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Kim N, Bonnycastle K, Kind PC, Cousin MA. Delayed recruitment of activity-dependent bulk endocytosis in Fmr1 knockout neurons. J Neurochem 2024. [PMID: 38978454 DOI: 10.1111/jnc.16178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/10/2024]
Abstract
The presynapse performs an essential role in brain communication via the activity-dependent release of neurotransmitters. However, the sequence of events through which a presynapse acquires functionality is relatively poorly understood, which is surprising, since mutations in genes essential for its operation are heavily implicated in neurodevelopmental disorders. We addressed this gap in knowledge by determining the developmental trajectory of synaptic vesicle (SV) recycling pathways in primary cultures of rat hippocampal neurons. Exploiting a series of optical and morphological assays, we revealed that the majority of nerve terminals displayed activity-dependent calcium influx from 3 days in vitro (DIV), immediately followed by functional evoked exocytosis and endocytosis, although the number of responsive nerve terminals continued to increase until the second week in vitro. However, the most intriguing discovery was that activity-dependent bulk endocytosis (ADBE) was only observed from DIV 14 onwards. Importantly, optimal ADBE recruitment was delayed until DIV 21 in Fmr1 knockout neurons, which model Fragile X Syndrome (FXS). This implicates the delayed recruitment of ADBE as a potential contributing factor in the development of circuit dysfunction in FXS, and potentially other neurodevelopmental disorders.
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Affiliation(s)
- Nawon Kim
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
| | - Katherine Bonnycastle
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
| | - Peter C Kind
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, University of Edinburgh, Edinburgh, UK
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2
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Carricaburu E, Benner O, Burlingham SR, Dos Santos Passos C, Hobaugh N, Karr CH, Chanda S. Gephyrin promotes autonomous assembly and synaptic localization of GABAergic postsynaptic components without presynaptic GABA release. Proc Natl Acad Sci U S A 2024; 121:e2315100121. [PMID: 38889143 PMCID: PMC11214061 DOI: 10.1073/pnas.2315100121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Synapses containing γ-aminobutyric acid (GABA) constitute the primary centers for inhibitory neurotransmission in our nervous system. It is unclear how these synaptic structures form and align their postsynaptic machineries with presynaptic terminals. Here, we monitored the cellular distribution of several GABAergic postsynaptic proteins in a purely glutamatergic neuronal culture derived from human stem cells, which virtually lacks any vesicular GABA release. We found that several GABAA receptor (GABAAR) subunits, postsynaptic scaffolds, and major cell-adhesion molecules can reliably coaggregate and colocalize at even GABA-deficient subsynaptic domains, but remain physically segregated from glutamatergic counterparts. Genetic deletions of both Gephyrin and a Gephyrin-associated guanosine di- or triphosphate (GDP/GTP) exchange factor Collybistin severely disrupted the coassembly of these postsynaptic compositions and their proper apposition with presynaptic inputs. Gephyrin-GABAAR clusters, developed in the absence of GABA transmission, could be subsequently activated and even potentiated by delayed supply of vesicular GABA. Thus, molecular organization of GABAergic postsynapses can initiate via a GABA-independent but Gephyrin-dependent intrinsic mechanism.
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Affiliation(s)
- Etta Carricaburu
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Orion Benner
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Scott R. Burlingham
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | | | - Natalia Hobaugh
- Biological Sciences Division, University of Chicago, Chicago, IL60637
| | - Charles H. Karr
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
| | - Soham Chanda
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO80523
- Molecular, Cellular and Integrated Neurosciences Program, Colorado State University, Fort Collins, CO80523
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO80523
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3
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Huang M, Pieraut S, Cao J, de Souza Polli F, Roncace V, Shen G, Ramos-Medina C, Lee H, Maximov A. Nr4a1 regulates cell-specific transcriptional programs in inhibitory GABAergic interneurons. Neuron 2024; 112:2031-2044.e7. [PMID: 38754414 PMCID: PMC11189749 DOI: 10.1016/j.neuron.2024.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/29/2024] [Accepted: 03/14/2024] [Indexed: 05/18/2024]
Abstract
The patterns of synaptic connectivity and physiological properties of diverse neuron types are shaped by distinct gene sets. Our study demonstrates that, in the mouse forebrain, the transcriptional profiles of inhibitory GABAergic interneurons are regulated by Nr4a1, an orphan nuclear receptor whose expression is transiently induced by sensory experiences and is required for normal learning. Nr4a1 exerts contrasting effects on the local axonal wiring of parvalbumin- and somatostatin-positive interneurons, which innervate different subcellular domains of their postsynaptic partners. The loss of Nr4a1 activity in these interneurons results in bidirectional, cell-type-specific transcriptional switches across multiple gene families, including those involved in surface adhesion and repulsion. Our findings reveal that combinatorial synaptic organizing codes are surprisingly flexible and highlight a mechanism by which inducible transcription factors can influence neural circuit structure and function.
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Affiliation(s)
- Min Huang
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; The Kellogg School of Science and Technology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Simon Pieraut
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jasmine Cao
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Filip de Souza Polli
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Vincenzo Roncace
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Gloria Shen
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Carlos Ramos-Medina
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - HeeYang Lee
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; The Kellogg School of Science and Technology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anton Maximov
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA; The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA.
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4
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Wise DL, Escobedo-Lozoya Y, Valakh V, Gao EY, Bhonsle A, Lei QL, Cheng X, Greene SB, Van Hooser SD, Nelson SB. Prolonged Activity Deprivation Causes Pre- and Postsynaptic Compensatory Plasticity at Neocortical Excitatory Synapses. eNeuro 2024; 11:ENEURO.0366-23.2024. [PMID: 38777611 PMCID: PMC11163391 DOI: 10.1523/eneuro.0366-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
Homeostatic plasticity stabilizes firing rates of neurons, but the pressure to restore low activity rates can significantly alter synaptic and cellular properties. Most previous studies of homeostatic readjustment to complete activity silencing in rodent forebrain have examined changes after 2 d of deprivation, but it is known that longer periods of deprivation can produce adverse effects. To better understand the mechanisms underlying these effects and to address how presynaptic as well as postsynaptic compartments change during homeostatic plasticity, we subjected mouse cortical slice cultures to a more severe 5 d deprivation paradigm. We developed and validated a computational framework to measure the number and morphology of presynaptic and postsynaptic compartments from super-resolution light microscopy images of dense cortical tissue. Using these tools, combined with electrophysiological miniature excitatory postsynaptic current measurements, and synaptic imaging at the electron microscopy level, we assessed the functional and morphological results of prolonged deprivation. Excitatory synapses were strengthened both presynaptically and postsynaptically. Surprisingly, we also observed a decrement in the density of excitatory synapses, both as measured from colocalized staining of pre- and postsynaptic proteins in tissue and from the number of dendritic spines. Overall, our results suggest that cortical networks deprived of activity progressively move toward a smaller population of stronger synapses.
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Affiliation(s)
- Derek L Wise
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | | | - Vera Valakh
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | - Emma Y Gao
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | - Aishwarya Bhonsle
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | - Qian L Lei
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | - Xinyu Cheng
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | - Samuel B Greene
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
| | | | - Sacha B Nelson
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454 9110
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5
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Uytiepo M, Zhu Y, Bushong E, Polli F, Chou K, Zhao E, Kim C, Luu D, Chang L, Quach T, Haberl M, Patapoutian L, Beutter E, Zhang W, Dong B, McCue E, Ellisman M, Maximov A. Synaptic architecture of a memory engram in the mouse hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.23.590812. [PMID: 38712256 PMCID: PMC11071366 DOI: 10.1101/2024.04.23.590812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Memory engrams are formed through experience-dependent remodeling of neural circuits, but their detailed architectures have remained unresolved. Using 3D electron microscopy, we performed nanoscale reconstructions of the hippocampal CA3-CA1 pathway following chemogenetic labeling of cellular ensembles with a remote history of correlated excitation during associative learning. Projection neurons involved in memory acquisition expanded their connectomes via multi-synaptic boutons without altering the numbers and spatial arrangements of individual axonal terminals and dendritic spines. This expansion was driven by presynaptic activity elicited by specific negative valence stimuli, regardless of the co-activation state of postsynaptic partners. The rewiring of initial ensembles representing an engram coincided with local, input-specific changes in the shapes and organelle composition of glutamatergic synapses, reflecting their weights and potential for further modifications. Our findings challenge the view that the connectivity among neuronal substrates of memory traces is governed by Hebbian mechanisms, and offer a structural basis for representational drifts.
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6
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Chen Y, Liu S, Jacobi AA, Jeng G, Ulrich JD, Stein IS, Patriarchi T, Hell JW. Rapid sequential clustering of NMDARs, CaMKII, and AMPARs upon activation of NMDARs at developing synapses. Front Synaptic Neurosci 2024; 16:1291262. [PMID: 38660466 PMCID: PMC11039796 DOI: 10.3389/fnsyn.2024.1291262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024] Open
Abstract
Rapid, synapse-specific neurotransmission requires the precise alignment of presynaptic neurotransmitter release and postsynaptic receptors. How postsynaptic glutamate receptor accumulation is induced during maturation is not well understood. We find that in cultures of dissociated hippocampal neurons at 11 days in vitro (DIV) numerous synaptic contacts already exhibit pronounced accumulations of the pre- and postsynaptic markers synaptotagmin, synaptophysin, synapsin, bassoon, VGluT1, PSD-95, and Shank. The presence of an initial set of AMPARs and NMDARs is indicated by miniature excitatory postsynaptic currents (mEPSCs). However, AMPAR and NMDAR immunostainings reveal rather smooth distributions throughout dendrites and synaptic enrichment is not obvious. We found that brief periods of Ca2+ influx through NMDARs induced a surprisingly rapid accumulation of NMDARs within 1 min, followed by accumulation of CaMKII and then AMPARs within 2-5 min. Postsynaptic clustering of NMDARs and AMPARs was paralleled by an increase in their mEPSC amplitudes. A peptide that blocked the interaction of NMDAR subunits with PSD-95 prevented the NMDAR clustering. NMDAR clustering persisted for 3 days indicating that brief periods of elevated glutamate fosters permanent accumulation of NMDARs at postsynaptic sites in maturing synapses. These data support the model that strong glutamatergic stimulation of immature glutamatergic synapses results in a fast and substantial increase in postsynaptic NMDAR content that required NMDAR binding to PSD-95 or its homologues and is followed by recruitment of CaMKII and subsequently AMPARs.
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Affiliation(s)
- Yucui Chen
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
| | - Shangming Liu
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Ariel A. Jacobi
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Grace Jeng
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Jason D. Ulrich
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
| | - Ivar S. Stein
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Tommaso Patriarchi
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Johannes W. Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
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7
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Marcó de la Cruz B, Campos J, Molinaro A, Xie X, Jin G, Wei Z, Acuna C, Sterky FH. Liprin-α proteins are master regulators of human presynapse assembly. Nat Neurosci 2024; 27:629-642. [PMID: 38472649 PMCID: PMC11001580 DOI: 10.1038/s41593-024-01592-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 01/30/2024] [Indexed: 03/14/2024]
Abstract
The formation of mammalian synapses entails the precise alignment of presynaptic release sites with postsynaptic receptors but how nascent cell-cell contacts translate into assembly of presynaptic specializations remains unclear. Guided by pioneering work in invertebrates, we hypothesized that in mammalian synapses, liprin-α proteins directly link trans-synaptic initial contacts to downstream steps. Here we show that, in human neurons lacking all four liprin-α isoforms, nascent synaptic contacts are formed but recruitment of active zone components and accumulation of synaptic vesicles is blocked, resulting in 'empty' boutons and loss of synaptic transmission. Interactions with presynaptic cell adhesion molecules of either the LAR-RPTP family or neurexins via CASK are required to localize liprin-α to nascent synaptic sites. Liprin-α subsequently recruits presynaptic components via a direct interaction with ELKS proteins. Thus, assembly of human presynaptic terminals is governed by a hierarchical sequence of events in which the recruitment of liprin-α proteins by presynaptic cell adhesion molecules is a critical initial step.
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Affiliation(s)
- Berta Marcó de la Cruz
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Joaquín Campos
- Chica and Heinz Schaller Foundation, Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Angela Molinaro
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Xingqiao Xie
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, China
| | - Gaowei Jin
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
| | - Zhiyi Wei
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, China
| | - Claudio Acuna
- Chica and Heinz Schaller Foundation, Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany.
| | - Fredrik H Sterky
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
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8
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Sell GL, Barrow SL, McAllister AK. Glutamate signaling and neuroligin/neurexin adhesion play opposing roles that are mediated by major histocompatibility complex I molecules in cortical synapse formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.05.583626. [PMID: 38496590 PMCID: PMC10942384 DOI: 10.1101/2024.03.05.583626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Although neurons release neurotransmitter before contact, the role for this release in synapse formation remains unclear. Cortical synapses do not require synaptic vesicle release for formation 1-4 , yet glutamate clearly regulates glutamate receptor trafficking 5,6 and induces spine formation 7-11 . Using a culture system to dissect molecular mechanisms, we found that glutamate rapidly decreases synapse density specifically in young cortical neurons in a local and calcium-dependent manner through decreasing NMDAR transport and surface expression as well as co-transport with neuroligin (NL1). Adhesion between NL1 and neurexin 1 protects against this glutamate-induced synapse loss. Major histocompatibility I (MHCI) molecules are required for the effects of glutamate in causing synapse loss through negatively regulating NL1 levels. Thus, like acetylcholine at the NMJ, glutamate acts as a dispersal signal for NMDARs and causes rapid synapse loss unless opposed by NL1-mediated trans-synaptic adhesion. Together, glutamate, MHCI and NL1 mediate a novel form of homeostatic plasticity in young neurons that induces rapid changes in NMDARs to regulate when and where nascent glutamatergic synapses are formed.
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9
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Mohrmann L, Seebach J, Missler M, Rohlmann A. Distinct Alterations in Dendritic Spine Morphology in the Absence of β-Neurexins. Int J Mol Sci 2024; 25:1285. [PMID: 38279285 PMCID: PMC10817056 DOI: 10.3390/ijms25021285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Dendritic spines are essential for synaptic function because they constitute the postsynaptic compartment of the neurons that receives the most excitatory input. The extracellularly shorter variant of the presynaptic cell adhesion molecules neurexins, β-neurexin, has been implicated in various aspects of synaptic function, including neurotransmitter release. However, its role in developing or stabilizing dendritic spines as fundamental computational units of excitatory synapses has remained unclear. Here, we show through morphological analysis that the deletion of β-neurexins in hippocampal neurons in vitro and in hippocampal tissue in vivo affects presynaptic dense-core vesicles, as hypothesized earlier, and, unexpectedly, alters the postsynaptic spine structure. Specifically, we observed that the absence of β-neurexins led to an increase in filopodial-like protrusions in vitro and more mature mushroom-type spines in the CA1 region of adult knockout mice. In addition, the deletion of β-neurexins caused alterations in the spine head dimension and an increase in spines with perforations of their postsynaptic density but no changes in the overall number of spines or synapses. Our results indicate that presynaptic β-neurexins play a role across the synaptic cleft, possibly by aligning with postsynaptic binding partners and glutamate receptors via transsynaptic columns.
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Affiliation(s)
| | | | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, University Münster, 48149 Münster, Germany; (L.M.); (J.S.)
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, University Münster, 48149 Münster, Germany; (L.M.); (J.S.)
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10
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Barabási DL, Schuhknecht GFP, Engert F. Functional neuronal circuits emerge in the absence of developmental activity. Nat Commun 2024; 15:364. [PMID: 38191595 PMCID: PMC10774424 DOI: 10.1038/s41467-023-44681-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 12/29/2023] [Indexed: 01/10/2024] Open
Abstract
The complex neuronal circuitry of the brain develops from limited information contained in the genome. After the genetic code instructs the birth of neurons, the emergence of brain regions, and the formation of axon tracts, it is believed that temporally structured spiking activity shapes circuits for behavior. Here, we challenge the learning-dominated assumption that spiking activity is required for circuit formation by quantifying its contribution to the development of visually-guided swimming in the larval zebrafish. We found that visual experience had no effect on the emergence of the optomotor response (OMR) in dark-reared zebrafish. We then raised animals while pharmacologically silencing action potentials with the sodium channel blocker tricaine. After washout of the anesthetic, fish could swim and performed with 75-90% accuracy in the OMR paradigm. Brain-wide imaging confirmed that neuronal circuits came 'online' fully tuned, without requiring activity-dependent plasticity. Thus, complex sensory-guided behaviors can emerge through activity-independent developmental mechanisms.
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Affiliation(s)
- Dániel L Barabási
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
- Biophysics Program, Harvard University, Cambridge, MA, USA.
| | | | - Florian Engert
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
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11
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Schaeuble D, Wallace T, Pace SA, Hentges ST, Myers B. Sex-specific prefrontal-hypothalamic control of behavior and stress responding. Psychoneuroendocrinology 2024; 159:106413. [PMID: 37890240 PMCID: PMC10842088 DOI: 10.1016/j.psyneuen.2023.106413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/30/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023]
Abstract
Depression and cardiovascular disease are both augmented by daily life stress. Yet, the biological mechanisms that translate psychological stress into affective and physiological outcomes are unknown. Previously, we demonstrated that stimulation of the ventromedial prefrontal cortex (vmPFC) has sexually divergent outcomes on behavior and physiology. Importantly, the vmPFC does not innervate the brain regions that initiate autonomic or neuroendocrine stress responses; thus, we hypothesized that intermediate synapses integrate cortical information to regulate stress responding. The posterior hypothalamus (PH) directly innervates stress-effector regions and receives substantial innervation from the vmPFC. In the current studies, circuit-specific approaches examined whether vmPFC synapses in the PH coordinate stress responding. Here we tested the effects of optogenetic vmPFC-PH circuit stimulation in male and female rats on social and motivational behaviors as well as physiological stress responses. Additionally, an intersectional genetic approach was used to knock down synaptobrevin in PH-projecting vmPFC neurons. Our collective results indicate that male vmPFC-PH circuitry promotes positive motivational valence and is both sufficient and necessary to reduce sympathetic-mediated stress responses. In females, the vmPFC-PH circuit does not affect social or preference behaviors but is sufficient and necessary to elevate neuroendocrine stress responses. Altogether, these data suggest cortical regulation of stress reactivity and behavior is mediated, in part, by projections to the hypothalamus that function in a sex-specific manner.
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Affiliation(s)
- Derek Schaeuble
- Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Tyler Wallace
- Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Sebastian A Pace
- Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Shane T Hentges
- Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Brent Myers
- Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
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12
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Kim B, Kim JS, Youn B, Moon C. Dopamine depletion alters neuroplasticity-related signaling in the rat hippocampus. Anim Cells Syst (Seoul) 2023; 27:436-446. [PMID: 38125760 PMCID: PMC10732217 DOI: 10.1080/19768354.2023.2294308] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Dopamine (DA) plays a significant role in regulating hippocampal function, particularly in modulating synaptic plasticity. Despite this, a comprehensive understanding of the molecular mechanisms involved in neuroplasticity-related signaling influenced by DA remains incomplete. This study aimed to elucidate the changes in the expression of key molecules related to hippocampal neuroplasticity following DA depletion in rats. To induce DA depletion, unilateral striatal infusions of 6-hydroxydopamine (6-OHDA) were administered to adult Sprague-Dawley rats. The subsequent loss of nigrostriatal DAergic signaling in these 6-OHDA-lesioned rats was confirmed using an apomorphine-induced rotation test at 4 weeks post-infusion and by assessing the expression levels of tyrosine hydroxylase (TH) through immunohistochemistry and western blotting at 7 weeks post-infusion. A decrease in DAergic signaling, evidenced by reduced TH-positive immunoreactivity, was also noted in the ipsilateral hippocampus of the lesioned rats. Interestingly, 6-OHDA infusion led to increased phosphorylation of pivotal hippocampal plasticity-related proteins, including extracellular signal-regulated kinase (ERK), protein kinase B (Akt), glycogen synthase kinase 3β (GSK3β), and cAMP response element-binding protein (CREB), in the ipsilateral hippocampus 7 weeks following the infusion. To extend these findings, in vitro experiments were conducted on primary hippocampal neurons exposed to DA and/or the active D1/D2 DA receptor antagonist, flupentixol (Flux). DA inhibited the constitutive phosphorylation of ERK, Akt, GSK3, and CREB, while Flux restored these phosphorylation levels. Taken together, these findings indicate that DA depletion triggers an increase in plasticity-related signaling in the hippocampus, suggesting a possible compensatory mechanism that promotes activity-independent neuroplasticity following DA depletion.
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Affiliation(s)
- Bohye Kim
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
| | - Joong-Sun Kim
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
| | - BuHyun Youn
- Department of Biological Science, Pusan National University, Busan, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
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13
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Terzi F, Knabbe J, Cambridge SB. In Vivo Optical Interrogation of Neuronal Responses to Genetic, Cell Type-Specific Silencing. J Neurosci 2023; 43:8607-8620. [PMID: 37923378 PMCID: PMC10727181 DOI: 10.1523/jneurosci.2253-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/05/2023] [Accepted: 06/26/2023] [Indexed: 11/07/2023] Open
Abstract
We established a low background, Cre-dependent version of the inducible Tet-On system for fast, cell type-specific transgene expression in vivo Coexpression of a constitutive, Cre-dependent fluorescent marker selectively allowed single-cell analyses before and after inducible, Tet-dependent transgene expression. Here, we used this method for precise, acute manipulation of neuronal activity in the living brain. The goal was to study neuronal network homeostasis at cellular resolution. Single induction of the potassium channel Kir2.1 produced cell type-specific silencing within hours that lasted for at least 3 d. Longitudinal in vivo imaging of spontaneous calcium transients and neuronal morphology demonstrated that prolonged silencing did not alter spine densities or synaptic input strength. Furthermore, selective induction of Kir2.1 in parvalbumin interneurons increased the activity of surrounding neurons in a distance-dependent manner. This high-resolution, inducible interference and interval imaging of individual cells (high I5, HighFive) method thus allows visualizing temporally precise, genetic perturbations of defined cells.SIGNIFICANCE STATEMENT Gene function is studied by KO or overexpression of a specific gene followed by analyses of phenotypic changes. However, being able to predict and analyze exactly those cells in which genetic manipulation will occur is not possible. We combined two prominent transgene overexpression methods to fluorescently highlight the targeted cells appropriately before cell type-specific transgene induction. By inducing a potassium channel that decreases neuronal firing, we investigated how neuronal networks in the living mouse brain possibly compensate swift changes in cellular activities. Unlike in vitro, known compensatory homeostatic mechanisms, such as changes in synapses, were not observed in vivo Overall, we demonstrated with our method rapid genetic manipulation and analysis of neuronal activities as well as precision transgene expression.
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Affiliation(s)
- Firat Terzi
- Heidelberg University, Heidelberg, 69120, Germany
| | | | - Sidney B Cambridge
- Heidelberg University, Heidelberg, 69120, Germany
- Dr. Senckenberg Anatomy, Institute for Anatomy II, Goethe-University Frankfurt am Main, Frankfurt, 60590, Germany
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14
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Wang Y, You L, Tan K, Li M, Zou J, Zhao Z, Hu W, Li T, Xie F, Li C, Yuan R, Ding K, Cao L, Xin F, Shang C, Liu M, Gao Y, Wei L, You Z, Gao X, Xiong W, Cao P, Luo M, Chen F, Li K, Wu J, Hong B, Yuan K. A common thalamic hub for general and defensive arousal control. Neuron 2023; 111:3270-3287.e8. [PMID: 37557180 DOI: 10.1016/j.neuron.2023.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/25/2023] [Accepted: 07/11/2023] [Indexed: 08/11/2023]
Abstract
The expression of defensive responses to alerting sensory cues requires both general arousal and a specific arousal state associated with defensive emotions. However, it remains unclear whether these two forms of arousal can be regulated by common brain regions. We discovered that the medial sector of the auditory thalamus (ATm) in mice is a thalamic hub controlling both general and defensive arousal. The spontaneous activity of VGluT2-expressing ATm (ATmVGluT2+) neurons was correlated with and causally contributed to wakefulness. In sleeping mice, sustained ATmVGluT2+ population responses were predictive of sensory-induced arousal, the likelihood of which was markedly decreased by inhibiting ATmVGluT2+ neurons or multiple downstream pathways. In awake mice, ATmVGluT2+ activation led to heightened arousal accompanied by excessive anxiety and avoidance behavior. Notably, blocking their neurotransmission abolished alerting stimuli-induced defensive behaviors. These findings may shed light on the comorbidity of sleep disturbances and abnormal sensory sensitivity in specific brain disorders.
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Affiliation(s)
- Yiwei Wang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Ling You
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - KaMun Tan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Meijie Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Jingshan Zou
- Hospital of Chengdu University of Traditional Chinese Medicine, Traditional Chinese Medicine Hospital of Sichuan Province, Chengdu 610036, China
| | - Zhifeng Zhao
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Automation, Tsinghua University, Beijing 100084, China
| | - Wenxin Hu
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
| | - Tianyu Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Fenghua Xie
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China
| | - Caiqin Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Ruizhi Yuan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Kai Ding
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Lingwei Cao
- Zhili College, Tsinghua University, Beijing 100084, China
| | - Fengyuan Xin
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Congping Shang
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
| | - Miaomiao Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Laboratory Animal Resources Center, Tsinghua University, Beijing 100084, China
| | - Yixiao Gao
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Liqiang Wei
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Zhiwei You
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China; Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China
| | - Xiaorong Gao
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China
| | - Wei Xiong
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Peng Cao
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
| | - Minmin Luo
- National Institute of Biological Sciences (NIBS), Beijing 102206, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Feng Chen
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Kun Li
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Jiamin Wu
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Automation, Tsinghua University, Beijing 100084, China
| | - Bo Hong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China.
| | - Kexin Yuan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China.
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15
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Young TR, Yamamoto M, Kikuchi SS, Yoshida AC, Abe T, Inoue K, Johansen JP, Benucci A, Yoshimura Y, Shimogori T. Thalamocortical control of cell-type specificity drives circuits for processing whisker-related information in mouse barrel cortex. Nat Commun 2023; 14:6077. [PMID: 37770450 PMCID: PMC10539368 DOI: 10.1038/s41467-023-41749-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 09/15/2023] [Indexed: 09/30/2023] Open
Abstract
Excitatory spiny stellate neurons are prominently featured in the cortical circuits of sensory modalities that provide high salience and high acuity representations of the environment. These specialized neurons are considered developmentally linked to bottom-up inputs from the thalamus, however, the molecular mechanisms underlying their diversification and function are unknown. Here, we investigated this in mouse somatosensory cortex, where spiny stellate neurons and pyramidal neurons have distinct roles in processing whisker-evoked signals. Utilizing spatial transcriptomics, we identified reciprocal patterns of gene expression which correlated with these cell-types and were linked to innervation by specific thalamic inputs during development. Genetic manipulation that prevents the acquisition of spiny stellate fate highlighted an important role for these neurons in processing distinct whisker signals within functional cortical columns, and as a key driver in the formation of specific whisker-related circuits in the cortex.
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Affiliation(s)
- Timothy R Young
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Mariko Yamamoto
- Division of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Satomi S Kikuchi
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Aya C Yoshida
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takaya Abe
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 6500047, Japan
| | - Kenichi Inoue
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 6500047, Japan
| | - Joshua P Johansen
- Laboratory for Neural Circuitry of Learning and Memory, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Andrea Benucci
- Laboratory for Neural Circuits and Behavior, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Yumiko Yoshimura
- Division of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Tomomi Shimogori
- Laboratory for Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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16
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Ramsay HJ, Gookin SE, Ramsey AM, Kareemo DJ, Crosby KC, Stich DG, Olah SS, Actor-Engel HS, Smith KR, Kennedy MJ. AMPA and GABAA receptor nanodomains assemble in the absence of synaptic neurotransmitter release. Front Mol Neurosci 2023; 16:1232795. [PMID: 37602191 PMCID: PMC10435253 DOI: 10.3389/fnmol.2023.1232795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Postsynaptic neurotransmitter receptors and their associated scaffolding proteins assemble into discrete, nanometer-scale subsynaptic domains (SSDs) within the postsynaptic membrane at both excitatory and inhibitory synapses. Intriguingly, postsynaptic receptor SSDs are mirrored by closely apposed presynaptic active zones. These trans-synaptic molecular assemblies are thought to be important for efficient neurotransmission because they concentrate postsynaptic receptors near sites of presynaptic neurotransmitter release. While previous studies have characterized the role of synaptic activity in sculpting the number, size, and distribution of postsynaptic SSDs at established synapses, it remains unknown whether neurotransmitter signaling is required for their initial assembly during synapse development. Here, we evaluated synaptic nano-architecture under conditions where presynaptic neurotransmitter release was blocked prior to, and throughout synaptogenesis with tetanus neurotoxin (TeNT). In agreement with previous work, neurotransmitter release was not required for the formation of excitatory or inhibitory synapses. The overall size of the postsynaptic specialization at both excitatory and inhibitory synapses was reduced at chronically silenced synapses. However, both AMPARs and GABAARs still coalesced into SSDs, along with their respective scaffold proteins. Presynaptic active zone assemblies, defined by RIM1, were smaller and more numerous at silenced synapses, but maintained alignment with postsynaptic AMPAR SSDs. Thus, basic features of synaptic nano-architecture, including assembly of receptors and scaffolds into trans-synaptically aligned structures, are intrinsic properties that can be further regulated by subsequent activity-dependent mechanisms.
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Affiliation(s)
- Harrison J. Ramsay
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Sara E. Gookin
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Austin M. Ramsey
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Dean J. Kareemo
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Kevin C. Crosby
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Dominik G. Stich
- Anschutz Medical Campus, Advanced Light Microscopy Core, University of Colorado, Aurora, CO, United States
| | - Samantha S. Olah
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Hannah S. Actor-Engel
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Katharine R. Smith
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
| | - Matthew J. Kennedy
- Anschutz Medical Campus, Department of Pharmacology, University of Colorado, Aurora, CO, United States
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17
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Krüssel S, Deb I, Son S, Ewall G, Chang M, Lee HK, do Heo W, Kwon HB. Exuberant de novo dendritic spine growth in mature neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.21.550095. [PMID: 37546796 PMCID: PMC10401948 DOI: 10.1101/2023.07.21.550095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Dendritic spines are structural correlates of excitatory synapses maintaining stable synaptic communications. However, this strong spine-synapse relationship was mainly characterized in excitatory pyramidal neurons (PyNs), raising a possibility that inferring synaptic density from dendritic spine number may not be universally applied to all neuronal types. Here we found that the ectopic expression of H-Ras increased dendritic spine numbers regardless of cortical cell types such as layer 2/3 pyramidal neurons (PyNs), parvalbumin (PV)- and vasoactive intestinal peptide (VIP)-positive interneurons (INs) in the primary motor cortex (M1). The probability of detecting dendritic spines was positively correlated with the magnitude of H-Ras activity, suggesting elevated local H-Ras activity is involved in the process of dendritic spine formation. H-Ras overexpression caused high spine turnover rate via adding more spines rather than eliminating them. Two-photon photolysis of glutamate triggered de novo dendritic spine formation in mature neurons, suggesting H-Ras induced spine formation is not restricted to the early development. In PyNs and PV-INs, but not VIP-INs, we observed a shift in average spine neck length towards longer filopodia-like phenotypes. The portion of dendritic spines lacking key excitatory synaptic proteins were significantly increased in H-Ras transfected neurons, suggesting that these increased spines have other distinct functions. High spine density caused by H-Ras did not result in change in the frequency or the amplitude of miniature excitatory postsynaptic currents (mEPSCs). Thus, our results propose that dendritic spines possess more multifaceted functions beyond the morphological proxy of excitatory synapse.
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Affiliation(s)
- Sarah Krüssel
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ishana Deb
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seungkyu Son
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gabrielle Ewall
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Minhyeok Chang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hey-Kyoung Lee
- Solomon H. Snyder Department of Neuroscience, Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Won do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyung-Bae Kwon
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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18
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Han Y, Goel P, Chen J, Perry S, Tran N, Nishimura S, Sanjani M, Chien C, Dickman D. Excess glutamate release triggers subunit-specific homeostatic receptor scaling. Cell Rep 2023; 42:112775. [PMID: 37436892 PMCID: PMC10529671 DOI: 10.1016/j.celrep.2023.112775] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/06/2023] [Accepted: 06/25/2023] [Indexed: 07/14/2023] Open
Abstract
Ionotropic glutamate receptors (GluRs) are targets for modulation in Hebbian and homeostatic synaptic plasticity and are remodeled by development, experience, and disease. We have probed the impact of synaptic glutamate levels on the two postsynaptic GluR subtypes at the Drosophila neuromuscular junction, GluRA and GluRB. We first demonstrate that GluRA and GluRB compete to establish postsynaptic receptive fields, and that proper GluR abundance and composition can be orchestrated in the absence of any synaptic glutamate release. However, excess glutamate adaptively tunes postsynaptic GluR abundance, echoing GluR scaling observed in mammalian systems. Furthermore, when GluRA vs. GluRB competition is eliminated, GluRB becomes insensitive to glutamate modulation. In contrast, GluRA is now homeostatically regulated by excess glutamate to maintain stable miniature activity, where Ca2+ permeability through GluRA receptors is required. Thus, excess glutamate, GluR competition, and Ca2+ signaling collaborate to selectively target GluR subtypes for homeostatic regulation at postsynaptic compartments.
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Affiliation(s)
- Yifu Han
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Pragya Goel
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiawen Chen
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Nancy Tran
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Samantha Nishimura
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Manisha Sanjani
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Chun Chien
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA.
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19
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Schaeuble D, Wallace T, Pace SA, Hentges ST, Myers B. Sex-specific prefrontal-hypothalamic control of behavior and stress responding. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.09.548297. [PMID: 37502938 PMCID: PMC10369879 DOI: 10.1101/2023.07.09.548297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Depression and cardiovascular disease are both augmented by daily life stress. Yet, the biological mechanisms that translate psychological stress into affective and physiological outcomes are unknown. Previously, we demonstrated that stimulation of the ventromedial prefrontal cortex (vmPFC) has sexually divergent outcomes on behavior and physiology. Importantly, the vmPFC does not innervate the brain regions that initiate autonomic or neuroendocrine stress responses; thus, we hypothesized that intermediate synapses integrate cortical information to regulate stress responding. The posterior hypothalamus (PH) directly innervates stress-effector regions and receives substantial innervation from the vmPFC. In the current studies, circuit-specific approaches examined whether vmPFC synapses in the PH coordinate stress responding. Here we tested the effects of optogenetic vmPFC-PH circuit stimulation in male and female rats on social and motivational behaviors as well as physiological stress responses. Additionally, an intersectional genetic approach was used to knock down synaptobrevin in PH-projecting vmPFC neurons. Our collective results indicate that male vmPFC-PH circuitry promotes positive motivational valence and is both sufficient and necessary to reduce sympathetic-mediated stress responses. In females, the vmPFC-PH circuit does not affect social or preference behaviors but is sufficient and necessary to elevate neuroendocrine stress responses. Altogether, these data suggest cortical regulation of stress reactivity and behavior is mediated, in part, by projections to the hypothalamus that function in a sex-specific manner.
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Affiliation(s)
- Derek Schaeuble
- Equal contribution
- Biomedical Sciences, Colorado State University, Fort Collins, CO,
USA
| | - Tyler Wallace
- Equal contribution
- Biomedical Sciences, Colorado State University, Fort Collins, CO,
USA
| | - Sebastian A. Pace
- Biomedical Sciences, Colorado State University, Fort Collins, CO,
USA
| | - Shane T. Hentges
- Integrative Physiology and Neuroscience, Washington State
University, Pullman, WA, USA
| | - Brent Myers
- Biomedical Sciences, Colorado State University, Fort Collins, CO,
USA
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20
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Kleinjan MS, Buchta WC, Ogelman R, Hwang IW, Kuwajima M, Hubbard DD, Kareemo DJ, Prikhodko O, Olah SL, Gomez Wulschner LE, Abraham WC, Franco SJ, Harris KM, Oh WC, Kennedy MJ. Dually innervated dendritic spines develop in the absence of excitatory activity and resist plasticity through tonic inhibitory crosstalk. Neuron 2023; 111:362-371.e6. [PMID: 36395772 PMCID: PMC9899020 DOI: 10.1016/j.neuron.2022.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/13/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022]
Abstract
Dendritic spines can be directly connected to both inhibitory and excitatory presynaptic terminals, resulting in nanometer-scale proximity of opposing synaptic functions. While dually innervated spines (DiSs) are observed throughout the central nervous system, their developmental timeline and functional properties remain uncharacterized. Here we used a combination of serial section electron microscopy, live imaging, and local synapse activity manipulations to investigate DiS development and function in rodent hippocampus. Dual innervation occurred early in development, even on spines where the excitatory input was locally silenced. Synaptic NMDA receptor currents were selectively reduced at DiSs through tonic GABAB receptor signaling. Accordingly, spine enlargement normally associated with long-term potentiation on singly innervated spines (SiSs) was blocked at DiSs. Silencing somatostatin interneurons or pharmacologically blocking GABABRs restored NMDA receptor function and structural plasticity to levels comparable to neighboring SiSs. Thus, hippocampal DiSs are stable structures where function and plasticity are potently regulated by nanometer-scale GABAergic signaling.
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Affiliation(s)
- Mason S Kleinjan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William C Buchta
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Roberto Ogelman
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - In-Wook Hwang
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Masaaki Kuwajima
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dusten D Hubbard
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dean J Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Olga Prikhodko
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Samantha L Olah
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Luis E Gomez Wulschner
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Santos J Franco
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kristen M Harris
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Won Chan Oh
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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21
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Hale WD, Südhof TC, Huganir RL. Engineered adhesion molecules drive synapse organization. Proc Natl Acad Sci U S A 2023; 120:e2215905120. [PMID: 36638214 PMCID: PMC9934208 DOI: 10.1073/pnas.2215905120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/04/2022] [Indexed: 01/15/2023] Open
Abstract
In multicellular organisms, cell-adhesion molecules connect cells into tissues and mediate intercellular signaling between these cells. In vertebrate brains, synaptic cell-adhesion molecules (SAMs) guide the formation, specification, and plasticity of synapses. Some SAMs, when overexpressed in cultured neurons or in heterologous cells co-cultured with neurons, drive formation of synaptic specializations onto the overexpressing cells. However, genetic deletion of the same SAMs from neurons often has no effect on synapse numbers, but frequently severely impairs synaptic transmission, suggesting that most SAMs control the function and plasticity of synapses (i.e., organize synapses) instead of driving their initial establishment (i.e., make synapses). Since few SAMs were identified that mediate initial synapse formation, it is difficult to develop methods that enable experimental control of synaptic connections by targeted expression of these SAMs. To overcome this difficulty, we engineered novel SAMs from bacterial proteins with no eukaryotic homologues that drive synapse formation. We named these engineered adhesion proteins "Barnoligin" and "Starexin" because they were assembled from parts of Barnase and Neuroligin-1 or of Barstar and Neurexin3β, respectively. Barnoligin and Starexin robustly induce the formation of synaptic specializations in a specific and directional manner in cultured neurons. Synapse formation by Barnoligin and Starexin requires both their extracellular Barnase- and Barstar-derived interaction domains and their Neuroligin- and Neurexin-derived intracellular signaling domains. Our findings support a model of synapse formation whereby trans-synaptic interactions by SAMs drive synapse organization via adhesive interactions that activate signaling cascades.
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Affiliation(s)
- W. Dylan Hale
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Richard L. Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
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22
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KASAI H. Unraveling the mysteries of dendritic spine dynamics: Five key principles shaping memory and cognition. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2023; 99:254-305. [PMID: 37821392 PMCID: PMC10749395 DOI: 10.2183/pjab.99.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 07/11/2023] [Indexed: 10/13/2023]
Abstract
Recent research extends our understanding of brain processes beyond just action potentials and chemical transmissions within neural circuits, emphasizing the mechanical forces generated by excitatory synapses on dendritic spines to modulate presynaptic function. From in vivo and in vitro studies, we outline five central principles of synaptic mechanics in brain function: P1: Stability - Underpinning the integral relationship between the structure and function of the spine synapses. P2: Extrinsic dynamics - Highlighting synapse-selective structural plasticity which plays a crucial role in Hebbian associative learning, distinct from pathway-selective long-term potentiation (LTP) and depression (LTD). P3: Neuromodulation - Analyzing the role of G-protein-coupled receptors, particularly dopamine receptors, in time-sensitive modulation of associative learning frameworks such as Pavlovian classical conditioning and Thorndike's reinforcement learning (RL). P4: Instability - Addressing the intrinsic dynamics crucial to memory management during continual learning, spotlighting their role in "spine dysgenesis" associated with mental disorders. P5: Mechanics - Exploring how synaptic mechanics influence both sides of synapses to establish structural traces of short- and long-term memory, thereby aiding the integration of mental functions. We also delve into the historical background and foresee impending challenges.
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Affiliation(s)
- Haruo KASAI
- International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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23
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Tan C, de Nola G, Qiao C, Imig C, Born RT, Brose N, Kaeser PS. Munc13 supports fusogenicity of non-docked vesicles at synapses with disrupted active zones. eLife 2022; 11:79077. [PMID: 36398873 PMCID: PMC9822248 DOI: 10.7554/elife.79077] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022] Open
Abstract
Active zones consist of protein scaffolds that are tightly attached to the presynaptic plasma membrane. They dock and prime synaptic vesicles, couple them to voltage-gated Ca2+ channels, and direct neurotransmitter release toward postsynaptic receptor domains. Simultaneous RIM + ELKS ablation disrupts these scaffolds, abolishes vesicle docking, and removes active zone-targeted Munc13, but some vesicles remain releasable. To assess whether this enduring vesicular fusogenicity is mediated by non-active zone-anchored Munc13 or is Munc13-independent, we ablated Munc13-1 and Munc13-2 in addition to RIM + ELKS in mouse hippocampal neurons. The hextuple knockout synapses lacked docked vesicles, but other ultrastructural features were near-normal despite the strong genetic manipulation. Removing Munc13 in addition to RIM + ELKS impaired action potential-evoked vesicle fusion more strongly than RIM + ELKS knockout by further decreasing the releasable vesicle pool. Hence, Munc13 can support some fusogenicity without RIM and ELKS, and presynaptic recruitment of Munc13, even without active zone anchoring, suffices to generate some fusion-competent vesicles.
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Affiliation(s)
- Chao Tan
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Giovanni de Nola
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Claire Qiao
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Cordelia Imig
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
| | - Richard T Born
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, United States
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24
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Dorkenwald S, Turner NL, Macrina T, Lee K, Lu R, Wu J, Bodor AL, Bleckert AA, Brittain D, Kemnitz N, Silversmith WM, Ih D, Zung J, Zlateski A, Tartavull I, Yu SC, Popovych S, Wong W, Castro M, Jordan CS, Wilson AM, Froudarakis E, Buchanan J, Takeno MM, Torres R, Mahalingam G, Collman F, Schneider-Mizell CM, Bumbarger DJ, Li Y, Becker L, Suckow S, Reimer J, Tolias AS, Macarico da Costa N, Reid RC, Seung HS. Binary and analog variation of synapses between cortical pyramidal neurons. eLife 2022; 11:e76120. [PMID: 36382887 PMCID: PMC9704804 DOI: 10.7554/elife.76120] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 11/15/2022] [Indexed: 11/17/2022] Open
Abstract
Learning from experience depends at least in part on changes in neuronal connections. We present the largest map of connectivity to date between cortical neurons of a defined type (layer 2/3 [L2/3] pyramidal cells in mouse primary visual cortex), which was enabled by automated analysis of serial section electron microscopy images with improved handling of image defects (250 × 140 × 90 μm3 volume). We used the map to identify constraints on the learning algorithms employed by the cortex. Previous cortical studies modeled a continuum of synapse sizes by a log-normal distribution. A continuum is consistent with most neural network models of learning, in which synaptic strength is a continuously graded analog variable. Here, we show that synapse size, when restricted to synapses between L2/3 pyramidal cells, is well modeled by the sum of a binary variable and an analog variable drawn from a log-normal distribution. Two synapses sharing the same presynaptic and postsynaptic cells are known to be correlated in size. We show that the binary variables of the two synapses are highly correlated, while the analog variables are not. Binary variation could be the outcome of a Hebbian or other synaptic plasticity rule depending on activity signals that are relatively uniform across neuronal arbors, while analog variation may be dominated by other influences such as spontaneous dynamical fluctuations. We discuss the implications for the longstanding hypothesis that activity-dependent plasticity switches synapses between bistable states.
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Affiliation(s)
- Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Computer Science Department, Princeton UniversityPrincetonUnited States
| | - Nicholas L Turner
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Computer Science Department, Princeton UniversityPrincetonUnited States
| | - Thomas Macrina
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Computer Science Department, Princeton UniversityPrincetonUnited States
| | - Kisuk Lee
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Brain & Cognitive Sciences Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Ran Lu
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Jingpeng Wu
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Agnes L Bodor
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | - Nico Kemnitz
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | | | - Dodam Ih
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Jonathan Zung
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Aleksandar Zlateski
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Ignacio Tartavull
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Szi-Chieh Yu
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Sergiy Popovych
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Computer Science Department, Princeton UniversityPrincetonUnited States
| | - William Wong
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Manuel Castro
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Chris S Jordan
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Alyssa M Wilson
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Emmanouil Froudarakis
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Center for Neuroscience and Artificial Intelligence, Baylor College of MedicineHoustonUnited States
| | | | - Marc M Takeno
- Allen Institute for Brain ScienceSeattleUnited States
| | - Russel Torres
- Allen Institute for Brain ScienceSeattleUnited States
| | | | | | | | | | - Yang Li
- Allen Institute for Brain ScienceSeattleUnited States
| | - Lynne Becker
- Allen Institute for Brain ScienceSeattleUnited States
| | - Shelby Suckow
- Allen Institute for Brain ScienceSeattleUnited States
| | - Jacob Reimer
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Center for Neuroscience and Artificial Intelligence, Baylor College of MedicineHoustonUnited States
| | - Andreas S Tolias
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Center for Neuroscience and Artificial Intelligence, Baylor College of MedicineHoustonUnited States
- Department of Electrical and Computer Engineering, Rice UniversityHoustonUnited States
| | | | - R Clay Reid
- Allen Institute for Brain ScienceSeattleUnited States
| | - H Sebastian Seung
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Computer Science Department, Princeton UniversityPrincetonUnited States
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25
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Somaiya RD, Stebbins K, Gingrich EC, Xie H, Campbell JN, Garcia ADR, Fox MA. Sonic hedgehog-dependent recruitment of GABAergic interneurons into the developing visual thalamus. eLife 2022; 11:e79833. [PMID: 36342840 PMCID: PMC9640189 DOI: 10.7554/elife.79833] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 10/10/2022] [Indexed: 11/09/2022] Open
Abstract
Axons of retinal ganglion cells (RGCs) play critical roles in the development of inhibitory circuits in visual thalamus. We previously reported that RGC axons signal astrocytes to induce the expression of fibroblast growth factor 15 (FGF15), a motogen required for GABAergic interneuron migration into visual thalamus. However, how retinal axons induce thalamic astrocytes to generate Fgf15 and influence interneuron migration remains unknown. Here, we demonstrate that impairing RGC activity had little impact on interneuron recruitment into mouse visual thalamus. Instead, our data show that retinal-derived sonic hedgehog (SHH) is essential for interneuron recruitment. Specifically, we show that thalamus-projecting RGCs express SHH and thalamic astrocytes generate downstream components of SHH signaling. Deletion of RGC-derived SHH leads to a significant decrease in Fgf15 expression, as well as in the percentage of interneurons recruited into visual thalamus. Overall, our findings identify a morphogen-dependent neuron-astrocyte signaling mechanism essential for the migration of thalamic interneurons.
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Affiliation(s)
- Rachana Deven Somaiya
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia TechBlacksburgUnited States
| | - Katelyn Stebbins
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia TechBlacksburgUnited States
- Virginia Tech Carilion School of MedicineRoanokeUnited States
| | - Ellen C Gingrich
- Department of Biology, Drexel UniversityPhiladelphiaUnited States
- Department of Neurobiology and Anatomy, Drexel University College of MedicinePhiladelphiaUnited States
| | - Hehuang Xie
- Fralin Life Sciences Institute at Virginia TechBlacksburgUnited States
- School of Neuroscience, College of Science, Virginia TechBlacksburgUnited States
- Genetics, Bioinformatics and Computational Biology Program, Virginia TechBlacksburgUnited States
- Department of Biomedical Sciences and Pathobiology, Virginia–Maryland College of Veterinary MedicineBlacksburgUnited States
| | - John N Campbell
- Department of Biology, University of VirginiaCharlottesvilleUnited States
- Neuroscience Graduate Program, University of VirginiaCharlottesvilleUnited States
| | - A Denise R Garcia
- Department of Biology, Drexel UniversityPhiladelphiaUnited States
- Department of Neurobiology and Anatomy, Drexel University College of MedicinePhiladelphiaUnited States
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- School of Neuroscience, College of Science, Virginia TechBlacksburgUnited States
- Department of Biological Sciences, College of Science, Virginia TechBlacksburgUnited States
- Department of Pediatrics, Virginia Tech Carilion School of MedicineRoanokeUnited States
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26
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Midorikawa M. Developmental and activity-dependent modulation of coupling distance between release site and Ca2+ channel. Front Cell Neurosci 2022; 16:1037721. [DOI: 10.3389/fncel.2022.1037721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Synapses are junctions between a presynaptic neuron and a postsynaptic cell specialized for fast and precise information transfer. The presynaptic terminal secretes neurotransmitters via exocytosis of synaptic vesicles. Exocytosis is a tightly regulated reaction that occurs within a millisecond of the arrival of an action potential. One crucial parameter in determining the characteristics of the transmitter release kinetics is the coupling distance between the release site and the Ca2+ channel. Still, the technical limitations have hindered detailed analysis from addressing how the coupling distance is regulated depending on the development or activity of the synapse. However, recent technical advances in electrophysiology and imaging are unveiling their different configurations in different conditions. Here, I will summarize developmental- and activity-dependent changes in the coupling distances revealed by recent studies.
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27
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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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28
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Wu MY, Zou WJ, Yu P, Yang Y, Li SJ, Liu Q, Xie J, Chen SQ, Lin WJ, Tang Y. Cranial irradiation impairs intrinsic excitability and synaptic plasticity of hippocampal CA1 pyramidal neurons with implications for cognitive function. Neural Regen Res 2022; 17:2253-2259. [PMID: 35259846 PMCID: PMC9083168 DOI: 10.4103/1673-5374.336875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Radiation therapy is a standard treatment for head and neck tumors. However, patients often exhibit cognitive impairments following radiation therapy. Previous studies have revealed that hippocampal dysfunction, specifically abnormal hippocampal neurogenesis or neuroinflammation, plays a key role in radiation-induced cognitive impairment. However, the long-term effects of radiation with respect to the electrophysiological adaptation of hippocampal neurons remain poorly characterized. We found that mice exhibited cognitive impairment 3 months after undergoing 10 minutes of cranial irradiation at a dose rate of 3 Gy/min. Furthermore, we observed a remarkable reduction in spike firing and excitatory synaptic input, as well as greatly enhanced inhibitory inputs, in hippocampal CA1 pyramidal neurons. Corresponding to the electrophysiological adaptation, we found reduced expression of synaptic plasticity marker VGLUT1 and increased expression of VGAT. Furthermore, in irradiated mice, long-term potentiation in the hippocampus was weakened and GluR1 expression was inhibited. These findings suggest that radiation can impair intrinsic excitability and synaptic plasticity in hippocampal CA1 pyramidal neurons.
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Affiliation(s)
- Min-Yi Wu
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Wen-Jun Zou
- State Key Laboratory of Organ Failure Research, Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Pei Yu
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Yuhua Yang
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Shao-Jian Li
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Qiang Liu
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Jiatian Xie
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Si-Qi Chen
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Wei-Jye Lin
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine; Medical Research Center, Sun Yat-sen Memorial Hospital; Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Yamei Tang
- Department of Neurology, Sun Yat-sen Memorial Hospital; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-sen Memorial Hospital; Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
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29
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Vadisiute A, Meijer E, Szabó F, Hoerder-Suabedissen A, Kawashita E, Hayashi S, Molnár Z. The role of snare proteins in cortical development. Dev Neurobiol 2022; 82:457-475. [PMID: 35724379 PMCID: PMC9539872 DOI: 10.1002/dneu.22892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 12/01/2022]
Abstract
Neural communication in the adult nervous system is mediated primarily through chemical synapses, where action potentials elicit Ca2+ signals, which trigger vesicular fusion and neurotransmitter release in the presynaptic compartment. At early stages of development, the brain is shaped by communication via trophic factors and other extracellular signaling, and by contact-mediated cell-cell interactions including chemical synapses. The patterns of early neuronal impulses and spontaneous and regulated neurotransmitter release guide the precise topography of axonal projections and contribute to determining cell survival. The study of the role of specific proteins of the synaptic vesicle release machinery in the establishment, plasticity, and maintenance of neuronal connections during development has only recently become possible, with the advent of mouse models where various members of the N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex have been genetically manipulated. We provide an overview of these models, focusing on the role of regulated vesicular release and/or cellular excitability in synaptic assembly, development and maintenance of cortical circuits, cell survival, circuit level excitation-inhibition balance, myelination, refinement, and plasticity of key axonal projections from the cerebral cortex. These models are important for understanding various developmental and psychiatric conditions, and neurodegenerative diseases.
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Affiliation(s)
- Auguste Vadisiute
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
| | - Elise Meijer
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
| | - Florina Szabó
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
| | - Anna Hoerder-Suabedissen
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
| | - Eri Kawashita
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
- Department of Pathological Biochemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto, Japan
| | - Shuichi Hayashi
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
- Department of Anatomy, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
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30
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Han Y, Chien C, Goel P, He K, Pinales C, Buser C, Dickman D. Botulinum neurotoxin accurately separates tonic vs. phasic transmission and reveals heterosynaptic plasticity rules in Drosophila. eLife 2022; 11:e77924. [PMID: 35993544 PMCID: PMC9439677 DOI: 10.7554/elife.77924] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/20/2022] [Indexed: 11/13/2022] Open
Abstract
In developing and mature nervous systems, diverse neuronal subtypes innervate common targets to establish, maintain, and modify neural circuit function. A major challenge towards understanding the structural and functional architecture of neural circuits is to separate these inputs and determine their intrinsic and heterosynaptic relationships. The Drosophila larval neuromuscular junction is a powerful model system to study these questions, where two glutamatergic motor neurons, the strong phasic-like Is and weak tonic-like Ib, co-innervate individual muscle targets to coordinate locomotor behavior. However, complete neurotransmission from each input has never been electrophysiologically separated. We have employed a botulinum neurotoxin, BoNT-C, that eliminates both spontaneous and evoked neurotransmission without perturbing synaptic growth or structure, enabling the first approach that accurately isolates input-specific neurotransmission. Selective expression of BoNT-C in Is or Ib motor neurons disambiguates the functional properties of each input. Importantly, the blended values of Is+Ib neurotransmission can be fully recapitulated by isolated physiology from each input. Finally, selective silencing by BoNT-C does not induce heterosynaptic structural or functional plasticity at the convergent input. Thus, BoNT-C establishes the first approach to accurately separate neurotransmission between tonic vs. phasic neurons and defines heterosynaptic plasticity rules in a powerful model glutamatergic circuit.
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Affiliation(s)
- Yifu Han
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Chun Chien
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Pragya Goel
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | - Kaikai He
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
| | | | | | - Dion Dickman
- Department of Neurobiology, University of Southern CaliforniaLos AngelesUnited States
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31
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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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32
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Li N, Chen S, Xu NJ, Sun S, Chen JJ, Liu XD. Scaffold Protein Lnx1 Stabilizes EphB Receptor Kinases for Synaptogenesis. Front Mol Neurosci 2022; 15:861873. [PMID: 35531068 PMCID: PMC9070102 DOI: 10.3389/fnmol.2022.861873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/04/2022] [Indexed: 12/04/2022] Open
Abstract
Postsynaptic structure assembly and remodeling are crucial for functional synapse formation during the establishment of neural circuits. However, how the specific scaffold proteins regulate this process during the development of the postnatal period is poorly understood. In this study, we find that the deficiency of ligand of Numb protein X 1 (Lnx1) leads to abnormal development of dendritic spines to impair functional synaptic formation. We further demonstrate that loss of Lnx1 promotes the internalization of EphB receptors from the cell surface. Constitutively active EphB2 intracellular signaling rescues synaptogenesis in Lnx1 mutant mice. Our data thus reveal a molecular mechanism whereby the Lnx1-EphB complex controls postsynaptic structure for synapse maturation during the adolescent period.
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Affiliation(s)
- Na Li
- Research Center of Translational Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Si Chen
- Research Center of Translational Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nan-Jie Xu
- Research Center of Translational Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Suya Sun
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin-Jin Chen
- Research Center of Translational Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xian-Dong Liu
- Department of Neurology and Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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33
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Ivanova D, Cousin MA. Synaptic Vesicle Recycling and the Endolysosomal System: A Reappraisal of Form and Function. Front Synaptic Neurosci 2022; 14:826098. [PMID: 35280702 PMCID: PMC8916035 DOI: 10.3389/fnsyn.2022.826098] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/03/2022] [Indexed: 12/15/2022] Open
Abstract
The endolysosomal system is present in all cell types. Within these cells, it performs a series of essential roles, such as trafficking and sorting of membrane cargo, intracellular signaling, control of metabolism and degradation. A specific compartment within central neurons, called the presynapse, mediates inter-neuronal communication via the fusion of neurotransmitter-containing synaptic vesicles (SVs). The localized recycling of SVs and their organization into functional pools is widely assumed to be a discrete mechanism, that only intersects with the endolysosomal system at specific points. However, evidence is emerging that molecules essential for endolysosomal function also have key roles within the SV life cycle, suggesting that they form a continuum rather than being isolated processes. In this review, we summarize the evidence for key endolysosomal molecules in SV recycling and propose an alternative model for membrane trafficking at the presynapse. This includes the hypotheses that endolysosomal intermediates represent specific functional SV pools, that sorting of cargo to SVs is mediated via the endolysosomal system and that manipulation of this process can result in both plastic changes to neurotransmitter release and pathophysiology via neurodegeneration.
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Affiliation(s)
- Daniela Ivanova
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
- *Correspondence: Daniela Ivanova,
| | - Michael A. Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, United Kingdom
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
- Michael A. Cousin,
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34
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Patel PA, Hegert JV, Cristian I, Kerr A, LaConte LEW, Fox MA, Srivastava S, Mukherjee K. Complete loss of the X-linked gene CASK causes severe cerebellar degeneration. J Med Genet 2022; 59:1044-1057. [PMID: 35149592 DOI: 10.1136/jmedgenet-2021-108115] [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: 07/29/2021] [Accepted: 01/13/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Heterozygous loss of X-linked genes like CASK and MeCP2 (Rett syndrome) causes developmental delay in girls, while in boys, loss of the only allele of these genes leads to epileptic encephalopathy. The mechanism for these disorders remains unknown. CASK-linked cerebellar hypoplasia is presumed to result from defects in Tbr1-reelin-mediated neuronal migration. METHOD Here we report clinical and histopathological analyses of a deceased 2-month-old boy with a CASK-null mutation. We next generated a mouse line where CASK is completely deleted (hemizygous and homozygous) from postmigratory neurons in the cerebellum. RESULT The CASK-null human brain was smaller in size but exhibited normal lamination without defective neuronal differentiation, migration or axonal guidance. The hypoplastic cerebellum instead displayed astrogliosis and microgliosis, which are markers for neuronal loss. We therefore hypothesise that CASK loss-induced cerebellar hypoplasia is the result of early neurodegeneration. Data from the murine model confirmed that in CASK loss, a small cerebellum results from postdevelopmental degeneration of cerebellar granule neurons. Furthermore, at least in the cerebellum, functional loss from CASK deletion is secondary to degeneration of granule cells and not due to an acute molecular functional loss of CASK. Intriguingly, female mice with heterozygous deletion of CASK in the cerebellum do not display neurodegeneration. CONCLUSION We suggest that X-linked neurodevelopmental disorders like CASK mutation and Rett syndrome are pathologically neurodegenerative; random X-chromosome inactivation in heterozygous mutant girls, however, results in 50% of cells expressing the functional gene, resulting in a non-progressive pathology, whereas complete loss of the only allele in boys leads to unconstrained degeneration and encephalopathy.
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Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Julia V Hegert
- Department of Pathology, Orlando Health, Orlando, Florida, USA
| | | | - Alicia Kerr
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | | | - Michael A Fox
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,School of Neuroscience, Blacksburg, Virginia, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA .,Department of Psychiatry, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, 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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36
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Graf J, Rahmati V, Majoros M, Witte OW, Geis C, Kiebel SJ, Holthoff K, Kirmse K. Network instability dynamics drive a transient bursting period in the developing hippocampus in vivo. eLife 2022; 11:82756. [PMID: 36534089 PMCID: PMC9762703 DOI: 10.7554/elife.82756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Spontaneous correlated activity is a universal hallmark of immature neural circuits. However, the cellular dynamics and intrinsic mechanisms underlying network burstiness in the intact developing brain are largely unknown. Here, we use two-photon Ca2+ imaging to comprehensively map the developmental trajectories of spontaneous network activity in the hippocampal area CA1 of mice in vivo. We unexpectedly find that network burstiness peaks after the developmental emergence of effective synaptic inhibition in the second postnatal week. We demonstrate that the enhanced network burstiness reflects an increased functional coupling of individual neurons to local population activity. However, pairwise neuronal correlations are low, and network bursts (NBs) recruit CA1 pyramidal cells in a virtually random manner. Using a dynamic systems modeling approach, we reconcile these experimental findings and identify network bi-stability as a potential regime underlying network burstiness at this age. Our analyses reveal an important role of synaptic input characteristics and network instability dynamics for NB generation. Collectively, our data suggest a mechanism, whereby developing CA1 performs extensive input-discrimination learning prior to the onset of environmental exploration.
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Affiliation(s)
- Jürgen Graf
- Department of Neurology, Jena University HospitalJenaGermany
| | - Vahid Rahmati
- Department of Neurology, Jena University HospitalJenaGermany,Section Translational Neuroimmunology, Jena University HospitalJenaGermany,Department of Psychology, Technical University DresdenDresdenGermany
| | - Myrtill Majoros
- Department of Neurology, Jena University HospitalJenaGermany
| | - Otto W Witte
- Department of Neurology, Jena University HospitalJenaGermany
| | - Christian Geis
- Department of Neurology, Jena University HospitalJenaGermany,Section Translational Neuroimmunology, Jena University HospitalJenaGermany
| | - Stefan J Kiebel
- Department of Psychology, Technical University DresdenDresdenGermany
| | - Knut Holthoff
- Department of Neurology, Jena University HospitalJenaGermany
| | - Knut Kirmse
- Department of Neurology, Jena University HospitalJenaGermany,Department of Neurophysiology, Institute of Physiology, University of WürzburgWürzburgGermany
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37
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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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38
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Niu F, Sharma A, Wang Z, Feng L, Muresanu DF, Sahib S, Tian ZR, Lafuente JV, Buzoianu AD, Castellani RJ, Nozari A, Menon PK, Patnaik R, Wiklund L, Sharma HS. Nanodelivery of oxiracetam enhances memory, functional recovery and induces neuroprotection following concussive head injury. PROGRESS IN BRAIN RESEARCH 2021; 265:139-230. [PMID: 34560921 DOI: 10.1016/bs.pbr.2021.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Military personnel are the most susceptible to concussive head injury (CHI) caused by explosion, blast or missile or blunt head trauma. Mild to moderate CHI could induce lifetime functional and cognitive disturbances causing significant decrease in quality of life. Severe CHI leads to instant death and lifetime paralysis. Thus, further exploration of novel therapeutic agents or new features of known pharmacological agents are needed to enhance quality of life of CHI victims. Previous reports from our laboratory showed that mild CHI induced by weight drop technique causing an impact of 0.224N results in profound progressive functional deficit, memory impairment and brain pathology from 5h after trauma that continued over several weeks of injury. In this investigation we report that TiO2 nanowired delivery of oxiracetam (50mg/kg, i.p.) daily for 5 days after CHI resulted in significant improvement of functional deficit on the 8th day. This was observed using Rota Rod treadmill, memory improvement assessed by the time spent in finding hidden platform under water. The motor function improvement is seen in oxiracetam treated CHI group by placing forepaw on an inclined mesh walking and foot print analysis for stride length and distance between hind feet. TiO2-nanowired oxiracetam also induced marked improvements in the cerebral blood flow, reduction in the BBB breakdown and edema formation as well as neuroprotection of neuronal, glial and myelin damages caused by CHI at light and electron microscopy on the 7th day after 5 days TiO2 oxiracetam treatment. Adverse biochemical events such as upregulation of CSF nitrite and nitrate, IL-6, TNF-a and p-Tau are also reduced significantly in oxiracetam treated CHI group. On the other hand post treatment of 100mg/kg dose of normal oxiracetam in identical conditions after CHI is needed to show slight but significant neuroprotection together with mild recovery of memory function and functional deficits on the 8th day. These observations are the first to point out that nanowired delivery of oxiracetam has superior neuroprotective ability in CHI. These results indicate a promising clinical future of TiO2 oxiracetam in treating CHI patients for better quality of life and neurorehabilitation, not reported earlier.
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Affiliation(s)
- Feng Niu
- CSPC NBP Pharmaceutical Medicine, Shijiazhuang, China
| | - Aruna Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| | - Zhenguo Wang
- CSPC NBP Pharmaceutical Medicine, Shijiazhuang, China
| | - Lianyuan Feng
- Department of Neurology, Bethune International Peace Hospital, Shijiazhuang, China
| | - Dafin F Muresanu
- Department of Clinical Neurosciences, University of Medicine & Pharmacy, Cluj-Napoca, Romania; "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania
| | - Seaab Sahib
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, AR, United States
| | - Z Ryan Tian
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, AR, United States
| | - José Vicente Lafuente
- LaNCE, Department of Neuroscience, University of the Basque Country (UPV/EHU), Leioa, Bizkaia, Spain
| | - Anca D Buzoianu
- Department of Clinical Pharmacology and Toxicology, "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Rudy J Castellani
- Department of Pathology, University of Maryland, Baltimore, MD, United States
| | - Ala Nozari
- Anesthesiology & Intensive Care, Massachusetts General Hospital, Boston, MA, United States
| | - Preeti K Menon
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Ranjana Patnaik
- Department of Biomaterials, School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi, India
| | - Lars Wiklund
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| | - Hari Shanker Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
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39
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Computational roles of intrinsic synaptic dynamics. Curr Opin Neurobiol 2021; 70:34-42. [PMID: 34303124 DOI: 10.1016/j.conb.2021.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/14/2021] [Accepted: 06/15/2021] [Indexed: 12/26/2022]
Abstract
Conventional theories assume that long-term information storage in the brain is implemented by modifying synaptic efficacy. Recent experimental findings challenge this view by demonstrating that dendritic spine sizes, or their corresponding synaptic weights, are highly volatile even in the absence of neural activity. Here, we review previous computational works on the roles of these intrinsic synaptic dynamics. We first present the possibility for neuronal networks to sustain stable performance in their presence, and we then hypothesize that intrinsic dynamics could be more than mere noise to withstand, but they may improve information processing in the brain.
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40
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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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41
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Kasai H, Ziv NE, Okazaki H, Yagishita S, Toyoizumi T. Spine dynamics in the brain, mental disorders and artificial neural networks. Nat Rev Neurosci 2021; 22:407-422. [PMID: 34050339 DOI: 10.1038/s41583-021-00467-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2021] [Indexed: 12/15/2022]
Abstract
In the brain, most synapses are formed on minute protrusions known as dendritic spines. Unlike their artificial intelligence counterparts, spines are not merely tuneable memory elements: they also embody algorithms that implement the brain's ability to learn from experience and cope with new challenges. Importantly, they exhibit structural dynamics that depend on activity, excitatory input and inhibitory input (synaptic plasticity or 'extrinsic' dynamics) and dynamics independent of activity ('intrinsic' dynamics), both of which are subject to neuromodulatory influences and reinforcers such as dopamine. Here we succinctly review extrinsic and intrinsic dynamics, compare these with parallels in machine learning where they exist, describe the importance of intrinsic dynamics for memory management and adaptation, and speculate on how disruption of extrinsic and intrinsic dynamics may give rise to mental disorders. Throughout, we also highlight algorithmic features of spine dynamics that may be relevant to future artificial intelligence developments.
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Affiliation(s)
- Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. .,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
| | - Noam E Ziv
- Technion Faculty of Medicine and Network Biology Research Labs, Technion City, Haifa, Israel
| | - Hitoshi Okazaki
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Sho Yagishita
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Taro Toyoizumi
- Laboratory for Neural Computation and Adaptation, RIKEN Center for Brain Science, Saitama, Japan.,Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
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42
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CAPS1 is involved in hippocampal synaptic plasticity and hippocampus-associated learning. Sci Rep 2021; 11:8656. [PMID: 33883618 PMCID: PMC8060421 DOI: 10.1038/s41598-021-88009-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/07/2021] [Indexed: 12/14/2022] Open
Abstract
Calcium-dependent activator protein for secretion 1 (CAPS1) is a key molecule in vesicular exocytosis, probably in the priming step. However, CAPS1's role in synaptic plasticity and brain function is elusive. Herein, we showed that synaptic plasticity and learning behavior were impaired in forebrain and/or hippocampus-specific Caps1 conditional knockout (cKO) mice by means of molecular, physiological, and behavioral analyses. Neonatal Caps1 cKO mice showed a decrease in the number of docked vesicles in the hippocampal CA3 region, with no detectable changes in the distribution of other major exocytosis-related molecules. Additionally, long-term potentiation (LTP) was partially and severely impaired in the CA1 and CA3 regions, respectively. CA1 LTP was reinforced by repeated high-frequency stimuli, whereas CA3 LTP was completely abolished. Accordingly, hippocampus-associated learning was severely impaired in adeno-associated virus (AAV) infection-mediated postnatal Caps1 cKO mice. Collectively, our findings suggest that CAPS1 is a key protein involved in the cellular mechanisms underlying hippocampal synaptic release and plasticity, which is crucial for hippocampus-associated learning.
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43
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Zhu Y, Uytiepo M, Bushong E, Haberl M, Beutter E, Scheiwe F, Zhang W, Chang L, Luu D, Chui B, Ellisman M, Maximov A. Nanoscale 3D EM reconstructions reveal intrinsic mechanisms of structural diversity of chemical synapses. Cell Rep 2021; 35:108953. [PMID: 33826888 PMCID: PMC8354523 DOI: 10.1016/j.celrep.2021.108953] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/21/2021] [Accepted: 03/15/2021] [Indexed: 10/25/2022] Open
Abstract
Chemical synapses of shared cellular origins have remarkably heterogeneous structures, but how this diversity is generated is unclear. Here, we use three-dimensional (3D) electron microscopy and artificial intelligence algorithms for image processing to reconstruct functional excitatory microcircuits in the mouse hippocampus and microcircuits in which neurotransmitter signaling is permanently suppressed with genetic tools throughout the lifespan. These nanoscale analyses reveal that experience is dispensable for morphogenesis of synapses with different geometric shapes and contents of membrane organelles and that arrangement of morphologically distinct connections in local networks is stochastic. Moreover, loss of activity increases the variability in sizes of opposed pre- and postsynaptic structures without disrupting their alignments, suggesting that inherently variable weights of naive connections become progressively matched with repetitive use. These results demonstrate that mechanisms for the structural diversity of neuronal synapses are intrinsic and provide insights into how circuits essential for memory storage assemble and integrate information.
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Affiliation(s)
- Yongchuan Zhu
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Marco Uytiepo
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Eric Bushong
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA
| | - Matthias Haberl
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA
| | - Elizabeth Beutter
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Frederieke Scheiwe
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Weiheng Zhang
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lyanne Chang
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Danielle Luu
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Brandon Chui
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Mark Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA.
| | - Anton Maximov
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Hayashi S, Hoerder-Suabedissen A, Kiyokage E, Maclachlan C, Toida K, Knott G, Molnár Z. Maturation of Complex Synaptic Connections of Layer 5 Cortical Axons in the Posterior Thalamic Nucleus Requires SNAP25. Cereb Cortex 2021; 31:2625-2638. [PMID: 33367517 PMCID: PMC8023812 DOI: 10.1093/cercor/bhaa379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
Synapses are able to form in the absence of neuronal activity, but how is their subsequent maturation affected in the absence of regulated vesicular release? We explored this question using 3D electron microscopy and immunoelectron microscopy analyses in the large, complex synapses formed between cortical sensory efferent axons and dendrites in the posterior thalamic nucleus. Using a Synaptosome-associated protein 25 conditional knockout (Snap25 cKO), we found that during the first 2 postnatal weeks the axonal boutons emerge and increase in the size similar to the control animals. However, by P18, when an adult-like architecture should normally be established, axons were significantly smaller with 3D reconstructions, showing that each Snap25 cKO bouton only forms a single synapse with the connecting dendritic shaft. No excrescences from the dendrites were formed, and none of the normally large glomerular axon endings were seen. These results show that activity mediated through regulated vesicular release from the presynaptic terminal is not necessary for the formation of synapses, but it is required for the maturation of the specialized synaptic structures between layer 5 corticothalamic projections in the posterior thalamic nucleus.
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Affiliation(s)
- Shuichi Hayashi
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
- Department of Anatomy, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan
| | - Anna Hoerder-Suabedissen
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Emi Kiyokage
- Department of Medical Technology, Kawasaki University of Medical Welfare, Kurashiki, Okayama 701-0193, Japan
| | - Catherine Maclachlan
- BioEM Facility, School of Life Sciences, EPFL, Lausanne 1015, Switzerland
- The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Kazunori Toida
- Department of Anatomy, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Graham Knott
- BioEM Facility, School of Life Sciences, EPFL, Lausanne 1015, Switzerland
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
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45
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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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46
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Kuhlmann N, Wagner Valladolid M, Quesada-Ramírez L, Farrer MJ, Milnerwood AJ. Chronic and Acute Manipulation of Cortical Glutamate Transmission Induces Structural and Synaptic Changes in Co-cultured Striatal Neurons. Front Cell Neurosci 2021; 15:569031. [PMID: 33679324 PMCID: PMC7930618 DOI: 10.3389/fncel.2021.569031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
In contrast to the prenatal topographic development of sensory cortices, striatal circuit organization is slow and requires the functional maturation of cortical and thalamic excitatory inputs throughout the first postnatal month. While mechanisms regulating synapse development and plasticity are quite well described at excitatory synapses of glutamatergic neurons in the neocortex, comparatively little is known of how this translates to glutamate synapses onto GABAergic neurons in the striatum. Here we investigate excitatory striatal synapse plasticity in an in vitro system, where glutamate can be studied in isolation from dopamine and other neuromodulators. We examined pre-and post-synaptic structural and functional plasticity in GABAergic striatal spiny projection neurons (SPNs), co-cultured with glutamatergic cortical neurons. After synapse formation, medium-term (24 h) TTX silencing increased the density of filopodia, and modestly decreased dendritic spine density, when assayed at 21 days in vitro (DIV). Spine reductions appeared to require residual spontaneous activation of ionotropic glutamate receptors. Conversely, chronic (14 days) TTX silencing markedly reduced spine density without any observed increase in filopodia density. Time-dependent, biphasic changes to the presynaptic marker Synapsin-1 were also observed, independent of residual spontaneous activity. Acute silencing (3 h) did not affect presynaptic markers or postsynaptic structures. To induce rapid, activity-dependent plasticity in striatal neurons, a chemical NMDA receptor-dependent “long-term potentiation (LTP)” paradigm was employed. Within 30 min, this increased spine and GluA1 cluster densities, and the percentage of spines containing GluA1 clusters, without altering the presynaptic signal. The results demonstrate that the growth and pruning of dendritic protrusions is an active process, requiring glutamate receptor activity in striatal projection neurons. Furthermore, NMDA receptor activation is sufficient to drive glutamatergic structural plasticity in SPNs, in the absence of dopamine or other neuromodulators.
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Affiliation(s)
- Naila Kuhlmann
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | | | - Lucía Quesada-Ramírez
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
| | - Matthew J Farrer
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Austen J Milnerwood
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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47
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Steinkellner T, Madany M, Haberl MG, Zell V, Li C, Hu J, Mackey M, Ramachandra R, Adams S, Ellisman MH, Hnasko TS, Boassa D. Genetic Probe for Visualizing Glutamatergic Synapses and Vesicles by 3D Electron Microscopy. ACS Chem Neurosci 2021; 12:626-639. [PMID: 33522227 PMCID: PMC7899175 DOI: 10.1021/acschemneuro.0c00643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/19/2021] [Indexed: 01/21/2023] Open
Abstract
Communication between neurons relies on the release of diverse neurotransmitters, which represent a key-defining feature of a neuron's chemical and functional identity. Neurotransmitters are packaged into vesicles by specific vesicular transporters. However, tools for labeling and imaging synapses and synaptic vesicles based on their neurochemical identity remain limited. We developed a genetically encoded probe to identify glutamatergic synaptic vesicles at the levels of both light and electron microscopy (EM) by fusing the mini singlet oxygen generator (miniSOG) probe to an intralumenal loop of the vesicular glutamate transporter-2. We then used a 3D imaging method, serial block-face scanning EM, combined with a deep learning approach for automatic segmentation of labeled synaptic vesicles to assess the subcellular distribution of transporter-defined vesicles at nanometer scale. These tools represent a new resource for accessing the subcellular structure and molecular machinery of neurotransmission and for transmitter-defined tracing of neuronal connectivity.
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Affiliation(s)
- Thomas Steinkellner
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Institute of Pharmacology, Center for Physiology and
Pharmacology, Medical University of Vienna, Vienna 1090,
Austria
| | - Matthew Madany
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Matthias G. Haberl
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
- Charité−Universitätsmedizin
Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität
zu Berlin, and Berlin Institute of Health, Neuroscience Research Center,
Berlin 10117, Germany
| | - Vivien Zell
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
| | - Carolina Li
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Junru Hu
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Mason Mackey
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Ranjan Ramachandra
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Stephen Adams
- Department of Pharmacology, University of
California, San Diego, La Jolla California 92093, United
States
| | - Mark H. Ellisman
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
| | - Thomas S. Hnasko
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Research Service, VA San Diego Healthcare
System, San Diego, California 92161, United
States
| | - Daniela Boassa
- Department of Neurosciences, University
of California, San Diego, La Jolla, California 92093, United
States
- Center for Research in Biological Systems, National
Center for Microscopy and Imaging Research, University of California, San
Diego, La Jolla, California 92093, United States
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48
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Blockus H, Polleux F. Developmental mechanisms underlying circuit wiring: Novel insights and challenges ahead. Curr Opin Neurobiol 2021; 66:205-211. [PMID: 33421713 PMCID: PMC8058300 DOI: 10.1016/j.conb.2020.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 12/31/2022]
Abstract
Synaptic connectivity within neural circuits is characterized by high degrees of cellular and subcellular specificity. This precision arises from the combined action of several classes of molecular cues, transmembrane receptors, secreted cues and extracellular matrix components, coordinating transitions between axon guidance, dendrite patterning, axon branching and synapse specificity. We focus this review on recent insights into some of the molecular and cellular mechanisms controlling these transitions and present the results of large-scale efforts and technological developments aimed at mapping neural connectivity at single cell resolution in the mouse cortex as a mammalian model organism. Finally, we outline some of the technical and conceptual challenges lying ahead as the field is starting to explore one of the most challenging problems in neuroscience: the molecular and cellular logic underlying the emergence of the connectome characterizing specific circuits within the central nervous system of mammals.
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Affiliation(s)
- Heike Blockus
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA.
| | - Franck Polleux
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
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49
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Vemula SK, Malci A, Junge L, Lehmann AC, Rama R, Hradsky J, Matute RA, Weber A, Prigge M, Naumann M, Kreutz MR, Seidenbecher CI, Gundelfinger ED, Herrera-Molina R. The Interaction of TRAF6 With Neuroplastin Promotes Spinogenesis During Early Neuronal Development. Front Cell Dev Biol 2020; 8:579513. [PMID: 33363141 PMCID: PMC7755605 DOI: 10.3389/fcell.2020.579513] [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] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/11/2020] [Indexed: 11/22/2022] Open
Abstract
Correct brain wiring depends on reliable synapse formation. Nevertheless, signaling codes promoting synaptogenesis are not fully understood. Here, we report a spinogenic mechanism that operates during neuronal development and is based on the interaction of tumor necrosis factor receptor-associated factor 6 (TRAF6) with the synaptic cell adhesion molecule neuroplastin. The interaction between these proteins was predicted in silico and verified by co-immunoprecipitation in extracts from rat brain and co-transfected HEK cells. Binding assays show physical interaction between neuroplastin’s C-terminus and the TRAF-C domain of TRAF6 with a Kd value of 88 μM. As the two proteins co-localize in primordial dendritic protrusions, we used young cultures of rat and mouse as well as neuroplastin-deficient mouse neurons and showed with mutagenesis, knock-down, and pharmacological blockade that TRAF6 is required by neuroplastin to promote early spinogenesis during in vitro days 6-9, but not later. Time-framed TRAF6 blockade during days 6–9 reduced mEPSC amplitude, number of postsynaptic sites, synapse density and neuronal activity as neurons mature. Our data unravel a new molecular liaison that may emerge during a specific window of the neuronal development to determine excitatory synapse density in the rodent brain.
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Affiliation(s)
- Sampath Kumar Vemula
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ayse Malci
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Lennart Junge
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Anne-Christin Lehmann
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ramya Rama
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Johannes Hradsky
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ricardo A Matute
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States.,Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O'Higgins, Santiago, Chile
| | - André Weber
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Matthias Prigge
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Michael R Kreutz
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Constanze I Seidenbecher
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Rodrigo Herrera-Molina
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O'Higgins, Santiago, Chile.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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50
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Savino E, Cervigni RI, Povolo M, Stefanetti A, Ferrante D, Valente P, Corradi A, Benfenati F, Guarnieri FC, Valtorta F. Proline-rich transmembrane protein 2 (PRRT2) regulates the actin cytoskeleton during synaptogenesis. Cell Death Dis 2020; 11:856. [PMID: 33056987 PMCID: PMC7560900 DOI: 10.1038/s41419-020-03073-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/13/2022]
Abstract
Mutations in proline-rich transmembrane protein 2 (PRRT2) have been recently identified as the leading cause of a clinically heterogeneous group of neurological disorders sharing a paroxysmal nature, including paroxysmal kinesigenic dyskinesia and benign familial infantile seizures. To date, studies aimed at understanding its physiological functions in neurons have mainly focused on its ability to regulate neurotransmitter release and neuronal excitability. Here, we show that PRRT2 expression in non-neuronal cell lines inhibits cell motility and focal adhesion turnover, increases cell aggregation propensity, and promotes the protrusion of filopodia, all processes impinging on the actin cytoskeleton. In primary hippocampal neurons, PRRT2 silencing affects the synaptic content of filamentous actin and perturbs actin dynamics. This is accompanied by defects in the density and maturation of dendritic spines. We identified cofilin, an actin-binding protein abundantly expressed at the synaptic level, as the ultimate effector of PRRT2. Indeed, PRRT2 silencing unbalances cofilin activity leading to the formation of cofilin-actin rods along neurites. The expression of a cofilin phospho-mimetic mutant (cof-S3E) is able to rescue PRRT2-dependent defects in synapse density, spine number and morphology, but not the alterations observed in neurotransmitter release. Our data support a novel function of PRRT2 in the regulation of the synaptic actin cytoskeleton and in the formation of synaptic contacts.
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Affiliation(s)
- Elisa Savino
- IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.,Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
| | - Romina Inès Cervigni
- IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.,Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
| | - Miriana Povolo
- IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.,Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
| | | | - Daniele Ferrante
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132, Genova, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132, Genova, Italy.,IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132, Genova, Italy.,IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy
| | - Fabio Benfenati
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy
| | - Fabrizia Claudia Guarnieri
- IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy.,Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
| | - Flavia Valtorta
- IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy. .,Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy.
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