1
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Niraula S, Doderer JJ, Indulkar S, Berry KP, Hauser WL, L'Esperance OJ, Deng JZ, Keeter G, Rouse AG, Subramanian J. Excitation-inhibition imbalance disrupts visual familiarity in amyloid and non-pathology conditions. Cell Rep 2023; 42:111946. [PMID: 36640331 PMCID: PMC9939293 DOI: 10.1016/j.celrep.2022.111946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/14/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023] Open
Abstract
Neuronal hyperactivity induces memory deficits in Alzheimer's disease. However, how hyperactivity disrupts memory is unclear. Using in vivo synaptic imaging in the mouse visual cortex, we show that structural excitatory-inhibitory synapse imbalance in the apical dendrites favors hyperactivity in early amyloidosis. Consistent with this, natural images elicit neuronal hyperactivity in these mice. Compensatory changes that maintain activity homeostasis disrupt functional connectivity and increase population sparseness such that a small fraction of neurons dominates population activity. These properties reduce the selectivity of neural response to natural images and render visual recognition memory vulnerable to interference. Deprivation of non-specific visual experiences improves the neural representation and behavioral expression of visual familiarity. In contrast, in non-pathological conditions, deprivation of non-specific visual experiences induces disinhibition, increases excitability, and disrupts visual familiarity. We show that disrupted familiarity occurs when the fraction of high-responsive neurons and the persistence of neural representation of a memory-associated stimulus are not constrained.
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Affiliation(s)
- Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Julia J Doderer
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Shreya Indulkar
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Kalen P Berry
- Division of Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - William L Hauser
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Oliver J L'Esperance
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Jasmine Z Deng
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Griffin Keeter
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Adam G Rouse
- Department of Neurosurgery, University of Kansas Medical Center, Kansas City, KS 66103, USA
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA.
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2
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Luo Z, Dong X, Yu J, Xia Y, Berry KP, Rao R, Xu L, Xue P, Chen T, Lin Y, Yu J, Huang G, Li H, Zhou W, Lu QR. Genomic and Transcriptomic Analyses Reveals ZNF124 as a Critical Regulator in Highly Aggressive Medulloblastomas. Front Cell Dev Biol 2021; 9:634056. [PMID: 33681213 PMCID: PMC7930499 DOI: 10.3389/fcell.2021.634056] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/28/2021] [Indexed: 12/21/2022] Open
Abstract
Medulloblastoma (MB) is the most common malignant pediatric brain tumor, however, the mechanisms underlying tumorigenesis in different MB subgroups remain incompletely understood. Although previous studies of MB predisposition have been conducted in tertiary referral centers primarily in Caucasian cohorts, it is not unclear clear whether there exist population-specific genetic alterations in MBs. In this study, we investigated the contribution of genomic and transcriptomic alterations to the risk of malignant MB in the Chinese population (designated as the Asian cohort). We analyze the genomic and transcriptomic alterations of the Asian MB cohort by using a combination of whole-exome sequencing (WES) and RNA-deep-sequencing. In addition, we integrate publicly available data with the Asian MB cohort and identify a subset of potential MB-driving genes specifically enriched in each of the MB subgroups. We further characterize a newly identified group-3-enriched transcriptional regulator, ZNF124, and demonstrate that ZNF124 is critical for the growth of the most aggressive group-3 MB cells. Together, our analyses indicate conserved yet distinct genetic alterations and gene expression patterns of MBs between different ethnic groups. Our studies further provide an important resource for identifying potential tumor-driving factors in MBs, enhancing our understanding of the disease process for developing ethnically targeted therapies in patients with MB.
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Affiliation(s)
- Zaili Luo
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xinran Dong
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jianzhong Yu
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yong Xia
- Department of Neurosurgery, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Kalen P Berry
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Rohit Rao
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Lingli Xu
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Ping Xue
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Tong Chen
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yifeng Lin
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jiyang Yu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Guoying Huang
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hao Li
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Wenhao Zhou
- Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Q Richard Lu
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
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3
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Zhang L, He X, Liu X, Zhang F, Huang LF, Potter AS, Xu L, Zhou W, Zheng T, Luo Z, Berry KP, Pribnow A, Smith SM, Fuller C, Jones BV, Fouladi M, Drissi R, Yang ZJ, Gustafson WC, Remke M, Pomeroy SL, Girard EJ, Olson JM, Morrissy AS, Vladoiu MC, Zhang J, Tian W, Xin M, Taylor MD, Potter SS, Roussel MF, Weiss WA, Lu QR. Single-Cell Transcriptomics in Medulloblastoma Reveals Tumor-Initiating Progenitors and Oncogenic Cascades during Tumorigenesis and Relapse. Cancer Cell 2019; 36:302-318.e7. [PMID: 31474569 PMCID: PMC6760242 DOI: 10.1016/j.ccell.2019.07.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 04/16/2019] [Accepted: 07/29/2019] [Indexed: 02/05/2023]
Abstract
Progenitor heterogeneity and identities underlying tumor initiation and relapse in medulloblastomas remain elusive. Utilizing single-cell transcriptomic analysis, we demonstrated a developmental hierarchy of progenitor pools in Sonic Hedgehog (SHH) medulloblastomas, and identified OLIG2-expressing glial progenitors as transit-amplifying cells at the tumorigenic onset. Although OLIG2+ progenitors become quiescent stem-like cells in full-blown tumors, they are highly enriched in therapy-resistant and recurrent medulloblastomas. Depletion of mitotic Olig2+ progenitors or Olig2 ablation impeded tumor initiation. Genomic profiling revealed that OLIG2 modulates chromatin landscapes and activates oncogenic networks including HIPPO-YAP/TAZ and AURORA-A/MYCN pathways. Co-targeting these oncogenic pathways induced tumor growth arrest. Together, our results indicate that glial lineage-associated OLIG2+ progenitors are tumor-initiating cells during medulloblastoma tumorigenesis and relapse, suggesting OLIG2-driven oncogenic networks as potential therapeutic targets.
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Affiliation(s)
- Liguo Zhang
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Xuelian He
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; Boston Children's Hospital, Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Xuezhao Liu
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Feng Zhang
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - L Frank Huang
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrew S Potter
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Lingli Xu
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Wenhao Zhou
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Tao Zheng
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zaili Luo
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Kalen P Berry
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Allison Pribnow
- Tumor Cell Biology Division, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Stephanie M Smith
- Tumor Cell Biology Division, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christine Fuller
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Blaise V Jones
- Radiology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Maryam Fouladi
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Rachid Drissi
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Zeng-Jie Yang
- Cancer Biology Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - W Clay Gustafson
- Department of Neurology, Pediatrics, and Surgery and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Marc Remke
- Department of Pediatric Oncology, Hematology, and Clinical Immunology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Scott L Pomeroy
- Boston Children's Hospital, Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Emily J Girard
- Division of Pediatric Hematology/Oncology, Fred Hutchinson Cancer Research Center, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA 98145-5005, USA
| | - James M Olson
- Division of Pediatric Hematology/Oncology, Fred Hutchinson Cancer Research Center, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA 98145-5005, USA
| | - A Sorana Morrissy
- Department of Biochemistry and Molecular Biology, The University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Maria C Vladoiu
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Jiao Zhang
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Weidong Tian
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Mei Xin
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Michael D Taylor
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - S Steven Potter
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Martine F Roussel
- Tumor Cell Biology Division, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - William A Weiss
- Department of Neurology, Pediatrics, and Surgery and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Q Richard Lu
- Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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4
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Berry KP, Lu QR. Chromatin modification and epigenetic control in functional nerve regeneration. Semin Cell Dev Biol 2019; 97:74-83. [PMID: 31301357 DOI: 10.1016/j.semcdb.2019.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 07/08/2019] [Indexed: 12/13/2022]
Abstract
The repair and functional recovery of the nervous system is a highly regulated process that requires the coordination of many different components including the proper myelination of regenerated axons. Dysmyelination and remyelination failures after injury result in defective nerve conduction, impairing normal nervous system functions. There are many convergent regulatory networks and signaling mechanisms between development and regeneration. For instance, the regulatory mechanisms required for oligodendrocyte lineage progression could potentially play fundamental roles in myelin repair. In recent years, epigenetic chromatin modifications have been implicated in CNS myelination and functional nerve restoration. The pro-regenerative transcriptional program is likely silenced or repressed in adult neural cells including neurons and myelinating cells in the central and peripheral nervous systems limiting the capacity for repair after injury. In this review, we will discuss the roles of epigenetic mechanisms, including histone modifications, chromatin remodeling, and DNA methylation, in the maintenance and establishment of the myelination program during normal oligodendrocyte development and regeneration. We also discuss how these epigenetic processes impact myelination and axonal regeneration, and facilitate the improvement of current preclinical therapeutics for functional nerve regeneration in neurodegenerative disorders or after injury.
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Affiliation(s)
- Kalen P Berry
- Department of Pediatrics, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Q Richard Lu
- Department of Pediatrics, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.
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5
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Xue Y, Berry KP, Boivin JR, Rowlands CJ, Takiguchi Y, Nedivi E, So PTC. Scanless volumetric imaging by selective access multifocal multiphoton microscopy. Optica 2019; 6:76-83. [PMID: 31984218 PMCID: PMC6980307 DOI: 10.1364/optica.6.000076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 12/17/2018] [Indexed: 05/14/2023]
Abstract
Simultaneous, high-resolution imaging across a large number of synaptic and dendritic sites is critical for understanding how neurons receive and integrate signals. Yet, functional imaging that targets a large number of submicrometer-sized synaptic and dendritic locations poses significant technical challenges. We demonstrate a new parallelized approach to address such questions, increasing the signal-to-noise ratio by an order of magnitude compared to previous approaches. This selective access multifocal multiphoton microscopy uses a spatial light modulator to generate multifocal excitation in three dimensions (3D) and a Gaussian-Laguerre phase plate to simultaneously detect fluorescence from these spots throughout the volume. We test the performance of this system by simultaneously recording Ca2+ dynamics from cultured neurons at 98-118 locations distributed throughout a 3D volume. This is the first demonstration of 3D imaging in a "single shot" and permits synchronized monitoring of signal propagation across multiple different dendrites.
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Affiliation(s)
- Yi Xue
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Laser Biomedical Research Center, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Kalen P. Berry
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Josiah R. Boivin
- Picower Institute, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Christopher J. Rowlands
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Yu Takiguchi
- Laser Biomedical Research Center, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Hamamatsu Photonics K.K., Hamamatsu, Japan
| | - Elly Nedivi
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Picower Institute, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
| | - Peter T. C. So
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Laser Biomedical Research Center, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA
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6
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Xue Y, Berry KP, Boivin JR, Wadduwage D, Nedivi E, So PTC. Scattering reduction by structured light illumination in line-scanning temporal focusing microscopy. Biomed Opt Express 2018; 9:5654-5666. [PMID: 30460153 PMCID: PMC6238912 DOI: 10.1364/boe.9.005654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/26/2018] [Accepted: 10/01/2018] [Indexed: 05/02/2023]
Abstract
Line-scanning temporal focusing microscopy (LineTFM) is capable of imaging biological samples more than 10 times faster than two-photon laser point-scanning microscopy (TPLSM), while achieving nearly the same lateral and axial spatial resolution. However, the image contrast taken by LineTFM is lower than that by TPLSM because LineTFM is severely influenced by biological tissue scattering. To reject the scattered photons, we implemented LineTFM using both structured illumination and uniform illumination combined with the HiLo post-processing algorithm, called HiLL microscopy (HiLo-Line-scanning temporal focusing microscopy). HiLL microscopy significantly reduces tissue scattering and improves image contrast. We demonstrate HiLL microscopy with in vivo brain imaging. This approach could potentially find applications in monitoring fast dynamic events and in mapping high resolution structures over a large volume.
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Affiliation(s)
- Yi Xue
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
- Laser Biomedical Research Center, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
| | - Kalen P. Berry
- Department of Biology, 77 Massachusetts Ave., Cambridge MA 02139,
USA
| | - Josiah R. Boivin
- Picower Institute for Learning and Memory,77 Massachusetts Ave., Cambridge, MA 02139,
USA
| | - Dushan Wadduwage
- Laser Biomedical Research Center, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
- Department of Biological Engineering, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
| | - Elly Nedivi
- Department of Biology, 77 Massachusetts Ave., Cambridge MA 02139,
USA
- Picower Institute for Learning and Memory,77 Massachusetts Ave., Cambridge, MA 02139,
USA
- Department of Brain and Cognitive Sciences, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
| | - Peter T. C. So
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
- Laser Biomedical Research Center, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
- Department of Biological Engineering, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
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7
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Abstract
During development, the environment exerts a profound influence on the wiring of brain circuits. Due to the limited resolution of studies in fixed tissue, this experience-dependent structural plasticity was once thought to be restricted to a specific developmental time window. The recent introduction of two-photon microscopy for in vivo imaging has opened the door to repeated monitoring of individual neurons and the study of structural plasticity mechanisms at a very fine scale. In this review, we focus on recent work showing that synaptic structural rearrangements are a key mechanism mediating neural circuit adaptation and behavioral plasticity in the adult brain. We examine this work in the context of classic studies in the visual systems of model organisms, which have laid much of the groundwork for our understanding of activity-dependent synaptic remodeling and its role in brain plasticity.
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Affiliation(s)
- Kalen P Berry
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; .,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Elly Nedivi
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; .,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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8
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Abstract
Since Cajal's first drawings of Golgi stained neurons, generations of researchers have been fascinated by the small protrusions, termed spines, studding many neuronal dendrites. Most excitatory synapses in the mammalian CNS are located on dendritic spines, making spines convenient proxies for excitatory synaptic presence. When in vivo imaging revealed that dendritic spines are dynamic structures, their addition and elimination were interpreted as excitatory synapse gain and loss, respectively. Spine imaging has since become a popular assay for excitatory circuit remodeling. In this review, we re-evaluate the validity of using spine dynamics as a straightforward reflection of circuit rewiring. Recent studies tracking both spines and synaptic markers in vivo reveal that 20% of spines lack PSD-95 and are short lived. Although they account for most spine dynamics, their remodeling is unlikely to impact long-term network structure. We discuss distinct roles that spine dynamics can play in circuit remodeling depending on synaptic content.
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Affiliation(s)
- Kalen P Berry
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elly Nedivi
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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9
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Villa KL, Berry KP, Subramanian J, Cha JW, Oh WC, Kwon HB, Kubota Y, So PTC, Nedivi E. Inhibitory Synapses Are Repeatedly Assembled and Removed at Persistent Sites In Vivo. Neuron 2016; 89:756-69. [PMID: 26853302 DOI: 10.1016/j.neuron.2016.01.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 06/11/2015] [Accepted: 12/24/2015] [Indexed: 11/24/2022]
Abstract
Older concepts of a hard-wired adult brain have been overturned in recent years by in vivo imaging studies revealing synaptic remodeling, now thought to mediate rearrangements in microcircuit connectivity. Using three-color labeling and spectrally resolved two-photon microscopy, we monitor in parallel the daily structural dynamics (assembly or removal) of excitatory and inhibitory postsynaptic sites on the same neurons in mouse visual cortex in vivo. We find that dynamic inhibitory synapses often disappear and reappear again in the same location. The starkest contrast between excitatory and inhibitory synapse dynamics is on dually innervated spines, where inhibitory synapses frequently recur while excitatory synapses are stable. Monocular deprivation, a model of sensory input-dependent plasticity, shortens inhibitory synapse lifetimes and lengthens intervals to recurrence, resulting in a new dynamic state with reduced inhibitory synaptic presence. Reversible structural dynamics indicate a fundamentally new role for inhibitory synaptic remodeling--flexible, input-specific modulation of stable excitatory connections.
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Affiliation(s)
- Katherine L Villa
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kalen P Berry
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jaichandar Subramanian
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jae Won Cha
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Won Chan Oh
- Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA
| | - Hyung-Bae Kwon
- Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA; Max Planck Institute of Neurobiology, Martinsried 82152, Germany
| | - Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; Department of Physiological Science, Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan; JST, CREST, Tokyo 102-0076, Japan
| | - Peter T C So
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elly Nedivi
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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