51
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Van Berkel AA, Koopmans F, Gonzalez-Lozano MA, Lammertse HCA, Feringa F, Bryois J, Sullivan PF, Smit AB, Toonen RF, Verhage M. Dysregulation of synaptic and developmental transcriptomic/proteomic profiles upon depletion of MUNC18-1. eNeuro 2022; 9:ENEURO.0186-22.2022. [PMID: 36257704 PMCID: PMC9668351 DOI: 10.1523/eneuro.0186-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/27/2022] [Accepted: 07/14/2022] [Indexed: 11/23/2022] Open
Abstract
Absence of presynaptic protein MUNC18-1 (gene: Stxbp1) leads to neuronal cell death at an immature stage before synapse formation. Here, we performed transcriptomic and proteomic profiling of immature Stxbp1 knockout (KO) cells to discover which cellular processes depend on MUNC18-1. Hippocampi of Stxbp1 KO mice showed cell-type specific dysregulation of 2123 transcripts primarily related to synaptic transmission and immune response. To further investigate direct, neuron-specific effects of MUNC18-1 depletion, a proteomic screen was performed on murine neuronal cultures at two developmental timepoints prior to onset of neuron degeneration. 399 proteins were differentially expressed, which were primarily involved in synaptic function (especially synaptic vesicle exocytosis) and neuron development. We further show that many of the downregulated proteins upon loss of MUNC18-1 are normally upregulated during this developmental stage. Thus, absence of MUNC18-1 extensively dysregulates the transcriptome and proteome, primarily affecting synaptic and developmental profiles. Lack of synaptic activity is unlikely to underlie these effects, as the changes were observed in immature neurons without functional synapses, and minimal overlap was found to activity-dependent proteins. We hypothesize that presence of MUNC18-1 is essential to advance neuron development, serving as a 'checkpoint' for neurons to initiate cell death in its absence.Significance StatementPresynaptic protein MUNC18-1 is essential for neuronal functioning. Pathogenic variants in its gene, STXBP1, are among the most common found in patients with developmental delay and epilepsy. To discern the pathogenesis in these patients, a thorough understanding of MUNC18-1's function in neurons is required. Here, we show that loss of MUNC18-1 results in extensive dysregulation of synaptic and developmental proteins in immature neurons before synapse formation. Many of the downregulated proteins are normally upregulated during this developmental stage. This indicates that MUNC18-1 is a critical regulator of neuronal development, which could play an important role in the pathogenesis of STXBP1 variant carriers.
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Affiliation(s)
- A A Van Berkel
- Dept. Functional Genomics, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
- Functional Genomics, Department of Human Genetics, CNCR, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
| | - F Koopmans
- Dept. Functional Genomics, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
- Dept. Molecular & Cellular Neurobiology, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - M A Gonzalez-Lozano
- Dept. Molecular & Cellular Neurobiology, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - H C A Lammertse
- Dept. Functional Genomics, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
- Functional Genomics, Department of Human Genetics, CNCR, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
| | - F Feringa
- Functional Genomics, Department of Human Genetics, CNCR, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
| | - J Bryois
- Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Nobels vag 12A, 171 77 Stockholm, Sweden
| | - P F Sullivan
- UNC Center for Psychiatric Genomics, University of North Carolina at Chapel Hill, 101 Manning Drive, Chapel Hill, NC 27599-7160, USA
- Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Nobels vag 12A, 171 77 Stockholm, Sweden
| | - A B Smit
- Dept. Molecular & Cellular Neurobiology, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - R F Toonen
- Dept. Functional Genomics, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - M Verhage
- Dept. Functional Genomics, CNCR, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
- Functional Genomics, Department of Human Genetics, CNCR, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
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52
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Simmons DH, Busch SE, Titley HK, Grasselli G, Shih J, Du X, Wei C, Gomez CM, Piochon C, Hansel C. Sensory Over-responsivity and Aberrant Plasticity in Cerebellar Cortex in a Mouse Model of Syndromic Autism. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2022; 2:450-459. [PMID: 36324646 PMCID: PMC9616247 DOI: 10.1016/j.bpsgos.2021.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/15/2021] [Accepted: 09/17/2021] [Indexed: 11/28/2022] Open
Abstract
Background Patients with autism spectrum disorder often show altered responses to sensory stimuli as well as motor deficits, including an impairment of delay eyeblink conditioning, which involves integration of sensory signals in the cerebellum. Here, we identify abnormalities in parallel fiber (PF) and climbing fiber (CF) signaling in the mouse cerebellar cortex that may contribute to these pathologies. Methods We used a mouse model for the human 15q11-13 duplication (patDp/+) and studied responses to sensory stimuli in Purkinje cells from awake mice using two-photon imaging of GCaMP6f signals. Moreover, we examined synaptic transmission and plasticity using in vitro electrophysiological, immunohistochemical, and confocal microscopic techniques. Results We found that spontaneous and sensory-evoked CF-calcium transients are enhanced in patDp/+ Purkinje cells, and aversive movements are more severe across sensory modalities. We observed increased expression of the synaptic organizer NRXN1 at CF synapses and ectopic spread of these synapses to fine dendrites. CF-excitatory postsynaptic currents recorded from Purkinje cells are enlarged in patDp/+ mice, while responses to PF stimulation are reduced. Confocal measurements show reduced PF+CF-evoked spine calcium transients, a key trigger for PF long-term depression, one of several plasticity types required for eyeblink conditioning learning. Long-term depression is impaired in patDp/+ mice but is rescued on pharmacological enhancement of calcium signaling. Conclusions Our findings suggest that this genetic abnormality causes a pathological inflation of CF signaling, possibly resulting from enhanced NRXN1 expression, with consequences for the representation of sensory stimuli by the CF input and for PF synaptic organization and plasticity.
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Affiliation(s)
- Dana H Simmons
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Silas E Busch
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Heather K Titley
- Department of Neurobiology, University of Chicago, Chicago, Illinois.,Department of Nursing, University of Alberta, Edmonton, Alberta, Canada
| | - Giorgio Grasselli
- Department of Neurobiology, University of Chicago, Chicago, Illinois.,Istituto Italiano di Tecnologia, Center for Synaptic Neuroscience and Technology, Genoa, Italy.,IRCC Ospedale Policlinico San Martino, Genoa, Italy
| | - Justine Shih
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Xiaofei Du
- Department of Neurology, University of Chicago, Chicago, Illinois
| | - Cenfu Wei
- Department of Neurology, University of Chicago, Chicago, Illinois
| | | | - Claire Piochon
- Department of Neurobiology, University of Chicago, Chicago, Illinois
| | - Christian Hansel
- Department of Neurobiology, University of Chicago, Chicago, Illinois
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53
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Qi C, Luo LD, Feng I, Ma S. Molecular mechanisms of synaptogenesis. Front Synaptic Neurosci 2022; 14:939793. [PMID: 36176941 PMCID: PMC9513053 DOI: 10.3389/fnsyn.2022.939793] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Synapses are the basic units for information processing and storage in the nervous system. It is only when the synaptic connection is established, that it becomes meaningful to discuss the structure and function of a circuit. In humans, our unparalleled cognitive abilities are correlated with an increase in the number of synapses. Additionally, genes involved in synaptogenesis are also frequently associated with neurological or psychiatric disorders, suggesting a relationship between synaptogenesis and brain physiology and pathology. Thus, understanding the molecular mechanisms of synaptogenesis is the key to the mystery of circuit assembly and neural computation. Furthermore, it would provide therapeutic insights for the treatment of neurological and psychiatric disorders. Multiple molecular events must be precisely coordinated to generate a synapse. To understand the molecular mechanisms underlying synaptogenesis, we need to know the molecular components of synapses, how these molecular components are held together, and how the molecular networks are refined in response to neural activity to generate new synapses. Thanks to the intensive investigations in this field, our understanding of the process of synaptogenesis has progressed significantly. Here, we will review the molecular mechanisms of synaptogenesis by going over the studies on the identification of molecular components in synapses and their functions in synaptogenesis, how cell adhesion molecules connect these synaptic molecules together, and how neural activity mobilizes these molecules to generate new synapses. Finally, we will summarize the human-specific regulatory mechanisms in synaptogenesis and results from human genetics studies on synaptogenesis and brain disorders.
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Affiliation(s)
- Cai Qi
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- *Correspondence: Cai Qi,
| | - Li-Da Luo
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, United States
| | - Irena Feng
- Boston University School of Medicine, Boston, MA, United States
| | - Shaojie Ma
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
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54
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Kim J, Wulschner LEG, Oh WC, Ko J. Trans
‐synaptic mechanisms orchestrated by mammalian synaptic cell adhesion molecules. Bioessays 2022; 44:e2200134. [DOI: 10.1002/bies.202200134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/18/2022] [Accepted: 08/31/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Jinhu Kim
- Department of Brain Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu Korea
- Center for Synapse Diversity and Specificity DGIST Daegu Korea
| | | | - Won Chan Oh
- Department of Pharmacology University of Colorado School of Medicine Aurora Colorado USA
| | - Jaewon Ko
- Department of Brain Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu Korea
- Center for Synapse Diversity and Specificity DGIST Daegu Korea
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Llorca A, Deogracias R. Origin, Development, and Synaptogenesis of Cortical Interneurons. Front Neurosci 2022; 16:929469. [PMID: 35833090 PMCID: PMC9272671 DOI: 10.3389/fnins.2022.929469] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian cerebral cortex represents one of the most recent and astonishing inventions of nature, responsible of a large diversity of functions that range from sensory processing to high-order cognitive abilities, such as logical reasoning or language. Decades of dedicated study have contributed to our current understanding of this structure, both at structural and functional levels. A key feature of the neocortex is its outstanding richness in cell diversity, composed by multiple types of long-range projecting neurons and locally connecting interneurons. In this review, we will describe the great diversity of interneurons that constitute local neocortical circuits and summarize the mechanisms underlying their development and their assembly into functional networks.
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Affiliation(s)
- Alfredo Llorca
- Visual Neuroscience Laboratory, Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburg, United Kingdom
- *Correspondence: Alfredo Llorca
| | - Ruben Deogracias
- Neuronal Circuits Formation and Brain Disorders Laboratory, Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain
- Ruben Deogracias
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56
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Xu Y, Wang ML, Tao H, Geng C, Guo F, Hu B, Wang R, Hou XY. ErbB4 in parvalbumin-positive interneurons mediates proactive interference in olfactory associative reversal learning. Neuropsychopharmacology 2022; 47:1292-1303. [PMID: 34707248 PMCID: PMC9117204 DOI: 10.1038/s41386-021-01205-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 09/04/2021] [Accepted: 10/02/2021] [Indexed: 11/09/2022]
Abstract
Consolidated memories influence later learning and cognitive processes when new information is overlapped with previous events. To reveal which cellular and molecular factors are associated with this proactive interference, we challenged mice with odor-reward associative learning followed by a reversal-learning task. The results showed that genetical ablation of ErbB4 in parvalbumin (PV)-positive interneurons improved performance in reversal-learning phase, with no alteration in learning phase, supporting that PV interneuron ErbB4 is required for proactive interference. Mechanistically, olfactory learning promoted PV interneuron excitatory synaptic plasticity and direct binding of ErbB4 with presynaptic Neurexin1β (NRXN1β) and postsynaptic scaffold PSD-95 in the prefrontal cortex. Interrupting ErbB4-NRXN1β interaction impaired network activity-driven excitatory inputs and excitatory synaptic transmission onto PV interneurons. Neuronal activity-induced ErbB4-PSD-95 association facilitated transsynaptic binding of ErbB4-NRXN1β and excitatory synapse formation in ErbB4-positive interneurons. Furthermore, ErbB4-NRXN1β binding was responsible for the activity-regulated activation of ErbB4 and extracellular signal-regulated kinase (ERK) 1/2 in PV interneurons, as well as synaptic plasticity-related expression of brain-derived neurotrophic factor (BDNF). Correlatedly, blocking ErbB4-NRXN1β coupling in the medial prefrontal cortex of adult mice facilitated reversal learning of an olfactory associative task. These findings provide novel insight into the physiological role of PV interneuron ErbB4 signaling in cognitive processes and reveal an associative learning-related transsynaptic NRXN1β-ErbB4-PSD-95 complex that affects the ERK1/2-BDNF pathway and underlies local inhibitory circuit plasticity and proactive interference.
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Affiliation(s)
- Yan Xu
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Meng-Lin Wang
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Hui Tao
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China ,grid.254147.10000 0000 9776 7793State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 211198 China
| | - Chi Geng
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Feng Guo
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Bin Hu
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Ran Wang
- grid.417303.20000 0000 9927 0537Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004 China
| | - Xiao-Yu Hou
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China. .,State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
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Burlingham SR, Wong NF, Peterkin L, Lubow L, Dos Santos Passos C, Benner O, Ghebrial M, Cast TP, Xu-Friedman MA, Südhof TC, Chanda S. Induction of synapse formation by de novo neurotransmitter synthesis. Nat Commun 2022; 13:3060. [PMID: 35650274 PMCID: PMC9160008 DOI: 10.1038/s41467-022-30756-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 05/17/2022] [Indexed: 11/09/2022] Open
Abstract
A vital question in neuroscience is how neurons align their postsynaptic structures with presynaptic release sites. Although synaptic adhesion proteins are known to contribute in this process, the role of neurotransmitters remains unclear. Here we inquire whether de novo biosynthesis and vesicular release of a noncanonical transmitter can facilitate the assembly of its corresponding postsynapses. We demonstrate that, in both stem cell-derived human neurons as well as in vivo mouse neurons of purely glutamatergic identity, ectopic expression of GABA-synthesis enzymes and vesicular transporters is sufficient to both produce GABA from ambient glutamate and transmit it from presynaptic terminals. This enables efficient accumulation and consistent activation of postsynaptic GABAA receptors, and generates fully functional GABAergic synapses that operate in parallel but independently of their glutamatergic counterparts. These findings suggest that presynaptic release of a neurotransmitter itself can signal the organization of relevant postsynaptic apparatus, which could be directly modified to reprogram the synapse identity of neurons.
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Affiliation(s)
- Scott R Burlingham
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Nicole F Wong
- Biological Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Lindsay Peterkin
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Lily Lubow
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | | | - Orion Benner
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Michael Ghebrial
- Biological Science, California State University Fullerton, Fullerton, CA, USA
| | - Thomas P Cast
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | | | - Thomas C Südhof
- Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Soham Chanda
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, USA.
- Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
- Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, CO, USA.
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Re-examination of the determinants of synaptic strength from the perspective of superresolution imaging. Curr Opin Neurobiol 2022; 74:102540. [DOI: 10.1016/j.conb.2022.102540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/04/2022] [Accepted: 03/03/2022] [Indexed: 11/21/2022]
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59
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Lim D, Kim D, Um JW, Ko J. Reassessing synaptic adhesion pathways. Trends Neurosci 2022; 45:517-528. [DOI: 10.1016/j.tins.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/12/2022] [Accepted: 04/19/2022] [Indexed: 01/19/2023]
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60
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Liu Z, Jiang M, Liakath-Ali K, Sclip A, Ko J, Zhang RS, Südhof TC. Deletion of Calsyntenin-3, an atypical cadherin, suppresses inhibitory synapses but increases excitatory parallel-fiber synapses in cerebellum. eLife 2022; 11:e70664. [PMID: 35420982 PMCID: PMC9064300 DOI: 10.7554/elife.70664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 04/14/2022] [Indexed: 01/11/2023] Open
Abstract
Cadherins contribute to the organization of nearly all tissues, but the functions of several evolutionarily conserved cadherins, including those of calsyntenins, remain enigmatic. Puzzlingly, two distinct, non-overlapping functions for calsyntenins were proposed: As postsynaptic neurexin ligands in synapse formation, or as presynaptic kinesin adaptors in vesicular transport. Here, we show that, surprisingly, acute CRISPR-mediated deletion of calsyntenin-3 in mouse cerebellum in vivo causes a large decrease in inhibitory synapse, but a robust increase in excitatory parallel-fiber synapses in Purkinje cells. As a result, inhibitory synaptic transmission was suppressed, whereas parallel-fiber synaptic transmission was enhanced in Purkinje cells by the calsyntenin-3 deletion. No changes in the dendritic architecture of Purkinje cells or in climbing-fiber synapses were detected. Sparse selective deletion of calsyntenin-3 only in Purkinje cells recapitulated the synaptic phenotype, indicating that calsyntenin-3 acts by a cell-autonomous postsynaptic mechanism in cerebellum. Thus, by inhibiting formation of excitatory parallel-fiber synapses and promoting formation of inhibitory synapses in the same neuron, calsyntenin-3 functions as a postsynaptic adhesion molecule that regulates the excitatory/inhibitory balance in Purkinje cells.
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Affiliation(s)
- Zhihui Liu
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Man Jiang
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Kif Liakath-Ali
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Alessandra Sclip
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and TechnologyDaeguRepublic of Korea
| | - Roger Shen Zhang
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
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Uemura T, Suzuki-Kouyama E, Kawase S, Kurihara T, Yasumura M, Yoshida T, Fukai S, Yamazaki M, Fei P, Abe M, Watanabe M, Sakimura K, Mishina M, Tabuchi K. Neurexins play a crucial role in cerebellar granule cell survival by organizing autocrine machinery for neurotrophins. Cell Rep 2022; 39:110624. [PMID: 35385735 DOI: 10.1016/j.celrep.2022.110624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 02/22/2022] [Accepted: 03/15/2022] [Indexed: 01/22/2023] Open
Abstract
Neurexins (NRXNs) are key presynaptic cell adhesion molecules that regulate synapse formation and function via trans-synaptic interaction with postsynaptic ligands. Here, we generate cerebellar granule cell (CGC)-specific Nrxn triple-knockout (TKO) mice for complete deletion of all NRXNs. Unexpectedly, most CGCs die in these mice, and this requirement for NRXNs for cell survival is reproduced in cultured CGCs. The axons of cultured Nrxn TKO CGCs that are not in contact with a postsynaptic structure show defects in the formation of presynaptic protein clusters and in action-potential-induced Ca2+ influxes. These cells also show impaired secretion of depolarization-induced, fluorescence-tagged brain-derived neurotrophic factor (BDNF) from their axons, and the cell-survival defect is rescued by the application of BDNF. These results suggest that CGC survival is maintained by autocrine neurotrophic factors and that NRXNs organize the presynaptic protein clusters and the autocrine neurotrophic-factor secretory machinery independent of contact with postsynaptic ligands.
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Affiliation(s)
- Takeshi Uemura
- Division of Gene Research, Research Center for Advanced Science, Shinshu University, Nagano 390-8621, Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano 390-8621, Japan; Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano 390-8621, Japan; Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan; JST CREST, Saitama 332-0012, Japan.
| | - Emi Suzuki-Kouyama
- Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano 390-8621, Japan; JST CREST, Saitama 332-0012, Japan
| | - Shiori Kawase
- Division of Gene Research, Research Center for Advanced Science, Shinshu University, Nagano 390-8621, Japan; Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano 390-8621, Japan; JST CREST, Saitama 332-0012, Japan
| | - Taiga Kurihara
- Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano 390-8621, Japan
| | - Misato Yasumura
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan; Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan; Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan; JST PRESTO, Saitama 332-0012, Japan
| | - Shuya Fukai
- JST CREST, Saitama 332-0012, Japan; Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Peng Fei
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan; Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan; Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan; Brain Science Laboratory, Research Organization of Science and Technology, Ritsumeikan University, Shiga 525-8577, Japan
| | - Katsuhiko Tabuchi
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano 390-8621, Japan; Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano 390-8621, Japan; JST PRESTO, Saitama 332-0012, Japan.
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62
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Deng K, Thorn P. Presynaptic-like mechanisms and the control of insulin secretion in pancreatic β-cells. Cell Calcium 2022; 104:102585. [DOI: 10.1016/j.ceca.2022.102585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 12/18/2022]
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Banerjee A, Imig C, Balakrishnan K, Kershberg L, Lipstein N, Uronen RL, Wang J, Cai X, Benseler F, Rhee JS, Cooper BH, Liu C, Wojcik SM, Brose N, Kaeser PS. Molecular and functional architecture of striatal dopamine release sites. Neuron 2022; 110:248-265.e9. [PMID: 34767769 PMCID: PMC8859508 DOI: 10.1016/j.neuron.2021.10.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 09/22/2021] [Accepted: 10/19/2021] [Indexed: 01/21/2023]
Abstract
Despite the importance of dopamine for striatal circuit function, mechanistic understanding of dopamine transmission remains incomplete. We recently showed that dopamine secretion relies on the presynaptic scaffolding protein RIM, indicating that it occurs at active zone-like sites similar to classical synaptic vesicle exocytosis. Here, we establish using a systematic gene knockout approach that Munc13 and Liprin-α, active zone proteins for vesicle priming and release site organization, are important for dopamine secretion. Furthermore, RIM zinc finger and C2B domains, which bind to Munc13 and Liprin-α, respectively, are needed to restore dopamine release after RIM ablation. In contrast, and different from typical synapses, the active zone scaffolds RIM-BP and ELKS, and RIM domains that bind to them, are expendable. Hence, dopamine release necessitates priming and release site scaffolding by RIM, Munc13, and Liprin-α, but other active zone proteins are dispensable. Our work establishes that efficient release site architecture mediates fast dopamine exocytosis.
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Affiliation(s)
- Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | | | - Lauren Kershberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Noa Lipstein
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Riikka-Liisa Uronen
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jiexin Wang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Xintong Cai
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Jeong Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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Kim J, Park D, Seo NY, Yoon TH, Kim GH, Lee SH, Seo J, Um JW, Lee KJ, Ko J. LRRTM3 regulates activity-dependent synchronization of synapse properties in topographically connected hippocampal neural circuits. Proc Natl Acad Sci U S A 2022; 119:e2110196119. [PMID: 35022233 PMCID: PMC8784129 DOI: 10.1073/pnas.2110196119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 12/03/2021] [Indexed: 11/18/2022] Open
Abstract
Synaptic cell-adhesion molecules (CAMs) organize the architecture and properties of neural circuits. However, whether synaptic CAMs are involved in activity-dependent remodeling of specific neural circuits is incompletely understood. Leucine-rich repeat transmembrane protein 3 (LRRTM3) is required for the excitatory synapse development of hippocampal dentate gyrus (DG) granule neurons. Here, we report that Lrrtm3-deficient mice exhibit selective reductions in excitatory synapse density and synaptic strength in projections involving the medial entorhinal cortex (MEC) and DG granule neurons, accompanied by increased neurotransmitter release and decreased excitability of granule neurons. LRRTM3 deletion significantly reduced excitatory synaptic innervation of hippocampal mossy fibers (Mf) of DG granule neurons onto thorny excrescences in hippocampal CA3 neurons. Moreover, LRRTM3 loss in DG neurons significantly decreased mossy fiber long-term potentiation (Mf-LTP). Remarkably, silencing MEC-DG circuits protected against the decrease in the excitatory synaptic inputs onto DG and CA3 neurons, excitability of DG granule neurons, and Mf-LTP in Lrrtm3-deficient mice. These results suggest that LRRTM3 may be a critical factor in activity-dependent synchronization of the topography of MEC-DG-CA3 excitatory synaptic connections. Collectively, our data propose that LRRTM3 shapes the target-specific structural and functional properties of specific hippocampal circuits.
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Affiliation(s)
- Jinhu Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Dongseok Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Na-Young Seo
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Neural Circuits Group, Korea Brain Research Institute (KBRI), Daegu 41062, Korea
| | - Taek-Han Yoon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Gyu Hyun Kim
- Neural Circuits Group, Korea Brain Research Institute (KBRI), Daegu 41062, Korea
| | - Sang-Hoon Lee
- Neural Circuits Group, Korea Brain Research Institute (KBRI), Daegu 41062, Korea
- Brain Research Core Facilities, KBRI, Daegu 41062, Korea
| | - Jinsoo Seo
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Kea Joo Lee
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
- Neural Circuits Group, Korea Brain Research Institute (KBRI), Daegu 41062, Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
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65
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Convergent selective signaling impairment exposes the pathogenicity of latrophilin-3 missense variants linked to inheritable ADHD susceptibility. Mol Psychiatry 2022; 27:2425-2438. [PMID: 35393556 PMCID: PMC9135631 DOI: 10.1038/s41380-022-01537-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 03/09/2022] [Accepted: 03/21/2022] [Indexed: 12/13/2022]
Abstract
Latrophilin-3 (Lphn3; also known as ADGRL3) is a member of the adhesion G Protein Coupled Receptor subfamily, which participates in the stabilization and maintenance of neuronal networks by mediating intercellular adhesion through heterophilic interactions with transmembrane ligands. Polymorphisms modifying the Lphn3 gene are associated with attention-deficit/hyperactivity disorder (ADHD) in children and its persistence into adulthood. How these genetic alterations affect receptor function remains unknown. Here, we conducted the functional validation of distinct ADHD-related Lphn3 variants bearing mutations in the receptor's adhesion motif-containing extracellular region. We found that all variants tested disrupted the ability of Lphn3 to stabilize intercellular adhesion in a manner that was distinct between ligands classes, but which did not depend on ligand-receptor interaction parameters, thus pointing to altered intrinsic receptor signaling properties. Using G protein signaling biosensors, we determined that Lphn3 couples to Gαi1, Gαi2, Gαs, Gαq, and Gα13. However, all ADHD-related receptor variants consistently lacked intrinsic as well as ligand-dependent Gα13 coupling efficiency while maintaining unaltered coupling to Gαi, Gαs, and Gαq. Consistent with these alterations, actin remodeling functions as well as actin-relevant RhoA signaling normally displayed by the constitutively active Lphn3 receptor were impeded by select receptor variants, thus supporting additional signaling defects. Taken together, our data point to Gα13 selective signaling impairments as representing a disease-relevant pathogenicity pathway that can be inherited through Lphn3 gene polymorphisms. This study highlights the intricate interplay between Lphn3 GPCR functions and the actin cytoskeleton in modulating neurodevelopmental cues related to ADHD etiology.
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66
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Oliver D, Ramachandran S, Philbrook A, Lambert CM, Nguyen KCQ, Hall DH, Francis MM. Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components. PLoS Genet 2022; 18:e1010016. [PMID: 35089924 PMCID: PMC8827443 DOI: 10.1371/journal.pgen.1010016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 02/09/2022] [Accepted: 01/03/2022] [Indexed: 12/02/2022] Open
Abstract
The functional properties of neural circuits are defined by the patterns of synaptic connections between their partnering neurons, but the mechanisms that stabilize circuit connectivity are poorly understood. We systemically examined this question at synapses onto newly characterized dendritic spines of C. elegans GABAergic motor neurons. We show that the presynaptic adhesion protein neurexin/NRX-1 is required for stabilization of postsynaptic structure. We find that early postsynaptic developmental events proceed without a strict requirement for synaptic activity and are not disrupted by deletion of neurexin/nrx-1. However, in the absence of presynaptic NRX-1, dendritic spines and receptor clusters become destabilized and collapse prior to adulthood. We demonstrate that NRX-1 delivery to presynaptic terminals is dependent on kinesin-3/UNC-104 and show that ongoing UNC-104 function is required for postsynaptic maintenance in mature animals. By defining the dynamics and temporal order of synapse formation and maintenance events in vivo, we describe a mechanism for stabilizing mature circuit connectivity through neurexin-based adhesion.
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Affiliation(s)
- Devyn Oliver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Alison Philbrook
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Christopher M. Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Michael M. Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
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67
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Wang CY, Trotter JH, Liakath-Ali K, Lee SJ, Liu X, Südhof TC. Molecular self-avoidance in synaptic neurexin complexes. SCIENCE ADVANCES 2021; 7:eabk1924. [PMID: 34919427 PMCID: PMC8682996 DOI: 10.1126/sciadv.abk1924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/01/2021] [Indexed: 05/30/2023]
Abstract
Synapses are thought to be organized by interactions of presynaptic neurexins with postsynaptic ligands, particularly with neuroligins and cerebellins. However, when a neuron forms adjacent pre- and postsynaptic specializations, as in dendrodendritic or axo-axonic synapses, nonfunctional cis neurexin/ligand interactions would be energetically favored. Here, we reveal an organizational principle for preventing synaptic cis interactions (“self-avoidance”). Using dendrodendritic synapses between mitral and granule cells in the olfactory bulb as a paradigm, we show that, owing to its higher binding affinity, cerebellin-1 blocks the cis interaction of neurexins with neuroligins, thereby enabling trans neurexin/neuroligin interaction. In mitral cells, ablating either cerebellin-1 or neuroligins severely impaired granule cell➔mitral cell synapses, as did overexpression of wild-type neurexins but not of mutant neurexins unable to bind to neuroligins. Our data uncover a molecular interaction network that organizes the self-avoidance of nonfunctional neurexin/ligand cis interactions, thus allowing assembly of physiological trans interactions.
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Affiliation(s)
- Cosmos Yuqi Wang
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Justin H. Trotter
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Kif Liakath-Ali
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Sung-Jin Lee
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Xinran Liu
- Department of Cell Biology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, School of Medicine, Stanford University, Stanford, CA 94305, USA
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68
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Liu Y, Shen L, Zhang Y, Zhao R, Liu C, Luo S, Chen J, Xia L, Li T, Peng Y, Xia K. Rare NRXN1 missense variants identified in autism interfered protein degradation and Drosophila sleeping. J Psychiatr Res 2021; 143:113-122. [PMID: 34487988 DOI: 10.1016/j.jpsychires.2021.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/28/2021] [Accepted: 09/01/2021] [Indexed: 11/29/2022]
Abstract
NRXN1 is involved in synaptogenesis and have been implicated in Autism spectrum disorders. However, many rare inherited missense variants of NRXN1 have not been thoroughly evaluated. Here, functional analyses in vitro and in Drosophila of three NRXN1 missense mutations, Y282H, L893V, and I1135V identified in ASD patients in our previous study were performed. Our results showed these three mutations interfered protein degradation compared with NRXN1-WT protein. Expressing human NRXN1 in Drosophila could lead to abnormal circadian rhythm and sleep behavior, and three mutated proteins caused milder phenotypes, indicating the mutations may change the function of NRXN1 slightly. These findings highlight the functional role of rare NRXN1 missense variants identified in autism patients, and provide clues for us to better understand the pathogenesis of abnormal circadian rhythm and sleep behavior of other organisms, including humans.
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Affiliation(s)
- Yalan Liu
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China; Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Lu Shen
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Yaowen Zhang
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Rongjuan Zhao
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Cenying Liu
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Sanchuan Luo
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Jingjing Chen
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Lu Xia
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Taoxi Li
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China; Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Yu Peng
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; Key Laboratory of Animal Models for Human Diseases of Hunan Province, Central South University, Changsha, China
| | - Kun Xia
- Center for Medical Genetics and Hunan Provincial Key Laboratory for Medical Genetics, School of Life Sciences, Central South University, Changsha, China; CAS Center for Excellence in Brain Science and Intelligences Technology (CEBSIT), Shanghai, China; Key Laboratory of Medical Information Research, Central South University, Changsha, Hunan, China.
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69
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Schizophrenia-associated LRRTM1 regulates cognitive behavior through controlling synaptic function in the mediodorsal thalamus. Mol Psychiatry 2021; 26:6912-6925. [PMID: 33981006 DOI: 10.1038/s41380-021-01146-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/16/2021] [Accepted: 04/22/2021] [Indexed: 01/08/2023]
Abstract
Reduced activity of the mediodorsal thalamus (MD) and abnormal functional connectivity of the MD with the prefrontal cortex (PFC) cause cognitive deficits in schizophrenia. However, the molecular basis of MD hypofunction in schizophrenia is not known. Here, we identified leucine-rich-repeat transmembrane neuronal protein 1 (LRRTM1), a postsynaptic cell-adhesion molecule, as a key regulator of excitatory synaptic function and excitation-inhibition balance in the MD. LRRTM1 is strongly associated with schizophrenia and is highly expressed in the thalamus. Conditional deletion of Lrrtm1 in the MD in adult mice reduced excitatory synaptic function and caused a parallel reduction in the afferent synaptic activity of the PFC, which was reversed by the reintroduction of LRRTM1 in the MD. Our results indicate that chronic reduction of synaptic strength in the MD by targeted deletion of Lrrtm1 functionally disengages the MD from the PFC and may account for cognitive, social, and sensorimotor gating deficits, reminiscent of schizophrenia.
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70
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Miyazaki T, Morimoto-Tomita M, Berthoux C, Konno K, Noam Y, Yamasaki T, Verhage M, Castillo PE, Watanabe M, Tomita S. Excitatory and inhibitory receptors utilize distinct post- and trans-synaptic mechanisms in vivo. eLife 2021; 10:59613. [PMID: 34658339 PMCID: PMC8550753 DOI: 10.7554/elife.59613] [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: 06/03/2020] [Accepted: 09/19/2021] [Indexed: 11/13/2022] Open
Abstract
Ionotropic neurotransmitter receptors at postsynapses mediate fast synaptic transmission upon binding of the neurotransmitter. Post- and trans-synaptic mechanisms through cytosolic, membrane, and secreted proteins have been proposed to localize neurotransmitter receptors at postsynapses. However, it remains unknown which mechanism is crucial to maintain neurotransmitter receptors at postsynapses. In this study, we ablated excitatory or inhibitory neurons in adult mouse brains in a cell-autonomous manner. Unexpectedly, we found that excitatory AMPA receptors remain at the postsynaptic density upon ablation of excitatory presynaptic terminals. In contrast, inhibitory GABAA receptors required inhibitory presynaptic terminals for their postsynaptic localization. Consistent with this finding, ectopic expression at excitatory presynapses of neurexin-3 alpha, a putative trans-synaptic interactor with the native GABAA receptor complex, could recruit GABAA receptors to contacted postsynaptic sites. These results establish distinct mechanisms for the maintenance of excitatory and inhibitory postsynaptic receptors in the mature mammalian brain.
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Affiliation(s)
- Taisuke Miyazaki
- Department of Cellular and Molecular Physiology, Department of Neuroscience, Yale University School of Medicine, New Haven, United States.,Department of Health Sciences, School of Medicine, Hokkaido University, Sapporo, Japan.,Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Megumi Morimoto-Tomita
- Department of Cellular and Molecular Physiology, Department of Neuroscience, Yale University School of Medicine, New Haven, United States
| | - Coralie Berthoux
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Kotaro Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Yoav Noam
- Department of Cellular and Molecular Physiology, Department of Neuroscience, Yale University School of Medicine, New Haven, United States
| | - Tokiwa Yamasaki
- Department of Cellular and Molecular Physiology, Department of Neuroscience, Yale University School of Medicine, New Haven, United States
| | - Matthijs Verhage
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU Medical Center, Amsterdam, Netherlands
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Susumu Tomita
- Department of Cellular and Molecular Physiology, Department of Neuroscience, Yale University School of Medicine, New Haven, United States
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71
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Avazzadeh S, Quinlan LR, Reilly J, McDonagh K, Jalali A, Wang Y, McInerney V, Krawczyk J, Ding Y, Fitzgerald J, O'Sullivan M, Forman EB, Lynch SA, Ennis S, Feerick N, Reilly R, Li W, Shen X, Yang G, Lu Y, Peeters H, Dockery P, O'Brien T, Shen S, Gallagher L. NRXN1α +/- is associated with increased excitability in ASD iPSC-derived neurons. BMC Neurosci 2021; 22:56. [PMID: 34525970 PMCID: PMC8442436 DOI: 10.1186/s12868-021-00661-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 09/01/2021] [Indexed: 12/14/2022] Open
Abstract
Background NRXN1 deletions are identified as one of major rare risk factors for autism spectrum disorder (ASD) and other neurodevelopmental disorders. ASD has 30% co-morbidity with epilepsy, and the latter is associated with excessive neuronal firing. NRXN1 encodes hundreds of presynaptic neuro-adhesion proteins categorized as NRXN1α/β/γ. Previous studies on cultured cells show that the short NRXN1β primarily exerts excitation effect, whereas the long NRXN1α which is more commonly deleted in patients involves in both excitation and inhibition. However, patient-derived models are essential for understanding functional consequences of NRXN1α deletions in human neurons. We recently derived induced pluripotent stem cells (iPSCs) from five controls and three ASD patients carrying NRXN1α+/- and showed increased calcium transients in patient neurons. Methods In this study we investigated the electrophysiological properties of iPSC-derived cortical neurons in control and ASD patients carrying NRXN1α+/- using patch clamping. Whole genome RNA sequencing was carried out to further understand the potential underlying molecular mechanism. Results NRXN1α+/- cortical neurons were shown to display larger sodium currents, higher AP amplitude and accelerated depolarization time. RNASeq analyses revealed transcriptomic changes with significant upregulation glutamatergic synapse and ion channels/transporter activity including voltage-gated potassium channels (GRIN1, GRIN3B, SLC17A6, CACNG3, CACNA1A, SHANK1), which are likely to couple with the increased excitability in NRXN1α+/- cortical neurons. Conclusions Together with recent evidence of increased calcium transients, our results showed that human NRXN1α+/- isoform deletions altered neuronal excitability and non-synaptic function, and NRXN1α+/- patient iPSCs may be used as an ASD model for therapeutic development with calcium transients and excitability as readouts. Supplementary Information The online version contains supplementary material available at 10.1186/s12868-021-00661-0.
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Affiliation(s)
- Sahar Avazzadeh
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland
| | - Leo R Quinlan
- Physiology and Cellular Physiology Research Laboratory, School of Medicine, CÚRAM SFI Centre for Research in Medical Devices, National University of Ireland (NUI), Galway, Ireland
| | - Jamie Reilly
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland
| | - Katya McDonagh
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland
| | | | - Yanqin Wang
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland.,Department of Physiology, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Veronica McInerney
- HRB Clinical Research Facility, National University of Ireland (NUI), Galway, Ireland
| | - Janusz Krawczyk
- Department of Haematology, Galway University Hospital, Galway, Ireland
| | - Yicheng Ding
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland
| | | | - Matthew O'Sullivan
- Trinity Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Eva B Forman
- Children's University Hospital, Temple Street, Dublin, Ireland
| | - Sally A Lynch
- Children's University Hospital, Temple Street, Dublin, Ireland.,Department of Clinical Genetics, OLCHC, Dublin 12, Ireland
| | - Sean Ennis
- School of Medicine and Medical Science, UCD Academic Centre On Rare Diseases, University College Dublin, Dublin, Ireland
| | - Niamh Feerick
- Centre for Bioengineering, Trinity College Institute of Neuroscience, School of Medicine, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - Richard Reilly
- Centre for Bioengineering, Trinity College Institute of Neuroscience, School of Medicine, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - Weidong Li
- Bio-X Institutes, Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders (Ministry of Education), Shanghai Key Laboratory of Psychotic Disorders, and Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Xu Shen
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, China
| | - Guangming Yang
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Yin Lu
- College of Pharmacy, Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine (TCM) Prevention and Treatment of Tumor, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Hilde Peeters
- Centre for Human Genetics, University Hospital Leuven, KU Leuven, 3000, Leuven, Belgium
| | - Peter Dockery
- Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland (NUI), Galway, Ireland
| | - Timothy O'Brien
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland
| | - Sanbing Shen
- School of Medicine, Regenerative Medicine Institute, Biomedical Science Building BMS-1021, National University of Ireland Galway, Dangan, Ireland. .,FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin, D02, Ireland.
| | - Louise Gallagher
- Trinity Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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72
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Miller DS, Wright KM. Neuronal Dystroglycan regulates postnatal development of CCK/cannabinoid receptor-1 interneurons. Neural Dev 2021; 16:4. [PMID: 34362433 PMCID: PMC8349015 DOI: 10.1186/s13064-021-00153-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/20/2021] [Indexed: 12/02/2022] Open
Abstract
Background The development of functional neural circuits requires the precise formation of synaptic connections between diverse neuronal populations. The molecular pathways that allow GABAergic interneuron subtypes in the mammalian brain to initially recognize their postsynaptic partners remain largely unknown. The transmembrane glycoprotein Dystroglycan is localized to inhibitory synapses in pyramidal neurons, where it is required for the proper function of CCK+ interneurons. However, the precise temporal requirement for Dystroglycan during inhibitory synapse development has not been examined. Methods In this study, we use NEXCre or Camk2aCreERT2 to conditionally delete Dystroglycan from newly-born or adult pyramidal neurons, respectively. We then analyze forebrain development from postnatal day 3 through adulthood, with a particular focus on CCK+ interneurons. Results In the absence of postsynaptic Dystroglycan in developing pyramidal neurons, presynaptic CCK+ interneurons fail to elaborate their axons and largely disappear from the cortex, hippocampus, amygdala, and olfactory bulb during the first two postnatal weeks. Other interneuron subtypes are unaffected, indicating that CCK+ interneurons are unique in their requirement for postsynaptic Dystroglycan. Dystroglycan does not appear to be required in adult pyramidal neurons to maintain CCK+ interneurons. Bax deletion did not rescue CCK+ interneurons in Dystroglycan mutants during development, suggesting that they are not eliminated by canonical apoptosis. Rather, we observed increased innervation of the striatum, suggesting that the few remaining CCK+ interneurons re-directed their axons to neighboring areas where Dystroglycan expression remained intact. Conclusion Together these findings show that Dystroglycan functions as part of a synaptic partner recognition complex that is required early for CCK+ interneuron development in the forebrain. Supplementary Information The online version contains supplementary material available at 10.1186/s13064-021-00153-1.
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Affiliation(s)
- Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, VIB 3435A, 3181 SW Sam Jackson Park Road, L474, Portland, OR, 97239-3098, USA.
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73
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Asede D, Okoh J, Ali S, Doddapaneni D, Bolton MM. Deletion of ErbB4 Disrupts Synaptic Transmission and Long-Term Potentiation of Thalamic Input to Amygdalar Medial Paracapsular Intercalated Cells. Front Synaptic Neurosci 2021; 13:697110. [PMID: 34393751 PMCID: PMC8355744 DOI: 10.3389/fnsyn.2021.697110] [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: 04/18/2021] [Accepted: 07/08/2021] [Indexed: 11/20/2022] Open
Abstract
Identification of candidate risk genes and alteration in the expression of proteins involved in regulating inhibitory neuron function in various psychiatric disorders, support the notion that GABAergic neuron dysfunction plays an important role in disease etiology. Genetic variations in neuregulin and its receptor kinase ErbB4, expressed exclusively by GABAergic neurons in the CNS, have been linked with schizophrenia. In the amygdala, ErbB4 is highly expressed in GABAergic intercalated cell clusters (ITCs), which play a critical role in amygdala-dependent behaviors. It is however unknown whether ErbB4 deletion from ITCs affects their synaptic properties and function in amygdala circuitry. Here, we examined the impact of ErbB4 deletion on inhibitory and excitatory circuits recruiting medial paracapsular ITCs (mpITCs) using electrophysiological techniques. Ablation of ErbB4 in mpITCs suppressed NMDA receptor-mediated synaptic transmission at thalamo-mpITC synapses and enhanced thalamic driven GABAergic transmission onto mpITCs. Furthermore, long-term potentiation (LTP) at thalamo-mpITC synapses was compromised in ErbB4 mutant mice, indicating that ErbB4 activity is critical for LTP at these synapses. Together, our findings suggest that ErbB4 deletion from mpITCs disrupts excitation-inhibition balance and learning mechanisms in amygdala circuits.
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Affiliation(s)
- Douglas Asede
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - James Okoh
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - Sabah Ali
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - Divyesh Doddapaneni
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
| | - M McLean Bolton
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
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74
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Development of neuronal circuits: From synaptogenesis to synapse plasticity. HANDBOOK OF CLINICAL NEUROLOGY 2021; 173:43-53. [PMID: 32958189 DOI: 10.1016/b978-0-444-64150-2.00005-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Optimal brain function critically hinges on the remarkably precise interconnections made among millions of neurons. These specialized interconnected neuronal junctions, termed synapses, are used for neuronal communication, whence the presynaptic neurons releases a specific neurotransmitter, which then binds to the appropriate protein receptor on the membrane of the postsynaptic neuron, activating and eliciting a response in this connected neuron. In this chapter, we discuss how synapses form and are modified as the brain matures. Genetic programs control most of the wiring in the brain, from allowing axons to choose where to target their synapses, to determining synapse identity. However, the final map of neuronal connectivity in the brain crucially relies on incoming sensory information during early childhood to strengthen and refine the preexisting synapses thus allowing both nature and nurture to shape the final structure and function of the nervous system (Fig. 5.1). Finally, we discuss how advances in the knowledge of basic mechanisms governing synapse formation and plasticity can shed light on the pathophysiology of neurodevelopmental disorders.
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75
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Südhof TC. The cell biology of synapse formation. J Cell Biol 2021; 220:e202103052. [PMID: 34086051 PMCID: PMC8186004 DOI: 10.1083/jcb.202103052] [Citation(s) in RCA: 121] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 04/25/2023] Open
Abstract
In a neural circuit, synapses transfer information rapidly between neurons and transform this information during transfer. The diverse computational properties of synapses are shaped by the interactions between pre- and postsynaptic neurons. How synapses are assembled to form a neural circuit, and how the specificity of synaptic connections is achieved, is largely unknown. Here, I posit that synaptic adhesion molecules (SAMs) organize synapse formation. Diverse SAMs collaborate to achieve the astounding specificity and plasticity of synapses, with each SAM contributing different facets. In orchestrating synapse assembly, SAMs likely act as signal transduction devices. Although many candidate SAMs are known, only a few SAMs appear to have a major impact on synapse formation. Thus, a limited set of collaborating SAMs likely suffices to account for synapse formation. Strikingly, several SAMs are genetically linked to neuropsychiatric disorders, suggesting that impairments in synapse assembly are instrumental in the pathogenesis of neuropsychiatric disorders.
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76
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The protective effect and potential mechanism of NRXN1 on learning and memory in ADHD rat models. Exp Neurol 2021; 344:113806. [PMID: 34228999 DOI: 10.1016/j.expneurol.2021.113806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 06/09/2021] [Accepted: 07/02/2021] [Indexed: 11/23/2022]
Abstract
The learning and memory network is highly complex and remains unclear. The hippocampus is the location of learning and memory function. Impairment of synaptic morphology and synaptic plasticity (i.e., long-term potentiation) appears to cause learning and memory deficits. Several studies have indicated the role of NRXN1 in regulating the synaptic function, but little is known on its role in learning and memory dysfunction associated with attention deficit and hyperactivity disorder (ADHD). Our results showed that overexpression and interference of NRXN1 in vivo, respectively, affected learning and memory, as was assessed by Morris water maze tests, in spontaneously hypertensive rats (SHRs) and Sprague Dawley (SD) rats. We found that SD rats performed better after methylphenidate (MPH) treatment in salvage trials. Accordingly, the change of NRXN1 led to altered synapse-related gene (PSD95, SYN1, GAP43, NLGN1) expression, further providing evidence of its role in the maintenance of synaptic plasticity. We also verified that the expression of synapse-related genes synchronously changed with NRXN1expression in the behavioral assessment. The expression of NRXN1 was confirmed to affect the expression of synapse-related genes after its interference and overexpression in the primary hippocampal neurons in vitro. These results confirmed our hypothesis that NRXN1 might nucleate an overall trans-synaptic signaling network that controls synaptic plasticity and is responsible for impairments in learning and memory in ADHD. These findings suggest a possible protective role of NRXN1 in learning and memory in ADHD. Further RNA-seq sequencing revealed significant differences in the expression of 5-hydroxytryptamine receptor (5-HT6R), which was further verified at the cellular level, and the mechanism of NRXN1 affecting synaptic plasticity was preliminarily discussed.
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77
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Klatt O, Repetto D, Brockhaus J, Reissner C, El Khallouqi A, Rohlmann A, Heine M, Missler M. Endogenous β-neurexins on axons and within synapses show regulated dynamic behavior. Cell Rep 2021; 35:109266. [PMID: 34133920 DOI: 10.1016/j.celrep.2021.109266] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/21/2020] [Accepted: 05/26/2021] [Indexed: 11/25/2022] Open
Abstract
Neurexins are key organizer molecules that regulate synaptic function and are implicated in autism and schizophrenia. β-neurexins interact with numerous cell adhesion and receptor molecules, but their neuronal localization remains elusive. Using single-molecule tracking and high-resolution microscopy to detect neurexin1β and neurexin3β in primary hippocampal neurons from knockin mice, we demonstrate that endogenous β-neurexins are present in fewer than half of excitatory and inhibitory synapses. Moreover, we observe a large extrasynaptic pool of β-neurexins on axons and show that axonal β-neurexins diffuse with higher surface mobility than those transiently confined within synapses. Stimulation of neuronal activity further increases the mobility of synaptic and axonal β-neurexins, whereas inhibition causes the opposite. Blocking ectodomain cleavage by metalloproteases also reduces β-neurexin mobility and enhances glutamate release. These findings suggest that the surface mobility of endogenous β-neurexins inside and outside of synapses is dynamically regulated and linked to neuronal activity.
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Affiliation(s)
- Oliver Klatt
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany; Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Daniele Repetto
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Johannes Brockhaus
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Carsten Reissner
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Abderazzaq El Khallouqi
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Martin Heine
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany.
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany.
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78
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Cross-platform validation of neurotransmitter release impairments in schizophrenia patient-derived NRXN1-mutant neurons. Proc Natl Acad Sci U S A 2021; 118:2025598118. [PMID: 34035170 DOI: 10.1073/pnas.2025598118] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterozygous NRXN1 deletions constitute the most prevalent currently known single-gene mutation associated with schizophrenia, and additionally predispose to multiple other neurodevelopmental disorders. Engineered heterozygous NRXN1 deletions impaired neurotransmitter release in human neurons, suggesting a synaptic pathophysiological mechanism. Utilizing this observation for drug discovery, however, requires confidence in its robustness and validity. Here, we describe a multicenter effort to test the generality of this pivotal observation, using independent analyses at two laboratories of patient-derived and newly engineered human neurons with heterozygous NRXN1 deletions. Using neurons transdifferentiated from induced pluripotent stem cells that were derived from schizophrenia patients carrying heterozygous NRXN1 deletions, we observed the same synaptic impairment as in engineered NRXN1-deficient neurons. This impairment manifested as a large decrease in spontaneous synaptic events, in evoked synaptic responses, and in synaptic paired-pulse depression. Nrxn1-deficient mouse neurons generated from embryonic stem cells by the same method as human neurons did not exhibit impaired neurotransmitter release, suggesting a human-specific phenotype. Human NRXN1 deletions produced a reproducible increase in the levels of CASK, an intracellular NRXN1-binding protein, and were associated with characteristic gene-expression changes. Thus, heterozygous NRXN1 deletions robustly impair synaptic function in human neurons regardless of genetic background, enabling future drug discovery efforts.
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79
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Scekic-Zahirovic J, Sanjuan-Ruiz I, Kan V, Megat S, De Rossi P, Dieterlé S, Cassel R, Jamet M, Kessler P, Wiesner D, Tzeplaeff L, Demais V, Sahadevan S, Hembach KM, Muller HP, Picchiarelli G, Mishra N, Antonucci S, Dirrig-Grosch S, Kassubek J, Rasche V, Ludolph A, Boutillier AL, Roselli F, Polymenidou M, Lagier-Tourenne C, Liebscher S, Dupuis L. Cytoplasmic FUS triggers early behavioral alterations linked to cortical neuronal hyperactivity and inhibitory synaptic defects. Nat Commun 2021; 12:3028. [PMID: 34021132 PMCID: PMC8140148 DOI: 10.1038/s41467-021-23187-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
Gene mutations causing cytoplasmic mislocalization of the RNA-binding protein FUS lead to severe forms of amyotrophic lateral sclerosis (ALS). Cytoplasmic accumulation of FUS is also observed in other diseases, with unknown consequences. Here, we show that cytoplasmic mislocalization of FUS drives behavioral abnormalities in knock-in mice, including locomotor hyperactivity and alterations in social interactions, in the absence of widespread neuronal loss. Mechanistically, we identified a progressive increase in neuronal activity in the frontal cortex of Fus knock-in mice in vivo, associated with altered synaptic gene expression. Synaptic ultrastructural and morphological defects were more pronounced in inhibitory than excitatory synapses and associated with increased synaptosomal levels of FUS and its RNA targets. Thus, cytoplasmic FUS triggers synaptic deficits, which is leading to increased neuronal activity in frontal cortex and causing related behavioral phenotypes. These results indicate that FUS mislocalization may trigger deleterious phenotypes beyond motor neuron impairment in ALS, likely relevant also for other neurodegenerative diseases characterized by FUS mislocalization.
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Affiliation(s)
- Jelena Scekic-Zahirovic
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Inmaculada Sanjuan-Ruiz
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Vanessa Kan
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany
- BioMedical Center, Medical Faculty, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Salim Megat
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Pierre De Rossi
- Department of Quantitative Biomedicine, University of Zurich, Zürich, Switzerland
| | - Stéphane Dieterlé
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Raphaelle Cassel
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
- Université de Strasbourg, UMR 7364 CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), Strasbourg, France
| | - Marguerite Jamet
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Pascal Kessler
- Université de Strasbourg, Inserm, Unité mixte de service du CRBS, UMS 038, Strasbourg, France
| | - Diana Wiesner
- Department of Neurology, Ulm University, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Ulm, Germany
| | - Laura Tzeplaeff
- Université de Strasbourg, UMR 7364 CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), Strasbourg, France
| | - Valérie Demais
- Plateforme Imagerie In Vitro, CNRS UPS-3156, NeuroPôle, Strasbourg, France
| | - Sonu Sahadevan
- Department of Quantitative Biomedicine, University of Zurich, Zürich, Switzerland
| | - Katharina M Hembach
- Department of Quantitative Biomedicine, University of Zurich, Zürich, Switzerland
| | | | - Gina Picchiarelli
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Nibha Mishra
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Stefano Antonucci
- Department of Neurology, Ulm University, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Ulm, Germany
| | - Sylvie Dirrig-Grosch
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France
| | - Jan Kassubek
- Department of Neurology, Ulm University, Ulm, Germany
| | - Volker Rasche
- Ulm University Medical Center, Department of Internal Medicine II, Ulm, Germany
| | - Albert Ludolph
- Department of Neurology, Ulm University, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Ulm, Germany
| | - Anne-Laurence Boutillier
- Université de Strasbourg, UMR 7364 CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), Strasbourg, France
| | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Ulm, Germany
| | | | - Clotilde Lagier-Tourenne
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany.
- BioMedical Center, Medical Faculty, Ludwig-Maximilians-University Munich, Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Luc Dupuis
- Université de Strasbourg, Inserm, Mécanismes centraux et périphériques de la neurodégénérescence, Strasbourg, France.
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80
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Neurexins regulate presynaptic GABA B-receptors at central synapses. Nat Commun 2021; 12:2380. [PMID: 33888718 PMCID: PMC8062527 DOI: 10.1038/s41467-021-22753-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 03/20/2021] [Indexed: 11/28/2022] Open
Abstract
Diverse signaling complexes are precisely assembled at the presynaptic active zone for dynamic modulation of synaptic transmission and synaptic plasticity. Presynaptic GABAB-receptors nucleate critical signaling complexes regulating neurotransmitter release at most synapses. However, the molecular mechanisms underlying assembly of GABAB-receptor signaling complexes remain unclear. Here we show that neurexins are required for the localization and function of presynaptic GABAB-receptor signaling complexes. At four model synapses, excitatory calyx of Held synapses in the brainstem, excitatory and inhibitory synapses on hippocampal CA1-region pyramidal neurons, and inhibitory basket cell synapses in the cerebellum, deletion of neurexins rendered neurotransmitter release significantly less sensitive to GABAB-receptor activation. Moreover, deletion of neurexins caused a loss of GABAB-receptors from the presynaptic active zone of the calyx synapse. These findings extend the role of neurexins at the presynaptic active zone to enabling GABAB-receptor signaling, supporting the notion that neurexins function as central organizers of active zone signaling complexes. Neurexins are evolutionarily conserved cell adhesion molecules that tune synapse formation and specification. Here the authors show that neurexins play similar roles in regulating presynaptic GABAB receptors at multiple CNS synapses.
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81
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Fuccillo MV, Pak C. Copy number variants in neurexin genes: phenotypes and mechanisms. Curr Opin Genet Dev 2021; 68:64-70. [PMID: 33756113 PMCID: PMC8491281 DOI: 10.1016/j.gde.2021.02.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 11/11/2022]
Abstract
Neurexins are central to trans-synaptic cell adhesion and signaling during synapse specification and maintenance. The past two decades of human genetics research have identified structural variations in the neurexin gene family, in particular NRXN1 copy number variants (CNVs), implicated in multiple neuropsychiatric and developmental disorders. The heterogeneity and reduced penetrance of NRXN1 deletions, in addition to the pleiotropic, circuit-specific functions of NRXN1, present substantial obstacles to understanding how compromised NRXN1 function predisposes individuals to neuropsychiatric disorders. Here, we provide an updated review of NRXN1 genetics in disease, followed by recently published work using both human induced pluripotent stem cell (iPSC) derived systems and animal models to understand the mechanisms of disease pathophysiology. Finally, we suggest our outlook on how the field should progress to improve our understanding of neurexin mediated disease pathogenesis. We believe that understanding how structural genetic variants in NRXN1 contribute to disease pathophysiology requires parallel approaches in iPSC and mouse model systems, each leveraging their unique strengths — analysis of genetic interactions and background effects in iPSCs and neural circuit and behavioral analysis in mice.
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Affiliation(s)
- Marc V Fuccillo
- Dept. of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - ChangHui Pak
- Dept. of Biochemistry & Molecular Biology, University of Massachusetts Amherst, Amherst, MA 01003, United States.
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82
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Khalaj AJ, Sterky FH, Sclip A, Schwenk J, Brunger AT, Fakler B, Südhof TC. Deorphanizing FAM19A proteins as pan-neurexin ligands with an unusual biosynthetic binding mechanism. J Cell Biol 2021; 219:151974. [PMID: 32706374 PMCID: PMC7480106 DOI: 10.1083/jcb.202004164] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022] Open
Abstract
Neurexins are presynaptic adhesion molecules that organize synapses by binding to diverse trans-synaptic ligands, but how neurexins are regulated is incompletely understood. Here we identify FAM19A/TAFA proteins, “orphan" cytokines, as neurexin regulators that interact with all neurexins, except for neurexin-1γ, via an unusual mechanism. Specifically, we show that FAM19A1-A4 bind to the cysteine-loop domain of neurexins by forming intermolecular disulfide bonds during transport through the secretory pathway. FAM19A-binding required both the cysteines of the cysteine-loop domain and an adjacent sequence of neurexins. Genetic deletion of neurexins suppressed FAM19A1 expression, demonstrating that FAM19As physiologically interact with neurexins. In hippocampal cultures, expression of exogenous FAM19A1 decreased neurexin O-glycosylation and suppressed its heparan sulfate modification, suggesting that FAM19As regulate the post-translational modification of neurexins. Given the selective expression of FAM19As in specific subtypes of neurons and their activity-dependent regulation, these results suggest that FAM19As serve as cell type–specific regulators of neurexin modifications.
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Affiliation(s)
- Anna J Khalaj
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Fredrik H Sterky
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Alessandra Sclip
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Jochen Schwenk
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Axel T Brunger
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Centres for Biological Signalling Studies (BIOSS) and Integrative Biological Signalling Studies (CIBSS), Freiburg, Germany.,Center for Basics in NeuroModulation, Freiburg, Germany
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
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83
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Emperador-Melero J, de Nola G, Kaeser PS. Intact synapse structure and function after combined knockout of PTPδ, PTPσ, and LAR. eLife 2021; 10:e66638. [PMID: 33656439 PMCID: PMC7963474 DOI: 10.7554/elife.66638] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/28/2021] [Indexed: 12/18/2022] Open
Abstract
It has long been proposed that leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) are cell-adhesion proteins that control synapse assembly. Their synaptic nanoscale localization, however, is not established, and synapse fine structure after knockout of the three vertebrate LAR-RPTPs (PTPδ, PTPσ, and LAR) has not been tested. Here, superresolution microscopy reveals that PTPδ localizes to the synaptic cleft precisely apposed to postsynaptic scaffolds of excitatory and inhibitory synapses. We next assessed synapse structure in newly generated triple-conditional-knockout mice for PTPδ, PTPσ, and LAR, complementing a recent independent study of synapse function after LAR-RPTP ablation (Sclip and Südhof, 2020). While mild effects on synaptic vesicle clustering and active zone architecture were detected, synapse numbers and their overall structure were unaffected, membrane anchoring of the active zone persisted, and vesicle docking and release were normal. Hence, despite their localization at synaptic appositions, LAR-RPTPs are dispensable for presynapse structure and function.
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Affiliation(s)
| | - Giovanni de Nola
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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84
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Tromp A, Mowry B, Giacomotto J. Neurexins in autism and schizophrenia-a review of patient mutations, mouse models and potential future directions. Mol Psychiatry 2021; 26:747-760. [PMID: 33191396 DOI: 10.1038/s41380-020-00944-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 01/29/2023]
Abstract
Mutations in the family of neurexins (NRXN1, NRXN2 and NRXN3) have been repeatedly identified in patients with autism spectrum disorder (ASD) and schizophrenia (SCZ). However, it remains unclear how these DNA variants affect neurexin functions and thereby predispose to these neurodevelopmental disorders. Understanding both the wild-type and pathologic roles of these genes in the brain could help unveil biological mechanisms underlying mental disorders. In this regard, numerous studies have focused on generating relevant loss-of-function (LOF) mammalian models. Although this has increased our knowledge about their normal functions, the potential pathologic role(s) of these human variants remains elusive. Indeed, after reviewing the literature, it seems apparent that a traditional LOF-genetic approach based on complete LOF might not be sufficient to unveil the role of these human mutations. First, these genes present a very complex transcriptome and total-LOF of all isoforms may not be the cause of toxicity in patients, particularly given evidence that causative variants act through haploinsufficiency. Moreover, human DNA variants may not all lead to LOF but potentially to intricate transcriptome changes that could also include the generation of aberrant isoforms acting as a gain-of-function (GOF). Furthermore, their transcriptomic complexity most likely renders them prone to genetic compensation when one tries to manipulate them using traditional site-directed mutagenesis approaches, and this could act differently from model to model leading to heterogeneous and conflicting phenotypes. This review compiles the relevant literature on variants identified in human studies and on the mouse models currently deployed, and offers suggestions for future research.
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Affiliation(s)
- Alisha Tromp
- Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia
| | - Bryan Mowry
- Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia.
- Queensland Centre for Mental Health Research, Brisbane, QLD, Australia.
| | - Jean Giacomotto
- Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia.
- Queensland Centre for Mental Health Research, Brisbane, QLD, Australia.
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85
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Abstract
The function of neuronal circuits relies on the properties of individual neuronal cells and their synapses. We propose that a substantial degree of synapse formation and function is instructed by molecular codes resulting from transcriptional programmes. Recent studies on the Neurexin protein family and its ligands provide fundamental insight into how synapses are assembled and remodelled, how synaptic properties are specified and how single gene mutations associated with neurodevelopmental and psychiatric disorders might modify the operation of neuronal circuits and behaviour. In this Review, we first summarize insights into Neurexin function obtained from various model organisms. We then discuss the mechanisms and logic of the cell type-specific regulation of Neurexin isoforms, in particular at the level of alternative mRNA splicing. Finally, we propose a conceptual framework for how combinations of synaptic protein isoforms act as 'senders' and 'readers' to instruct synapse formation and the acquisition of cell type-specific and synapse-specific functional properties.
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86
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Gandini MA, Zamponi GW. Voltage‐gated calcium channel nanodomains: molecular composition and function. FEBS J 2021; 289:614-633. [DOI: 10.1111/febs.15759] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 12/16/2022]
Affiliation(s)
- Maria A. Gandini
- Department of Physiology and Pharmacology Alberta Children’s Hospital Research Institute Hotchkiss Brain Institute Cumming School of Medicine University of Calgary AB Canada
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology Alberta Children’s Hospital Research Institute Hotchkiss Brain Institute Cumming School of Medicine University of Calgary AB Canada
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87
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Chowdhury D, Watters K, Biederer T. Synaptic recognition molecules in development and disease. Curr Top Dev Biol 2021; 142:319-370. [PMID: 33706921 DOI: 10.1016/bs.ctdb.2020.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Synaptic connectivity patterns underlie brain functions. How recognition molecules control where and when neurons form synapses with each other, therefore, is a fundamental question of cellular neuroscience. This chapter delineates adhesion and signaling complexes as well as secreted factors that contribute to synaptic partner recognition in the vertebrate brain. The sections follow a developmental perspective and discuss how recognition molecules (1) guide initial synaptic wiring, (2) provide for the rejection of incorrect partner choices, (3) contribute to synapse specification, and (4) support the removal of inappropriate synapses once formed. These processes involve a rich repertoire of molecular players and key protein families are described, notably the Cadherin and immunoglobulin superfamilies, Semaphorins/Plexins, Leucine-rich repeat containing proteins, and Neurexins and their binding partners. Molecular themes that diversify these recognition systems are defined and highlighted throughout the text, including the neuron-type specific expression and combinatorial action of recognition factors, alternative splicing, and post-translational modifications. Methodological innovations advancing the field such as proteomic approaches and single cell expression studies are additionally described. Further, the chapter highlights the importance of choosing an appropriate brain region to analyze synaptic recognition factors and the advantages offered by laminated structures like the hippocampus or retina. In a concluding section, the profound disease relevance of aberrant synaptic recognition for neurodevelopmental and psychiatric disorders is discussed. Based on the current progress, an outlook is presented on research goals that can further advance insights into how recognition molecules provide for the astounding precision and diversity of synaptic connections.
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Affiliation(s)
| | - Katherine Watters
- Department of Neurology, Yale School of Medicine, New Haven, CT, United States; Neuroscience Graduate Program, Tufts University School of Medicine, Boston, MA, United States
| | - Thomas Biederer
- Department of Neurology, Yale School of Medicine, New Haven, CT, United States.
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88
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Kim HY, Um JW, Ko J. Proper synaptic adhesion signaling in the control of neural circuit architecture and brain function. Prog Neurobiol 2021; 200:101983. [PMID: 33422662 DOI: 10.1016/j.pneurobio.2020.101983] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022]
Abstract
Trans-synaptic cell-adhesion molecules are critical for governing various stages of synapse development and specifying neural circuit properties via the formation of multifarious signaling pathways. Recent studies have pinpointed the putative roles of trans-synaptic cell-adhesion molecules in mediating various cognitive functions. Here, we review the literature on the roles of a diverse group of central synaptic organizers, including neurexins (Nrxns), leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs), and their associated binding proteins, in regulating properties of specific type of synapses and neural circuits. In addition, we highlight the findings that aberrant synaptic adhesion signaling leads to alterations in the structures, transmission, and plasticity of specific synapses across diverse brain areas. These results seem to suggest that proper trans-synaptic signaling pathways by Nrxns, LAR-RPTPs, and their interacting network is likely to constitute central molecular complexes that form the basis for cognitive functions, and that these complexes are heterogeneously and complexly disrupted in many neuropsychiatric and neurodevelopmental disorders.
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Affiliation(s)
- Hee Young Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea; Core Protein Resources Center, DGIST, Daegu, 42988, South Korea.
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea.
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89
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Ruden JB, Dugan LL, Konradi C. Parvalbumin interneuron vulnerability and brain disorders. Neuropsychopharmacology 2021; 46:279-287. [PMID: 32722660 PMCID: PMC7852528 DOI: 10.1038/s41386-020-0778-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/02/2020] [Accepted: 07/21/2020] [Indexed: 12/31/2022]
Abstract
Parvalbumin-expressing interneurons (PV-INs) are highly vulnerable to stressors and have been implicated in many neuro-psychiatric diseases such as schizophrenia, Alzheimer's disease, autism spectrum disorder, and bipolar disorder. We examined the literature about the current knowledge of the physiological properties of PV-INs and gathered results from diverse research areas to provide insight into their vulnerability to stressors. Among the factors that confer heightened vulnerability are the substantial energy requirements, a strong excitatory drive, and a unique developmental trajectory. Understanding these stressors and elaborating on their impact on PV-IN health is a step toward developing therapies to protect these neurons in various disease states and to retain critical brain functions.
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Affiliation(s)
- Jacob B Ruden
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Laura L Dugan
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
- Division of Geriatric Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christine Konradi
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA.
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90
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Uchigashima M, Konno K, Demchak E, Cheung A, Watanabe T, Keener DG, Abe M, Le T, Sakimura K, Sasaoka T, Uemura T, Imamura Kawasawa Y, Watanabe M, Futai K. Specific Neuroligin3-αNeurexin1 signaling regulates GABAergic synaptic function in mouse hippocampus. eLife 2020; 9:e59545. [PMID: 33355091 PMCID: PMC7758064 DOI: 10.7554/elife.59545] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
Synapse formation and regulation require signaling interactions between pre- and postsynaptic proteins, notably cell adhesion molecules (CAMs). It has been proposed that the functions of neuroligins (Nlgns), postsynaptic CAMs, rely on the formation of trans-synaptic complexes with neurexins (Nrxns), presynaptic CAMs. Nlgn3 is a unique Nlgn isoform that localizes at both excitatory and inhibitory synapses. However, Nlgn3 function mediated via Nrxn interactions is unknown. Here we demonstrate that Nlgn3 localizes at postsynaptic sites apposing vesicular glutamate transporter 3-expressing (VGT3+) inhibitory terminals and regulates VGT3+ inhibitory interneuron-mediated synaptic transmission in mouse organotypic slice cultures. Gene expression analysis of interneurons revealed that the αNrxn1+AS4 splice isoform is highly expressed in VGT3+ interneurons as compared with other interneurons. Most importantly, postsynaptic Nlgn3 requires presynaptic αNrxn1+AS4 expressed in VGT3+ interneurons to regulate inhibitory synaptic transmission. Our results indicate that specific Nlgn-Nrxn signaling generates distinct functional properties at synapses.
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Affiliation(s)
- Motokazu Uchigashima
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
- Department of Cellular Neuropathology, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Kohtarou Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Emily Demchak
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Takuya Watanabe
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - David G Keener
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Timmy Le
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Toshikuni Sasaoka
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Takeshi Uemura
- Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu UniversityNaganoJapan
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu UniversityNaganoJapan
| | - Yuka Imamura Kawasawa
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
- Department of Pharmacology Pennsylvania State University College of MedicineHersheyUnited States
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
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91
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Liu QR, Canseco-Alba A, Liang Y, Ishiguro H, Onaivi ES. Low Basal CB2R in Dopamine Neurons and Microglia Influences Cannabinoid Tetrad Effects. Int J Mol Sci 2020; 21:E9763. [PMID: 33371336 PMCID: PMC7767340 DOI: 10.3390/ijms21249763] [Citation(s) in RCA: 12] [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: 11/01/2020] [Revised: 12/04/2020] [Accepted: 12/17/2020] [Indexed: 12/13/2022] Open
Abstract
There are two well-characterized cannabinoid receptors (CB1R and CB2R and other candidates): the central nervous system (CNS) enriched CB1R and peripheral tissue enriched CB2R with a wide dynamic range of expression levels in different cell types of human tissues. Hepatocytes and neurons express low baseline CB1R and CB2R, respectively, and their cell-type-specific functions are not well defined. Here we report inducible expression of CB1R in the liver by high-fat and high sugar diet and CB2R in cortical neurons by methamphetamine. While there is less controversy about hepatocyte CB1R, the presence of functional neuronal CB2R is still debated to date. We found that neuron CB2R basal expression was higher than that of hepatocyte CB1R by measuring mRNA levels of specific isoform CB2A in neurons isolated by fluorescence-activated cell sorting (FACS) and CB1A in hepatocytes isolated by collagenase perfusion of liver. For in vivo studies, we generated hepatocyte, dopaminergic neuron, and microglia-specific conditional knockout mice (Abl-Cnr1Δ, Dat-Cnr2Δ, and Cx3cr1-Cnr2Δ) of CB1R and CB2R by crossing Cnr1f/f and Cnr2f/f strains to Abl-Cre, Dat-Cre, and Cx3cr1-Cre deleter mouse strains, respectively. Our data reveals that neuron and microglia CB2Rs are involved in the "tetrad" effects of the mixed agonist WIN 55212-2, CB1R selective agonist arachidonyl-2'-chloroethylamide (ACEA), and CB2R selective agonist JWH133. Dat-Cnr2Δ and Cx3cr1-Cnr2Δ mice showed genotypic differences in hypomobility, hypothermia, analgesia, and catalepsy induced by the synthetic cannabinoids. Alcohol conditioned place preference was abolished in DAT-Cnr2Δ mice and remained intact in Cx3cr1-Cnr2Δ mice in comparison to WT mice. These Cre-loxP recombinant mouse lines provide unique approaches in cannabinoid research for dissecting the complex endocannabinoid system that is implicated in many chronic disorders.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Cannabinoids/pharmacology
- Dopaminergic Neurons/drug effects
- Dopaminergic Neurons/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microglia/drug effects
- Microglia/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB1/physiology
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Receptor, Cannabinoid, CB2/physiology
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Affiliation(s)
- Qing-Rong Liu
- Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, MD 21224, USA
| | - Ana Canseco-Alba
- Department of Biology, William Paterson University, Wayne, NJ 07470, USA;
| | - Ying Liang
- College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China;
| | - Hiroki Ishiguro
- Department of Neuropsychiatry, Graduate School of Medical Science, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan;
| | - Emmanuel S. Onaivi
- Department of Biology, William Paterson University, Wayne, NJ 07470, USA;
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92
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Sun Z, Südhof TC. A simple Ca 2+-imaging approach to neural network analyses in cultured neurons. J Neurosci Methods 2020; 349:109041. [PMID: 33340555 DOI: 10.1016/j.jneumeth.2020.109041] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 12/08/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Ca2+-imaging is a powerful tool to measure neuronal dynamics and network activity. To monitor network-level changes in cultured neurons, neuronal activity is often evoked by electrical or optogenetic stimulation and assessed using multi-electrode arrays or sophisticated imaging. Although such approaches allow detailed network analyses, multi-electrode arrays lack single-cell precision, whereas optical physiology generally requires advanced instrumentation that may not be universally available. NEW METHOD Here we developed a simple, stimulation-free protocol with associated Matlab algorithms that enables scalable analyses of spontaneous network activity in cultured human and mouse neurons. The approach allows analysis of the overall network activity and of single-neuron dynamics, and is amenable to screening purposes. RESULTS We validated the new protocol by assessing human neurons with a heterozygous conditional deletion of Munc18-1, and mouse neurons with a homozygous conditional deletion of neurexins. The approach described enabled identification of differential changes in these mutant neurons, allowing quantifications of the synchronous firing rate at the network level and of the amplitude and frequency of Ca2+-spikes at the single-neuron level. These results demonstrate the utility of the approach. COMPARISION WITH EXISTING METHODS Compared with current imaging platforms, our method is simple, scalable, accessible, and easy to implement. It enables quantification of more detailed parameters than multi-electrode arrays, but does not have the resolution and depth of more sophisticated yet labour-intensive methods, such as patch-clamp electrophysiology. CONCLUSION The method reported here is scalable for a rapid direct assessment of neuronal function in culture, and can be applied to both human and mouse neurons. Thus, the method can serve as a basis for phenotypical analysis of mutations and for drug discovery efforts.
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Affiliation(s)
- Zijun Sun
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
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93
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Fukai S, Yoshida T. Roles of type IIa receptor protein tyrosine phosphatases as synaptic organizers. FEBS J 2020; 288:6913-6926. [PMID: 33301645 DOI: 10.1111/febs.15666] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/26/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022]
Abstract
Neurons establish circuits for brain functions such as cognition, emotion, learning, and memory. Their connections are mediated by synapses, which are specialized cell-cell adhesions responsible for neuronal signal transmission. During neurodevelopment, synapse formation is triggered by interactions of cell adhesion molecules termed synaptic organizers or synapse organizers. Type IIa receptor protein tyrosine phosphatases (IIa RPTPs; also known as leukocyte common antigen-related receptor tyrosine phosphatases or LAR-RPTPs) play important roles in axon guidance and neurite extension, and also serve as presynaptic organizers. IIa RPTPs transsynaptically interact with multiple sets of postsynaptic organizers, mostly in a splicing-dependent fashion. Here, we review and update research progress on IIa RPTPs, particularly regarding their functional roles in vivo demonstrated using conditional knockout approach and structural insights into their extracellular and intracellular molecular interactions revealed by crystallography and other biophysical techniques. Future directions in the research field of IIa RPTPs are also discussed, including recent findings of the molecular assembly mechanism underlying the formation of synapse-specific nanostructures essential for synaptic functions.
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Affiliation(s)
- Shuya Fukai
- Department of Chemistry, Graduate School of Science, Kyoto University, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
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94
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Rizalar FS, Roosen DA, Haucke V. A Presynaptic Perspective on Transport and Assembly Mechanisms for Synapse Formation. Neuron 2020; 109:27-41. [PMID: 33098763 DOI: 10.1016/j.neuron.2020.09.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/26/2020] [Accepted: 09/25/2020] [Indexed: 01/01/2023]
Abstract
Neurons are highly polarized cells with a single axon and multiple dendrites derived from the cell body to form tightly associated pre- and postsynaptic compartments. As the biosynthetic machinery is largely restricted to the somatodendritic domain, the vast majority of presynaptic components are synthesized in the neuronal soma, packaged into synaptic precursor vesicles, and actively transported along the axon to sites of presynaptic biogenesis. In contrast with the significant progress that has been made in understanding synaptic transmission and processing of information at the post-synapse, comparably little is known about the formation and dynamic remodeling of the presynaptic compartment. We review here our current understanding of the mechanisms that govern the biogenesis, transport, and assembly of the key components for presynaptic neurotransmission, discuss how alterations in presynaptic assembly may impact nervous system function or lead to disease, and outline key open questions for future research.
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Affiliation(s)
- Filiz Sila Rizalar
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Dorien A Roosen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany; Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany.
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95
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SPARCL1 Promotes Excitatory But Not Inhibitory Synapse Formation and Function Independent of Neurexins and Neuroligins. J Neurosci 2020; 40:8088-8102. [PMID: 32973045 DOI: 10.1523/jneurosci.0454-20.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/17/2020] [Accepted: 07/12/2020] [Indexed: 12/17/2022] Open
Abstract
Emerging evidence supports roles for secreted extracellular matrix proteins in boosting synaptogenesis, synaptic transmission, and synaptic plasticity. SPARCL1 (also known as Hevin), a secreted non-neuronal protein, was reported to increase synaptogenesis by simultaneously binding to presynaptic neurexin-1α and to postsynaptic neuroligin-1B, thereby catalyzing formation of trans-synaptic neurexin/neuroligin complexes. However, neurexins and neuroligins do not themselves mediate synaptogenesis, raising the question of how SPARCL1 enhances synapse formation by binding to these molecules. Moreover, it remained unclear whether SPARCL1 acts on all synapses containing neurexins and neuroligins or only on a subset of synapses, and whether it enhances synaptic transmission in addition to boosting synaptogenesis or induces silent synapses. To explore these questions, we examined the synaptic effects of SPARCL1 and their dependence on neurexins and neuroligins. Using mixed neuronal and glial cultures from neonatal mouse cortex of both sexes, we show that SPARCL1 selectively increases excitatory but not inhibitory synapse numbers, enhances excitatory but not inhibitory synaptic transmission, and augments NMDAR-mediated synaptic responses more than AMPAR-mediated synaptic responses. None of these effects were mediated by SPARCL1-binding to neurexins or neuroligins. Neurons from triple neurexin-1/2/3 or from quadruple neuroligin-1/2/3/4 conditional KO mice that lacked all neurexins or all neuroligins were fully responsive to SPARCL1. Together, our results reveal that SPARCL1 selectively boosts excitatory but not inhibitory synaptogenesis and synaptic transmission by a novel mechanism that is independent of neurexins and neuroligins.SIGNIFICANCE STATEMENT Emerging evidence supports roles for extracellular matrix proteins in boosting synapse formation and function. Previous studies demonstrated that SPARCL1, a secreted non-neuronal protein, promotes synapse formation in rodent and human neurons. However, it remained unclear whether SPARCL1 acts on all or on only a subset of synapses, induces functional or largely inactive synapses, and generates synapses by bridging presynaptic neurexins and postsynaptic neuroligins. Here, we report that SPARCL1 selectively induces excitatory synapses, increases their efficacy, and enhances their NMDAR content. Moreover, using rigorous genetic manipulations, we show that SPARCL1 does not require neurexins and neuroligins for its activity. Thus, SPARCL1 selectively boosts excitatory synaptogenesis and synaptic transmission by a novel mechanism that is independent of neurexins and neuroligins.
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96
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Chou VT, Johnson SA, Van Vactor D. Synapse development and maturation at the drosophila neuromuscular junction. Neural Dev 2020; 15:11. [PMID: 32741370 PMCID: PMC7397595 DOI: 10.1186/s13064-020-00147-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
Synapses are the sites of neuron-to-neuron communication and form the basis of the neural circuits that underlie all animal cognition and behavior. Chemical synapses are specialized asymmetric junctions between a presynaptic neuron and a postsynaptic target that form through a series of diverse cellular and subcellular events under the control of complex signaling networks. Once established, the synapse facilitates neurotransmission by mediating the organization and fusion of synaptic vesicles and must also retain the ability to undergo plastic changes. In recent years, synaptic genes have been implicated in a wide array of neurodevelopmental disorders; the individual and societal burdens imposed by these disorders, as well as the lack of effective therapies, motivates continued work on fundamental synapse biology. The properties and functions of the nervous system are remarkably conserved across animal phyla, and many insights into the synapses of the vertebrate central nervous system have been derived from studies of invertebrate models. A prominent model synapse is the Drosophila melanogaster larval neuromuscular junction, which bears striking similarities to the glutamatergic synapses of the vertebrate brain and spine; further advantages include the simplicity and experimental versatility of the fly, as well as its century-long history as a model organism. Here, we survey findings on the major events in synaptogenesis, including target specification, morphogenesis, and the assembly and maturation of synaptic specializations, with a emphasis on work conducted at the Drosophila neuromuscular junction.
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Affiliation(s)
- Vivian T Chou
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Seth A Johnson
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
| | - David Van Vactor
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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97
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Qin L, Guo S, Han Y, Wang X, Zhang B. Functional mosaic organization of neuroligins in neuronal circuits. Cell Mol Life Sci 2020; 77:3117-3127. [PMID: 32077971 PMCID: PMC11104838 DOI: 10.1007/s00018-020-03478-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 11/30/2022]
Abstract
Complex brain circuitry with feedforward and feedback systems regulates neuronal activity, enabling neural networks to process and drive the entire spectrum of cognitive, behavioral, sensory, and motor functions. Simultaneous orchestration of distinct cells and interconnected neural circuits is underpinned by hundreds of synaptic adhesion molecules that span synaptic junctions. Dysfunction of a single molecule or molecular interaction at synapses can lead to disrupted circuit activity and brain disorders. Neuroligins, a family of cell adhesion molecules, were first identified as postsynaptic-binding partners of presynaptic neurexins and are essential for synapse specification and maturation. Here, we review recent advances in our understanding of how this family of adhesion molecules controls neuronal circuit assembly by acting in a synapse-specific manner.
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Affiliation(s)
- Liming Qin
- School of Chemical Biology and Biotechnology, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Sile Guo
- School of Chemical Biology and Biotechnology, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Ying Han
- School of Chemical Biology and Biotechnology, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Xiankun Wang
- School of Chemical Biology and Biotechnology, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Bo Zhang
- School of Chemical Biology and Biotechnology, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
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98
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Lukacsovich D, Winterer J, Que L, Luo W, Lukacsovich T, Földy C. Single-Cell RNA-Seq Reveals Developmental Origins and Ontogenetic Stability of Neurexin Alternative Splicing Profiles. Cell Rep 2020; 27:3752-3759.e4. [PMID: 31242409 DOI: 10.1016/j.celrep.2019.05.090] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 02/08/2019] [Accepted: 05/22/2019] [Indexed: 12/12/2022] Open
Abstract
Neurexins are key synaptic organizers that are expressed in thousands of alternatively spliced isoforms. Because transsynaptic neurexin interactions with different postsynaptic molecules are largely isoform dependent, a cell type-level census of different neurexin isoforms could predict molecular interactions relating to synapse identity and function. Using single-cell transcriptomics to study the origin of neurexin diversity in multiple murine mature and embryonic cell types, we have discovered shared neurexin expression patterns in developmentally related cells. By comparing neurexin profiles in immature embryonic neurons, we show that neurexin profiles are specified during early development and remain unchanged throughout neuronal maturation. Thus, our findings reveal ontogenetic stability and provide a cell type-level census of neurexin isoform expression in the cortex.
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Affiliation(s)
- David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Jochen Winterer
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Lin Que
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Wenshu Luo
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Tamas Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Natural Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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99
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Deletion of NRXN1α impairs long-range and local connectivity in amygdala fear circuit. Transl Psychiatry 2020; 10:242. [PMID: 32684634 PMCID: PMC7370229 DOI: 10.1038/s41398-020-00926-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 01/26/2023] Open
Abstract
Neurexins are a family of presynaptic cell adhesion proteins that regulate synaptic structure and maintain normal synaptic transmission. Mutations in the α-isoform of neurexin1-gene (NRXN1α) are linked with cognitive and emotional dysregulation, which are heavily dependent on the amygdala and medial prefrontal cortex (mPFC). It is however not known whether deletion of NRXN1α gene affect specific synaptic elements within the amygdala microcircuit and connectivity with mPFC. In this study, we show that NRXN1α deletion impairs synaptic transmission between the dorsal medial prefrontal cortex (dmPFC) and basal amygdala (BA) principal neurons. Stimulation of dmPFC fibers resulted in reduced paired pulse ratio (PPR) and AMPA/NMDA ratio at dmPFC to BA synapses in NRXN1α-knockout (KO) (NRXN1α KO) mice suggestive of pre- and postsynaptic deficits but there was no change at the lateral amygdala (LA) to BA synapses following LA stimulation. However, feedforward inhibition from either pathway was significantly reduced, suggestive of input-independent deficit in GABAergic transmission within BA. We further analyzed BA inhibitory network and found reduced connectivity between BA GABAergic and glutamatergic neurons in NRXN1α KO mice. As this circuit is tightly linked with fear regulation, we subjected NRXN1α KO and WT mice to discriminative fear conditioning and found a deficit in fear memory retrieval in NRXN1α KO mice compared with WT mice. Together, we provide novel evidence that deletion of NRNX1α disrupts amygdala fear circuit.
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100
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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