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Vandael D, Jonas P. Structure, biophysics, and circuit function of a "giant" cortical presynaptic terminal. Science 2024; 383:eadg6757. [PMID: 38452088 DOI: 10.1126/science.adg6757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024]
Abstract
The hippocampal mossy fiber synapse, formed between axons of dentate gyrus granule cells and dendrites of CA3 pyramidal neurons, is a key synapse in the trisynaptic circuitry of the hippocampus. Because of its comparatively large size, this synapse is accessible to direct presynaptic recording, allowing a rigorous investigation of the biophysical mechanisms of synaptic transmission and plasticity. Furthermore, because of its placement in the very center of the hippocampal memory circuit, this synapse seems to be critically involved in several higher network functions, such as learning, memory, pattern separation, and pattern completion. Recent work based on new technologies in both nanoanatomy and nanophysiology, including presynaptic patch-clamp recording, paired recording, super-resolution light microscopy, and freeze-fracture and "flash-and-freeze" electron microscopy, has provided new insights into the structure, biophysics, and network function of this intriguing synapse. This brings us one step closer to answering a fundamental question in neuroscience: how basic synaptic properties shape higher network computations.
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Affiliation(s)
- David Vandael
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
| | - Peter Jonas
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
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2
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Asiminas A, Booker SA, Dando OR, Kozic Z, Arkell D, Inkpen FH, Sumera A, Akyel I, Kind PC, Wood ER. Experience-dependent changes in hippocampal spatial activity and hippocampal circuit function are disrupted in a rat model of Fragile X Syndrome. Mol Autism 2022; 13:49. [PMID: 36536454 PMCID: PMC9764562 DOI: 10.1186/s13229-022-00528-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is a common single gene cause of intellectual disability and autism spectrum disorder. Cognitive inflexibility is one of the hallmarks of FXS with affected individuals showing extreme difficulty adapting to novel or complex situations. To explore the neural correlates of this cognitive inflexibility, we used a rat model of FXS (Fmr1-/y). METHODS We recorded from the CA1 in Fmr1-/y and WT littermates over six 10-min exploration sessions in a novel environment-three sessions per day (ITI 10 min). Our recordings yielded 288 and 246 putative pyramidal cells from 7 WT and 7 Fmr1-/y rats, respectively. RESULTS On the first day of exploration of a novel environment, the firing rate and spatial tuning of CA1 pyramidal neurons was similar between wild-type (WT) and Fmr1-/y rats. However, while CA1 pyramidal neurons from WT rats showed experience-dependent changes in firing and spatial tuning between the first and second day of exposure to the environment, these changes were decreased or absent in CA1 neurons of Fmr1-/y rats. These findings were consistent with increased excitability of Fmr1-/y CA1 neurons in ex vivo hippocampal slices, which correlated with reduced synaptic inputs from the medial entorhinal cortex. Lastly, activity patterns of CA1 pyramidal neurons were dis-coordinated with respect to hippocampal oscillatory activity in Fmr1-/y rats. LIMITATIONS It is still unclear how the observed circuit function abnormalities give rise to behavioural deficits in Fmr1-/y rats. Future experiments will focus on this connection as well as the contribution of other neuronal cell types in the hippocampal circuit pathophysiology associated with the loss of FMRP. It would also be interesting to see if hippocampal circuit deficits converge with those seen in other rodent models of intellectual disability. CONCLUSIONS In conclusion, we found that hippocampal place cells from Fmr1-/y rats show similar spatial firing properties as those from WT rats but do not show the same experience-dependent increase in spatial specificity or the experience-dependent changes in network coordination. Our findings offer support to a network-level origin of cognitive deficits in FXS.
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Affiliation(s)
- Antonis Asiminas
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.5254.60000 0001 0674 042XPresent Address: Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Sam A. Booker
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Owen R. Dando
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988UK Dementia Research Institute at the Edinburgh Medical School, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Zrinko Kozic
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Daisy Arkell
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Felicity H. Inkpen
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Anna Sumera
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Irem Akyel
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Peter C. Kind
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK ,Centre for Brain Development and Repair, Bangalore, 560065 India
| | - Emma R. Wood
- grid.4305.20000 0004 1936 7988Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, EH8 9XD UK ,grid.4305.20000 0004 1936 7988Patrick Wild Centre, University of Edinburgh, Edinburgh, EH8 9XD UK ,Centre for Brain Development and Repair, Bangalore, 560065 India
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3
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Shing N, Walker MC, Chang P. The Role of Aberrant Neural Oscillations in the Hippocampal-Medial Prefrontal Cortex Circuit in Neurodevelopmental and Neurological Disorders. Neurobiol Learn Mem 2022; 195:107683. [PMID: 36174886 DOI: 10.1016/j.nlm.2022.107683] [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: 03/01/2022] [Revised: 09/09/2022] [Accepted: 09/20/2022] [Indexed: 11/30/2022]
Abstract
The hippocampus (HPC) and medial prefrontal cortex (mPFC) have well-established roles in cognition, emotion, and sensory processing. In recent years, interests have shifted towards developing a deeper understanding of the mechanisms underlying interactions between the HPC and mPFC in achieving these functions. Considerable research supports the idea that synchronized activity between the HPC and the mPFC is a general mechanism by which brain functions are regulated. In this review, we summarize current knowledge on the hippocampal-medial prefrontal cortex (HPC-mPFC) circuit in normal brain function with a focus on oscillations and highlight several neurodevelopmental and neurological disorders associated with aberrant HPC-mPFC circuitry. We further discuss oscillatory dynamics across the HPC-mPFC circuit as potentially useful biomarkers to assess interventions for neurodevelopmental and neurological disorders. Finally, advancements in brain stimulation, gene therapy and pharmacotherapy are explored as promising therapies for disorders with aberrant HPC-mPFC circuit dynamics.
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Affiliation(s)
- Nathanael Shing
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK; Department of Medicine, University of Central Lancashire, Preston, PR17BH, UK
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Pishan Chang
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT.
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4
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Rusakov DA, Giese KP, Sandi C, Dommett E, Overton PG. Remembering Mike Stewart. Neuropharmacology 2022; 207:108962. [PMID: 35051447 DOI: 10.1016/j.neuropharm.2022.108962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Dmitri A Rusakov
- UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK.
| | - Karl Peter Giese
- Institute of Psychiatry, Physiology and Neuroscience, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Carmen Sandi
- Swiss Federal Institute of Technology in Lausanne (EPFL), Rte Cantonale, 1015, Lausanne, Switzerland
| | - Eleanore Dommett
- Institute of Psychiatry, Physiology and Neuroscience, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Paul G Overton
- Department of Psychology, University of Sheffield, Vicar Lane, Sheffield, S1 2LT, UK
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5
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Rusakov DA. Obituary for Professor Michael G. Stewart: Life in Neurosciences. Brain Res Bull 2022; 180:147-149. [DOI: 10.1016/j.brainresbull.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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6
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Mouse models of aneuploidy to understand chromosome disorders. Mamm Genome 2021; 33:157-168. [PMID: 34719726 PMCID: PMC8913467 DOI: 10.1007/s00335-021-09930-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/20/2021] [Indexed: 12/04/2022]
Abstract
An organism or cell carrying a number of chromosomes that is not a multiple of the haploid count is in a state of aneuploidy. This condition results in significant changes in the level of expression of genes that are gained or lost from the aneuploid chromosome(s) and most cases in humans are not compatible with life. However, a few aneuploidies can lead to live births, typically associated with deleterious phenotypes. We do not understand why phenotypes arise from aneuploid syndromes in humans. Animal models have the potential to provide great insight, but less than a handful of mouse models of aneuploidy have been made, and no ideal system exists in which to study the effects of aneuploidy per se versus those of raised gene dosage. Here, we give an overview of human aneuploid syndromes, the effects on physiology of having an altered number of chromosomes and we present the currently available mouse models of aneuploidy, focusing on models of trisomy 21 (which causes Down syndrome) because this is the most common, and therefore, the most studied autosomal aneuploidy. Finally, we discuss the potential role of carrying an extra chromosome on aneuploid phenotypes, independent of changes in gene dosage, and methods by which this could be investigated further.
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7
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Ding G, Li X, Hou X, Zhou W, Gong Y, Liu F, He Y, Song J, Wang J, Basil P, Li W, Qian S, Saha P, Wang J, Cui C, Yang T, Zou K, Han Y, Amos CI, Xu Y, Chen L, Sun Z. REV-ERB in GABAergic neurons controls diurnal hepatic insulin sensitivity. Nature 2021; 592:763-767. [PMID: 33762728 PMCID: PMC8085086 DOI: 10.1038/s41586-021-03358-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 02/12/2021] [Indexed: 02/08/2023]
Abstract
Systemic insulin sensitivity shows a diurnal rhythm with a peak upon waking1,2. The molecular mechanism that underlies this temporal pattern is unclear. Here we show that the nuclear receptors REV-ERB-α and REV-ERB-β (referred to here as 'REV-ERB') in the GABAergic (γ-aminobutyric acid-producing) neurons in the suprachiasmatic nucleus (SCN) (SCNGABA neurons) control the diurnal rhythm of insulin-mediated suppression of hepatic glucose production in mice, without affecting diurnal eating or locomotor behaviours during regular light-dark cycles. REV-ERB regulates the rhythmic expression of genes that are involved in neurotransmission in the SCN, and modulates the oscillatory firing activity of SCNGABA neurons. Chemogenetic stimulation of SCNGABA neurons at waking leads to glucose intolerance, whereas restoration of the temporal pattern of either SCNGABA neuron firing or REV-ERB expression rescues the time-dependent glucose metabolic phenotype caused by REV-ERB depletion. In individuals with diabetes, an increased level of blood glucose after waking is a defining feature of the 'extended dawn phenomenon'3,4. Patients with type 2 diabetes with the extended dawn phenomenon exhibit a differential temporal pattern of expression of REV-ERB genes compared to patients with type 2 diabetes who do not have the extended dawn phenomenon. These findings provide mechanistic insights into how the central circadian clock regulates the diurnal rhythm of hepatic insulin sensitivity, with implications for our understanding of the extended dawn phenomenon in type 2 diabetes.
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Affiliation(s)
- Guolian Ding
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Xin Li
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Wenjun Zhou
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Yingyun Gong
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Fuqiang Liu
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Yanlin He
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Laboratory of Brain Glycemia and Metabolism Control, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Jia Song
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Jing Wang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Paul Basil
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Wenbo Li
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Sichong Qian
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
| | - Pradip Saha
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Jinbang Wang
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Chen Cui
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Tingting Yang
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Kexin Zou
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - Younghun Han
- Department of Medicine, Section of Epidemiology and Population Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Christopher I Amos
- Department of Medicine, Section of Epidemiology and Population Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Li Chen
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China.
| | - Zheng Sun
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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8
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Moriwaki T, Abe S, Oshimura M, Kazuki Y. Transchromosomic technology for genomically humanized animals. Exp Cell Res 2020; 390:111914. [PMID: 32142854 DOI: 10.1016/j.yexcr.2020.111914] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/16/2020] [Accepted: 02/19/2020] [Indexed: 12/15/2022]
Abstract
"Genomically" humanized animals are invaluable tools for generating human disease models and for biomedical research. Humanized animal models have generally been developed via conventional transgenic technologies; however, conventional gene delivery vectors such as viruses, plasmids, bacterial artificial chromosomes, P1 phase-derived artificial chromosomes, and yeast artificial chromosomes have limitations for transgenic animal creation as their loading gene capacity is restricted, and the expression of transgenes is unstable. Transchromosomic (Tc) techniques using mammalian artificial chromosomes, including human chromosome fragments, human artificial chromosomes, and mouse artificial chromosomes, have overcome these limitations. These tools can carry multiple genes or Mb-sized genomic loci and their associated regulatory elements, which has facilitated the creation of more useful and complex transgenic models for human disease, drug development, and humanized animal research. This review describes the history of Tc animal development, the applications of Tc animals, and future prospects.
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Affiliation(s)
- Takashi Moriwaki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan
| | - Satoshi Abe
- Trans Chromosomics, Inc., 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan
| | - Mitsuo Oshimura
- Trans Chromosomics, Inc., 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan; Chromosome Engineering Research Center (CERC), Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan
| | - Yasuhiro Kazuki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan; Chromosome Engineering Research Center (CERC), Tottori University, 86 Nishi-cho, Yonago, Tottori, 683-8503, Japan.
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9
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Zeng G, Huang X, Jiang T, Yu S. Short-term synaptic plasticity expands the operational range of long-term synaptic changes in neural networks. Neural Netw 2019; 118:140-147. [DOI: 10.1016/j.neunet.2019.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 04/23/2019] [Accepted: 06/03/2019] [Indexed: 02/04/2023]
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10
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Ahlfors H, Anyanwu N, Pakanavicius E, Dinischiotu N, Lana-Elola E, Watson-Scales S, Tosh J, Wiseman F, Briscoe J, Page K, Fisher EMC, Tybulewicz VLJ. Gene expression dysregulation domains are not a specific feature of Down syndrome. Nat Commun 2019; 10:2489. [PMID: 31171815 PMCID: PMC6554309 DOI: 10.1038/s41467-019-10129-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/18/2019] [Indexed: 11/19/2022] Open
Abstract
Down syndrome (DS), trisomy of human chromosome 21 (Hsa21), results in a broad range of phenotypes. A recent study reported that DS cells show genome-wide transcriptional changes in which up- or down-regulated genes are clustered in gene expression dysregulation domains (GEDDs). GEDDs were also reported in fibroblasts derived from a DS mouse model duplicated for some Hsa21-orthologous genes, indicating cross-species conservation of this phenomenon. Here we investigate GEDDs using the Dp1Tyb mouse model of DS, which is duplicated for the entire Hsa21-orthologous region of mouse chromosome 16. Our statistical analysis shows that GEDDs are present both in DS cells and in Dp1Tyb mouse fibroblasts and hippocampus. However, we find that GEDDs do not depend on the DS genotype but occur whenever gene expression changes. We conclude that GEDDs are not a specific feature of DS but instead result from the clustering of co-regulated genes, a function of mammalian genome organisation. Gene expression dysregulation domains (GEDDs) have been reported in Down syndrome (DS) cells, where changes in gene expression are clustered. Here the authors find that, while GEDDs are present in DS cells and in the Dp1Tyb mouse model of DS, GEDDs do not depend on the DS genotype and occur whenever gene expression changes, suggesting they result from the clustering of co-regulated genes as a function of mammalian genome organisation.
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Affiliation(s)
- Helena Ahlfors
- NE Thames Regional Genetics Laboratory, GOSH NHS Foundation Trust, London, WC1N 3JH, UK
| | | | | | | | | | | | - Justin Tosh
- UCL Institute of Neurology, London, WC1N 3BG, UK
| | | | | | - Karen Page
- Department of Mathematics, University College London, London, WC1E 6BT, UK
| | | | - Victor L J Tybulewicz
- The Francis Crick Institute, London, NW1 1AT, UK. .,Imperial College, London, W12 0NN, UK.
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11
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Rama S, Jensen TP, Rusakov DA. Glutamate Imaging Reveals Multiple Sites of Stochastic Release in the CA3 Giant Mossy Fiber Boutons. Front Cell Neurosci 2019; 13:243. [PMID: 31213985 PMCID: PMC6558140 DOI: 10.3389/fncel.2019.00243] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/16/2019] [Indexed: 11/17/2022] Open
Abstract
One of the most studied central synapses which have provided fundamental insights into cellular mechanisms of neural connectivity is the “giant” excitatory connection between hippocampal mossy fibers (MFs) and CA3 pyramidal cells. Its large presynaptic bouton features multiple release sites and is densely packed with thousands of synaptic vesicles, to sustain a highly facilitating “detonator” transmission. However, whether glutamate release sites at this synapse act independently, in a stochastic manner, or rather synchronously, remains poorly understood. This knowledge is critical for a better understanding of mechanisms underpinning presynaptic plasticity and postsynaptic signal integration rules. Here, we use the optical glutamate sensor SF-iGluSnFR and the intracellular Ca2+ indicator Cal-590 to monitor spike-evoked glutamate release and presynaptic calcium entry in MF boutons. Multiplexed imaging reveals that distinct sites in individual MF giant boutons release glutamate in a probabilistic fashion, also showing use-dependent short-term facilitation. The present approach provides novel insights into the basic mechanisms of neurotransmitter release at excitatory synapses.
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Affiliation(s)
- Sylvain Rama
- UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Thomas P Jensen
- UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Dmitri A Rusakov
- UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
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12
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Loss of function of NCOR1 and NCOR2 impairs memory through a novel GABAergic hypothalamus-CA3 projection. Nat Neurosci 2019; 22:205-217. [PMID: 30664766 PMCID: PMC6361549 DOI: 10.1038/s41593-018-0311-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 11/30/2018] [Indexed: 12/26/2022]
Abstract
Nuclear receptor corepressor 1 (NCOR1) and NCOR2 (also known as SMRT) regulate gene expression by activating histone deacetylase 3 through their deacetylase activation domain (DAD). We show that mice with DAD knock-in mutations have memory deficits, reduced anxiety levels, and reduced social interactions. Mice with NCOR1 and NORC2 depletion specifically in GABAergic neurons (NS-V mice) recapitulated the memory deficits and had reduced GABAA receptor subunit α2 (GABRA2) expression in lateral hypothalamus GABAergic (LHGABA) neurons. This was associated with LHGABA neuron hyperexcitability and impaired hippocampal long-term potentiation, through a monosynaptic LHGABA to CA3GABA projection. Optogenetic activation of this projection caused memory deficits, whereas targeted manipulation of LHGABA or CA3GABA neuron activity reversed memory deficits in NS-V mice. We describe de novo variants in NCOR1, NCOR2 or HDAC3 in patients with intellectual disability or neurodevelopmental disorders. These findings identify a hypothalamus-hippocampus projection that may link endocrine signals with synaptic plasticity through NCOR-mediated regulation of GABA signaling.
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Zhao X, Bhattacharyya A. Human Models Are Needed for Studying Human Neurodevelopmental Disorders. Am J Hum Genet 2018; 103:829-857. [PMID: 30526865 DOI: 10.1016/j.ajhg.2018.10.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/09/2018] [Indexed: 12/19/2022] Open
Abstract
The analysis of animal models of neurological disease has been instrumental in furthering our understanding of neurodevelopment and brain diseases. However, animal models are limited in revealing some of the most fundamental aspects of development, genetics, pathology, and disease mechanisms that are unique to humans. These shortcomings are exaggerated in disorders that affect the brain, where the most significant differences between humans and animal models exist, and could underscore failures in targeted therapeutic interventions in affected individuals. Human pluripotent stem cells have emerged as a much-needed model system for investigating human-specific biology and disease mechanisms. However, questions remain regarding whether these cell-culture-based models are sufficient or even necessary. In this review, we summarize human-specific features of neurodevelopment and the most common neurodevelopmental disorders, present discrepancies between animal models and human diseases, demonstrate how human stem cell models can provide meaningful information, and discuss the challenges that exist in our pursuit to understand distinctively human aspects of neurodevelopment and brain disease. This information argues for a more thoughtful approach to disease modeling through consideration of the valuable features and limitations of each model system, be they human or animal, to mimic disease characteristics.
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Affiliation(s)
- Xinyu Zhao
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
| | - Anita Bhattacharyya
- Waisman Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA; Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI 53705, USA.
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14
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Wiseman FK, Pulford LJ, Barkus C, Liao F, Portelius E, Webb R, Chávez-Gutiérrez L, Cleverley K, Noy S, Sheppard O, Collins T, Powell C, Sarell CJ, Rickman M, Choong X, Tosh JL, Siganporia C, Whittaker HT, Stewart F, Szaruga M, Murphy MP, Blennow K, de Strooper B, Zetterberg H, Bannerman D, Holtzman DM, Tybulewicz VLJ, Fisher EMC. Trisomy of human chromosome 21 enhances amyloid-β deposition independently of an extra copy of APP. Brain 2018; 141:2457-2474. [PMID: 29945247 PMCID: PMC6061702 DOI: 10.1093/brain/awy159] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/13/2018] [Accepted: 04/18/2018] [Indexed: 01/11/2023] Open
Abstract
Down syndrome, caused by trisomy of chromosome 21, is the single most common risk factor for early-onset Alzheimer's disease. Worldwide approximately 6 million people have Down syndrome, and all these individuals will develop the hallmark amyloid plaques and neurofibrillary tangles of Alzheimer's disease by the age of 40 and the vast majority will go on to develop dementia. Triplication of APP, a gene on chromosome 21, is sufficient to cause early-onset Alzheimer's disease in the absence of Down syndrome. However, whether triplication of other chromosome 21 genes influences disease pathogenesis in the context of Down syndrome is unclear. Here we show, in a mouse model, that triplication of chromosome 21 genes other than APP increases amyloid-β aggregation, deposition of amyloid-β plaques and worsens associated cognitive deficits. This indicates that triplication of chromosome 21 genes other than APP is likely to have an important role to play in Alzheimer's disease pathogenesis in individuals who have Down syndrome. We go on to show that the effect of trisomy of chromosome 21 on amyloid-β aggregation correlates with an unexpected shift in soluble amyloid-β 40/42 ratio. This alteration in amyloid-β isoform ratio occurs independently of a change in the carboxypeptidase activity of the γ-secretase complex, which cleaves the peptide from APP, or the rate of extracellular clearance of amyloid-β. These new mechanistic insights into the role of triplication of genes on chromosome 21, other than APP, in the development of Alzheimer's disease in individuals who have Down syndrome may have implications for the treatment of this common cause of neurodegeneration.
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Affiliation(s)
- Frances K Wiseman
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
- The LonDownS Consortium, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Denmark Hill, London, SE5 8AF, UK
| | - Laura J Pulford
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Chris Barkus
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3PH, UK
| | - Fan Liao
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, 63110, USA
| | - Erik Portelius
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, S-405 30, Sweden
| | - Robin Webb
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, 40507, USA
| | - Lucia Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain and Disease Research, VIB-Leuven 3000, Center for Human Genetics, Universitaire Ziekenhuizen and LIND, KU Leuven, Leuven, Belgium
| | - Karen Cleverley
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Sue Noy
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Olivia Sheppard
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Toby Collins
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Caroline Powell
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London W1W 7FF, UK
| | - Claire J Sarell
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, 33 Cleveland Street, London W1W 7FF, UK
| | - Matthew Rickman
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Xun Choong
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Justin L Tosh
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Carlos Siganporia
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Heather T Whittaker
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
| | - Floy Stewart
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, 63110, USA
| | - Maria Szaruga
- VIB-KU Leuven Center for Brain and Disease Research, VIB-Leuven 3000, Center for Human Genetics, Universitaire Ziekenhuizen and LIND, KU Leuven, Leuven, Belgium
| | - London Down syndrome consortium
- The LonDownS Consortium, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Denmark Hill, London, SE5 8AF, UK
| | - Michael P Murphy
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, 40507, USA
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, S-405 30, Sweden
| | - Bart de Strooper
- VIB-KU Leuven Center for Brain and Disease Research, VIB-Leuven 3000, Center for Human Genetics, Universitaire Ziekenhuizen and LIND, KU Leuven, Leuven, Belgium
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute, London, WC2B 4AN, UK
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, S-405 30, Sweden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute, London, WC2B 4AN, UK
| | - David Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3PH, UK
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri, 63110, USA
| | - Victor L J Tybulewicz
- The LonDownS Consortium, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Denmark Hill, London, SE5 8AF, UK
- Francis Crick Institute, London, NW1 1AT, UK
- Department of Medicine, Imperial College, London, SW7 2AZ, UK
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG UK
- The LonDownS Consortium, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Denmark Hill, London, SE5 8AF, UK
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15
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Herault Y, Delabar JM, Fisher EMC, Tybulewicz VLJ, Yu E, Brault V. Rodent models in Down syndrome research: impact and future opportunities. Dis Model Mech 2018; 10:1165-1186. [PMID: 28993310 PMCID: PMC5665454 DOI: 10.1242/dmm.029728] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Down syndrome is caused by trisomy of chromosome 21. To date, a multiplicity of mouse models with Down-syndrome-related features has been developed to understand this complex human chromosomal disorder. These mouse models have been important for determining genotype-phenotype relationships and identification of dosage-sensitive genes involved in the pathophysiology of the condition, and in exploring the impact of the additional chromosome on the whole genome. Mouse models of Down syndrome have also been used to test therapeutic strategies. Here, we provide an overview of research in the last 15 years dedicated to the development and application of rodent models for Down syndrome. We also speculate on possible and probable future directions of research in this fast-moving field. As our understanding of the syndrome improves and genome engineering technologies evolve, it is necessary to coordinate efforts to make all Down syndrome models available to the community, to test therapeutics in models that replicate the whole trisomy and design new animal models to promote further discovery of potential therapeutic targets. Summary: Mouse models have boosted therapeutic options for Down syndrome, and improved models are being developed to better understand the pathophysiology of this genetic condition.
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Affiliation(s)
- Yann Herault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris
| | - Jean M Delabar
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, UMR8251, CNRS, 75205 Paris, France.,INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et la Moelle épinière, ICM, 75013 Paris, France.,Brain and Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, 75013 Paris, France
| | - Elizabeth M C Fisher
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, WC1N 3BG, UK.,LonDownS Consortium, London, W1T 7NF UK
| | - Victor L J Tybulewicz
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,LonDownS Consortium, London, W1T 7NF UK.,The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,Department of Medicine, Imperial College, London, SW7 2AZ, UK
| | - Eugene Yu
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,The Children's Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genetics Program, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.,Department of Cellular and Molecular Biology, Roswell Park Division of Graduate School, Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY 14263, USA
| | - Veronique Brault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
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16
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Chung BYT, Bailey CDC. Similar nicotinic excitability responses across the developing hippocampal formation are regulated by small-conductance calcium-activated potassium channels. J Neurophysiol 2018; 119:1707-1722. [PMID: 29384449 DOI: 10.1152/jn.00426.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The hippocampal formation forms a cognitive circuit that is critical for learning and memory. Cholinergic input to nicotinic acetylcholine receptors plays an important role in the normal development of principal neurons within the hippocampal formation. However, the ability of nicotinic receptors to stimulate principal neurons across all regions of the developing hippocampal formation has not been determined. We show in this study that heteromeric nicotinic receptors mediate direct inward current and depolarization responses in principal neurons across the hippocampal formation of the young postnatal mouse. These responses were found in principal neurons of the CA1, CA3, dentate gyrus, subiculum, and entorhinal cortex layer VI, and they varied in magnitude across regions with the greatest responses occurring in the subiculum and entorhinal cortex. Despite this regional variation in the magnitude of passive responses, heteromeric nicotinic receptor stimulation increased the excitability of active principal neurons by a similar amount in all regions. Pharmacological experiments found this similar excitability response to be regulated by small-conductance calcium-activated potassium (SK) channels, which exhibited regional differences in their influence on neuron activity that offset the observed regional differences in passive nicotinic responses. These findings demonstrate that SK channels play a role to coordinate the magnitude of heteromeric nicotinic excitability responses across the hippocampal formation at a time when nicotinic signaling drives the development of this cognitive brain region. This coordinated input may contribute to the normal development, synchrony, and maturation of the hippocampal formation learning and memory network. NEW & NOTEWORTHY This study demonstrates that small-conductance calcium-activated potassium channels regulate similar-magnitude excitability responses to heteromeric nicotinic acetylcholine receptor stimulation in active principal neurons across multiple regions of the developing mouse hippocampal formation. Given the importance of nicotinic neurotransmission for the development of principal neurons within the hippocampal formation, this coordinated excitability response is positioned to influence the normal development, synchrony, and maturation of the hippocampal formation learning and memory network.
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Affiliation(s)
- Beryl Y T Chung
- Department of Biomedical Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Craig D C Bailey
- Department of Biomedical Sciences, University of Guelph , Guelph, Ontario , Canada
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17
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Raveau M, Polygalov D, Boehringer R, Amano K, Yamakawa K, McHugh TJ. Alterations of in vivo CA1 network activity in Dp(16)1Yey Down syndrome model mice. eLife 2018; 7:31543. [PMID: 29485402 PMCID: PMC5841929 DOI: 10.7554/elife.31543] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 02/25/2018] [Indexed: 12/14/2022] Open
Abstract
Down syndrome, the leading genetic cause of intellectual disability, results from an extra-copy of chromosome 21. Mice engineered to model this aneuploidy exhibit Down syndrome-like memory deficits in spatial and contextual tasks. While abnormal neuronal function has been identified in these models, most studies have relied on in vitro measures. Here, using in vivo recording in the Dp(16)1Yey model, we find alterations in the organization of spiking of hippocampal CA1 pyramidal neurons, including deficits in the generation of complex spikes. These changes lead to poorer spatial coding during exploration and less coordinated activity during sharp-wave ripples, events involved in memory consolidation. Further, the density of CA1 inhibitory neurons expressing neuropeptide Y, a population key for the generation of pyramidal cell bursts, were significantly increased in Dp(16)1Yey mice. Our data refine the ‘over-suppression’ theory of Down syndrome pathophysiology and suggest specific neuronal subtypes involved in hippocampal dysfunction in these model mice.
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Affiliation(s)
- Matthieu Raveau
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Denis Polygalov
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
| | - Roman Boehringer
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
| | - Kenji Amano
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
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18
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Naert G, Ferré V, Keller E, Slender A, Gibbins D, Fisher EMC, Tybulewicz VLJ, Maurice T. In vivo and ex vivo analyses of amyloid toxicity in the Tc1 mouse model of Down syndrome. J Psychopharmacol 2018; 32:174-190. [PMID: 29215943 PMCID: PMC5815426 DOI: 10.1177/0269881117743484] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
RATIONALE The prevalence of Alzheimer's disease is increased in people with Down syndrome. The pathology appears much earlier than in the general population, suggesting a predisposition to develop Alzheimer's disease. Down syndrome results from trisomy of human chromosome 21, leading to overexpression of possible Alzheimer's disease candidate genes, such as amyloid precursor protein gene. To better understand how the Down syndrome context results in increased vulnerability to Alzheimer's disease, we analysed amyloid-β [25-35] peptide toxicity in the Tc1 mouse model of Down syndrome, in which ~75% of protein coding genes are functionally trisomic but, importantly, not amyloid precursor protein. RESULTS Intracerebroventricular injection of oligomeric amyloid-β [25-35] peptide in three-month-old wildtype mice induced learning deficits, oxidative stress, synaptic marker alterations, activation of glycogen synthase kinase-3β, inhibition of protein kinase B (AKT), and apoptotic pathways as compared to scrambled peptide-treated wildtype mice. Scrambled peptide-treated Tc1 mice presented high levels of toxicity markers as compared to wildtype mice. Amyloid-β [25-35] peptide injection in Tc1 mice induced significant learning deficits and enhanced glycogen synthase kinase-3β activity in the cortex and expression of apoptotic markers in the hippocampus and cortex. Interestingly, several markers, including oxidative stress, synaptic markers, glycogen synthase kinase-3β activity in the hippocampus and AKT activity in the hippocampus and cortex, were unaffected by amyloid-β [25-35] peptide injection in Tc1 mice. CONCLUSIONS Tc1 mice present several toxicity markers similar to those observed in amyloid-β [25-35] peptide-treated wildtype mice, suggesting that developmental modifications in these mice modify their response to amyloid peptide. However, amyloid toxicity led to severe memory deficits in this Down syndrome mouse model.
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Affiliation(s)
- Gaëlle Naert
- INSERM U1198, Montpellier, France
- EPHE, Paris, France
| | | | | | | | | | | | | | - Tangui Maurice
- INSERM U1198, Montpellier, France
- EPHE, Paris, France
- Tangui Maurice, INSERM U1198, University of Montpellier, CC105, Place Eugene Bataillon, Montpellier Cedex 5, 34095, France.
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19
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Roeper J. Closing gaps in brain disease-from overlapping genetic architecture to common motifs of synapse dysfunction. Curr Opin Neurobiol 2017; 48:45-51. [PMID: 28968515 DOI: 10.1016/j.conb.2017.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
Abstract
Recent progress in the synaptic pathophysiology of brain diseases is reviewed. To emphasize the emergence of common motifs in synapse dysfunctions across neurodevelopmental, psychiatric and neurological disorders, conventional clinical boundaries are disregarded and a decidedly trans-diagnostic, potentially unifying view of altered synapse function is promoted. Based on the overlapping genetic architecture of brain disorders, which often converges on genes related to synaptic functions, disease-related changes in basic pre-synaptic and post-synaptic communication, neuromodulation-gated changes in Hebbian plasticity, dynamic interactions between Hebbian and homeostatic plasticity, and changes in synaptic maintenance by autophagy and glial-mediated phagocytosis are highlighted.
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Affiliation(s)
- Jochen Roeper
- Institute of Neurophysiology, Goethe University, Frankfurt, Germany.
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20
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Reberger R, Dall'Oglio A, Jung CR, Rasia-Filho AA. Structure and diversity of human dendritic spines evidenced by a new three-dimensional reconstruction procedure for Golgi staining and light microscopy. J Neurosci Methods 2017; 293:27-36. [PMID: 28887132 DOI: 10.1016/j.jneumeth.2017.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/30/2017] [Accepted: 09/03/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Different approaches aim to unravel detailed morphological features of neural cells. Dendritic spines are multifunctional units that reflect cellular connectivity, synaptic strength and plasticity. NEW METHOD A novel three-dimensional (3D) reconstruction procedure is introduced for visualization of dendritic spines from human postmortem brain tissue using brightfield microscopy. The segmentation model was based on thresholding the intensity values of the dendritic spine image along 'z' stacks. We used median filtering and removed false positives. Fine adjustments during image processing confirmed that the reconstructed image of the spines corresponded to the actual original data. RESULTS Examples are shown for the cortical amygdaloid nucleus and the CA3 hippocampal area. Structure of spine heads and necks was evaluated at different angles. Our 3D reconstruction images display dendritic spines either isolated or in clusters, in a continuum of shapes and sizes, from simple to more elaborated forms, including the presence of spinule and complex 'thorny excrescences'. COMPARISON WITH EXISTING METHODS The procedure has the advantages already described for the adapted "single-section" Golgi method, since it provides suitable results using human brains fixed in formalin for long time, is relatively easy, requires minimal equipment, and uses an algorithm for 3D reconstruction that provides high quality images and more precise morphological data. CONCLUSION The procedure described here allows the reliable visualization and study of human dendritic spines with broad applications for normal controls and pathological studies.
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Affiliation(s)
- Roman Reberger
- Friedrich Alexander Universität Erlangen-Nürnberg, Medical Engineering Program, Erlangen, Germany; Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil
| | - Aline Dall'Oglio
- Federal University of Health Sciences, Department of Basic Sciences/Physiology, Porto Alegre, Brazil
| | - Claudio R Jung
- Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil
| | - Alberto A Rasia-Filho
- Federal University of Health Sciences, Department of Basic Sciences/Physiology, Porto Alegre, Brazil; Federal University of Rio Grande do Sul, Neuroscience Program, Porto Alegre, Brazil.
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21
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Clark CA, Fernandez F, Sakhon S, Spanò G, Edgin JO. The medial temporal memory system in Down syndrome: Translating animal models of hippocampal compromise. Hippocampus 2017; 27:683-691. [PMID: 28346765 PMCID: PMC8109260 DOI: 10.1002/hipo.22724] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/06/2016] [Accepted: 03/07/2017] [Indexed: 01/19/2023]
Abstract
Recent studies have highlighted the dentate gyrus as a region of increased vulnerability in mouse models of Down syndrome (DS). It is unclear to what extent these findings are reflected in the memory profile of people with the condition. We developed a series of novel tasks to probe distinct medial temporal functions in children and young adults with DS, including object, spatial, and temporal order memory. Relative to mental age-matched controls (n = 45), individuals with DS (n = 28) were unimpaired on subtests involving short-term object or configural recall that was divorced from spatial or temporal contexts. By contrast, the DS group had difficulty recalling spatial locations when contextual information was salient and recalling the order in which objects were serially presented. Results are consistent with dysfunction of spatial and temporal contextual pattern separation abilities in individuals with DS, mediated by the hippocampus, including the dentate gyrus. Amidst increasing calls to bridge human and animal work, the memory profile demonstrated here in humans with DS is strikingly similar to that of the Ts65Dn mouse model of DS. The study highlights the trisynaptic circuit as a potentially fruitful intervention target to mitigate cognitive impairments associated with DS.
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Affiliation(s)
- Caron A.C. Clark
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
- Department of Educational Psychology, University of Nebraska, Lincoln, Nebraska
| | - Fabian Fernandez
- Department of Psychology, BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, Arizona
- Department of Neurology, BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, Arizona
| | - Stella Sakhon
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
| | - Goffredina Spanò
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
| | - Jamie O. Edgin
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
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22
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Intersectin 1 is a component of the Reelin pathway to regulate neuronal migration and synaptic plasticity in the hippocampus. Proc Natl Acad Sci U S A 2017; 114:5533-5538. [PMID: 28484035 DOI: 10.1073/pnas.1704447114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Brain development and function depend on the directed and coordinated migration of neurons from proliferative zones to their final position. The secreted glycoprotein Reelin is an important factor directing neuronal migration. Loss of Reelin function results in the severe developmental disorder lissencephaly and is associated with neurological diseases in humans. Reelin signals via the lipoprotein receptors very low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2), but the exact mechanism by which these receptors control cellular function is poorly understood. We report that loss of the signaling scaffold intersectin 1 (ITSN1) in mice leads to defective neuronal migration and ablates Reelin stimulation of hippocampal long-term potentiation (LTP). Knockout (KO) mice lacking ITSN1 suffer from dispersion of pyramidal neurons and malformation of the radial glial scaffold, akin to the hippocampal lamination defects observed in VLDLR or ApoER2 mutants. ITSN1 genetically interacts with Reelin receptors, as evidenced by the prominent neuronal migration and radial glial defects in hippocampus and cortex seen in double-KO mice lacking ITSN1 and ApoER2. These defects were similar to, albeit less severe than, those observed in Reelin-deficient or VLDLR/ ApoER2 double-KO mice. Molecularly, ITSN1 associates with the VLDLR and its downstream signaling adaptor Dab1 to facilitate Reelin signaling. Collectively, these data identify ITSN1 as a component of Reelin signaling that acts predominantly by facilitating the VLDLR-Dab1 axis to direct neuronal migration in the cortex and hippocampus and to augment synaptic plasticity.
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23
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Spanò G, Intraub H, Edgin JO. Testing the "Boundaries" of boundary extension: Anticipatory scene representation across development and disorder. Hippocampus 2017; 27:726-739. [PMID: 28329909 DOI: 10.1002/hipo.22728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 01/14/2017] [Accepted: 01/19/2017] [Indexed: 12/28/2022]
Abstract
Recent studies have suggested that Boundary Extension (BE), a scene construction error, may be linked to the function of the hippocampus. In this study, we tested BE in two groups with variations in hippocampal development and disorder: a typically developing sample ranging from preschool to adolescence and individuals with Down syndrome. We assessed BE across three different test modalities: drawing, visual recognition, and a 3D scene boundary reconstruction task. Despite confirmed fluctuations in memory function measured through a neuropsychological assessment, the results showed consistent BE in all groups across test modalities, confirming the near universal nature of BE. These results indicate that BE is an essential function driven by a complex set of processes, that occur even in the face of delayed memory development and hippocampal dysfunction in special populations.
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Affiliation(s)
- G Spanò
- Department of Psychology, University of Arizona, Tucson, Arizona, 85721.,Cognitive Science Program, University of Arizona, Tucson, Arizona, 85721
| | - H Intraub
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware, 19716
| | - J O Edgin
- Department of Psychology, University of Arizona, Tucson, Arizona, 85721.,Cognitive Science Program, University of Arizona, Tucson, Arizona, 85721.,Sonoran University Center for Excellence in Developmental Disabilities, University of Arizona, Tucson, Arizona, 85721
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24
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Nanoscale diffusion in the synaptic cleft and beyond measured with time-resolved fluorescence anisotropy imaging. Sci Rep 2017; 7:42022. [PMID: 28181535 PMCID: PMC5299514 DOI: 10.1038/srep42022] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 01/05/2017] [Indexed: 12/11/2022] Open
Abstract
Neural activity relies on molecular diffusion within nanoscopic spaces outside and inside nerve cells, such as synaptic clefts or dendritic spines. Measuring diffusion on this small scale in situ has not hitherto been possible, yet this knowledge is critical for understanding the dynamics of molecular events and electric currents that shape physiological signals throughout the brain. Here we advance time-resolved fluorescence anisotropy imaging combined with two-photon excitation microscopy to map nanoscale diffusivity in ex vivo brain slices. We find that in the brain interstitial gaps small molecules move on average ~30% slower than in a free medium whereas inside neuronal dendrites this retardation is ~70%. In the synaptic cleft free nanodiffusion is decelerated by ~46%. These quantities provide previously unattainable basic constrains for the receptor actions of released neurotransmitters, the electrical conductance of the brain interstitial space and the limiting rate of molecular interactions or conformational changes in the synaptic microenvironment.
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Powell NM, Modat M, Cardoso MJ, Ma D, Holmes HE, Yu Y, O’Callaghan J, Cleary JO, Sinclair B, Wiseman FK, Tybulewicz VLJ, Fisher EMC, Lythgoe MF, Ourselin S. Fully-Automated μMRI Morphometric Phenotyping of the Tc1 Mouse Model of Down Syndrome. PLoS One 2016; 11:e0162974. [PMID: 27658297 PMCID: PMC5033246 DOI: 10.1371/journal.pone.0162974] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/31/2016] [Indexed: 01/07/2023] Open
Abstract
We describe a fully automated pipeline for the morphometric phenotyping of mouse brains from μMRI data, and show its application to the Tc1 mouse model of Down syndrome, to identify new morphological phenotypes in the brain of this first transchromosomic animal carrying human chromosome 21. We incorporate an accessible approach for simultaneously scanning multiple ex vivo brains, requiring only a 3D-printed brain holder, and novel image processing steps for their separation and orientation. We employ clinically established multi-atlas techniques–superior to single-atlas methods–together with publicly-available atlas databases for automatic skull-stripping and tissue segmentation, providing high-quality, subject-specific tissue maps. We follow these steps with group-wise registration, structural parcellation and both Voxel- and Tensor-Based Morphometry–advantageous for their ability to highlight morphological differences without the laborious delineation of regions of interest. We show the application of freely available open-source software developed for clinical MRI analysis to mouse brain data: NiftySeg for segmentation and NiftyReg for registration, and discuss atlases and parameters suitable for the preclinical paradigm. We used this pipeline to compare 29 Tc1 brains with 26 wild-type littermate controls, imaged ex vivo at 9.4T. We show an unexpected increase in Tc1 total intracranial volume and, controlling for this, local volume and grey matter density reductions in the Tc1 brain compared to the wild-types, most prominently in the cerebellum, in agreement with human DS and previous histological findings.
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Affiliation(s)
- Nick M. Powell
- Translational Imaging Group, Centre for Medical Image Computing, University College London, 3rd Floor, Wolfson House, 4 Stephenson Way, London NW1 2HE, United Kingdom
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
- * E-mail:
| | - Marc Modat
- Translational Imaging Group, Centre for Medical Image Computing, University College London, 3rd Floor, Wolfson House, 4 Stephenson Way, London NW1 2HE, United Kingdom
| | - M. Jorge Cardoso
- Translational Imaging Group, Centre for Medical Image Computing, University College London, 3rd Floor, Wolfson House, 4 Stephenson Way, London NW1 2HE, United Kingdom
| | - Da Ma
- Translational Imaging Group, Centre for Medical Image Computing, University College London, 3rd Floor, Wolfson House, 4 Stephenson Way, London NW1 2HE, United Kingdom
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - Holly E. Holmes
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - Yichao Yu
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - James O’Callaghan
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - Jon O. Cleary
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
- Melbourne Brain Centre Imaging Unit, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ben Sinclair
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - Frances K. Wiseman
- Department of Neurodegenerative Disease, Institute of Neurology, University College, London WC1N 3BG, United Kingdom
| | - Victor L. J. Tybulewicz
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
- Imperial College, London W12 0NN, United Kingdom
| | - Elizabeth M. C. Fisher
- Department of Neurodegenerative Disease, Institute of Neurology, University College, London WC1N 3BG, United Kingdom
| | - Mark F. Lythgoe
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, Paul O’Gorman Building, 72 Huntley Street, London WC1E 6DD, United Kingdom
| | - Sébastien Ourselin
- Translational Imaging Group, Centre for Medical Image Computing, University College London, 3rd Floor, Wolfson House, 4 Stephenson Way, London NW1 2HE, United Kingdom
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Romano E, Cosentino L, Laviola G, De Filippis B. Genes and sex hormones interaction in neurodevelopmental disorders. Neurosci Biobehav Rev 2016; 67:9-24. [DOI: 10.1016/j.neubiorev.2016.02.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/01/2016] [Indexed: 12/14/2022]
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Hall JH, Wiseman FK, Fisher EMC, Tybulewicz VLJ, Harwood JL, Good MA. Tc1 mouse model of trisomy-21 dissociates properties of short- and long-term recognition memory. Neurobiol Learn Mem 2016; 130:118-28. [PMID: 26868479 PMCID: PMC4898594 DOI: 10.1016/j.nlm.2016.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 02/02/2016] [Accepted: 02/05/2016] [Indexed: 01/31/2023]
Abstract
The present study examined memory function in Tc1 mice, a transchromosomic model of Down syndrome (DS). Tc1 mice demonstrated an unusual delay-dependent deficit in recognition memory. More specifically, Tc1 mice showed intact immediate (30sec), impaired short-term (10-min) and intact long-term (24-h) memory for objects. A similar pattern was observed for olfactory stimuli, confirming the generality of the pattern across sensory modalities. The specificity of the behavioural deficits in Tc1 mice was confirmed using APP overexpressing mice that showed the opposite pattern of object memory deficits. In contrast to object memory, Tc1 mice showed no deficit in either immediate or long-term memory for object-in-place information. Similarly, Tc1 mice showed no deficit in short-term memory for object-location information. The latter result indicates that Tc1 mice were able to detect and react to spatial novelty at the same delay interval that was sensitive to an object novelty recognition impairment. These results demonstrate (1) that novelty detection per se and (2) the encoding of visuo-spatial information was not disrupted in adult Tc1 mice. The authors conclude that the task specific nature of the short-term recognition memory deficit suggests that the trisomy of genes on human chromosome 21 in Tc1 mice impacts on (perirhinal) cortical systems supporting short-term object and olfactory recognition memory.
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Affiliation(s)
| | - Frances K Wiseman
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Victor L J Tybulewicz
- Francis Crick Institute, The Ridgeway, Mill Hill, London NW7 1AA, UK; Imperial College, London W12 0NN, UK
| | - John L Harwood
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK
| | - Mark A Good
- School of Psychology, Cardiff University, CF10 3AT, UK.
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Spanò G, Edgin JO. Everyday memory in individuals with Down syndrome: Validation of the Observer Memory Questionnaire - Parent Form. Child Neuropsychol 2016; 23:523-535. [PMID: 26981787 DOI: 10.1080/09297049.2016.1150446] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The memory profile of individuals with Down syndrome (DS) has mainly been examined through traditional laboratory tasks, often revealing substantial deficits in episodic and declarative memory. Little is known about the relation between memory abilities as measured in the laboratory versus naturalistic settings in this population, and no questionnaire assessments of everyday memory have been formally validated for this group. The current study's aims were twofold: 1) to describe the psychometric characteristics of a parent-reported everyday memory measure (the Observer Memory Questionnaire - Parent Form, OMQ-PF) in this population with known hippocampal and memory impairment (i.e., DS, ages 7-35 years), and 2) to determine if the measure has the sensitivity to detect impairments, thus providing some of the first data to document parent reports of everyday memory in individuals with DS. The results indicate that this scale is a reliable instrument for detecting and tracking memory deficits over time in this population. We found a correlation between parent reports of everyday memory difficulties and well-replicated deficits in a laboratory-based memory task (i.e., place-object paired associates learning). Our results suggest that the OMQ-PF has the potential to be used as a tool to help to track the status of memory function in this group both for use in descriptive studies and in studies of behavior and pharmacological intervention.
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Affiliation(s)
- Goffredina Spanò
- a Department of Psychology , University of Arizona , Tucson , USA
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29
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Choong XY, Tosh JL, Pulford LJ, Fisher EMC. Dissecting Alzheimer disease in Down syndrome using mouse models. Front Behav Neurosci 2015; 9:268. [PMID: 26528151 PMCID: PMC4602094 DOI: 10.3389/fnbeh.2015.00268] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/21/2015] [Indexed: 11/13/2022] Open
Abstract
Down syndrome (DS) is a common genetic condition caused by the presence of three copies of chromosome 21 (trisomy 21). This greatly increases the risk of Alzheimer disease (AD), but although virtually all people with DS have AD neuropathology by 40 years of age, not all develop dementia. To dissect the genetic contribution of trisomy 21 to DS phenotypes including those relevant to AD, a range of DS mouse models has been generated which are trisomic for chromosome segments syntenic to human chromosome 21. Here, we consider key characteristics of human AD in DS (AD-DS), and our current state of knowledge on related phenotypes in AD and DS mouse models. We go on to review important features needed in future models of AD-DS, to understand this type of dementia and so highlight pathogenic mechanisms relevant to all populations at risk of AD.
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Affiliation(s)
- Xun Yu Choong
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Justin L Tosh
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Laura J Pulford
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
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