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Heck N, Santos MD. Dendritic Spines in Learning and Memory: From First Discoveries to Current Insights. ADVANCES IN NEUROBIOLOGY 2023; 34:311-348. [PMID: 37962799 DOI: 10.1007/978-3-031-36159-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The central nervous system is composed of neural ensembles, and their activity patterns are neural correlates of cognitive functions. Those ensembles are networks of neurons connected to each other by synapses. Most neurons integrate synaptic signal through a remarkable subcellular structure called spine. Dendritic spines are protrusions whose diverse shapes make them appear as a specific neuronal compartment, and they have been the focus of studies for more than a century. Soon after their first description by Ramón y Cajal, it has been hypothesized that spine morphological changes could modify neuronal connectivity and sustain cognitive abilities. Later studies demonstrated that changes in spine density and morphology occurred in experience-dependent plasticity during development, and in clinical cases of mental retardation. This gave ground for the assumption that dendritic spines are the particular locus of cerebral plasticity. With the discovery of synaptic long-term potentiation, a research program emerged with the aim to establish whether dendritic spine plasticity could explain learning and memory. The development of live imaging methods revealed on the one hand that dendritic spine remodeling is compatible with learning process and, on the other hand, that their long-term stability is compatible with lifelong memories. Furthermore, the study of the mechanisms of spine growth and maintenance shed new light on the rules of plasticity. In behavioral paradigms of memory, spine formation or elimination and morphological changes were found to correlate with learning. In a last critical step, recent experiments have provided evidence that dendritic spines play a causal role in learning and memory.
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Affiliation(s)
- Nicolas Heck
- Laboratory Neurosciences Paris Seine, Sorbonne Université, Paris, France.
| | - Marc Dos Santos
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Tiberi A, Carucci NM, Testa G, Rizzi C, Pacifico P, Borgonovo G, Arisi I, D’Onofrio M, Brandi R, Gan WB, Capsoni S, Cattaneo A. Reduced levels of NGF shift astrocytes toward a neurotoxic phenotype. Front Cell Dev Biol 2023; 11:1165125. [PMID: 37143894 PMCID: PMC10151754 DOI: 10.3389/fcell.2023.1165125] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
Nerve growth factor (NGF) is critical for neuronal physiology during development and adulthood. Despite the well-recognized effect of NGF on neurons, less is known about whether NGF can actually affect other cell types in the central nervous system (CNS). In this work, we show that astrocytes are susceptible to changes in ambient levels of NGF. First, we observe that interfering with NGF signaling in vivo via the constitutive expression of an antiNGF antibody induces astrocytic atrophy. A similar asthenic phenotype is encountered in an uncleavable proNGF transgenic mouse model (TgproNGF#72), effectively increasing the brain proNGF levels. To examine whether this effect on astrocytes is cell-autonomous, we cultured wild-type primary astrocytes in the presence of antiNGF antibodies, uncovering that a short incubation period is sufficient to potently and rapidly trigger calcium oscillations. Acute induction of calcium oscillations by antiNGF antibodies is followed by progressive morphological changes similar to those observed in antiNGF AD11 mice. Conversely, incubation with mature NGF has no effect on either calcium activity nor on astrocytic morphology. At longer timescales, transcriptomic analysis revealed that NGF-deprived astrocytes acquire a proinflammatory profile. In particular, antiNGF-treated astrocytes show upregulation of neurotoxic transcripts and downregulation of neuroprotective mRNAs. Consistent with that data, culturing wild-type neurons in the presence of NGF-deprived astrocytes leads to neuronal cell death. Finally, we report that in both awake and anesthetized mice, astrocytes in layer I of the motor cortex respond with an increase in calcium activity to acute NGF inhibition using either NGF-neutralizing antibodies or a TrkA-Fc NGF scavenger. Moreover, in vivo calcium imaging in the cortex of the 5xFAD neurodegeneration mouse model shows an increased level of spontaneous calcium activity in astrocytes, which is significantly reduced after acute administration of NGF. In conclusion, we unveil a novel neurotoxic mechanism driven by astrocytes, triggered by their sensing and reacting to changes in the levels of ambient NGF.
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Affiliation(s)
- Alexia Tiberi
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
| | | | | | | | | | | | - Ivan Arisi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Mara D’Onofrio
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Rossella Brandi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Wen-Biao Gan
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
- Shenzhen Bay Laboratory, Shenzhen, China
| | - Simona Capsoni
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Institute of Physiology, Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Antonino Cattaneo
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
- *Correspondence: Antonino Cattaneo,
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53
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Wouterlood FG. Techniques to Render Dendritic Spines Visible in the Microscope. ADVANCES IN NEUROBIOLOGY 2023; 34:69-102. [PMID: 37962794 DOI: 10.1007/978-3-031-36159-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
A tiny detail visible on certain neurons at the limit of resolution in light microscopy went in 130 years of neuroscience research through a dazzling career from suspicious staining artifact to what we recognize today as a complex postsynaptic molecular machine: the dendritic spine.This chapter deals with techniques to make spines visible. The original technique, Golgi silver staining, is still being used today. Electron microscopy and automated field ion beam scanning electron microscopy are ultrahigh resolution techniques, albeit specialized. Other methods are intracellular injection, uptake of dyes, and recently the exploitation of genetically modified animals in which certain neurons express fluorescent protein in all their processes, including the nooks and crannies of their dendritic spines.
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Affiliation(s)
- Floris G Wouterlood
- Department of Anatomy & Neurosciences, Amsterdam UMC, Amsterdam, The Netherlands
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54
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Petanjek Z, Banovac I, Sedmak D, Hladnik A. Dendritic Spines: Synaptogenesis and Synaptic Pruning for the Developmental Organization of Brain Circuits. ADVANCES IN NEUROBIOLOGY 2023; 34:143-221. [PMID: 37962796 DOI: 10.1007/978-3-031-36159-3_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Synaptic overproduction and elimination is a regular developmental event in the mammalian brain. In the cerebral cortex, synaptic overproduction is almost exclusively correlated with glutamatergic synapses located on dendritic spines. Therefore, analysis of changes in spine density on different parts of the dendritic tree in identified classes of principal neurons could provide insight into developmental reorganization of specific microcircuits.The activity-dependent stabilization and selective elimination of the initially overproduced synapses is a major mechanism for generating diversity of neural connections beyond their genetic determination. The largest number of overproduced synapses was found in the monkey and human cerebral cortex. The highest (exceeding adult values by two- to threefold) and most protracted overproduction (up to third decade of life) was described for associative layer IIIC pyramidal neurons in the human dorsolateral prefrontal cortex.Therefore, the highest proportion and extraordinarily extended phase of synaptic spine overproduction is a hallmark of neural circuitry in human higher-order associative areas. This indicates that microcircuits processing the most complex human cognitive functions have the highest level of developmental plasticity. This finding is the backbone for understanding the effect of environmental impact on the development of the most complex, human-specific cognitive and emotional capacities, and on the late onset of human-specific neuropsychiatric disorders, such as autism and schizophrenia.
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Affiliation(s)
- Zdravko Petanjek
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia.
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia.
| | - Ivan Banovac
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Dora Sedmak
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Ana Hladnik
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
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55
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Bulovaite E, Qiu Z, Kratschke M, Zgraj A, Fricker DG, Tuck EJ, Gokhale R, Koniaris B, Jami SA, Merino-Serrais P, Husi E, Mendive-Tapia L, Vendrell M, O'Dell TJ, DeFelipe J, Komiyama NH, Holtmaat A, Fransén E, Grant SGN. A brain atlas of synapse protein lifetime across the mouse lifespan. Neuron 2022; 110:4057-4073.e8. [PMID: 36202095 PMCID: PMC9789179 DOI: 10.1016/j.neuron.2022.09.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 07/01/2022] [Accepted: 09/07/2022] [Indexed: 11/12/2022]
Abstract
The lifetime of proteins in synapses is important for their signaling, maintenance, and remodeling, and for memory duration. We quantified the lifetime of endogenous PSD95, an abundant postsynaptic protein in excitatory synapses, at single-synapse resolution across the mouse brain and lifespan, generating the Protein Lifetime Synaptome Atlas. Excitatory synapses have a wide range of PSD95 lifetimes extending from hours to several months, with distinct spatial distributions in dendrites, neurons, and brain regions. Synapses with short protein lifetimes are enriched in young animals and in brain regions controlling innate behaviors, whereas synapses with long protein lifetimes accumulate during development, are enriched in the cortex and CA1 where memories are stored, and are preferentially preserved in old age. Synapse protein lifetime increases throughout the brain in a mouse model of autism and schizophrenia. Protein lifetime adds a further layer to synapse diversity and enriches prevailing concepts in brain development, aging, and disease.
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Affiliation(s)
- Edita Bulovaite
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Zhen Qiu
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Maximilian Kratschke
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Adrianna Zgraj
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - David G Fricker
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Eleanor J Tuck
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Ragini Gokhale
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Babis Koniaris
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; School of Computing, Edinburgh Napier University, Edinburgh EH10 5DT, UK
| | - Shekib A Jami
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Paula Merino-Serrais
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, UPM, 28223 Madrid, Spain; Instituto Cajal, CSIC, 28002 Madrid, Spain
| | - Elodie Husi
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Lorena Mendive-Tapia
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Marc Vendrell
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Thomas J O'Dell
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, UPM, 28223 Madrid, Spain; Instituto Cajal, CSIC, 28002 Madrid, Spain
| | - Noboru H Komiyama
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK; The Patrick Wild Centre for Research into Autism, Fragile X Syndrome & Intellectual Disabilities, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Anthony Holtmaat
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Erik Fransén
- Department of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden; Science for Life Laboratory, KTH Royal Institute of Technology, 171 65 Solna, Sweden
| | - Seth G N Grant
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK.
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56
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Ciganok-Hückels N, Jehasse K, Kricsfalussy-Hrabár L, Ritter M, Rüland T, Kampa BM. Postnatal development of electrophysiological and morphological properties in layer 2/3 and layer 5 pyramidal neurons in the mouse primary visual cortex. Cereb Cortex 2022; 33:5875-5884. [PMID: 36453454 PMCID: PMC10183751 DOI: 10.1093/cercor/bhac467] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/04/2022] [Accepted: 11/05/2022] [Indexed: 12/03/2022] Open
Abstract
Abstract
Eye-opening is a critical point for laminar maturation of pyramidal neurons (PNs) in primary visual cortex. Knowing both the intrinsic properties and morphology of PNs from the visual cortex during development is crucial to contextualize the integration of visual inputs at different age stages. Few studies have reported changes in intrinsic excitability in these neurons but were restricted to only one layer or one stage of cortical development. Here, we used in vitro whole-cell patch-clamp to investigate the developmental impact on electrophysiological properties of layer 2/3 and layer 5 PNs in mouse visual cortex. Additionally, we evaluated the morphological changes before and after eye-opening and compared these in adult mice. Overall, we found a decrease in intrinsic excitability in both layers after eye-opening which remained stable between juvenile and adult mice. The basal dendritic length increased in layer 5 neurons, whereas spine density increased in layer 2/3 neurons after eye-opening. These data show increased number of synapses after onset of sensory input paralleled with a reduced excitability, presumably as homeostatic mechanism. Altogether, we provide a database of the properties of PNs in mouse visual cortex by considering the layer- and time-specific changes of these neurons during sensory development.
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Affiliation(s)
- Natalja Ciganok-Hückels
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
| | - Kevin Jehasse
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
| | | | - Mira Ritter
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
| | - Thomas Rüland
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
- Institute for Biological Information Processing (IBI-1), Forschungszentrum Jülich , 52428 Jülich , Germany
| | - Björn M Kampa
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
- JARA BRAIN, Institute of Neuroscience and Medicine (INM-10), Forschungszentrum Jülich , 52428 Jülich , Germany
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57
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Vardalaki D, Chung K, Harnett MT. Filopodia are a structural substrate for silent synapses in adult neocortex. Nature 2022; 612:323-327. [PMID: 36450984 DOI: 10.1038/s41586-022-05483-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/25/2022] [Indexed: 12/05/2022]
Abstract
Newly generated excitatory synapses in the mammalian cortex lack sufficient AMPA-type glutamate receptors to mediate neurotransmission, resulting in functionally silent synapses that require activity-dependent plasticity to mature. Silent synapses are abundant in early development, during which they mediate circuit formation and refinement, but they are thought to be scarce in adulthood1. However, adults retain a capacity for neural plasticity and flexible learning that suggests that the formation of new connections is still prevalent. Here we used super-resolution protein imaging to visualize synaptic proteins at 2,234 synapses from layer 5 pyramidal neurons in the primary visual cortex of adult mice. Unexpectedly, about 25% of these synapses lack AMPA receptors. These putative silent synapses were located at the tips of thin dendritic protrusions, known as filopodia, which were more abundant by an order of magnitude than previously believed (comprising about 30% of all dendritic protrusions). Physiological experiments revealed that filopodia do indeed lack AMPA-receptor-mediated transmission, but they exhibit NMDA-receptor-mediated synaptic transmission. We further showed that functionally silent synapses on filopodia can be unsilenced through Hebbian plasticity, recruiting new active connections into a neuron's input matrix. These results challenge the model that functional connectivity is largely fixed in the adult cortex and demonstrate a new mechanism for flexible control of synaptic wiring that expands the learning capabilities of the mature brain.
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Affiliation(s)
- Dimitra Vardalaki
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA.,Department of Brain & Cognitive Sciences, MIT, Cambridge, MA, USA
| | - Kwanghun Chung
- Department of Brain & Cognitive Sciences, MIT, Cambridge, MA, USA.,Picower Institute for Learning and Memory, MIT, Cambridge, MA, USA.,Institute for Medical Engineering and Science, MIT, Cambridge, MA, USA.,Department of Chemical Engineering, MIT, Cambridge, MA, USA.,Broad Institute of Harvard University and MIT, Cambridge, MA, USA
| | - Mark T Harnett
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA. .,Department of Brain & Cognitive Sciences, MIT, Cambridge, MA, USA.
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58
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Yang X, Chen C, Qu D, Liu Y, Wang N, Wang H, Fan Y, Zhou Y, Yu B, Xue Q, Wu Y, Lu H. Aberrant expression of FBXO22 is associated with propofol-induced synaptic plasticity and cognitive dysfunction in adult mice. Front Aging Neurosci 2022; 14:1028148. [DOI: 10.3389/fnagi.2022.1028148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022] Open
Abstract
Recent observation demonstrated that prolonged anesthesia modifies brain synaptic architecture in all ages, including adult. Propofol is the most commonly utilized anesthetics at clinic. Whether repeated administration of propofol modulates cognitive impairment in adults and changes synaptic plasticity remains, however, to be explored. In this study, we first discovered that repeated and prolonged exposure to propofol-induced cognitive impairment in adult rodents. Then, we examined the property of hippocampal primary neurons and slices after propofol treatment in mice, including synaptic protein profile, dendritic spine density, as well as synaptic transmission. We found the distinctive change of the F-box only protein 22 (FBXO22), an F-box E3 ligase, during this process and further explored its role. Knockdown experiments showed the downregulation of FBXO22 restored the changes by propofol treatment on hippocampal primary neurons and attenuated propofol-induced hippocampal dependent cognitive dysfunction. Our results showed that FBXO22 is involved in the regulation of repeated propofol treatment induced changes of synaptic plasticity and cognitive dysfunction in adult mice. Repeated propofol treatment leads to cognitive dysfunction by regulating FBXO22 in adult rodents.
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Frias ES, Hoseini MS, Krukowski K, Paladini MS, Grue K, Ureta G, Rienecker KDA, Walter P, Stryker MP, Rosi S. Aberrant cortical spine dynamics after concussive injury are reversed by integrated stress response inhibition. Proc Natl Acad Sci U S A 2022; 119:e2209427119. [PMID: 36227915 PMCID: PMC9586300 DOI: 10.1073/pnas.2209427119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of long-term neurological disability in the world and the strongest environmental risk factor for the development of dementia. Even mild TBI (resulting from concussive injuries) is associated with a greater than twofold increase in the risk of dementia onset. Little is known about the cellular mechanisms responsible for the progression of long-lasting cognitive deficits. The integrated stress response (ISR), a phylogenetically conserved pathway involved in the cellular response to stress, is activated after TBI, and inhibition of the ISR-even weeks after injury-can reverse behavioral and cognitive deficits. However, the cellular mechanisms by which ISR inhibition restores cognition are unknown. Here, we used longitudinal two-photon imaging in vivo after concussive injury in mice to study dendritic spine dynamics in the parietal cortex, a brain region involved in working memory. Concussive injury profoundly altered spine dynamics measured up to a month after injury. Strikingly, brief pharmacological treatment with the drug-like small-molecule ISR inhibitor ISRIB entirely reversed structural changes measured in the parietal cortex and the associated working memory deficits. Thus, both neural and cognitive consequences of concussive injury are mediated in part by activation of the ISR and can be corrected by its inhibition. These findings suggest that targeting ISR activation could serve as a promising approach to the clinical treatment of chronic cognitive deficits after TBI.
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Affiliation(s)
- Elma S. Frias
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Mahmood S. Hoseini
- Department of Physiology, University of California, San Francisco, CA 94143
| | - Karen Krukowski
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Maria Serena Paladini
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Katherine Grue
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Gonzalo Ureta
- Department of Translational Research, Protein Folding and Disease Laboratory, Fundación Ciencia & Vida, Santiago, 7750000, Chile
| | - Kira D. A. Rienecker
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Michael P. Stryker
- Department of Physiology, University of California, San Francisco, CA 94143
- Kavli Institute of Fundamental Neuroscience, University of California, San Francisco, CA 94143
| | - Susanna Rosi
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
- Kavli Institute of Fundamental Neuroscience, University of California, San Francisco, CA 94143
- Department of Neurological Surgery, University of California, San Francisco, CA 94143
- Weill Institute for Neuroscience, University of California, San Francisco, CA 94143
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60
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Li C, Wu XJ, Li W. Neuropeptide S promotes maintenance of newly formed dendritic spines and performance improvement after motor learning in mice. Peptides 2022; 156:170860. [PMID: 35970276 DOI: 10.1016/j.peptides.2022.170860] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/18/2022] [Accepted: 08/10/2022] [Indexed: 10/15/2022]
Abstract
Neuropeptide S (NPS), an endogenous neuropeptide consisting of 20 amino acids, selectively binds and activates G protein-coupled receptor named neuropeptide S receptor (NPSR) to regulate a variety of physiological functions. NPS/NPSR system has been shown to play a pivotal role in regulating learning and memory in rodents. However, it remains unclear that how NPS/NPSR system affects neuronal functions and synaptic plasticity after learning. We found that intracerebroventricular (i.c.v.) injection of NPS promoted performance improvement and reduced sleep duration after motor learning, which could be blocked by pre-treatment with intraperitoneal (i.p.) injection of NPSR antagonist SHA 68. Using intravital two-photon imaging, we examined the effect of NPS on the postsynaptic dendritic spines of layer V pyramidal neurons in the mouse primary motor cortex after motor learning. We found that i.c.v. injection of NPS strengthened learning-induce new spines and facilitated their survival over time. Furthermore, i.c.v. injection of NPS increased calcium activity of apical dendrites and dendritic spines of layer V pyramidal neurons in the mouse primary motor cortex during the running period. These findings suggest that activation of NPSR by NPS increases synaptic calcium activity and learning-related synapse maintenance, thereby contributing to performance improvement after motor learning.
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Affiliation(s)
- Cong Li
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen 518107, China
| | - Xu-Jun Wu
- Institute of Neurological and Psychiatric Disorders, Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Wei Li
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen 518107, China; School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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61
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Cheng L, Su Y, Zhi K, Xie Y, Zhang C, Meng X. Conditional deletion of MAD2B in forebrain neurons enhances hippocampus-dependent learning and memory in mice. Front Cell Neurosci 2022; 16:956029. [PMID: 36212696 PMCID: PMC9538151 DOI: 10.3389/fncel.2022.956029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Mitotic arrest deficient 2-like protein 2 (MAD2B) is not only a DNA damage repair agent but also a cell cycle regulator that is widely expressed in the hippocampus and the cerebral cortex. However, the functions of MAD2B in hippocampal and cerebral cortical neurons are poorly understood. In this study, we crossed MAD2Bflox/flox and calcium/calmodulin-dependent protein kinase II alpha (Camk2a)-Cre mice to conditionally knock out MAD2B in the forebrain pyramidal neurons by the Cre/loxP recombinase system. First, RNA sequencing suggested that the differentially expressed genes in the hippocampus and the cerebral cortex between the WT and the MAD2B cKO mice were related to learning and memory. Then, the results of behavioral tests, including the Morris water maze test, the novel object recognition test, and the contextual fear conditioning experiment, suggested that the learning and memory abilities of the MAD2B cKO mice had improved. Moreover, conditional knockout of MAD2B increased the number of neurons without affecting the number of glial cells in the hippocampal CA1 and the cerebral cortex. At the same time, the number of doublecortin-positive (DCX+) cells was increased in the dentate gyrus (DG) of the MAD2B cKO mice. In addition, as shown by Golgi staining, the MAD2B cKO mice had more mushroom-like and long-like spines than the WT mice. Transmission electron microscopy (TEM) revealed that spine synapses increased and shaft synapses decreased in the CA1 of the MAD2B cKO mice. Taken together, our findings indicated that MAD2B plays an essential role in regulating learning and memory.
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Affiliation(s)
- Li Cheng
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanfang Su
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kaining Zhi
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yaru Xie
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Chun Zhang
| | - Xianfang Meng
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Xianfang Meng
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62
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Arias A, Manubens-Gil L, Dierssen M. Fluorescent transgenic mouse models for whole-brain imaging in health and disease. Front Mol Neurosci 2022; 15:958222. [PMID: 36211979 PMCID: PMC9538927 DOI: 10.3389/fnmol.2022.958222] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/08/2022] [Indexed: 11/25/2022] Open
Abstract
A paradigm shift is occurring in neuroscience and in general in life sciences converting biomedical research from a descriptive discipline into a quantitative, predictive, actionable science. Living systems are becoming amenable to quantitative description, with profound consequences for our ability to predict biological phenomena. New experimental tools such as tissue clearing, whole-brain imaging, and genetic engineering technologies have opened the opportunity to embrace this new paradigm, allowing to extract anatomical features such as cell number, their full morphology, and even their structural connectivity. These tools will also allow the exploration of new features such as their geometrical arrangement, within and across brain regions. This would be especially important to better characterize brain function and pathological alterations in neurological, neurodevelopmental, and neurodegenerative disorders. New animal models for mapping fluorescent protein-expressing neurons and axon pathways in adult mice are key to this aim. As a result of both developments, relevant cell populations with endogenous fluorescence signals can be comprehensively and quantitatively mapped to whole-brain images acquired at submicron resolution. However, they present intrinsic limitations: weak fluorescent signals, unequal signal strength across the same cell type, lack of specificity of fluorescent labels, overlapping signals in cell types with dense labeling, or undetectable signal at distal parts of the neurons, among others. In this review, we discuss the recent advances in the development of fluorescent transgenic mouse models that overcome to some extent the technical and conceptual limitations and tradeoffs between different strategies. We also discuss the potential use of these strains for understanding disease.
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Affiliation(s)
- Adrian Arias
- Department of System Biology, Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Linus Manubens-Gil
- Institute for Brain and Intelligence, Southeast University, Nanjing, China
| | - Mara Dierssen
- Department of System Biology, Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Experimental and Health Sciences, University Pompeu Fabra, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
- *Correspondence: Mara Dierssen,
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63
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Qi C, Luo LD, Feng I, Ma S. Molecular mechanisms of synaptogenesis. Front Synaptic Neurosci 2022; 14:939793. [PMID: 36176941 PMCID: PMC9513053 DOI: 10.3389/fnsyn.2022.939793] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Synapses are the basic units for information processing and storage in the nervous system. It is only when the synaptic connection is established, that it becomes meaningful to discuss the structure and function of a circuit. In humans, our unparalleled cognitive abilities are correlated with an increase in the number of synapses. Additionally, genes involved in synaptogenesis are also frequently associated with neurological or psychiatric disorders, suggesting a relationship between synaptogenesis and brain physiology and pathology. Thus, understanding the molecular mechanisms of synaptogenesis is the key to the mystery of circuit assembly and neural computation. Furthermore, it would provide therapeutic insights for the treatment of neurological and psychiatric disorders. Multiple molecular events must be precisely coordinated to generate a synapse. To understand the molecular mechanisms underlying synaptogenesis, we need to know the molecular components of synapses, how these molecular components are held together, and how the molecular networks are refined in response to neural activity to generate new synapses. Thanks to the intensive investigations in this field, our understanding of the process of synaptogenesis has progressed significantly. Here, we will review the molecular mechanisms of synaptogenesis by going over the studies on the identification of molecular components in synapses and their functions in synaptogenesis, how cell adhesion molecules connect these synaptic molecules together, and how neural activity mobilizes these molecules to generate new synapses. Finally, we will summarize the human-specific regulatory mechanisms in synaptogenesis and results from human genetics studies on synaptogenesis and brain disorders.
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Affiliation(s)
- Cai Qi
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- *Correspondence: Cai Qi,
| | - Li-Da Luo
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, United States
| | - Irena Feng
- Boston University School of Medicine, Boston, MA, United States
| | - Shaojie Ma
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
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64
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Qiao Q, Wu C, Ma L, Zhang H, Li M, Wu X, Gan WB. Motor learning-induced new dendritic spines are preferentially involved in the learned task than existing spines. Cell Rep 2022; 40:111229. [PMID: 35977515 DOI: 10.1016/j.celrep.2022.111229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/25/2022] [Accepted: 07/26/2022] [Indexed: 11/25/2022] Open
Abstract
Learning induces the formation of new synapses in addition to changes of existing synapse strength. However, it remains unclear whether new synapses serve different functions from existing synapses. By performing two-photon structural and Ca2+ imaging of postsynaptic dendritic spines in layer 2/3 pyramidal neurons, we show that new spine formation increases in the mouse motor cortex 8-24 h after motor training. New spines, not existing spine populations, are preferentially active when mice perform the learned task rather than a new task. New spine activity is also more synchronized with dendritic/somatic activity when the learned task, not a new task, is carried out. Furthermore, new spines are formed to increase the task specificity in a subset of neurons, and their survival is not affected when a new task is learned. These findings suggest that newly formed synapses preferentially increase the task specificity of neurons over existing synapses at the retention stage of motor learning.
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Affiliation(s)
- Qian Qiao
- Shenzhen Bay Laboratory, Shenzhen 518132, China; School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Chunling Wu
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Lei Ma
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Hua Zhang
- Shenzhen Bay Laboratory, Shenzhen 518132, China; School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Miao Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Xujun Wu
- Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Wen-Biao Gan
- Shenzhen Bay Laboratory, Shenzhen 518132, China; School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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65
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Ball JB, Green-Fulgham SM, Watkins LR. Mechanisms of Microglia-Mediated Synapse Turnover and Synaptogenesis. Prog Neurobiol 2022; 218:102336. [DOI: 10.1016/j.pneurobio.2022.102336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/30/2022] [Accepted: 08/02/2022] [Indexed: 10/31/2022]
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66
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Triantopoulou N, Vidaki M. Local mRNA translation and cytoskeletal reorganization: Mechanisms that tune neuronal responses. Front Mol Neurosci 2022; 15:949096. [PMID: 35979146 PMCID: PMC9376447 DOI: 10.3389/fnmol.2022.949096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/07/2022] [Indexed: 12/31/2022] Open
Abstract
Neurons are highly polarized cells with significantly long axonal and dendritic extensions that can reach distances up to hundreds of centimeters away from the cell bodies in higher vertebrates. Their successful formation, maintenance, and proper function highly depend on the coordination of intricate molecular networks that allow axons and dendrites to quickly process information, and respond to a continuous and diverse cascade of environmental stimuli, often without enough time for communication with the soma. Two seemingly unrelated processes, essential for these rapid responses, and thus neuronal homeostasis and plasticity, are local mRNA translation and cytoskeletal reorganization. The axonal cytoskeleton is characterized by high stability and great plasticity; two contradictory attributes that emerge from the powerful cytoskeletal rearrangement dynamics. Cytoskeletal reorganization is crucial during nervous system development and in adulthood, ensuring the establishment of proper neuronal shape and polarity, as well as regulating intracellular transport and synaptic functions. Local mRNA translation is another mechanism with a well-established role in the developing and adult nervous system. It is pivotal for axonal guidance and arborization, synaptic formation, and function and seems to be a key player in processes activated after neuronal damage. Perturbations in the regulatory pathways of local translation and cytoskeletal reorganization contribute to various pathologies with diverse clinical manifestations, ranging from intellectual disabilities (ID) to autism spectrum disorders (ASD) and schizophrenia (SCZ). Despite the fact that both processes are essential for the orchestration of pathways critical for proper axonal and dendritic function, the interplay between them remains elusive. Here we review our current knowledge on the molecular mechanisms and specific interaction networks that regulate and potentially coordinate these interconnected processes.
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Affiliation(s)
- Nikoletta Triantopoulou
- Division of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas (IMBB-FORTH), Heraklion, Greece
| | - Marina Vidaki
- Division of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas (IMBB-FORTH), Heraklion, Greece
- *Correspondence: Marina Vidaki,
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67
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Voglewede MM, Zhang H. Polarity proteins: Shaping dendritic spines and memory. Dev Biol 2022; 488:68-73. [PMID: 35580729 PMCID: PMC9953585 DOI: 10.1016/j.ydbio.2022.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 02/01/2023]
Abstract
The morphogenesis and plasticity of dendritic spines are associated with synaptic strength, learning, and memory. Dendritic spines are highly compartmentalized structures, which makes proteins involved in cellular polarization and membrane compartmentalization likely candidates regulating their formation and maintenance. Indeed, recent studies suggest polarity proteins help form and maintain dendritic spines by compartmentalizing the spine neck and head. Here, we review emerging evidence that polarity proteins regulate dendritic spine plasticity and stability through the cytoskeleton, scaffolding molecules, and signaling molecules. We specifically analyze various polarity complexes known to contribute to different forms of cell polarization processes and examine the essential conceptual context linking these groups of polarity proteins to dendritic spine morphogenesis, plasticity, and cognitive functions.
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Affiliation(s)
| | - Huaye Zhang
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA.
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68
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Abstract
Humans have the remarkable ability to continually store new memories, while maintaining old memories for a lifetime. How the brain avoids catastrophic forgetting of memories due to interference between encoded memories is an open problem in computational neuroscience. Here we present a model for continual learning in a recurrent neural network combining Hebbian learning, synaptic decay and a novel memory consolidation mechanism: memories undergo stochastic rehearsals with rates proportional to the memory's basin of attraction, causing self-amplified consolidation. This mechanism gives rise to memory lifetimes that extend much longer than the synaptic decay time, and retrieval probability of memories that gracefully decays with their age. The number of retrievable memories is proportional to a power of the number of neurons. Perturbations to the circuit model cause temporally-graded retrograde and anterograde deficits, mimicking observed memory impairments following neurological trauma.
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69
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Redman WT, Wolcott NS, Montelisciani L, Luna G, Marks TD, Sit KK, Yu CH, Smith S, Goard MJ. Long-term transverse imaging of the hippocampus with glass microperiscopes. eLife 2022; 11:75391. [PMID: 35775393 PMCID: PMC9249394 DOI: 10.7554/elife.75391] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/12/2022] [Indexed: 11/19/2022] Open
Abstract
The hippocampus consists of a stereotyped neuronal circuit repeated along the septal-temporal axis. This transverse circuit contains distinct subfields with stereotyped connectivity that support crucial cognitive processes, including episodic and spatial memory. However, comprehensive measurements across the transverse hippocampal circuit in vivo are intractable with existing techniques. Here, we developed an approach for two-photon imaging of the transverse hippocampal plane in awake mice via implanted glass microperiscopes, allowing optical access to the major hippocampal subfields and to the dendritic arbor of pyramidal neurons. Using this approach, we tracked dendritic morphological dynamics on CA1 apical dendrites and characterized spine turnover. We then used calcium imaging to quantify the prevalence of place and speed cells across subfields. Finally, we measured the anatomical distribution of spatial information, finding a non-uniform distribution of spatial selectivity along the DG-to-CA1 axis. This approach extends the existing toolbox for structural and functional measurements of hippocampal circuitry.
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Affiliation(s)
- William T Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, United States
| | - Nora S Wolcott
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States
| | - Luca Montelisciani
- Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, Netherlands
| | - Gabriel Luna
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Tyler D Marks
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Kevin K Sit
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
| | - Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Spencer Smith
- Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Michael J Goard
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States.,Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
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70
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Lee S, Lee K, Choi M, Park J. Implantable acousto-optic window for monitoring ultrasound-mediated neuromodulation in vivo. NEUROPHOTONICS 2022; 9:032203. [PMID: 35874142 PMCID: PMC9298854 DOI: 10.1117/1.nph.9.3.032203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Significance: Ultrasound has recently received considerable attention in neuroscience because it provides noninvasive control of deep brain activity. Although the feasibility of ultrasound stimulation has been reported in preclinical and clinical settings, its mechanistic understanding remains limited. While optical microscopy has become the "gold standard" tool for investigating population-level neural functions in vivo, its application for ultrasound neuromodulation has been technically challenging, as most conventional ultrasonic transducers are not designed to be compatible with optical microscopy. Aim: We aimed to develop a transparent acoustic transducer based on a glass coverslip called the acousto-optic window (AOW), which simultaneously provides ultrasound neuromodulation and microscopic monitoring of neural responses in vivo. Approach: The AOW was fabricated by the serial deposition of transparent acoustic stacks on a circular glass coverslip, comprising a piezoelectric material, polyvinylidene fluoride-trifluoroethylene, and indium-tin-oxide electrodes. The fabricated AOW was implanted into a transgenic neural-activity reporter mouse after open craniotomy. Two-photon microscopy was used to observe neuronal activity in response to ultrasonic stimulation through the AOW. Results: The AOW allowed microscopic imaging of calcium activity in cortical neurons in response to ultrasound stimulation. The optical transparency was ∼ 40 % over the visible and near-infrared spectra, and the ultrasonic pressure was 0.035 MPa at 10 MHz corresponding to 10 mW / cm 2 . In anesthetized Gad2-GCaMP6-tdTomato mice, we observed robust ultrasound-evoked activation of inhibitory cortical neurons at depths up to 200 μ m . Conclusions: The AOW is an implantable ultrasonic transducer that is broadly compatible with optical imaging modalities. The AOW will facilitate our understanding of ultrasound neuromodulation in vivo.
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Affiliation(s)
- Sungho Lee
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| | - Keunhyung Lee
- Sungkyunkwan University, Department of Intelligent Precision Healthcare Convergence, Suwon, Republic of Korea
| | - Myunghwan Choi
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| | - Jinhyoung Park
- Sungkyunkwan University, Department of Intelligent Precision Healthcare Convergence, Suwon, Republic of Korea
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
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71
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Chen M, Qi J, Poo M, Yang Y. Stability and dynamics of dendritic spines in macaque prefrontal cortex. Natl Sci Rev 2022; 9:nwac125. [PMID: 36196248 PMCID: PMC9521340 DOI: 10.1093/nsr/nwac125] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/08/2022] [Accepted: 06/15/2022] [Indexed: 11/16/2022] Open
Abstract
Formation and elimination of synapses reflect structural plasticity of neuronal connectivity. Here we performed high-resolution two-photon imaging of dendritic spines in the prefrontal cortex of four macaque monkeys and found that spines were in general highly stable, with low percentages undergoing synaptic turnover. By observing the same spines at weekly intervals, we found that newly formed spines were more susceptible to elimination, with only 40% persisting over a period of months. Analyses of spatial distribution of large numbers of spines revealed that spine distribution was neither uniform nor random, favoring inter-spine distances of 2–4 μm. Furthermore, spine formation and elimination occurred more often in low- and high-density dendritic segments, respectively, and preferentially within a hot zone of ∼4 μm from existing spines. Our results demonstrate long-term stability and spatially regulated spine dynamics in the macaque cortex and provide a structural basis for understanding neural circuit plasticity in the primate brain.
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72
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Keeping Synapses in Shape: Degradation Pathways in the Healthy and Aging Brain. Neuronal Signal 2022; 6:NS20210063. [PMID: 35813265 PMCID: PMC9208270 DOI: 10.1042/ns20210063] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
Synapses maintain their molecular composition, plasticity and function through the concerted action of protein synthesis and removal. The complex and polarized neuronal architecture poses specific challenges to the logistics of protein and organelle turnover since protein synthesis and degradation mainly happen in the cell soma. In addition, post-mitotic neurons accumulate damage over a lifetime, challenging neuronal degradative pathways and making them particularly susceptible to the effects of aging. This review will summarize the current knowledge on neuronal protein turnover mechanisms with a particular focus on the presynapse, including the proteasome, autophagy and the endolysosomal route and their roles in regulating presynaptic proteostasis and function. In addition, the author will discuss how physiological brain aging, which entails a progressive decline in cognitive functions, affects synapses and the degradative machinery.
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73
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Gonzalez KC, Losonczy A, Negrean A. Dendritic Excitability and Synaptic Plasticity In Vitro and In Vivo. Neuroscience 2022; 489:165-175. [PMID: 34998890 PMCID: PMC9392867 DOI: 10.1016/j.neuroscience.2021.12.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 02/06/2023]
Abstract
Much of our understanding of dendritic and synaptic physiology comes from in vitro experimentation, where the afforded mechanical stability and convenience of applying drugs allowed patch-clamping based recording techniques to investigate ion channel distributions, their gating kinetics, and to uncover dendritic integrative and synaptic plasticity rules. However, with current efforts to study these questions in vivo, there is a great need to translate existing knowledge between in vitro and in vivo experimental conditions. In this review, we identify discrepancies between in vitro and in vivo ionic composition of extracellular media and discuss how changes in ionic composition alter dendritic excitability and plasticity induction. Here, we argue that under physiological in vivo ionic conditions, dendrites are expected to be more excitable and the threshold for synaptic plasticity induction to be lowered. Consequently, the plasticity rules described in vitro vary significantly from those implemented in vivo.
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Affiliation(s)
- Kevin C Gonzalez
- Department of Neuroscience, Columbia University, New York, NY, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, USA.
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, USA; Kavli Institute for Brain Science, New York, NY, USA.
| | - Adrian Negrean
- Department of Neuroscience, Columbia University, New York, NY, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, USA.
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74
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Long-term in vivo imaging of mouse spinal cord through an optically cleared intervertebral window. Nat Commun 2022; 13:1959. [PMID: 35414131 PMCID: PMC9005710 DOI: 10.1038/s41467-022-29496-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
The spinal cord accounts for the main communication pathway between the brain and the peripheral nervous system. Spinal cord injury is a devastating and largely irreversible neurological trauma, and can result in lifelong disability and paralysis with no available cure. In vivo spinal cord imaging in mouse models without introducing immunological artifacts is critical to understand spinal cord pathology and discover effective treatments. We developed a minimally invasive intervertebral window by retaining the ligamentum flavum to protect the underlying spinal cord. By introducing an optical clearing method, we achieve repeated two-photon fluorescence and stimulated Raman scattering imaging at subcellular resolution with up to 15 imaging sessions over 6-167 days and observe no inflammatory response. Using this optically cleared intervertebral window, we study neuron-glia dynamics following laser axotomy and observe strengthened contact of microglia with the nodes of Ranvier during axonal degeneration. By enabling long-term, repetitive, stable, high-resolution and inflammation-free imaging of mouse spinal cord, our method provides a reliable platform in the research aiming at interpretation of spinal cord physiology and pathology.
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75
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Shipton OA, Tang CS, Paulsen O, Vargas-Caballero M. Differential vulnerability of hippocampal CA3-CA1 synapses to Aβ. Acta Neuropathol Commun 2022; 10:45. [PMID: 35379353 PMCID: PMC8981624 DOI: 10.1186/s40478-022-01350-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/18/2022] [Indexed: 11/25/2022] Open
Abstract
Amyloid-beta (Aβ) and tau protein are both involved in the pathogenesis of Alzheimer’s disease. Aβ produces synaptic deficits in wild-type mice that are not seen in Mapt−/− mice, suggesting that tau protein is required for these effects of Aβ. However, whether some synapses are more selectively affected and what factors may determine synaptic vulnerability to Aβ are poorly understood. Here we first observed that burst timing-dependent long-term potentiation (b-LTP) in hippocampal CA3-CA1 synapses, which requires GluN2B subunit-containing NMDA receptors (NMDARs), was inhibited by human Aβ1–42 (hAβ) in wild-type (WT) mice, but not in tau-knockout (Mapt−/−) mice. We then tested whether NMDAR currents were affected by hAβ; we found that hAβ reduced the postsynaptic NMDAR current in WT mice but not in Mapt−/− mice, while the NMDAR current was reduced to a similar extent by the GluN2B-selective NMDAR antagonist Ro 25–6981. To further investigate a possible difference in GluN2B-containing NMDARs in Mapt−/− mice, we used optogenetics to compare NMDAR/AMPAR ratio of EPSCs in CA1 synapses with input from left vs right CA3. It was previously reported in WT mice that hippocampal synapses in CA1 that receive input from the left CA3 display a higher NMDAR charge transfer and a higher Ro-sensitivity than synapses in CA1 that receive input from the right CA3. Here we observed the same pattern in Mapt−/− mice, thus differential NMDAR subunit expression does not explain the difference in hAβ effect on LTP. Finally, we asked whether synapses with left vs right CA3 input are differentially affected by hAβ in WT mice. We found that NMDAR current in synapses with input from the left CA3 were reduced while synapses with input from the right CA3 were unaffected by acute hAβ exposure. These results suggest that hippocampal CA3-CA1 synapses with presynaptic axon originating in the left CA3 are selectively vulnerable to Aβ and that a genetic knock out of tau protein protects them from Aβ synaptotoxicity.
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76
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Large-scale structural network change correlates with clinical response to rTMS in depression. Neuropsychopharmacology 2022; 47:1096-1105. [PMID: 35110687 PMCID: PMC8938539 DOI: 10.1038/s41386-021-01256-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/06/2021] [Accepted: 12/13/2021] [Indexed: 12/12/2022]
Abstract
Response to repetitive transcranial magnetic stimulation (rTMS) among individuals with major depressive disorder (MDD) varies widely. The neural mechanisms underlying rTMS are thought to involve changes in large-scale networks. Whether structural network integrity and plasticity are associated with response to rTMS therapy is unclear. Structural MRIs were acquired from a series of 70 adult healthy controls and 268 persons with MDD who participated in two arms of a large randomized, non-inferiority trial, THREE-D, comparing intermittent theta-burst stimulation to high-frequency rTMS of the left dorsolateral prefrontal cortex (DLPFC). Patients were grouped according to percentage improvement on the 17-item Hamilton Depression Rating Score at treatment completion. For the entire sample and then for each treatment arm, multivariate analyses were used to characterize structural covariance networks (SCN) from cortical gray matter thickness, volume, and surface area maps from T1-weighted MRI. The association between SCNs and clinical improvement was assessed. For both study arms, cortical thickness and volume SCNs distinguished healthy controls from MDD (p = 0.005); however, post-hoc analyses did not reveal a significant association between pre-treatment SCN expression and clinical improvement. We also isolated an anticorrelated SCN between the left DLPFC rTMS target site and the subgenual anterior cingulate cortex across cortical measures (p = 0.0004). Post-treatment change in cortical thickness SCN architecture was associated with clinical improvement in treatment responders (p = 0.001), but not in non-responders. Structural network changes may underpin clinical response to rTMS, and SCNs are useful for understanding the pathophysiology of depression and neural mechanisms of plasticity and response to circuit-based treatments.
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77
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Cong Q, Soteros BM, Huo A, Li Y, Tenner AJ, Sia GM. C1q and SRPX2 regulate microglia mediated synapse elimination during early development in the visual thalamus but not the visual cortex. Glia 2022; 70:451-465. [PMID: 34762332 PMCID: PMC8732326 DOI: 10.1002/glia.24114] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/06/2021] [Accepted: 10/25/2021] [Indexed: 12/16/2022]
Abstract
The classical complement cascade mediates synapse elimination in the visual thalamus during early brain development. However, whether the primary visual cortex also undergoes complement-mediated synapse elimination during early visual system development remains unknown. Here, we examined microglia-mediated synapse elimination in the visual thalamus and the primary visual cortex of early postnatal C1q and SRPX2 knockout mice. In the lateral geniculate nucleus, deletion of C1q caused a persistent decrease in synapse elimination and microglial synapse engulfment, while deletion of SRPX2 caused a transient increase in the same readouts. In the C1q-SRPX2 double knockout mice, the C1q knockout phenotypes were dominant over the SRPX2 knockout phenotypes, a result which is consistent with SRPX2 being an inhibitor of C1q. We found that genetic deletion of either C1q or SRPX2 did not affect synapse elimination or microglial engulfment of synapses in layer 4 of the primary visual cortex in early brain development. Together, these results show that the classical complement pathway regulates microglia-mediated synapse elimination in the visual thalamus but not the visual cortex during early development of the central nervous system.
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Affiliation(s)
- Qifei Cong
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA,Institutes of Neuroscience, Soochow University, Suzhou, China.,Corresponding author: ,
| | - Breeanne M. Soteros
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Anran Huo
- Institutes of Neuroscience, Soochow University, Suzhou, China
| | - Yang Li
- Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Andrea J. Tenner
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA,Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.,Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA
| | - Gek Ming Sia
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA,Corresponding author: ,
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78
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Shi Y, Cui M, Ochs K, Brendel M, Strübing FL, Briel N, Eckenweber F, Zou C, Banati RB, Liu GJ, Middleton RJ, Rupprecht R, Rudolph U, Zeilhofer HU, Rammes G, Herms J, Dorostkar MM. Long-term diazepam treatment enhances microglial spine engulfment and impairs cognitive performance via the mitochondrial 18 kDa translocator protein (TSPO). Nat Neurosci 2022; 25:317-329. [PMID: 35228700 DOI: 10.1038/s41593-022-01013-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/14/2022] [Indexed: 01/08/2023]
Abstract
Benzodiazepines are widely administered drugs to treat anxiety and insomnia. In addition to tolerance development and abuse liability, their chronic use may cause cognitive impairment and increase the risk for dementia. However, the mechanism by which benzodiazepines might contribute to persistent cognitive decline remains unknown. Here we report that diazepam, a widely prescribed benzodiazepine, impairs the structural plasticity of dendritic spines, causing cognitive impairment in mice. Diazepam induces these deficits via the mitochondrial 18 kDa translocator protein (TSPO), rather than classical γ-aminobutyric acid type A receptors, which alters microglial morphology, and phagocytosis of synaptic material. Collectively, our findings demonstrate a mechanism by which TSPO ligands alter synaptic plasticity and, as a consequence, cause cognitive impairment.
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Affiliation(s)
- Yuan Shi
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Mochen Cui
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Katharina Ochs
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Felix L Strübing
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Nils Briel
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Florian Eckenweber
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Chengyu Zou
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Richard B Banati
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia.,Brain and Mind Centre, Medical Imaging Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney NSW, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia.,Brain and Mind Centre, Medical Imaging Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney NSW, Australia
| | - Ryan J Middleton
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Uwe Rudolph
- Department of Comparative Biosciences, College of Veterinary Medicine, and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Gerhard Rammes
- Department of Anesthesiology and Intensive Care Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Jochen Herms
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Mario M Dorostkar
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.
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79
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Yang N, Liu F, Zhang X, Chen C, Xia Z, Fu S, Wang J, Xu J, Cui S, Zhang Y, Yi M, Wan Y, Li Q, Xu S. A Hybrid Titanium-Softmaterial, High-Strength, Transparent Cranial Window for Transcranial Injection and Neuroimaging. BIOSENSORS 2022; 12:bios12020129. [PMID: 35200389 PMCID: PMC8870569 DOI: 10.3390/bios12020129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/12/2022] [Accepted: 02/15/2022] [Indexed: 05/04/2023]
Abstract
A transparent and penetrable cranial window is essential for neuroimaging, transcranial injection and comprehensive understanding of cortical functions. For these applications, cranial windows made from glass coverslip, polydimethylsiloxane (PDMS), polymethylmethacrylate, crystal and silicone hydrogel have offered remarkable convenience. However, there is a lack of high-strength, high-transparency, penetrable cranial window with clinical application potential. We engineer high-strength hybrid Titanium-PDMS (Ti-PDMS) cranial windows, which allow large transparent area for in vivo two-photon imaging, and provide a soft window for transcranial injection. Laser scanning and 3D printing techniques are used to match the hybrid cranial window to different skull morphology. A multi-cycle degassing pouring process ensures a good combination of PDMS and Ti frame. Ti-PDMS cranial windows have a high fracture strength matching human skull bone, excellent light transmittance up to 94.4%, and refractive index close to biological tissue. Ti-PDMS cranial windows show excellent bio-compatibility during 21-week implantation in mice. Dye injection shows that the PDMS window has a "self-sealing" to keep liquid from leaking out. Two-photon imaging for brain tissues could be achieved up to 450 µm in z-depth. As a novel brain-computer-interface, this Ti-PDMS device offers an alternative choice for in vivo drug delivery, optical experiments, ultrasonic treatment and electrophysiology recording.
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Affiliation(s)
- Nana Yang
- Key Laboratory for the Physics & Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; (N.Y.); (J.X.)
| | - Fengyu Liu
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
- Correspondence: (F.L.); (S.X.)
| | - Xinyue Zhang
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China; (X.Z.); (Q.L.)
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China
| | - Chenni Chen
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Zhiyuan Xia
- Department of Material Science and Engineering, College of Engineering, Peking University, Beijing 100871, China;
| | - Su Fu
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Jiaxin Wang
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Jingjing Xu
- Key Laboratory for the Physics & Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; (N.Y.); (J.X.)
- School of Microelectronics, Shandong University, Jinan 250100, China
| | - Shuang Cui
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Yong Zhang
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Ming Yi
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - You Wan
- Neuroscience Research Institute, Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (C.C.); (S.F.); (J.W.); (S.C.); (Y.Z.); (M.Y.); (Y.W.)
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing 100191, China
| | - Qing Li
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China; (X.Z.); (Q.L.)
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China
| | - Shengyong Xu
- Key Laboratory for the Physics & Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China; (N.Y.); (J.X.)
- Correspondence: (F.L.); (S.X.)
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80
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Terashima H, Minatohara K, Maruoka H, Okabe S. Imaging neural circuit pathology of autism spectrum disorders: autism-associated genes, animal models and the application of in vivo two-photon imaging. Microscopy (Oxf) 2022; 71:i81-i99. [DOI: 10.1093/jmicro/dfab039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/11/2021] [Accepted: 11/08/2021] [Indexed: 11/12/2022] Open
Abstract
Abstract
Recent advances in human genetics identified genetic variants involved in causing autism spectrum disorders (ASDs). Mouse models that mimic mutations found in patients with ASD exhibit behavioral phenotypes consistent with ASD symptoms. These mouse models suggest critical biological factors of ASD etiology. Another important implication of ASD genetics is the enrichment of ASD risk genes in molecules involved in developing synapses and regulating neural circuit function. Sophisticated in vivo imaging technologies applied to ASD mouse models identify common synaptic impairments in the neocortex, with genetic-mutation-specific defects in local neural circuits. In this article, we review synapse- and circuit-level phenotypes identified by in vivo two-photon imaging in multiple mouse models of ASD and discuss the contributions of altered synapse properties and neural circuit activity to ASD pathogenesis.
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Affiliation(s)
- Hiroshi Terashima
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Keiichiro Minatohara
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisato Maruoka
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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81
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Grossman YS, Fillinger C, Manganaro A, Voren G, Waldman R, Zou T, Janssen WG, Kenny PJ, Dumitriu D. Structure and function differences in the prelimbic cortex to basolateral amygdala circuit mediate trait vulnerability in a novel model of acute social defeat stress in male mice. Neuropsychopharmacology 2022; 47:788-799. [PMID: 34799681 PMCID: PMC8782864 DOI: 10.1038/s41386-021-01229-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/22/2021] [Accepted: 10/30/2021] [Indexed: 02/03/2023]
Abstract
Stressful life events are ubiquitous and well-known to negatively impact mental health. However, in both humans and animal models, there is large individual variability in how individuals respond to stress, with some but not all experiencing long-term adverse consequences. While there is growing understanding of the neurobiological underpinnings of the stress response, much less is known about how neurocircuits shaped by lifetime experiences are activated during an initial stressor and contribute to this selective vulnerability versus resilience. We developed a model of acute social defeat stress (ASDS) that allows classification of male mice into "susceptible" (socially avoidant) versus "resilient" (expressing control-level social approach) one hour after exposure to six minutes of social stress. Using circuit tracing and high-resolution confocal imaging, we explored differences in activation and dendritic spine density and morphology in the prelimbic cortex to basolateral amygdala (PL→BLA) circuit in resilient versus susceptible mice. Susceptible mice had greater PL→BLA recruitment during ASDS and activated PL→BLA neurons from susceptible mice had more and larger mushroom spines compared to resilient mice. We hypothesized identified structure/function differences indicate an overactive PL→BLA response in susceptible mice and used an intersectional chemogenetic approach to inhibit the PL→BLA circuit during or prior to ASDS. We found in both cases that this blocked ASDS-induced social avoidance. Overall, we show PL→BLA structure/function differences mediate divergent behavioral responses to ASDS in male mice. These results support PL→BLA circuit overactivity during stress as a biomarker of trait vulnerability and potential target for prevention of stress-induced psychopathology.
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Affiliation(s)
- Yael S Grossman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry, Duke University School of Medicine, Durham, NC, USA
| | - Clementine Fillinger
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alessia Manganaro
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA
| | - George Voren
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rachel Waldman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tiffany Zou
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - William G Janssen
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Paul J Kenny
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dani Dumitriu
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Environmental Medicine & Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA.
- New York State Psychiatric Institute, Columbia University, New York, NY, USA.
- Sackler Institute, Columbia University, New York, NY, USA.
- Columbia Population Research Center, Columbia University, New York, NY, USA.
- Zuckerman Institute, Columbia University, New York, NY, USA.
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82
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Misrani A, Tabassum S, Huo Q, Tabassum S, Jiang J, Ahmed A, Chen X, Zhou J, Zhang J, Liu S, Feng X, Long C, Yang L. Mitochondrial Deficits With Neural and Social Damage in Early-Stage Alzheimer's Disease Model Mice. Front Aging Neurosci 2021; 13:748388. [PMID: 34955809 PMCID: PMC8704997 DOI: 10.3389/fnagi.2021.748388] [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: 07/27/2021] [Accepted: 11/16/2021] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disorder worldwide. Mitochondrial dysfunction is thought to be an early event in the onset and progression of AD; however, the precise underlying mechanisms remain unclear. In this study, we investigated mitochondrial proteins involved in organelle dynamics, morphology and energy production in the medial prefrontal cortex (mPFC) and hippocampus (HIPP) of young (1∼2 months), adult (4∼5 months) and aged (9∼10, 12∼18 months) APP/PS1 mice. We observed increased levels of mitochondrial fission protein, Drp1, and decreased levels of ATP synthase subunit, ATP5A, leading to abnormal mitochondrial morphology, increased oxidative stress, glial activation, apoptosis, and altered neuronal morphology as early as 4∼5 months of age in APP/PS1 mice. Electrophysiological recordings revealed abnormal miniature excitatory postsynaptic current in the mPFC together with a minor connectivity change between the mPFC and HIPP, correlating with social deficits. These results suggest that abnormal mitochondrial dynamics, which worsen with disease progression, could be a biomarker of early-stage AD. Therapeutic interventions that improve mitochondrial function thus represent a promising approach for slowing the progression or delaying the onset of AD.
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Affiliation(s)
- Afzal Misrani
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China.,School of Life Sciences, South China Normal University, Guangzhou, China.,South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
| | - Sidra Tabassum
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China.,School of Life Sciences, South China Normal University, Guangzhou, China.,South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
| | - Qingwei Huo
- South China Research Center for Acupuncture and Moxibustion, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Sumaiya Tabassum
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jinxiang Jiang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Adeel Ahmed
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiangmao Chen
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jianwen Zhou
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jiajia Zhang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Sha Liu
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiaoyi Feng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China.,South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
| | - Li Yang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
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83
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Hosokawa T, Liu PW. Regulation of the Stability and Localization of Post-synaptic Membrane Proteins by Liquid-Liquid Phase Separation. Front Physiol 2021; 12:795757. [PMID: 34975543 PMCID: PMC8716852 DOI: 10.3389/fphys.2021.795757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/17/2021] [Indexed: 12/01/2022] Open
Abstract
Synaptic plasticity is a cellular mechanism of learning and memory. The synaptic strength can be persistently upregulated or downregulated to update the information sent to the neuronal network and form a memory engram. For its molecular mechanism, the stability of α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate-type glutamate receptor (AMPAR), a glutamatergic ionotropic receptor, on the postsynaptic membrane has been studied for these two decades. Since AMPAR is not saturated on the postsynaptic membrane during a single event of neurotransmitter release, the number and nanoscale localization of AMPAR is critical for regulating the efficacy of synaptic transmission. The observation of AMPAR on the postsynaptic membrane by super-resolution microscopy revealed that AMPAR forms a nanodomain that is defined as a stable segregated cluster on the postsynaptic membrane to increase the efficacy of synaptic transmission. Postsynaptic density (PSD), an intracellular protein condensate underneath the postsynaptic membrane, regulates AMPAR dynamics via the intracellular domain of Stargazin, an auxiliary subunit of AMPAR. Recently, it was reported that PSD is organized by liquid-liquid phase separation (LLPS) to form liquid-like protein condensates. Furthermore, the calcium signal induced by the learning event triggers the persistent formation of sub-compartments of different protein groups inside protein condensates. This explains the formation of nanodomains via synaptic activation. The liquid-like properties of LLPS protein condensates are ideal for the molecular mechanism of synaptic plasticity. In this review, we summarize the recent progress in the properties and regulation of synaptic plasticity, postsynaptic receptors, PSD, and LLPS.
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84
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Sleep promotes the formation of dendritic filopodia and spines near learning-inactive existing spines. Proc Natl Acad Sci U S A 2021; 118:2114856118. [PMID: 34873044 DOI: 10.1073/pnas.2114856118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2021] [Indexed: 01/20/2023] Open
Abstract
Changes in synaptic connections are believed to underlie long-term memory storage. Previous studies have suggested that sleep is important for synapse formation after learning, but how sleep is involved in the process of synapse formation remains unclear. To address this question, we used transcranial two-photon microscopy to investigate the effect of postlearning sleep on the location of newly formed dendritic filopodia and spines of layer 5 pyramidal neurons in the primary motor cortex of adolescent mice. We found that newly formed filopodia and spines were partially clustered with existing spines along individual dendritic segments 24 h after motor training. Notably, posttraining sleep was critical for promoting the formation of dendritic filopodia and spines clustered with existing spines within 8 h. A fraction of these filopodia was converted into new spines and contributed to clustered spine formation 24 h after motor training. This sleep-dependent spine formation via filopodia was different from retraining-induced new spine formation, which emerged from dendritic shafts without prior presence of filopodia. Furthermore, sleep-dependent new filopodia and spines tended to be formed away from existing spines that were active at the time of motor training. Taken together, these findings reveal a role of postlearning sleep in regulating the number and location of new synapses via promoting filopodial formation.
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85
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Melander JB, Nayebi A, Jongbloets BC, Fortin DA, Qin M, Ganguli S, Mao T, Zhong H. Distinct in vivo dynamics of excitatory synapses onto cortical pyramidal neurons and parvalbumin-positive interneurons. Cell Rep 2021; 37:109972. [PMID: 34758304 PMCID: PMC8631347 DOI: 10.1016/j.celrep.2021.109972] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/03/2021] [Accepted: 10/19/2021] [Indexed: 11/18/2022] Open
Abstract
Cortical function relies on the balanced activation of excitatory and inhibitory neurons. However, little is known about the organization and dynamics of shaft excitatory synapses onto cortical inhibitory interneurons. Here, we use the excitatory postsynaptic marker PSD-95, fluorescently labeled at endogenous levels, as a proxy for excitatory synapses onto layer 2/3 pyramidal neurons and parvalbumin-positive (PV+) interneurons in the barrel cortex of adult mice. Longitudinal in vivo imaging under baseline conditions reveals that, although synaptic weights in both neuronal types are log-normally distributed, synapses onto PV+ neurons are less heterogeneous and more stable. Markov model analyses suggest that the synaptic weight distribution is set intrinsically by ongoing cell-type-specific dynamics, and substantial changes are due to accumulated gradual changes. Synaptic weight dynamics are multiplicative, i.e., changes scale with weights, although PV+ synapses also exhibit an additive component. These results reveal that cell-type-specific processes govern cortical synaptic strengths and dynamics. Melander et al. use a genetic strategy to visualize excitatory neuronal connections that cannot be inferred from morphology, and they monitor how the connections change over weeks in mice. They find distinct characteristics between synapses onto cells that “suppress” brain activity and those onto cells that “excite” brain activity.
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Affiliation(s)
- Joshua B Melander
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Neurosciences PhD Program, Stanford University, Stanford, CA 94305, USA
| | - Aran Nayebi
- Neurosciences PhD Program, Stanford University, Stanford, CA 94305, USA
| | - Bart C Jongbloets
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Dale A Fortin
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Maozhen Qin
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Surya Ganguli
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Haining Zhong
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
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86
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Super-resolution microscopy: a closer look at synaptic dysfunction in Alzheimer disease. Nat Rev Neurosci 2021; 22:723-740. [PMID: 34725519 DOI: 10.1038/s41583-021-00531-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2021] [Indexed: 11/08/2022]
Abstract
The synapse has emerged as a critical neuronal structure in the degenerative process of Alzheimer disease (AD), in which the pathogenic signals of two key players - amyloid-β (Aβ) and tau - converge, thereby causing synaptic dysfunction and cognitive deficits. The synapse presents a dynamic, confined microenvironment in which to explore how key molecules travel, localize, interact and assume different levels of organizational complexity, thereby affecting neuronal function. However, owing to their small size and the diffraction-limited resolution of conventional light microscopic approaches, investigating synaptic structure and dynamics has been challenging. Super-resolution microscopy (SRM) techniques have overcome the resolution barrier and are revolutionizing our quantitative understanding of biological systems in unprecedented spatio-temporal detail. Here we review critical new insights provided by SRM into the molecular architecture and dynamic organization of the synapse and, in particular, the interactions between Aβ and tau in this compartment. We further highlight how SRM can transform our understanding of the molecular pathological mechanisms that underlie AD. The application of SRM for understanding the roles of synapses in AD pathology will provide a stepping stone towards a broader understanding of dysfunction in other subcellular compartments and at cellular and circuit levels in this disease.
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87
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The effects of melatonin on the striatum. MARMARA MEDICAL JOURNAL 2021. [DOI: 10.5472/marumj.1012077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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88
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Dynamics of Dendritic Spines in Dorsal Striatum after Retrieval of Moderate and Strong Inhibitory Avoidance Learning. Neuroscience 2021; 497:134-145. [PMID: 34648867 DOI: 10.1016/j.neuroscience.2021.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/27/2021] [Accepted: 10/01/2021] [Indexed: 11/22/2022]
Abstract
In marked contrast to the ample literature showing that the dorsal striatum is engaged in memory consolidation, little is known about its involvement in memory retrieval. Recent findings demonstrated significant increments in dendritic spine density and mushroom spine counts in dorsal striatum after memory consolidation of moderate inhibitory avoidance (IA) training; further increments were found after strong training. Here, we provide evidence that in this region spine counts were also increased as a consequence of retrieval of moderate IA training, and even higher mushroom spine counts after retrieval of strong training; by contrast, there were fewer thin spines after retrieval. Similar changes in mushroom and thin spine populations were found in the ventral striatum (nucleus accumbens), but they were related to the aversive stimulation and not to memory retrieval. These results suggest that memory retrieval is a dynamic process which produces neuronal structural plasticity that might be necessary for maintaining or strengthening assemblies that encode stored information.
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89
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Walker CK, Herskowitz JH. Dendritic Spines: Mediators of Cognitive Resilience in Aging and Alzheimer's Disease. Neuroscientist 2021; 27:487-505. [PMID: 32812494 PMCID: PMC8130863 DOI: 10.1177/1073858420945964] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cognitive resilience is often defined as the ability to remain cognitively normal in the face of insults to the brain. These insults can include disease pathology, such as plaques and tangles associated with Alzheimer's disease, stroke, traumatic brain injury, or other lesions. Factors such as physical or mental activity and genetics may contribute to cognitive resilience, but the neurobiological underpinnings remain ill-defined. Emerging evidence suggests that dendritic spine structural plasticity is one plausible mechanism. In this review, we highlight the basic structure and function of dendritic spines and discuss how spine density and morphology change in aging and Alzheimer's disease. We note evidence that spine plasticity mediates resilience to stress, and we tackle dendritic spines in the context of cognitive resilience to Alzheimer's disease. Finally, we examine how lifestyle and genetic factors may influence dendritic spine plasticity to promote cognitive resilience before discussing evidence for actin regulatory kinases as therapeutic targets for Alzheimer's disease.
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Affiliation(s)
- Courtney K. Walker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Jeremy H. Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
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90
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Zheng J, Suo L, Zhou Y, Jia L, Li J, Kuang Y, Cui D, Zhang X, Wu Q. Pyk2 suppresses contextual fear memory in an autophosphorylation-independent manner. J Mol Cell Biol 2021; 13:808-821. [PMID: 34529077 PMCID: PMC8782590 DOI: 10.1093/jmcb/mjab057] [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: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Clustered protocadherins (Pcdhs) are a large family of cadherin-like cell adhesion proteins that are central for neurite self-avoidance and neuronal connectivity in the brain. Their downstream non-receptor tyrosine kinase Pyk2 (proline-rich tyrosine kinase 2, also known as Ptk2b, Cakb, Raftk, Fak2, and Cadtk) is predominantly expressed in the hippocampus. We constructed Pyk2 null mouse lines and found that these mutant mice showed enhancement in contextual fear memory, without any change in auditory-cued and spatial-referenced learning and memory. In addition, by preparing Y402F mutant mice, we observed that Pyk2 suppressed contextual fear memory in an autophosphorylation-independent manner. Moreover, using high-throughput RNA sequencing, we found that immediate early genes, such as Npas4, cFos, Zif268/Egr1, Arc, and Nr4a1, were enhanced in Pyk2 null mice. We further showed that Pyk2 disruption affected pyramidal neuronal complexity and spine dynamics. Thus, we demonstrated that Pyk2 is a novel fear memory suppressor molecule and Pyk2 null mice provide a model for understanding fear-related disorders. These findings have interesting implications regarding dysregulation of the Pcdh‒Pyk2 axis in neuropsychiatric disorders.
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Affiliation(s)
- Jin Zheng
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Lun Suo
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Yuxiao Zhou
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Liling Jia
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Jingwei Li
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Donghong Cui
- Shanghai Mental Health Center, Shanghai Key Laboratory of Psychotic Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Xuehong Zhang
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiang Wu
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
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91
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Deng J, Xie H, Chen Y, Peng Z, Zhao J, Zhou Y, Chen C, Zhang K. Comparative study of the reorganization in bilateral motor and sensory cortices after spinal cord hemisection in mice. Neuroreport 2021; 32:1082-1090. [PMID: 34173791 DOI: 10.1097/wnr.0000000000001694] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The effects of spinal cord injury (SCI) on sensorimotor cortex plasticity have not been well studied. Therefore, to explore the reorganization after SCI, we dynamically monitored postsynaptic dendritic spines of pyramidal neurons in vivo. METHODS Thy1-YFP transgenic mice were randomly divided into two groups: the control and SCI group. We then opened the spinal vertebral plates of all mice and sectioned one-half of the spinal cord in SCI group. The relevant areas were imaged bilaterally at 0, 3, 14 and 28 days post-SCI. The rates of elimination, formation and stable spines were evaluated. RESULTS At the early stage, the rate of stable and elimination spines experienced a similar change trend. But the rate of formation spines in the contralateral sensory cortex was significantly increased after SCI compared with those in the control group. At the late stage, spines of three types remodeled very differently between the sensory and motor cortex. Compared with those in the control group, spines in the bilateral sensory cortex demonstrated obvious differences in the rate of stable and elimination spines but not formation spines, while spines in the motor cortex, especially in the contralateral cortex increased significantly in the rate of formation after SCI. As for survival rate, differences mainly appeared in time frame instead of cortex type or region. CONCLUSIONS The dendritic spines in hindlimb representation area of the sensorimotor cortex experienced bilaterally remodeling after SCI. And those spines in the sensory and motor cortex experienced great but different change trends after SCI.
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Affiliation(s)
| | - Huimin Xie
- Department of Plastic and Reconstructive surgery, General Hospital of Chinese PLA
| | - Youbai Chen
- Department of Anesthesiology, District Hospital of Shun Yi, Beijing
| | | | - Jiajia Zhao
- Department of Anesthesiology, District Hospital of Shun Yi, Beijing
| | - Yanmei Zhou
- Department of Neuroscience, Shenzhen Bay Laboratory, Shenzhen
| | | | - Kexue Zhang
- Department of Pediatric Surgery, General Hospital of Chinese PLA, Beijing, People's Republic of China
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92
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Ma X, Wei J, Cui Y, Xia B, Zhang L, Nehme A, Zuo Y, Ferguson D, Levitt P, Qiu S. Disrupted Timing of MET Signaling Derails the Developmental Maturation of Cortical Circuits and Leads to Altered Behavior in Mice. Cereb Cortex 2021; 32:1769-1786. [PMID: 34470051 PMCID: PMC9016286 DOI: 10.1093/cercor/bhab323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 01/21/2023] Open
Abstract
The molecular regulation of the temporal dynamics of circuit maturation is a key contributor to the emergence of normal structure-function relations. Developmental control of cortical MET receptor tyrosine kinase, expressed early postnatally in subpopulations of excitatory neurons, has a pronounced impact on the timing of glutamatergic synapse maturation and critical period plasticity. Here, we show that using a controllable overexpression (cto-Met) transgenic mouse, extending the duration of MET signaling after endogenous Met is switched off leads to altered molecular constitution of synaptic proteins, persistent activation of small GTPases Cdc42 and Rac1, and sustained inhibitory phosphorylation of cofilin. These molecular changes are accompanied by an increase in the density of immature dendritic spines, impaired cortical circuit maturation of prefrontal cortex layer 5 projection neurons, and altered laminar excitatory connectivity. Two photon in vivo imaging of dendritic spines reveals that cto-Met enhances de novo spine formation while inhibiting spine elimination. Extending MET signaling for two weeks in developing cortical circuits leads to pronounced repetitive activity and impaired social interactions in adult mice. Collectively, our data revealed that temporally controlled MET signaling as a critical mechanism for controlling cortical circuit development and emergence of normal behavior.
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Affiliation(s)
- Xiaokuang Ma
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Jing Wei
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Yuehua Cui
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Baomei Xia
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Le Zhang
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Antoine Nehme
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Yi Zuo
- Department of Molecular, Cellular and Developmental Neurobiology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
| | - Deveroux Ferguson
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
| | - Pat Levitt
- Program in Developmental Neuroscience and Developmental Neurogenetics, The Saban Research Institute and Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA 90027, USA
| | - Shenfeng Qiu
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85004, USA
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93
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Marks TD, Goard MJ. Stimulus-dependent representational drift in primary visual cortex. Nat Commun 2021; 12:5169. [PMID: 34453051 PMCID: PMC8397766 DOI: 10.1038/s41467-021-25436-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
To produce consistent sensory perception, neurons must maintain stable representations of sensory input. However, neurons in many regions exhibit progressive drift across days. Longitudinal studies have found stable responses to artificial stimuli across sessions in visual areas, but it is unclear whether this stability extends to naturalistic stimuli. We performed chronic 2-photon imaging of mouse V1 populations to directly compare the representational stability of artificial versus naturalistic visual stimuli over weeks. Responses to gratings were highly stable across sessions. However, neural responses to naturalistic movies exhibited progressive representational drift across sessions. Differential drift was present across cortical layers, in inhibitory interneurons, and could not be explained by differential response strength or higher order stimulus statistics. However, representational drift was accompanied by similar differential changes in local population correlation structure. These results suggest representational stability in V1 is stimulus-dependent and may relate to differences in preexisting circuit architecture of co-tuned neurons.
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Affiliation(s)
- Tyler D Marks
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA
| | - Michael J Goard
- Neuroscience Research Institute, University of California, Santa Barbara, CA, USA.
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA.
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, USA.
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94
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Law E, Li Y, Kahraman O, Haselwandter CA. Stochastic self-assembly of reaction-diffusion patterns in synaptic membranes. Phys Rev E 2021; 104:014403. [PMID: 34412234 DOI: 10.1103/physreve.104.014403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/14/2021] [Indexed: 11/07/2022]
Abstract
Synaptic receptor and scaffold molecules self-assemble into membrane protein domains, which play an important role in signal transmission across chemical synapses. Experiment and theory have shown that the formation of receptor-scaffold domains of the characteristic size observed in nerve cells can be understood from the receptor and scaffold reaction and diffusion processes suggested by experiments. We employ here kinetic Monte Carlo (KMC) simulations to explore the self-assembly of synaptic receptor-scaffold domains in a stochastic lattice model of receptor and scaffold reaction-diffusion dynamics. For reaction and diffusion rates within the ranges of values suggested by experiments we find, in agreement with previous mean-field calculations, self-assembly of receptor-scaffold domains of a size similar to that observed in experiments. Comparisons between the results of our KMC simulations and mean-field solutions suggest that the intrinsic noise associated with receptor and scaffold reaction and diffusion processes accelerates the self-assembly of receptor-scaffold domains, and confers increased robustness to domain formation. In agreement with experimental observations, our KMC simulations yield a prevalence of scaffolds over receptors in receptor-scaffold domains. Our KMC simulations show that receptor and scaffold reaction-diffusion dynamics can inherently give rise to plasticity in the overall properties of receptor-scaffold domains, which may be utilized by nerve cells to regulate the receptor number at chemical synapses.
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Affiliation(s)
- Everest Law
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Yiwei Li
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Osman Kahraman
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Christoph A Haselwandter
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
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95
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Braun NJ, Liao D, Alford PW. Orientation of neurites influences severity of mechanically induced tau pathology. Biophys J 2021; 120:3272-3282. [PMID: 34293301 PMCID: PMC8392125 DOI: 10.1016/j.bpj.2021.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 06/11/2021] [Accepted: 07/13/2021] [Indexed: 01/03/2023] Open
Abstract
Chronic traumatic encephalopathy is a neurodegenerative disease associated with repeated traumatic brain injury (TBI). Chronic traumatic encephalopathy is a tauopathy, in which cognitive decline is accompanied by the accumulation of neurofibrillary tangles of the protein tau in patients' brains. We recently found that mechanical force alone can induce tau mislocalization to dendritic spines and loss of synaptic function in in vitro neuronal cultures with random cell organization. However, in the brain, neurons are highly aligned, so here we aimed to determine how neuronal organization influences early-stage tauopathy caused by mechanical injury. Using microfabricated cell culture constructs to control the growth of neurites and an in vitro simulated TBI device to apply controlled mechanical deformation, we found that neuronal orientation with respect to the direction of a uniaxial high-strain-rate stretch injury influences the degree of tau pathology in injured neurons. We found that a mechanical stretch applied parallel to the neurite alignment induces greater mislocalization of tau proteins to dendritic spines than does a stretch with the same strain applied perpendicular to the neurites. Synaptic function, characterized by the amplitude of miniature excitatory postsynaptic currents, was similarly decreased in neurons with neurites aligned parallel to stretch, whereas in neurons aligned perpendicular to stretch, it had little to no functional loss. Experimental injury parameters (strain, strain rate, direction of stretch) were combined with a standard viscoelastic solid model to show that in our in vitro model, neurite work density during stretch correlates with tau mislocalization. These findings suggest that in a TBI, the magnitude of brain deformation is not wholly predictive of neurodegenerative consequences of TBI but that deformation relative to local neuronal architecture and the neurite mechanical energy during injury are better metrics for predicting trauma-induced tauopathy.
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Affiliation(s)
| | - Dezhi Liao
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota.
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96
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Laviv T, Yasuda R. Imaging neuronal protein signaling dynamics in vivo. Curr Opin Neurobiol 2021; 69:68-75. [PMID: 33684848 PMCID: PMC8387335 DOI: 10.1016/j.conb.2021.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/31/2021] [Accepted: 02/05/2021] [Indexed: 11/16/2022]
Abstract
The activity patterns of Individual neurons are highly coordinated and synchronized within neuronal circuits in the brain, much like individual orchestra tools playing together to achieve harmony. Inside neurons, complex protein signaling cascades provide the molecular notes and instructions to each neuron. However, until recently, the dynamic nature of intracellular protein signaling in the intact brain has been eluded. In this review, we focus on recent advancements and the development of approaches to study neuronal signaling dynamics in vivo. We will discuss approaches for the implementation of biosensors for monitoring of protein signaling activities at the levels of individual synapses, dendritic branches, cell-wide neuromodulation, and transcription in the nucleus. Future improvement in these methods and their utilization will undoubtedly yield new insights regarding the intricate link between functional and molecular neuronal dynamics and how they underlie animal's behavior.
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Affiliation(s)
- Tal Laviv
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, 69978 Tel Aviv, Israel.
| | - Ryohei Yasuda
- Department of Neuronal Signal Transduction, Max Planck Institute for Neuroscience, Jupiter, FL, 33458, USA.
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97
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Osborne BF, Beamish SB, Schwarz JM. The effects of early-life immune activation on microglia-mediated neuronal remodeling and the associated ontogeny of hippocampal-dependent learning in juvenile rats. Brain Behav Immun 2021; 96:239-255. [PMID: 34126173 PMCID: PMC8319153 DOI: 10.1016/j.bbi.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/11/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022] Open
Abstract
Many neurodevelopmental disorders and associated learning deficits have been linked to early-life immune activation or ongoing immune dysregulation (Laskaris et al., 2016; O'Connor et al., 2014; Frick et al., 2013). Neuroscientists have begun to understand how the maturation of neural circuits allows for the emergence of cognitive and learning behaviors; yet we know very little about how these developing neural circuits are perturbed by certain events, including risk-factors such as early-life immune activation and immune dysregulation. To answer these questions, we examined the impact of early-life immune activation on the emergence of hippocampal-dependent learning in juvenile male and female rats using a well-characterized hippocampal-dependent learning task and we investigated the corresponding, dynamic multicellular interactions in the hippocampus that may contribute to these learning deficits. We found that even low levels of immune activation can result in hippocampal-depedent learning deficits days later, but only when this activation occurs during a sensitive period of development. The initial immune response and associated cytokine production in the hippocampus resolved within 24 h, several days prior to the observed learning deficit, but notably the initial immune response was followed by altered microglial-neuronal communication and synapse remodeling that changed the structure of hippocampal neurons during this period of juvenile brain development. We conclude that immune activation or dysregulation during a sensitive period of hippocampal development can precipitate the emergence of learning deficits via a multi-cellular process that may be initiated by, but not the direct result of the initial cytokine response. SIGNIFICANCE STATEMENT: Many neurodevelopmental disorders have been linked to early-life immune activation or immune dysregulation; however, very little is known about how dynamic changes in neuroimmune cells mediate the transition from normal brain function to the early stages of cognitive disorders, or how changes in immune signaling are subsequently integrated into developing neuronal networks. The current experiments examined the consequences of immune activation on the cellular and molecular changes that accompany the emergence of learning deficits during a sensitive period of hippocampal development. These findings have the potential to significantly advance our understanding of how early-life immune activation or dysregulation can result in the emergence of cognitive and learning deficits that are the largest source of years lived with disability in humans.
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Affiliation(s)
- Brittany F. Osborne
- University of Delaware, Department of Psychological & Brain Sciences, 108 Wolf Hall, Newark, DE, 19716, USA
| | - Sarah B. Beamish
- University of Delaware, Department of Psychological & Brain Sciences, 108 Wolf Hall, Newark, DE, 19716, USA
| | - Jaclyn M. Schwarz
- University of Delaware, Department of Psychological & Brain Sciences, 108 Wolf Hall, Newark, DE, 19716, USA
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98
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Pérez-Ortega J, Alejandre-García T, Yuste R. Long-term stability of cortical ensembles. eLife 2021; 10:e64449. [PMID: 34328414 PMCID: PMC8376248 DOI: 10.7554/elife.64449] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 07/29/2021] [Indexed: 12/25/2022] Open
Abstract
Neuronal ensembles, coactive groups of neurons found in spontaneous and evoked cortical activity, are causally related to memories and perception, but it is still unknown how stable or flexible they are over time. We used two-photon multiplane calcium imaging to track over weeks the activity of the same pyramidal neurons in layer 2/3 of the visual cortex from awake mice and recorded their spontaneous and visually evoked responses. Less than half of the neurons remained active across any two imaging sessions. These stable neurons formed ensembles that lasted weeks, but some ensembles were also transient and appeared only in one single session. Stable ensembles preserved most of their neurons for up to 46 days, our longest imaged period, and these 'core' cells had stronger functional connectivity. Our results demonstrate that neuronal ensembles can last for weeks and could, in principle, serve as a substrate for long-lasting representation of perceptual states or memories.
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Affiliation(s)
- Jesús Pérez-Ortega
- Department of Biological Sciences, Columbia UniversityNew YorkUnited States
| | | | - Rafael Yuste
- Department of Biological Sciences, Columbia UniversityNew YorkUnited States
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Actin Cytoskeleton Role in the Maintenance of Neuronal Morphology and Long-Term Memory. Cells 2021; 10:cells10071795. [PMID: 34359964 PMCID: PMC8305626 DOI: 10.3390/cells10071795] [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: 06/15/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 12/15/2022] Open
Abstract
Evidence indicates that long-term memory formation creates long-lasting changes in neuronal morphology within a specific neuronal network that forms the memory trace. Dendritic spines, which include most of the excitatory synapses in excitatory neurons, are formed or eliminated by learning. These changes may be long-lasting and correlate with memory strength. Moreover, learning-induced changes in the morphology of existing spines can also contribute to the formation of the neuronal network that underlies memory. Altering spines morphology after memory consolidation can erase memory. These observations strongly suggest that learning-induced spines modifications can constitute the changes in synaptic connectivity within the neuronal network that form memory and that stabilization of this network maintains long-term memory. The formation and elimination of spines and other finer morphological changes in spines are mediated by the actin cytoskeleton. The actin cytoskeleton forms networks within the spine that support its structure. Therefore, it is believed that the actin cytoskeleton mediates spine morphogenesis induced by learning. Any long-lasting changes in the spine morphology induced by learning require the preservation of the spine actin cytoskeleton network to support and stabilize the spine new structure. However, the actin cytoskeleton is highly dynamic, and the turnover of actin and its regulatory proteins that determine and support the actin cytoskeleton network structure is relatively fast. Molecular models, suggested here, describe ways to overcome the dynamic nature of the actin cytoskeleton and the fast protein turnover and to support an enduring actin cytoskeleton network within the spines, spines stability and long-term memory. These models are based on long-lasting changes in actin regulatory proteins concentrations within the spine or the formation of a long-lasting scaffold and the ability for its recurring rebuilding within the spine. The persistence of the actin cytoskeleton network within the spine is suggested to support long-lasting spine structure and the maintenance of long-term memory.
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Shao LX, Liao C, Gregg I, Davoudian PA, Savalia NK, Delagarza K, Kwan AC. Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo. Neuron 2021; 109:2535-2544.e4. [PMID: 34228959 DOI: 10.1016/j.neuron.2021.06.008] [Citation(s) in RCA: 199] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/16/2021] [Accepted: 06/07/2021] [Indexed: 12/18/2022]
Abstract
Psilocybin is a serotonergic psychedelic with untapped therapeutic potential. There are hints that the use of psychedelics can produce neural adaptations, although the extent and timescale of the impact in a mammalian brain are unknown. In this study, we used chronic two-photon microscopy to image longitudinally the apical dendritic spines of layer 5 pyramidal neurons in the mouse medial frontal cortex. We found that a single dose of psilocybin led to ∼10% increases in spine size and density, driven by an elevated spine formation rate. The structural remodeling occurred quickly within 24 h and was persistent 1 month later. Psilocybin also ameliorated stress-related behavioral deficit and elevated excitatory neurotransmission. Overall, the results demonstrate that psilocybin-evoked synaptic rewiring in the cortex is fast and enduring, potentially providing a structural trace for long-term integration of experiences and lasting beneficial actions.
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Affiliation(s)
- Ling-Xiao Shao
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Clara Liao
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Ian Gregg
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Pasha A Davoudian
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Neil K Savalia
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Kristina Delagarza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Alex C Kwan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA.
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