus-thalamic circuit is a common mechanism underlying epileptic seizures and ASD.
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16
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Omidi G, Rezvani-Kamran A, Ganji A, Komaki S, Etaee F, Asadbegi M, Komaki A. Effects of Hypericum scabrum extract on dentate gyrus synaptic plasticity in high fat diet-fed rats. J Physiol Sci 2020; 70:19. [PMID: 32209056 PMCID: PMC7093352 DOI: 10.1186/s12576-020-00747-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 03/09/2020] [Indexed: 01/09/2023]
Abstract
High-fat diet (HFD) can induce deficits in neural function, oxidative stress, and decrease hippocampal neurogenesis. Hypericum (H.) scabrum extract (Ext) contains compounds that could treat neurological disorders. This study aimed to examine the neuroprotective impacts of the H. scabrum Ext on hippocampal synaptic plasticity in rats that were fed HFD. Fifty-four male Wistar rats (220 ± 10 g) were randomly arranged in six groups: (1) HFD group; (2) HFD + Ext300 group; (3) HFD + Ext100 group; (4) Control group; (5) Ext 300 mg/kg group; (6) Ext 100 mg/kg group. These protocols were administrated for 3 months. After this stage, a stimulating electrode was implanted in the perforant pathway (PP), and a bipolar recording electrode was embedded into the dentate gyrus (DG). Long-term potentiation (LTP) was provoked by high-frequency stimulation (HFS) of the PP. Field excitatory postsynaptic potentials (EPSP) and population spikes (PS) were recorded at 5, 30, and 60 min after HFS. The HFD group exhibited a large and significant decrease in their PS amplitude and EPSP slope as compared to the control and extract groups. In reverse, H. scabrum administration in the HFD + Ext rats reversed the effect of HFD on the PS amplitude and EPSP slope. The results of the study support that H. scabrum Ext can inhibit diminished synaptic plasticity caused by the HFD. These effects are probably due to the extreme antioxidant impacts of the Ext and its capability to scavenge free radicals.
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Affiliation(s)
- Ghazaleh Omidi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Arezoo Rezvani-Kamran
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Ahmad Ganji
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Somayeh Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Farshid Etaee
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Rahe Sabz Addiction Rehabilitation Clinic, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoumeh Asadbegi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran. .,Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 65178/518, Hamadan, Iran.
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17
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Troyano-Rodriguez E, Wirsig-Wiechmann CR, Ahmad M. Neuroligin-2 Determines Inhibitory Synaptic Transmission in the Lateral Septum to Optimize Stress-Induced Neuronal Activation and Avoidance Behavior. Biol Psychiatry 2019; 85:1046-1055. [PMID: 30878196 PMCID: PMC6555663 DOI: 10.1016/j.biopsych.2019.01.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Investigations in the neocortex have revealed that the balance of excitatory and inhibitory synaptic transmission (E/I ratio) is important for proper information processing. The disturbance of this balance underlies many neuropsychiatric illnesses, including autism spectrum disorder and schizophrenia. However, little is known about the contribution of E/I balance to the functioning of subcortical brain regions, such as the lateral septum (LS), a structure that plays important roles in regulating anxiety-related behavior. METHODS We manipulated E/I balance in the mouse LS by localized conditional deletion of neuroligin-2, a postsynaptic cell adhesion protein located at gamma-aminobutyric acidergic synapses and important for inhibitory synaptic transmission. We then performed analyses of synaptic transmission in the LS, stress-induced expression of immediate early gene c-fos, and anxiety-related and depression-related behavior. RESULTS The absence of neuroligin-2 in the LS in the mature mouse brain resulted in postsynaptic impairment of inhibitory synaptic transmission. Importantly, the reduced inhibition and resulting E/I imbalance decreased the responsiveness of LS neurons to stress. Furthermore, this E/I imbalance in the LS was associated with impaired stress-induced activation of downstream hypothalamic nuclei and reduced avoidance behavior of the animals in the elevated plus maze. CONCLUSIONS Our results described the synaptic function of neuroligin-2 in the LS, uncovered a positive association between c-Fos-expressing neurons in the LS and downstream hypothalamic areas and avoidance behavior, and demonstrated that intact inhibitory synaptic transmission and proper E/I balance are required for the optimal functioning of this subcortical circuit.
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Affiliation(s)
| | | | - Mohiuddin Ahmad
- Department of Cell Biology and Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
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18
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Chiou TT, Long P, Schumann-Gillett A, Kanamarlapudi V, Haas SA, Harvey K, O'Mara ML, De Blas AL, Kalscheuer VM, Harvey RJ. Mutation p.R356Q in the Collybistin Phosphoinositide Binding Site Is Associated With Mild Intellectual Disability. Front Mol Neurosci 2019; 12:60. [PMID: 30914922 PMCID: PMC6422930 DOI: 10.3389/fnmol.2019.00060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/19/2019] [Indexed: 11/13/2022] Open
Abstract
The recruitment of inhibitory GABAA receptors to neuronal synapses requires a complex interplay between receptors, neuroligins, the scaffolding protein gephyrin and the GDP-GTP exchange factor collybistin (CB). Collybistin is regulated by protein-protein interactions at the N-terminal SH3 domain, which can bind neuroligins 2/4 and the GABAAR α2 subunit. Collybistin also harbors a RhoGEF domain which mediates interactions with gephyrin and catalyzes GDP-GTP exchange on Cdc42. Lastly, collybistin has a pleckstrin homology (PH) domain, which binds phosphoinositides, such as phosphatidylinositol 3-phosphate (PI3P/PtdIns3P) and phosphatidylinositol 4-monophosphate (PI4P/PtdIns4P). PI3P located in early/sorting endosomes has recently been shown to regulate the postsynaptic clustering of gephyrin and GABAA receptors and consequently the strength of inhibitory synapses in cultured hippocampal neurons. This process is disrupted by mutations in the collybistin gene (ARHGEF9), which cause X-linked intellectual disability (XLID) by a variety of mechanisms converging on disrupted gephyrin and GABAA receptor clustering at central synapses. Here we report a novel missense mutation (chrX:62875607C>T, p.R356Q) in ARHGEF9 that affects one of the two paired arginine residues in the PH domain that were predicted to be vital for binding phosphoinositides. Functional assays revealed that recombinant collybistin CB3SH3- R356Q was deficient in PI3P binding and was not able to translocate EGFP-gephyrin to submembrane microaggregates in an in vitro clustering assay. Expression of the PI3P-binding mutants CB3SH3- R356Q and CB3SH3- R356N/R357N in cultured hippocampal neurones revealed that the mutant proteins did not accumulate at inhibitory synapses, but instead resulted in a clear decrease in the overall number of synaptic gephyrin clusters compared to controls. Molecular dynamics simulations suggest that the p.R356Q substitution influences PI3P binding by altering the range of structural conformations adopted by collybistin. Taken together, these results suggest that the p.R356Q mutation in ARHGEF9 is the underlying cause of XLID in the probands, disrupting gephyrin clustering at inhibitory GABAergic synapses via loss of collybistin PH domain phosphoinositide binding.
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Affiliation(s)
- Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Philip Long
- Department of Pharmacology, UCL School of Pharmacy, London, United Kingdom
| | | | | | - Stefan A Haas
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Kirsten Harvey
- Department of Pharmacology, UCL School of Pharmacy, London, United Kingdom
| | - Megan L O'Mara
- Research School of Chemistry, The Australian National University, Canberra, ACT, Australia
| | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Vera M Kalscheuer
- Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Robert J Harvey
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,Sunshine Coast Health Institute, Birtinya, QLD, Australia
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19
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Vnencak M, Schölvinck ML, Schwarzacher SW, Deller T, Willem M, Jedlicka P. Lack of β-amyloid cleaving enzyme-1 (BACE1) impairs long-term synaptic plasticity but enhances granule cell excitability and oscillatory activity in the dentate gyrus in vivo. Brain Struct Funct 2019; 224:1279-1290. [PMID: 30701309 DOI: 10.1007/s00429-019-01836-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 01/16/2019] [Indexed: 12/11/2022]
Abstract
BACE1 is a β-secretase involved in the cleavage of amyloid precursor protein and the pathogenesis of Alzheimer's disease (AD). The entorhinal cortex and the dentate gyrus are important for learning and memory, which are affected in the early stages of AD. Since BACE1 is a potential target for AD therapy, it is crucial to understand its physiological role in these brain regions. Here, we examined the function of BACE1 in the dentate gyrus. We show that loss of BACE1 in the dentate gyrus leads to increased granule cell excitability, indicated by enhanced efficiency of synaptic potentials to generate granule cell spikes. The increase in granule cell excitability was accompanied by prolonged paired-pulse inhibition, altered network gamma oscillations, and impaired synaptic plasticity at entorhinal-dentate synapses of the perforant path. In summary, this is the first detailed electrophysiological study of BACE1 deletion at the network level in vivo. The results suggest that BACE1 is important for normal dentate gyrus network function. This has implications for the use of BACE1 inhibitors as therapeutics for AD therapy, since BACE1 inhibition could similarly disrupt synaptic plasticity and excitability in the entorhinal-dentate circuitry.
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Affiliation(s)
- Matej Vnencak
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt am Main, Germany. .,Otorhinolaryngology, Head and Neck Surgery, Turku University Hospital, University of Turku, PL 52, 20521, Turku, Finland.
| | - Marieke L Schölvinck
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt am Main, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt am Main, Germany
| | - Michael Willem
- BioMedical Center, Biochemistry, Ludwig-Maximilians-University, Munich, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt am Main, Germany. .,ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Rudolf-Buchheim-Str. 6, 35392, Giessen, Germany.
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20
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Sorting nexin 27 rescues neuroligin 2 from lysosomal degradation to control inhibitory synapse number. Biochem J 2019; 476:293-306. [PMID: 30602588 DOI: 10.1042/bcj20180504] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 01/14/2023]
Abstract
Retromer is an evolutionarily conserved endosomal trafficking complex that mediates the retrieval of cargo proteins from a degradative pathway for sorting back to the cell surface. To promote cargo recycling, the core retromer trimer of VPS (vacuolar protein sorting)26, VPS29 and VPS35 recognises cargo either directly, or through an adaptor protein, the most well characterised of which is the PDZ [postsynaptic density 95 (PSD95), disk large, zona occludens] domain-containing sorting nexin SNX27. Neuroligins (NLGs) are postsynaptic trans-synaptic scaffold proteins that function in the clustering of postsynaptic proteins to maintain synaptic stability. Here, we show that each of the NLGs (NLG1-3) bind to SNX27 in a direct PDZ ligand-dependent manner. Depletion of SNX27 from neurons leads to a decrease in levels of each NLG protein and, for NLG2, this occurs as a result of enhanced lysosomal degradation. Notably, while depletion of the core retromer component VPS35 leads to a decrease in NLG1 and NLG3 levels, NLG2 is unaffected, suggesting that, for this cargo, SNX27 acts independently of retromer. Consistent with loss of SNX27 leading to enhanced lysosomal degradation of NLG2, knockdown of SNX27 results in fewer NLG2 clusters in cultured neurons, and loss of SNX27 or VPS35 reduces the size and number of gephyrin clusters. Together, these data indicate that NLGs are SNX27-retromer cargoes and suggest that SNX27-retromer controls inhibitory synapse number, at least in part through trafficking of NLG2.
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21
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Van Zandt M, Weiss E, Almyasheva A, Lipior S, Maisel S, Naegele JR. Adeno-associated viral overexpression of neuroligin 2 in the mouse hippocampus enhances GABAergic synapses and impairs hippocampal-dependent behaviors. Behav Brain Res 2018; 362:7-20. [PMID: 30605713 DOI: 10.1016/j.bbr.2018.12.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 12/14/2018] [Accepted: 12/29/2018] [Indexed: 10/27/2022]
Abstract
The cell adhesion molecule neuroligin2 (NLGN2) regulates GABAergic synapse development, but its role in neural circuit function in the adult hippocampus is unclear. We investigated GABAergic synapses and hippocampus-dependent behaviors following viral-vector-mediated overexpression of NLGN2. Transducing hippocampal neurons with AAV-NLGN2 increased neuronal expression of NLGN2 and membrane localization of GABAergic postsynaptic proteins gephyrin and GABAARγ2, and presynaptic vesicular GABA transporter protein (VGAT) suggesting trans-synaptic enhancement of GABAergic synapses. In contrast, glutamatergic postsynaptic density protein-95 (PSD-95) and presynaptic vesicular glutamate transporter (VGLUT) protein were unaltered. Moreover, AAV-NLGN2 significantly increased parvalbumin immunoreactive (PV+) synaptic boutons co-localized with postsynaptic gephyrin+ puncta. Furthermore, these changes were demonstrated to lead to cognitive impairments as shown in a battery of hippocampal-dependent mnemonic tasks and social behaviors.
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Affiliation(s)
- M Van Zandt
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States
| | - E Weiss
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States
| | - A Almyasheva
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States
| | - S Lipior
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States
| | - S Maisel
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States
| | - J R Naegele
- Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT, United States.
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22
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IgSF9b regulates anxiety behaviors through effects on centromedial amygdala inhibitory synapses. Nat Commun 2018; 9:5400. [PMID: 30573727 PMCID: PMC6302093 DOI: 10.1038/s41467-018-07762-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 11/21/2018] [Indexed: 02/06/2023] Open
Abstract
Abnormalities in synaptic inhibition play a critical role in psychiatric disorders, and accordingly, it is essential to understand the molecular mechanisms linking components of the inhibitory postsynapse to psychiatrically relevant neural circuits and behaviors. Here we study the role of IgSF9b, an adhesion protein that has been associated with affective disorders, in the amygdala anxiety circuitry. We show that deletion of IgSF9b normalizes anxiety-related behaviors and neural processing in mice lacking the synapse organizer Neuroligin-2 (Nlgn2), which was proposed to complex with IgSF9b. This normalization occurs through differential effects of Nlgn2 and IgSF9b at inhibitory synapses in the basal and centromedial amygdala (CeM), respectively. Moreover, deletion of IgSF9b in the CeM of adult Nlgn2 knockout mice has a prominent anxiolytic effect. Our data place IgSF9b as a key regulator of inhibition in the amygdala and indicate that IgSF9b-expressing synapses in the CeM may represent a target for anxiolytic therapies. IgSF9b is a synaptic adhesion protein that has been linked to psychiatric disorders. Here the authors show that deletion of IgSF9b regulates anxiety-like behaviour in mice by increasing inhibitory synaptic transmission in the centromedial amygdala.
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23
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Seok BS, Cao F, Bélanger-Nelson E, Provost C, Gibbs S, Jia Z, Mongrain V. The effect of Neuroligin-2 absence on sleep architecture and electroencephalographic activity in mice. Mol Brain 2018; 11:52. [PMID: 30231918 PMCID: PMC6146600 DOI: 10.1186/s13041-018-0394-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/06/2018] [Indexed: 02/06/2023] Open
Abstract
Sleep disorders are comorbid with most psychiatric disorders, but the link between these is not well understood. Neuroligin-2 (NLGN2) is a cell adhesion molecule that plays roles in synapse formation and neurotransmission. Moreover, NLGN2 has been associated with psychiatric disorders, but its implication in sleep remains underexplored. In the present study, the effect of Nlgn2 knockout (Nlgn2−/−) on sleep architecture and electroencephalographic (EEG) activity in mice has been investigated. The EEG and electromyogram (EMG) were recorded in Nlgn2−/− mice and littermates for 24 h from which three vigilance states (i.e., wakefulness, rapid eye movement [REM] sleep, non-REM [NREM] sleep) were visually identified. Spectral analysis of the EEG was performed for the three states. Nlgn2−/− mice showed more wakefulness and less NREM and REM sleep compared to wild-type (Nlgn2+/+) mice, especially during the dark period. This was accompanied by changes in the number and duration of individual episodes of wakefulness and sleep, indexing changes in state consolidation, as well as widespread changes in EEG spectral activity in all states. Abnormal ‘hypersynchronized’ EEG events have also been observed predominantly in Nlgn2−/− mice. These events were mainly observed during wakefulness and REM sleep. In addition, Nlgn2−/− mice showed alterations in the daily time course of NREM sleep delta (1–4 Hz) activity, pointing to modifications in the dynamics of sleep homeostasis. These data suggest that NLGN2 participates in the regulation of sleep duration as well as EEG activity during wakefulness and sleep.
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Affiliation(s)
- Bong Soo Seok
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada.,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada
| | | | - Erika Bélanger-Nelson
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada
| | - Chloé Provost
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada
| | - Steve Gibbs
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada.,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada
| | | | - Valérie Mongrain
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada. .,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada.
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Acupuncture Rescues Cognitive Impairment and Upregulates Dopamine- β-Hydroxylase Expression in Chronic Cerebral Hypoperfusion Rats. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5423961. [PMID: 30112399 PMCID: PMC6077593 DOI: 10.1155/2018/5423961] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/05/2018] [Accepted: 06/20/2018] [Indexed: 01/22/2023]
Abstract
Alteration of dopamine (DA) and noradrenaline (NA) contributes to cognitive function. Acupuncture has been shown to affect DA and NA in chronic cerebral hypoperfusion (CCH) rats. However, the effect of acupuncture on DA-β-hydroxylase (DBH), the biosynthetic enzyme of NA, remains unknown. In CCH rats we established chronic hypoperfusion by bilateral common carotid artery occlusion (two-vessel occlusion, 2VO) and treated them with acupuncture. Acupuncture displayed beneficial effects on hippocampus-dependent memory impairments, including nonspatial and spatial memory. That is also reflected in hippocampus long-term-potentiation (LTP). Moreover, DBH expression in the hippocampus and DBH activity in cerebrospinal fluid were upregulated after acupuncture treatment. In conclusion, these in vivo findings suggest that acupuncture exerts a therapeutic effect on hippocampus-dependent memory and hippocampus LTP in CCH rats, which may be partially related to the modulation of DBH in the hippocampus.
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Gamlin CR, Yu WQ, Wong ROL, Hoon M. Assembly and maintenance of GABAergic and Glycinergic circuits in the mammalian nervous system. Neural Dev 2018; 13:12. [PMID: 29875009 PMCID: PMC5991458 DOI: 10.1186/s13064-018-0109-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/06/2018] [Indexed: 12/19/2022] Open
Abstract
Inhibition in the central nervous systems (CNS) is mediated by two neurotransmitters: gamma-aminobutyric acid (GABA) and glycine. Inhibitory synapses are generally GABAergic or glycinergic, although there are synapses that co-release both neurotransmitter types. Compared to excitatory circuits, much less is known about the cellular and molecular mechanisms that regulate synaptic partner selection and wiring patterns of inhibitory circuits. Recent work, however, has begun to fill this gap in knowledge, providing deeper insight into whether GABAergic and glycinergic circuit assembly and maintenance rely on common or distinct mechanisms. Here we summarize and contrast the developmental mechanisms that regulate the selection of synaptic partners, and that promote the formation, refinement, maturation and maintenance of GABAergic and glycinergic synapses and their respective wiring patterns. We highlight how some parts of the CNS demonstrate developmental changes in the type of inhibitory transmitter or receptor composition at their inhibitory synapses. We also consider how perturbation of the development or maintenance of one type of inhibitory connection affects other inhibitory synapse types in the same circuit. Mechanistic insight into the development and maintenance of GABAergic and glycinergic inputs, and inputs that co-release both these neurotransmitters could help formulate comprehensive therapeutic strategies for treating disorders of synaptic inhibition.
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Affiliation(s)
- Clare R Gamlin
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Wan-Qing Yu
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Mrinalini Hoon
- Department of Biological Structure, University of Washington, Seattle, WA, USA. .,Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA.
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26
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Jiang DY, Wu Z, Forsyth CT, Hu Y, Yee SP, Chen G. GABAergic deficits and schizophrenia-like behaviors in a mouse model carrying patient-derived neuroligin-2 R215H mutation. Mol Brain 2018; 11:31. [PMID: 29859117 PMCID: PMC5984814 DOI: 10.1186/s13041-018-0375-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/24/2018] [Indexed: 01/03/2023] Open
Abstract
Schizophrenia (SCZ) is a severe mental disorder characterized by delusion, hallucination, and cognitive deficits. We have previously identified from schizophrenia patients a loss-of-function mutation Arg215→His215 (R215H) of neuroligin 2 (NLGN2) gene, which encodes a cell adhesion molecule critical for GABAergic synapse formation and function. Here, we generated a novel transgenic mouse line with neuroligin-2 (NL2) R215H mutation. The single point mutation caused a significant loss of NL2 protein in vivo, reduced GABAergic transmission, and impaired hippocampal activation. Importantly, R215H KI mice displayed anxiety-like behavior, impaired pre-pulse inhibition (PPI), cognition deficits and abnormal stress responses, recapitulating several key aspects of schizophrenia-like behaviors. Our results demonstrate a significant impact of a single point mutation NL2 R215H on brain functions, providing a novel animal model for the study of schizophrenia and neuropsychiatric disorders.
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Affiliation(s)
- Dong-Yun Jiang
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802 USA
| | - Zheng Wu
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802 USA
| | - Cody Tieu Forsyth
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802 USA
| | - Yi Hu
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802 USA
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health center, Farmington, CT 06030 USA
| | - Gong Chen
- Department of Biology, Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802 USA
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Wu M, Tian HL, Liu X, Lai JHC, Du S, Xia J. Impairment of Inhibitory Synapse Formation and Motor Behavior in Mice Lacking the NL2 Binding Partner LHFPL4/GARLH4. Cell Rep 2018; 23:1691-1705. [DOI: 10.1016/j.celrep.2018.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/26/2018] [Accepted: 04/02/2018] [Indexed: 12/25/2022] Open
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Monday HR, Younts TJ, Castillo PE. Long-Term Plasticity of Neurotransmitter Release: Emerging Mechanisms and Contributions to Brain Function and Disease. Annu Rev Neurosci 2018; 41:299-322. [PMID: 29709205 DOI: 10.1146/annurev-neuro-080317-062155] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Long-lasting changes of brain function in response to experience rely on diverse forms of activity-dependent synaptic plasticity. Chief among them are long-term potentiation and long-term depression of neurotransmitter release, which are widely expressed by excitatory and inhibitory synapses throughout the central nervous system and can dynamically regulate information flow in neural circuits. This review article explores recent advances in presynaptic long-term plasticity mechanisms and contributions to circuit function. Growing evidence indicates that presynaptic plasticity may involve structural changes, presynaptic protein synthesis, and transsynaptic signaling. Presynaptic long-term plasticity can alter the short-term dynamics of neurotransmitter release, thereby contributing to circuit computations such as novelty detection, modifications of the excitatory/inhibitory balance, and sensory adaptation. In addition, presynaptic long-term plasticity underlies forms of learning and its dysregulation participates in several neuropsychiatric conditions, including schizophrenia, autism, intellectual disabilities, neurodegenerative diseases, and drug abuse.
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Affiliation(s)
- Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
| | - Thomas J Younts
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
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Synaptic Plasticity and Excitation-Inhibition Balance in the Dentate Gyrus: Insights from In Vivo Recordings in Neuroligin-1, Neuroligin-2, and Collybistin Knockouts. Neural Plast 2018; 2018:6015753. [PMID: 29670649 PMCID: PMC5835277 DOI: 10.1155/2018/6015753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/02/2017] [Accepted: 12/11/2017] [Indexed: 01/29/2023] Open
Abstract
The hippocampal dentate gyrus plays a role in spatial learning and memory and is thought to encode differences between similar environments. The integrity of excitatory and inhibitory transmission and a fine balance between them is essential for efficient processing of information. Therefore, identification and functional characterization of crucial molecular players at excitatory and inhibitory inputs is critical for understanding the dentate gyrus function. In this minireview, we discuss recent studies unraveling molecular mechanisms of excitatory/inhibitory synaptic transmission, long-term synaptic plasticity, and dentate granule cell excitability in the hippocampus of live animals. We focus on the role of three major postsynaptic proteins localized at excitatory (neuroligin-1) and inhibitory synapses (neuroligin-2 and collybistin). In vivo recordings of field potentials have the advantage of characterizing the effects of the loss of these proteins on the input-output function of granule cells embedded in a network with intact connectivity. The lack of neuroligin-1 leads to deficient synaptic plasticity and reduced excitation but normal granule cell output, suggesting unaltered excitation-inhibition ratio. In contrast, the lack of neuroligin-2 and collybistin reduces inhibition resulting in a shift towards excitation of the dentate circuitry.
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Beining M, Mongiat LA, Schwarzacher SW, Cuntz H, Jedlicka P. T2N as a new tool for robust electrophysiological modeling demonstrated for mature and adult-born dentate granule cells. eLife 2017; 6:e26517. [PMID: 29165247 PMCID: PMC5737656 DOI: 10.7554/elife.26517] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 11/21/2017] [Indexed: 12/18/2022] Open
Abstract
Compartmental models are the theoretical tool of choice for understanding single neuron computations. However, many models are incomplete, built ad hoc and require tuning for each novel condition rendering them of limited usability. Here, we present T2N, a powerful interface to control NEURON with Matlab and TREES toolbox, which supports generating models stable over a broad range of reconstructed and synthetic morphologies. We illustrate this for a novel, highly detailed active model of dentate granule cells (GCs) replicating a wide palette of experiments from various labs. By implementing known differences in ion channel composition and morphology, our model reproduces data from mouse or rat, mature or adult-born GCs as well as pharmacological interventions and epileptic conditions. This work sets a new benchmark for detailed compartmental modeling. T2N is suitable for creating robust models useful for large-scale networks that could lead to novel predictions. We discuss possible T2N application in degeneracy studies.
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Affiliation(s)
- Marcel Beining
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck SocietyFrankfurtGermany
- Frankfurt Institute for Advanced StudiesFrankfurtGermany
- Institute of Clinical Neuroanatomy, Neuroscience CenterGoethe UniversityFrankfurtGermany
- Faculty of BiosciencesGoethe UniversityFrankfurtGermany
| | - Lucas Alberto Mongiat
- Instituto de Investigación en Biodiversidad y MedioambienteUniversidad Nacional del Comahue-CONICETSan Carlos de BarilocheArgentina
| | | | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck SocietyFrankfurtGermany
- Frankfurt Institute for Advanced StudiesFrankfurtGermany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience CenterGoethe UniversityFrankfurtGermany
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31
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Bauer S, van Alphen N, Becker A, Chiocchetti A, Deichmann R, Deller T, Freiman T, Freitag CM, Gehrig J, Hermsen AM, Jedlicka P, Kell C, Klein KM, Knake S, Kullmann DM, Liebner S, Norwood BA, Omigie D, Plate K, Reif A, Reif PS, Reiss Y, Roeper J, Ronellenfitsch MW, Schorge S, Schratt G, Schwarzacher SW, Steinbach JP, Strzelczyk A, Triesch J, Wagner M, Walker MC, von Wegner F, Rosenow F. Personalized translational epilepsy research - Novel approaches and future perspectives: Part II: Experimental and translational approaches. Epilepsy Behav 2017; 76:7-12. [PMID: 28917498 DOI: 10.1016/j.yebeh.2017.06.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 06/05/2017] [Indexed: 11/30/2022]
Abstract
Despite the availability of more than 15 new "antiepileptic drugs", the proportion of patients with pharmacoresistant epilepsy has remained constant at about 20-30%. Furthermore, no disease-modifying treatments shown to prevent the development of epilepsy following an initial precipitating brain injury or to reverse established epilepsy have been identified to date. This is likely in part due to the polyetiologic nature of epilepsy, which in turn requires personalized medicine approaches. Recent advances in imaging, pathology, genetics, and epigenetics have led to new pathophysiological concepts and the identification of monogenic causes of epilepsy. In the context of these advances, the First International Symposium on Personalized Translational Epilepsy Research (1st ISymPTER) was held in Frankfurt on September 8, 2016, to discuss novel approaches and future perspectives for personalized translational research. These included new developments and ideas in a range of experimental and clinical areas such as deep phenotyping, quantitative brain imaging, EEG/MEG-based analysis of network dysfunction, tissue-based translational studies, innate immunity mechanisms, microRNA as treatment targets, functional characterization of genetic variants in human cell models and rodent organotypic slice cultures, personalized treatment approaches for monogenic epilepsies, blood-brain barrier dysfunction, therapeutic focal tissue modification, computational modeling for target and biomarker identification, and cost analysis in (monogenic) disease and its treatment. This report on the meeting proceedings is aimed at stimulating much needed investments of time and resources in personalized translational epilepsy research. This Part II includes the experimental and translational approaches and a discussion of the future perspectives, while the diagnostic methods, EEG network analysis, biomarkers, and personalized treatment approaches were addressed in Part I [1].
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Affiliation(s)
- Sebastian Bauer
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Natascha van Alphen
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Albert Becker
- Institute for Neuropathology, University Bonn, 53105 Bonn, Germany
| | - Andreas Chiocchetti
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Ralf Deichmann
- Brain Imaging Center (BIC) Frankfurt, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Thomas Freiman
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Christine M Freitag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Johannes Gehrig
- Emmy-Noether Group Kell, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Anke M Hermsen
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Christian Kell
- Emmy-Noether Group Kell, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Karl Martin Klein
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Susanne Knake
- Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Dimitri M Kullmann
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Stefan Liebner
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Braxton A Norwood
- Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Diana Omigie
- Max-Planck-Institute for Empirical Aesthetics, 60322 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Karlheinz Plate
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Andreas Reif
- Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Philipp S Reif
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Yvonne Reiss
- Edinger-Institute Frankfurt, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Jochen Roeper
- Institute of Neurophysiology, Neuroscience Center, Goethe-University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Michael W Ronellenfitsch
- Dr. Senckenberg Institute for Neurooncology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Stephanie Schorge
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Gerhard Schratt
- Institute of Physiological Chemistry, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, 60590 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Joachim P Steinbach
- Dr. Senckenberg Institute for Neurooncology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Adam Strzelczyk
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Jochen Triesch
- Frankfurt Institute for Advanced Studies (FIAS), 60438 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Marlies Wagner
- Institute of Neuroradiology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Matthew C Walker
- Institute of Neurology, University College London (UCL), London WC1E 6BT, United Kingdom
| | - Frederic von Wegner
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1)
| | - Felix Rosenow
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, Goethe University Frankfurt, 60528 Frankfurt, Germany; Epilepsy Center Marburg, Department of Neurology, Philipps-University Marburg, 35043 Marburg, Germany; Center for Personalized Translational Epilepsy Research (CePTER), 60528 Frankfurt, Germany(1).
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Krueger-Burg D, Papadopoulos T, Brose N. Organizers of inhibitory synapses come of age. Curr Opin Neurobiol 2017; 45:66-77. [DOI: 10.1016/j.conb.2017.04.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022]
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Loss of Neuroligin3 specifically downregulates retinal GABAAα2 receptors without abolishing direction selectivity. PLoS One 2017; 12:e0181011. [PMID: 28708891 PMCID: PMC5510863 DOI: 10.1371/journal.pone.0181011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 06/23/2017] [Indexed: 11/19/2022] Open
Abstract
The postsynaptic adhesion proteins Neuroligins (NLs) are essential for proper synapse function, and their alterations are associated with a variety of neurodevelopmental disorders. It is increasingly clear that each NL isoform occupies specific subsets of synapses and is able to regulate the function of discrete networks. Studies of NL2 and NL4 in the retina in particular have contributed towards uncovering their role in inhibitory synapse function. In this study we show that NL3 is also predominantly expressed at inhibitory postsynapses in the retinal inner plexiform layer (IPL), where it colocalizes with both GABAA- and glycinergic receptor clusters in a 3:2 ratio. In the NL3 deletion-mutant (knockout or KO) mouse, we uncovered a dramatic reduction of the number of GABAAα2-subunit containing GABAA receptor clusters at the IPL. Retinal activity was thereafter assessed in KO and wild-type (WT) littermates by multi-electrode-array recordings of the output cells of retina, the retinal ganglion cells (RGCs). RGCs in the NL3 KO showed reduced spontaneous activity and an altered response to white noise stimulation. Moreover, upon application of light flashes, the proportion of cells firing at light offset (OFF RGCs) was significantly lower in the NL3 KO compared to WT littermates, whereas the relative number of cells firing at light onset (ON RGCs) increased. Interestingly, although GABAAα2-bearing receptors have been related to direction-selective circuits of the retina, features of direction selective-retinal ganglion cells recorded remained unperturbed in the NL3 KO. Together our data underscore the importance of NL3 for the integrity of specific GABAAergic retinal circuits and identifies NL3 as an important regulator of retinal activity.
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Endres K, Deller T. Regulation of Alpha-Secretase ADAM10 In vitro and In vivo: Genetic, Epigenetic, and Protein-Based Mechanisms. Front Mol Neurosci 2017; 10:56. [PMID: 28367112 PMCID: PMC5355436 DOI: 10.3389/fnmol.2017.00056] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/20/2017] [Indexed: 12/21/2022] Open
Abstract
ADAM10 (A Disintegrin and Metalloproteinase 10) has been identified as the major physiological alpha-secretase in neurons, responsible for cleaving APP in a non-amyloidogenic manner. This cleavage results in the production of a neuroprotective APP-derived fragment, APPs-alpha, and an attenuated production of neurotoxic A-beta peptides. An increase in ADAM10 activity shifts the balance of APP processing toward APPs-alpha and protects the brain from amyloid deposition and disease. Thus, increasing ADAM10 activity has been proposed an attractive target for the treatment of neurodegenerative diseases and it appears to be timely to investigate the physiological mechanisms regulating ADAM10 expression. Therefore, in this article, we will (1) review reports on the physiological regulation of ADAM10 at the transcriptional level, by epigenetic factors, miRNAs and/or protein interactions, (2) describe conditions, which change ADAM10 expression in vitro and in vivo, (3) report how neuronal ADAM10 expression may be regulated in humans, and (4) discuss how this knowledge on the physiological and pathophysiological regulation of ADAM10 may help to preserve or restore brain function.
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Affiliation(s)
- Kristina Endres
- Clinic of Psychiatry and Psychotherapy, University Medical Center Johannes Gutenberg-University Mainz Mainz, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt/Main, Germany
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Conditional ablation of neuroligin-1 in CA1 pyramidal neurons blocks LTP by a cell-autonomous NMDA receptor-independent mechanism. Mol Psychiatry 2017; 22:375-383. [PMID: 27217145 PMCID: PMC5122464 DOI: 10.1038/mp.2016.80] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/26/2016] [Accepted: 03/02/2016] [Indexed: 02/05/2023]
Abstract
Neuroligins are postsynaptic cell-adhesion molecules implicated in autism and other neuropsychiatric disorders. Despite extensive work, the role of neuroligins in synapse function and plasticity, especially N-methyl-d-aspartate (NMDA) receptor (NMDAR)-dependent long-term potentiation (LTP), remains unclear. To establish which synaptic functions unequivocally require neuroligins, we analyzed single and triple conditional knockout (cKO) mice for all three major neuroligin isoforms (NL1-NL3). We inactivated neuroligins by stereotactic viral expression of Cre-recombinase in hippocampal CA1 region pyramidal neurons at postnatal day 0 (P0) or day 21 (P21) and measured synaptic function, synaptic plasticity and spine numbers in acute hippocampal slices 2-3 weeks later. Surprisingly, we find that ablation of neuroligins in newborn or juvenile mice only modestly impaired basal synaptic function in hippocampus and caused no alteration in postsynaptic spine numbers. However, triple cKO of NL1-NL3 or single cKO of NL1 impaired NMDAR-mediated excitatory postsynaptic currents and abolished NMDAR-dependent LTP. Strikingly, the NL1 cKO also abolished LTP elicited by activation of L-type Ca2+-channels during blockade of NMDARs. These findings demonstrate that neuroligins are generally not essential for synapse formation in CA1 pyramidal neurons but shape synaptic properties and that NL1 specifically is required for LTP induced by postsynaptic Ca2+-elevations, a function which may contribute to the pathophysiological role of neuroligins in brain disorders.
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Bezaire MJ, Raikov I, Burk K, Vyas D, Soltesz I. Interneuronal mechanisms of hippocampal theta oscillations in a full-scale model of the rodent CA1 circuit. eLife 2016; 5:e18566. [PMID: 28009257 DOI: 10.7554/elife.18566.001] [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] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 12/15/2016] [Indexed: 05/25/2023] Open
Abstract
The hippocampal theta rhythm plays important roles in information processing; however, the mechanisms of its generation are not well understood. We developed a data-driven, supercomputer-based, full-scale (1:1) model of the rodent CA1 area and studied its interneurons during theta oscillations. Theta rhythm with phase-locked gamma oscillations and phase-preferential discharges of distinct interneuronal types spontaneously emerged from the isolated CA1 circuit without rhythmic inputs. Perturbation experiments identified parvalbumin-expressing interneurons and neurogliaform cells, as well as interneuronal diversity itself, as important factors in theta generation. These simulations reveal new insights into the spatiotemporal organization of the CA1 circuit during theta oscillations.
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Affiliation(s)
- Marianne J Bezaire
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Ivan Raikov
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
- Department of Neurosurgery, Stanford University, Stanford, United States
| | - Kelly Burk
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Dhrumil Vyas
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, United States
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Bezaire MJ, Raikov I, Burk K, Vyas D, Soltesz I. Interneuronal mechanisms of hippocampal theta oscillations in a full-scale model of the rodent CA1 circuit. eLife 2016; 5. [PMID: 28009257 PMCID: PMC5313080 DOI: 10.7554/elife.18566] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 12/15/2016] [Indexed: 12/16/2022] Open
Abstract
The hippocampal theta rhythm plays important roles in information processing; however, the mechanisms of its generation are not well understood. We developed a data-driven, supercomputer-based, full-scale (1:1) model of the rodent CA1 area and studied its interneurons during theta oscillations. Theta rhythm with phase-locked gamma oscillations and phase-preferential discharges of distinct interneuronal types spontaneously emerged from the isolated CA1 circuit without rhythmic inputs. Perturbation experiments identified parvalbumin-expressing interneurons and neurogliaform cells, as well as interneuronal diversity itself, as important factors in theta generation. These simulations reveal new insights into the spatiotemporal organization of the CA1 circuit during theta oscillations. DOI:http://dx.doi.org/10.7554/eLife.18566.001
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Affiliation(s)
- Marianne J Bezaire
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Ivan Raikov
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States.,Department of Neurosurgery, Stanford University, Stanford, United States
| | - Kelly Burk
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Dhrumil Vyas
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, United States
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Fekete CD, Goz RU, Dinallo S, Miralles CP, Chiou TT, Bear J, Fiondella CG, LoTurco JJ, De Blas AL. In vivo transgenic expression of collybistin in neurons of the rat cerebral cortex. J Comp Neurol 2016; 525:1291-1311. [PMID: 27804142 DOI: 10.1002/cne.24137] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 01/12/2023]
Abstract
Collybistin (CB) is a guanine nucleotide exchange factor selectively localized to γ-aminobutyric acid (GABA)ergic and glycinergic postsynapses. Active CB interacts with gephyrin, inducing the submembranous clustering and the postsynaptic accumulation of gephyrin, which is a scaffold protein that recruits GABAA receptors (GABAA Rs) at the postsynapse. CB is expressed with or without a src homology 3 (SH3) domain. We have previously reported the effects on GABAergic synapses of the acute overexpression of CBSH3- or CBSH3+ in cultured hippocampal (HP) neurons. In the present communication, we are studying the effects on GABAergic synapses after chronic in vivo transgenic expression of CB2SH3- or CB2SH3+ in neurons of the adult rat cerebral cortex. The embryonic precursors of these cortical neurons were in utero electroporated with CBSH3- or CBSH3+ DNAs, migrated to the appropriate cortical layer, and became integrated in cortical circuits. The results show that: 1) the strength of inhibitory synapses in vivo can be enhanced by increasing the expression of CB in neurons; and 2) there are significant differences in the results between in vivo and in culture studies. J. Comp. Neurol. 525:1291-1311, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Christopher D Fekete
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Roman U Goz
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Sean Dinallo
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Celia P Miralles
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - John Bear
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Christopher G Fiondella
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Joseph J LoTurco
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
| | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, 06269
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Feng P, Akladious AA, Hu Y. Hippocampal and motor fronto-cortical neuroligin1 is increased in an animal model of depression. Psychiatry Res 2016; 243:210-8. [PMID: 27423632 DOI: 10.1016/j.psychres.2016.06.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/09/2016] [Accepted: 06/26/2016] [Indexed: 01/04/2023]
Abstract
Neuroligins (NLGNs) regulate synaptic excitability, neuronal signaling and sleep. We hypothesize that alteration of NLGNs is involved in the pathology of depression and tested the hypothesis in a model of depression using Wistar Kyoto (WKy) rat and its control, the Wistar (Wis) rat. We first evaluated behavioral deficits using the forced swim test and then characterized alterations of NLGN1 and NLGN2 with RT-PCR and Western Blotting in the prefrontal cortex, motor frontal cortex and hippocampus. Compared with controls of Wis rats, (1) the WKy rats had significantly shorter swim time and longer immobile time; (2) NLGN1 mRNA levels was higher in the motor frontal cortex and hippocampus in the WKy model; (3) NLGN1 protein was significantly higher in the motor frontal cortex, the prefrontal cortex and the hippocampus in the WKy model; (4) NLGN2 mRNA was significantly higher in the motor frontal cortex but significantly lower in the hippocampus in the WKy model. We concluded that NLGN1 gene and protein expression is higher in the motor frontal cortex, hippocampus and in the prefrontal cortex in the WKy rats suggesting that alterations of NLGN1 is involved in the pathology of depression but need to be further evaluated in human.
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Affiliation(s)
- Pingfu Feng
- Louis Stokes Cleveland DVA Medical Center, Cleveland, OH, USA; Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| | | | - Yufen Hu
- Louis Stokes Cleveland DVA Medical Center, Cleveland, OH, USA; Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Alvarez FJ. Gephyrin and the regulation of synaptic strength and dynamics at glycinergic inhibitory synapses. Brain Res Bull 2016; 129:50-65. [PMID: 27612963 DOI: 10.1016/j.brainresbull.2016.09.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/23/2016] [Accepted: 09/05/2016] [Indexed: 01/23/2023]
Abstract
Glycinergic synapses predominate in brainstem and spinal cord where they modulate motor and sensory processing. Their postsynaptic mechanisms have been considered rather simple because they lack a large variety of glycine receptor isoforms and have relatively simple postsynaptic densities at the ultrastructural level. However, this simplicity is misleading being their postsynaptic regions regulated by a variety of complex mechanisms controlling the efficacy of synaptic inhibition. Early studies suggested that glycinergic inhibitory strength and dynamics depend largely on structural features rather than on molecular complexity. These include regulation of the number of postsynaptic glycine receptors, their localization and the amount of co-localized GABAA receptors and GABA-glycine co-transmission. These properties we now know are under the control of gephyrin. Gephyrin is the first postsynaptic scaffolding protein ever discovered and it was recently found to display a large degree of variation and regulation by splice variants, posttranslational modifications, intracellular trafficking and interactions with the underlying cytoskeleton. Many of these mechanisms are governed by converging excitatory activity and regulate gephyrin oligomerization and receptor binding, the architecture of the postsynaptic density (and by extension the whole synaptic complex), receptor retention and stability. These newly uncovered molecular mechanisms define the size and number of gephyrin postsynaptic regions and the numbers and proportions of glycine and GABAA receptors contained within. All together, they control the emergence of glycinergic synapses of different strength and temporal properties to best match the excitatory drive received by each individual neuron or local dendritic compartment.
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Affiliation(s)
- Francisco J Alvarez
- Department of Physiology, Emory University, Atlanta, GA 30322-3110, United States.
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Su J, Chen J, Lippold K, Monavarfeshani A, Carrillo GL, Jenkins R, Fox MA. Collagen-derived matricryptins promote inhibitory nerve terminal formation in the developing neocortex. J Cell Biol 2016; 212:721-36. [PMID: 26975851 PMCID: PMC4792079 DOI: 10.1083/jcb.201509085] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Inhibitory synapses comprise only ∼20% of the total synapses in the mammalian brain but play essential roles in controlling neuronal activity. In fact, perturbing inhibitory synapses is associated with complex brain disorders, such as schizophrenia and epilepsy. Although many types of inhibitory synapses exist, these disorders have been strongly linked to defects in inhibitory synapses formed by Parvalbumin-expressing interneurons. Here, we discovered a novel role for an unconventional collagen-collagen XIX-in the formation of Parvalbumin(+) inhibitory synapses. Loss of this collagen results not only in decreased inhibitory synapse number, but also in the acquisition of schizophrenia-related behaviors. Mechanistically, these studies reveal that a proteolytically released fragment of this collagen, termed a matricryptin, promotes the assembly of inhibitory nerve terminals through integrin receptors. Collectively, these studies not only identify roles for collagen-derived matricryptins in cortical circuit formation, but they also reveal a novel paracrine mechanism that regulates the assembly of these synapses.
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Affiliation(s)
- Jianmin Su
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016
| | - Jiang Chen
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016
| | - Kumiko Lippold
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016
| | - Aboozar Monavarfeshani
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016 Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | | | - Rachel Jenkins
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Michael A Fox
- Virginia Tech Carilion Research Institute, Roanoke, VA 24016 Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
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NPY+-, but not PV+- GABAergic neurons mediated long-range inhibition from infra- to prelimbic cortex. Transl Psychiatry 2016; 6:e736. [PMID: 26882036 PMCID: PMC4872436 DOI: 10.1038/tp.2016.7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/22/2015] [Accepted: 01/14/2016] [Indexed: 01/10/2023] Open
Abstract
Anxiety disorders are thought to reflect deficits in the regulation of fear memories. While the amygdala has long been considered a site of storage of fear memories, newer findings suggest that the prefrontal cortex (PFC) is essential in the regulation of amygdala-dependent memories and fear expression. Here, activation of the prelimbic cortex (PrL) enhances the expression of fear, while an elevated activity in the infralimbic cortex (IL) enhances fear extinction. Despite the presence of these facts, we still know very little about the synaptic interconnectivity within the PFC. The aim of the present study was to investigate the inhibitory circuits between prelimbic and IL using morphological and electrophysiological methods. Our immunohistochemical analysis revealed that the distribution of PV(+)- and NPY(+)-GABAergic neurons was strikingly different within the PFC. In addition, we provided the first experimental evidence that the pyramidal neurons in the PrL received a direct inhibitory input mediated by bipolar NPY(+)-GABAergic projection neurons in the IL. Deletion of the anxiety-related neuroligin 2 gene caused a decrease of this direct synaptic inhibition that originated from the IL. Thus, our data suggested that activation of the IL might not only directly activate the corresponding downstream anxiolytic pathway, but also suppress the PrL-related anxiogenic pathway and thus could differentially bias the regulation of fear expression and extinction.
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O'Sullivan GA, Jedlicka P, Chen HX, Kalbouneh H, Ippolito A, Deller T, Nawrotzki RA, Kuhse J, Kalaidzidis YL, Kirsch J, Schwarzacher SW, Betz H. Forebrain-specific loss of synaptic GABAA receptors results in altered neuronal excitability and synaptic plasticity in mice. Mol Cell Neurosci 2016; 72:101-13. [PMID: 26829712 DOI: 10.1016/j.mcn.2016.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 11/16/2015] [Accepted: 01/25/2016] [Indexed: 10/22/2022] Open
Abstract
Mutations that result in the defective trafficking of γ2 subunit containing GABAA receptors (γ2-GABAARs) are known to reduce synaptic inhibition. Whether perturbed clustering of non-mutated GABAARs similarly reduces synaptic inhibition in vivo is less clear. In this study we provide evidence that the loss of postsynaptic γ2-GABAARs upon postnatal ablation of gephyrin, the major scaffolding protein of inhibitory postsynapses, from mature principal neurons within the forebrain results in reduced induction of long-term potentiation (LTP) and impaired network excitability within the hippocampal dentate gyrus. The preferential reduction in not only synaptic γ2-GABAAR cluster number at dendritic sites but also the decrease in γ2-GABAAR density within individual clusters at dendritic inhibitory synapses suggests that distal synapses are more sensitive to the loss of gephyrin expression than proximal synapses. The fact that these mice display behavioural features of anxiety and epilepsy emphasises the importance of postsynaptic γ2-GABAAR clustering for synaptic inhibition.
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Affiliation(s)
- Gregory A O'Sullivan
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstrasse 46, 60318 Frankfurt/Main, Germany; Max-Planck-Institute of Cell Biology & Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, 60590 Frankfurt/Main, Germany
| | - Hong-Xing Chen
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstrasse 46, 60318 Frankfurt/Main, Germany
| | - Heba Kalbouneh
- Institute of Anatomy & Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Angelo Ippolito
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, 60590 Frankfurt/Main, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, 60590 Frankfurt/Main, Germany
| | - Ralph A Nawrotzki
- Institute of Anatomy & Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Jochen Kuhse
- Institute of Anatomy & Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Yannis L Kalaidzidis
- Max-Planck-Institute of Cell Biology & Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Joachim Kirsch
- Institute of Anatomy & Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Stephan W Schwarzacher
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, 60590 Frankfurt/Main, Germany
| | - Heinrich Betz
- Department of Neurochemistry, Max-Planck-Institute for Brain Research, Deutschordenstrasse 46, 60318 Frankfurt/Main, Germany
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Ko J, Choii G, Um JW. The balancing act of GABAergic synapse organizers. Trends Mol Med 2016; 21:256-68. [PMID: 25824541 DOI: 10.1016/j.molmed.2015.01.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/25/2015] [Accepted: 01/27/2015] [Indexed: 12/14/2022]
Abstract
GABA (γ-aminobutyric acid) is the main neurotransmitter at inhibitory synapses in the mammalian brain. It is essential for maintaining the excitation and inhibition (E/I) ratio, whose imbalance underlies various brain diseases. Emerging information about inhibitory synapse organizers provides a novel molecular framework for understanding E/I balance at the synapse, circuit, and systems levels. This review highlights recent advances in deciphering these components of the inhibitory synapse and their roles in the development, transmission, and circuit properties of inhibitory synapses. We also discuss how their dysfunction may lead to a variety of brain disorders, suggesting new therapeutic strategies based on balancing the E/I ratio.
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Zhang B, Chen LY, Liu X, Maxeiner S, Lee SJ, Gokce O, Südhof TC. Neuroligins Sculpt Cerebellar Purkinje-Cell Circuits by Differential Control of Distinct Classes of Synapses. Neuron 2015; 87:781-96. [PMID: 26291161 DOI: 10.1016/j.neuron.2015.07.020] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 05/25/2015] [Accepted: 07/22/2015] [Indexed: 10/23/2022]
Abstract
Neuroligins are postsynaptic cell-adhesion molecules that bind presynaptic neurexins and are genetically linked to autism. Neuroligins are proposed to organize synaptogenesis and/or synaptic transmission, but no systematic analysis of neuroligins in a defined circuit is available. Here, we show that conditional deletion of all neuroligins in cerebellar Purkinje cells caused loss of distal climbing-fiber synapses and weakened climbing-fiber but not parallel-fiber synapses, consistent with alternative use of neuroligins and cerebellins as neurexin ligands for the excitatory climbing-fiber versus parallel-fiber synapses. Moreover, deletion of neuroligins increased the size of inhibitory basket/stellate-cell synapses but simultaneously severely impaired their function. Multiple neuroligin isoforms differentially contributed to climbing-fiber and basket/stellate-cell synapse functions, such that inhibitory synapse-specific neuroligin-2 was unexpectedly essential for maintaining normal climbing-fiber synapse numbers. Using systematic analyses of all neuroligins in a defined neural circuit, our data thus show that neuroligins differentially contribute to various Purkinje-cell synapses in the cerebellum in vivo.
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Affiliation(s)
- Bo Zhang
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA
| | - Lulu Y Chen
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA
| | - Xinran Liu
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Stephan Maxeiner
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA
| | - Sung-Jin Lee
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA
| | - Ozgun Gokce
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Room G1021, Stanford, CA 94305, USA.
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Salehi I, Karamian R, Komaki A, Tahmasebi L, Taheri M, Nazari M, Shahidi S, Sarihi A. Effects of vitamin E on lead-induced impairments in hippocampal synaptic plasticity. Brain Res 2015; 1629:270-81. [PMID: 26462654 DOI: 10.1016/j.brainres.2015.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/20/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
Abstract
Lead (Pb) exposure during development is associated with impaired cognitive function and long-term potentiation (LTP). Vitamin E (VE) is an antioxidant that could have protective effects against Pb intoxication. In this study, we examined the protective effects of vitamin E against Pb-induced LTP impairments. Forty-six adult male Wistar rats were randomly divided into 6 treatment groups: (1) control; (2) Pb exposure; (3) VE; (4) Pb +VE; (5) Pb exposure followed by VE 2 months after exposure; (6) VE followed by Pb exposure 1 month after treatment. Rats were exposed to Pb through daily consumption of Pb-contaminated distilled water; VE was administered by daily gavage for 3 months. After this period, the population spike (PS) amplitudes and the slopes of excitatory postsynaptic potentials (EPSPs) were measured in the dentate gyrus (DG) area of the hippocampus in adult rats in response to electrical stimulation applied to the perforant pathway in vivo. Blood samples were also collected to evaluate malondialdehyde (MDA) levels, total antioxidant capacity (TAC), and total oxidant status (TOS). Biochemical analyses demonstrated significant increases in plasma MDA and TOS levels in the Pb-exposed group compared to the control group. VE-protected groups revealed significant increases in TAC levels. Our results demonstrate that Pb decreased EPSP slopes and PS amplitudes compared to the control group, whereas VE increased these parameters compared to the control group. Co-administration of VE with Pb exposure inhibited Pb-induced effects. These findings suggest that VE via its antioxidant activity reverses Pb-induced impairments of synaptic plasticity in the DG.
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Affiliation(s)
- Iraj Salehi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Ruhollah Karamian
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Lida Tahmasebi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoumeh Taheri
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoumeh Nazari
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Siamak Shahidi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
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47
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Hammer M, Krueger-Burg D, Tuffy LP, Cooper BH, Taschenberger H, Goswami SP, Ehrenreich H, Jonas P, Varoqueaux F, Rhee JS, Brose N. Perturbed Hippocampal Synaptic Inhibition and γ-Oscillations in a Neuroligin-4 Knockout Mouse Model of Autism. Cell Rep 2015; 13:516-523. [PMID: 26456829 PMCID: PMC5862414 DOI: 10.1016/j.celrep.2015.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/23/2015] [Accepted: 09/02/2015] [Indexed: 12/02/2022] Open
Abstract
Loss-of-function mutations in the synaptic adhesion protein Neuroligin-4 are among the most common genetic abnormalities associated with autism spectrum disorders, but little is known about the function of Neuroligin-4 and the consequences of its loss. We assessed synaptic and network characteristics in Neuroligin-4 knockout mice, focusing on the hippocampus as a model brain region with a critical role in cognition and memory, and found that Neuroligin-4 deletion causes subtle defects of the protein composition and function of GABAergic synapses in the hippocampal CA3 region. Interestingly, these subtle synaptic changes are accompanied by pronounced perturbations of γ-oscillatory network activity, which has been implicated in cognitive function and is altered in multiple psychiatric and neurodevelopmental disorders. Our data provide important insights into the mechanisms by which Neuroligin-4-dependent GABAergic synapses may contribute to autism phenotypes and indicate new strategies for therapeutic approaches.
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Affiliation(s)
- Matthieu Hammer
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Liam Patrick Tuffy
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Benjamin Hillman Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Holger Taschenberger
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Sarit Pati Goswami
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Peter Jonas
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Frederique Varoqueaux
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
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48
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Javdani F, Holló K, Hegedűs K, Kis G, Hegyi Z, Dócs K, Kasugai Y, Fukazawa Y, Shigemoto R, Antal M. Differential expression patterns of K(+) /Cl(-) cotransporter 2 in neurons within the superficial spinal dorsal horn of rats. J Comp Neurol 2015; 523:1967-83. [PMID: 25764511 DOI: 10.1002/cne.23774] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 01/21/2023]
Abstract
γ-Aminobutyric acid (GABA)- and glycine-mediated hyperpolarizing inhibition is associated with a chloride influx that depends on the inwardly directed chloride electrochemical gradient. In neurons, the extrusion of chloride from the cytosol primarily depends on the expression of an isoform of potassium-chloride cotransporters (KCC2s). KCC2 is crucial in the regulation of the inhibitory tone of neural circuits, including pain processing neural assemblies. Thus we investigated the cellular distribution of KCC2 in neurons underlying pain processing in the superficial spinal dorsal horn of rats by using high-resolution immunocytochemical methods. We demonstrated that perikarya and dendrites widely expressed KCC2, but axon terminals proved to be negative for KCC2. In single ultrathin sections, silver deposits labeling KCC2 molecules showed different densities on the surface of dendritic profiles, some of which were negative for KCC2. In freeze fracture replicas and tissue sections double stained for the β3-subunit of GABAA receptors and KCC2, GABAA receptors were revealed on dendritic segments with high and also with low KCC2 densities. By measuring the distances between spots immunoreactive for gephyrin (a scaffolding protein of GABAA and glycine receptors) and KCC2 on the surface of neurokinin 1 (NK1) receptor-immunoreactive dendrites, we found that gephyrin-immunoreactive spots were located at various distances from KCC2 cotransporters; 5.7 % of them were recovered in the middle of 4-10-µm-long dendritic segments that were free of KCC2 immunostaining. The variable local densities of KCC2 may result in variable postsynaptic potentials evoked by the activation of GABAA and glycine receptors along the dendrites of spinal neurons.
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Affiliation(s)
- Fariba Javdani
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Krisztina Holló
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Krisztina Hegedűs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Gréta Kis
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Zoltán Hegyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Klaudia Dócs
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Yu Kasugai
- Department of Pharmacology, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Yugo Fukazawa
- Division of Cell Biology and Neuroscience, Faculty of Medical Sciences, University of Fukui, Yoshida, 910-1193, Japan
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria, Klosterneuburg, 3400, Austria
| | - Miklós Antal
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
- MTA-DE Neuroscience Research Group, Debrecen, 4012, Hungary
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49
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Alterations in Brain Inflammation, Synaptic Proteins, and Adult Hippocampal Neurogenesis during Epileptogenesis in Mice Lacking Synapsin2. PLoS One 2015; 10:e0132366. [PMID: 26177381 PMCID: PMC4503715 DOI: 10.1371/journal.pone.0132366] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/12/2015] [Indexed: 01/27/2023] Open
Abstract
Synapsins are pre-synaptic vesicle-associated proteins linked to the pathogenesis of epilepsy through genetic association studies in humans. Deletion of synapsins causes an excitatory/inhibitory imbalance, exemplified by the epileptic phenotype of synapsin knockout mice. These mice develop handling-induced tonic-clonic seizures starting at the age of about 3 months. Hence, they provide an opportunity to study epileptogenic alterations in a temporally controlled manner. Here, we evaluated brain inflammation, synaptic protein expression, and adult hippocampal neurogenesis in the epileptogenic (1 and 2 months of age) and tonic-clonic (3.5-4 months) phase of synapsin 2 knockout mice using immunohistochemical and biochemical assays. In the epileptogenic phase, region-specific microglial activation was evident, accompanied by an increase in the chemokine receptor CX3CR1, interleukin-6, and tumor necrosis factor-α, and a decrease in chemokine keratinocyte chemoattractant/ growth-related oncogene. Both post-synaptic density-95 and gephyrin, scaffolding proteins at excitatory and inhibitory synapses, respectively, showed a significant up-regulation primarily in the cortex. Furthermore, we observed an increase in the inhibitory adhesion molecules neuroligin-2 and neurofascin and potassium chloride co-transporter KCC2. Decreased expression of γ-aminobutyric acid receptor-δ subunit and cholecystokinin was also evident. Surprisingly, hippocampal neurogenesis was reduced in the epileptogenic phase. Taken together, we report molecular alterations in brain inflammation and excitatory/inhibitory balance that could serve as potential targets for therapeutics and diagnostic biomarkers. In addition, the regional differences in brain inflammation and synaptic protein expression indicate an epileptogenic zone from where the generalized seizures in synapsin 2 knockout mice may be initiated or spread.
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50
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Karamian R, Komaki A, Salehi I, Tahmasebi L, Komaki H, Shahidi S, Sarihi A. Vitamin C reverses lead-induced deficits in hippocampal synaptic plasticity in rats. Brain Res Bull 2015; 116:7-15. [DOI: 10.1016/j.brainresbull.2015.05.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 04/11/2015] [Accepted: 05/08/2015] [Indexed: 12/11/2022]
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