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López-Hidalgo R, Ballestín R, Lorenzo L, Sánchez-Martí S, Blasco-Ibáñez JM, Crespo C, Nacher J, Varea E. Early chronic fasudil treatment rescues hippocampal alterations in the Ts65Dn model for down syndrome. Neurochem Int 2024; 174:105679. [PMID: 38309665 DOI: 10.1016/j.neuint.2024.105679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/05/2024]
Abstract
Down syndrome (DS) is the most common genetic disorder associated with intellectual disability. To study this syndrome, several mouse models have been developed. Among the most common is the Ts65Dn model, which mimics most of the alterations observed in DS. Ts65Dn mice, as humans with DS, show defects in the structure, density, and distribution of dendritic spines in the cerebral cortex and hippocampus. Fasudil is a potent inhibitor of the RhoA kinase pathway, which is involved in the formation and stabilization of dendritic spines. Our study analysed the effect of early chronic fasudil treatment on the alterations observed in the hippocampus of the Ts65Dn model. We observed that treating Ts65Dn mice with fasudil induced an increase in neural plasticity in the hippocampus: there was an increment in the expression of PSA-NCAM and BDNF, in the dendritic branching and spine density of granule neurons, as well as in cell proliferation and neurogenesis in the subgranular zone. Finally, the treatment reduced the unbalance between excitation and inhibition present in this model. Overall, early chronic treatment with fasudil increases cell plasticity and eliminates differences with euploid animals.
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Affiliation(s)
- Rosa López-Hidalgo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Raúl Ballestín
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Lorena Lorenzo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Sandra Sánchez-Martí
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - José Miguel Blasco-Ibáñez
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Carlos Crespo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Juan Nacher
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain; CIBERSAM, Spanish National Network for Research in Mental Health, Madrid, Spain; Institute of research of the Clinic Hospital from Valencia (INCLIVA), Valencia, Spain
| | - Emilio Varea
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain.
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2
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Bartesaghi R. Brain circuit pathology in Down syndrome: from neurons to neural networks. Rev Neurosci 2022; 34:365-423. [PMID: 36170842 DOI: 10.1515/revneuro-2022-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/28/2022] [Indexed: 11/15/2022]
Abstract
Down syndrome (DS), a genetic pathology caused by triplication of chromosome 21, is characterized by brain hypotrophy and impairment of cognition starting from infancy. While studies in mouse models of DS have elucidated the major neuroanatomical and neurochemical defects of DS, comparatively fewer investigations have focused on the electrophysiology of the DS brain. Electrical activity is at the basis of brain functioning. Therefore, knowledge of the way in which brain circuits operate in DS is fundamental to understand the causes of behavioral impairment and devise targeted interventions. This review summarizes the state of the art regarding the electrical properties of the DS brain, starting from individual neurons and culminating in signal processing in whole neuronal networks. The reported evidence derives from mouse models of DS and from brain tissues and neurons derived from individuals with DS. EEG data recorded in individuals with DS are also provided as a key tool to understand the impact of brain circuit alterations on global brain activity.
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Affiliation(s)
- Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
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3
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Klein JA, Haydar TF. Neurodevelopment in Down syndrome: Concordance in humans and models. Front Cell Neurosci 2022; 16:941855. [PMID: 35910249 PMCID: PMC9334873 DOI: 10.3389/fncel.2022.941855] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Great strides have been made over the past 30 years in understanding the neurodevelopmental changes underlying the intellectual disability (ID) in Down syndrome (DS). Detailed studies of human tissue coupled with findings from rodent and induced pluripotent stem cells (iPSCs) model systems have uncovered the changes in neurogenesis, synaptic connectivity, and myelination that drive the anatomical and physiological changes resulting in the disability. However, there remain significant conflicting data between human studies and the models. To fully understand the development of ID in DS, these inconsistencies need to be reconciled. Here, we review the well documented neurodevelopmental phenotypes found in individuals with DS and examine the degree to which widely used models recapitulate these phenotypes. Resolving these areas of discord will further research on the molecular underpinnings and identify potential treatments to improve the independence and quality of life of people with DS.
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Affiliation(s)
- Jenny A. Klein
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
| | - Tarik F. Haydar
- Children’s National Hospital, Center for Neuroscience Research, Washington, DC, United States
- Departments of Pediatrics, Physiology and Pharmacology, School of Medicine and Health Sciences, George Washington University, Washington, DC, United States
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4
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Stagni F, Bartesaghi R. The Challenging Pathway of Treatment for Neurogenesis Impairment in Down Syndrome: Achievements and Perspectives. Front Cell Neurosci 2022; 16:903729. [PMID: 35634470 PMCID: PMC9130961 DOI: 10.3389/fncel.2022.903729] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/19/2022] [Indexed: 12/17/2022] Open
Abstract
Down syndrome (DS), also known as trisomy 21, is a genetic disorder caused by triplication of Chromosome 21. Gene triplication may compromise different body functions but invariably impairs intellectual abilities starting from infancy. Moreover, after the fourth decade of life people with DS are likely to develop Alzheimer’s disease. Neurogenesis impairment during fetal life stages and dendritic pathology emerging in early infancy are thought to be key determinants of alterations in brain functioning in DS. Although the progressive improvement in medical care has led to a notable increase in life expectancy for people with DS, there are currently no treatments for intellectual disability. Increasing evidence in mouse models of DS reveals that pharmacological interventions in the embryonic and neonatal periods may greatly benefit brain development and cognitive performance. The most striking results have been obtained with pharmacotherapies during embryonic life stages, indicating that it is possible to pharmacologically rescue the severe neurodevelopmental defects linked to the trisomic condition. These findings provide hope that similar benefits may be possible for people with DS. This review summarizes current knowledge regarding (i) the scope and timeline of neurogenesis (and dendritic) alterations in DS, in order to delineate suitable windows for treatment; (ii) the role of triplicated genes that are most likely to be the key determinants of these alterations, in order to highlight possible therapeutic targets; and (iii) prenatal and neonatal treatments that have proved to be effective in mouse models, in order to rationalize the choice of treatment for human application. Based on this body of evidence we will discuss prospects and challenges for fetal therapy in individuals with DS as a potential means of drastically counteracting the deleterious effects of gene triplication.
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Affiliation(s)
- Fiorenza Stagni
- Department for Life Quality Studies, University of Bologna, Rimini, Italy
| | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- *Correspondence: Renata Bartesaghi,
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5
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Signalling pathways contributing to learning and memory deficits in the Ts65Dn mouse model of Down syndrome. Neuronal Signal 2021; 5:NS20200011. [PMID: 33763235 PMCID: PMC7955101 DOI: 10.1042/ns20200011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 01/30/2023] Open
Abstract
Down syndrome (DS) is a genetic trisomic disorder that produces life-long changes in physiology and cognition. Many of the changes in learning and memory seen in DS are reminiscent of disorders involving the hippocampal/entorhinal circuit. Mouse models of DS typically involve trisomy of murine chromosome 16 is homologous for many of the genes triplicated in human trisomy 21, and provide us with good models of changes in, and potential pharmacotherapy for, human DS. Recent careful dissection of the Ts65Dn mouse model of DS has revealed differences in key signalling pathways from the basal forebrain to the hippocampus and associated rhinal cortices, as well as changes in the microstructure of the hippocampus itself. In vivo behavioural and electrophysiological studies have shown that Ts65Dn animals have difficulties in spatial memory that mirror hippocampal deficits, and have changes in hippocampal electrophysiological phenomenology that may explain these differences, and align with expectations generated from in vitro exploration of this model. Finally, given the existing data, we will examine the possibility for pharmacotherapy for DS, and outline the work that remains to be done to fully understand this system.
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6
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Duchon A, Del Mar Muniz Moreno M, Martin Lorenzo S, Silva de Souza MP, Chevalier C, Nalesso V, Meziane H, Loureiro de Sousa P, Noblet V, Armspach JP, Brault V, Herault Y. Multi-influential genetic interactions alter behaviour and cognition through six main biological cascades in Down syndrome mouse models. Hum Mol Genet 2021; 30:771-788. [PMID: 33693642 PMCID: PMC8161522 DOI: 10.1093/hmg/ddab012] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022] Open
Abstract
Down syndrome (DS) is the most common genetic form of intellectual disability caused by the presence of an additional copy of human chromosome 21 (Hsa21). To provide novel insights into genotype–phenotype correlations, we used standardized behavioural tests, magnetic resonance imaging and hippocampal gene expression to screen several DS mouse models for the mouse chromosome 16 region homologous to Hsa21. First, we unravelled several genetic interactions between different regions of chromosome 16 and how they contribute significantly to altering the outcome of the phenotypes in brain cognition, function and structure. Then, in-depth analysis of misregulated expressed genes involved in synaptic dysfunction highlighted six biological cascades centred around DYRK1A, GSK3β, NPY, SNARE, RHOA and NPAS4. Finally, we provide a novel vision of the existing altered gene–gene crosstalk and molecular mechanisms targeting specific hubs in DS models that should become central to better understanding of DS and improving the development of therapies.
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Affiliation(s)
- Arnaud Duchon
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Maria Del Mar Muniz Moreno
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Sandra Martin Lorenzo
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Marcia Priscilla Silva de Souza
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Claire Chevalier
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Valérie Nalesso
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Hamid Meziane
- Université de Strasbourg, CNRS, INSERM, Institut Clinique de la Souris (ICS), CELPHEDIA, PHENOMIN, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | | | - Vincent Noblet
- Université de Strasbourg, CNRS UMR 7357, ICube, FMTS, 67000 Strasbourg, France
| | - Jean-Paul Armspach
- Université de Strasbourg, CNRS UMR 7357, ICube, FMTS, 67000 Strasbourg, France
| | - Veronique Brault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France.,Université de Strasbourg, CNRS, INSERM, Institut Clinique de la Souris (ICS), CELPHEDIA, PHENOMIN, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
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7
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Piriform cortex alterations in the Ts65Dn model for down syndrome. Brain Res 2020; 1747:147031. [PMID: 32726601 DOI: 10.1016/j.brainres.2020.147031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/02/2020] [Accepted: 07/22/2020] [Indexed: 11/22/2022]
Abstract
The piriform cortex is involved in olfactory information processing, that is altered in Down Syndrome. Moreover, piriform cortex has a crucial involvement in epilepsy generation and is one of the first regions affected in Alzheimer's Disease, both maladies being prevalent among Down Syndrome individuals. In this work, we studied the alterations in neuronal morphology, synaptology and structural plasticity in the piriform cortex of the Ts65Dn mouse model, which is the most used model for the study of this syndrome and mimics some of their alterations. We have observed that Ts65Dn piriform cortex displays: a reduction in dendritic arborisation, a higher density of inhibitory synapses (GAD67), a lower density of excitatory synapses (vGLUT1) and a higher density of inhibitory postsynaptic puncta (gephyrin). Under electron microscopy the excitatory presynaptic and postsynaptic elements were larger in trisomic mice than in controls. Similar results were obtained using confocal microscopy. There were less immature neurons in piriform cortex layer II in addition to a reduction in the expression of PSA-NCAM in the neuropil that subsequently can reflect impairment in structural plasticity. These data support the idea of an impaired environment with altered ratio of inhibition and excitation that involves a reduction in plasticity and dendritic atrophy, providing a possible substrate for the olfactory processing impairment observed in DS individuals.
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Zorrilla de San Martin J, Donato C, Peixoto J, Aguirre A, Choudhary V, De Stasi AM, Lourenço J, Potier MC, Bacci A. Alterations of specific cortical GABAergic circuits underlie abnormal network activity in a mouse model of Down syndrome. eLife 2020; 9:58731. [PMID: 32783810 PMCID: PMC7481006 DOI: 10.7554/elife.58731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 08/11/2020] [Indexed: 12/21/2022] Open
Abstract
Down syndrome (DS) results in various degrees of cognitive deficits. In DS mouse models, recovery of behavioral and neurophysiological deficits using GABAAR antagonists led to hypothesize an excessive activity of inhibitory circuits in this condition. Nonetheless, whether over-inhibition is present in DS and whether this is due to specific alterations of distinct GABAergic circuits is unknown. In the prefrontal cortex of Ts65Dn mice (a well-established DS model), we found that the dendritic synaptic inhibitory loop formed by somatostatin-positive Martinotti cells (MCs) and pyramidal neurons (PNs) was strongly enhanced, with no alteration in their excitability. Conversely, perisomatic inhibition from parvalbumin-positive (PV) interneurons was unaltered, but PV cells of DS mice lost their classical fast-spiking phenotype and exhibited increased excitability. These microcircuit alterations resulted in reduced pyramidal-neuron firing and increased phase locking to cognitive-relevant network oscillations in vivo. These results define important synaptic and circuit mechanisms underlying cognitive dysfunctions in DS. Down syndrome is a genetic disorder caused by the presence of a third copy of chromosome 21. Affected individuals show delayed growth, characteristic facial features, altered brain development; with mild to severe intellectual disability. The exact mechanisms underlying the intellectual disability in Down syndrome are unclear, although studies in mice have provided clues. Drugs that reduce the inhibitory activity in the brain improve cognition in a mouse model of Down syndrome. This suggests that excessive inhibitory activity may contribute to the cognitive impairments. Many different neural circuits generate inhibitory activity in the brain. These circuits contain cells called interneurons. Sub-types of interneurons act via different mechanisms to reduce the activity of neurons. Identifying the interneurons that are affected in Down syndrome would thus improve our understanding of the brain basis of the disorder. Zorrilla de San Martin et al. compared mice with Down syndrome to unaffected control mice. The results revealed an increased activity in two types of inhibitory brain circuits in Down syndrome. The first contains interneurons called Martinotti cells. These help the brain to combine inputs from different sources. The second contains interneurons called parvalbumin-positive basket cells. These help different areas of the brain to synchronize their activity, which in turn makes it easier for those areas to exchange information. By mapping the changes in inhibitory circuits in Down syndrome, Zorrilla de San Martin et al. have provided new insights into the biological basis of the disorder. Future studies should examine whether targeting specific circuits with pharmacological treatments could ultimately help reduce the associated impairments.
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Affiliation(s)
| | - Cristina Donato
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | - Jérémy Peixoto
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | - Andrea Aguirre
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | - Vikash Choudhary
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | | | - Joana Lourenço
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | - Marie-Claude Potier
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
| | - Alberto Bacci
- Institut du Cerveau (ICM), CNRS UMR 7225 - Inserm U1127, Sorbonne Université, Paris, France
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Semilunar Granule Cells Are the Primary Source of the Perisomatic Excitatory Innervation onto Parvalbumin-Expressing Interneurons in the Dentate Gyrus. eNeuro 2020; 7:ENEURO.0323-19.2020. [PMID: 32571963 PMCID: PMC7340841 DOI: 10.1523/eneuro.0323-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 11/21/2022] Open
Abstract
We analyzed the origin and relevance of the perisomatic excitatory inputs on the parvalbumin interneurons of the granule cell layer in mouse. Confocal analysis of the glutamatergic innervation showed that it represents ∼50% of the perisomatic synapses that parvalbumin cells receive. This excitatory input may originate from granule cell collaterals, the mossy cells, or even supramammillary nucleus. First, we assessed the input from the mossy cells on parvalbumin interneurons. Axon terminals of mossy cells were visualized by their calretinin content. Using multicolor confocal microscopy, we observed that less than 10% of perisomatic excitatory innervation of parvalbumin cells could originate from mossy cells. Correlative light and electron microscopy revealed that innervation from mossy cells, although present, was indeed infrequent, except for those parvalbumin cells whose somata were located in the inner molecular layer. Second, we investigated the potential input from supramammillary nucleus on parvalbumin cell somata using anterograde tracing or immunocytochemistry against vesicular glutamate transporter 2 (VGLUT2) and found only occasional contacts. Third, we intracellularly filled dentate granule cells in acute slice preparations using whole-cell recording and examined whether their axon collaterals target parvalbumin interneurons. We found that typical granule cells do not innervate the perisomatic region of these GABAergic cells. In sharp contrast, semilunar granule cells (SGCs), a scarce granule cell subtype often contacted the parvalbumin cell soma and proximal dendrites. Our data, therefore, show that perisomatic excitatory drive of parvalbumin interneurons in the granular layer of the dentate gyrus is abundant and originates primarily from SGCs.
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10
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Hamburg S, Rosch R, Startin CM, Friston KJ, Strydom A. Dynamic Causal Modeling of the Relationship between Cognition and Theta-alpha Oscillations in Adults with Down Syndrome. Cereb Cortex 2020; 29:2279-2290. [PMID: 30877793 PMCID: PMC6458903 DOI: 10.1093/cercor/bhz043] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 02/09/2019] [Indexed: 01/17/2023] Open
Abstract
Individuals with Down syndrome (DS) show high inter-subject variability in cognitive ability and have an ultra-high risk of developing dementia (90% lifetime prevalence). Elucidating factors underlying variability in cognitive function can inform us about intellectual disability (ID) and may improve our understanding of factors associated with later cognitive decline. Increased neuronal inhibition has been posited to contribute to ID in DS. Combining electroencephalography (EEG) with dynamic causal modeling (DCM) provides a non-invasive method for investigating excitatory/inhibitory mechanisms. Resting-state EEG recordings were obtained from 36 adults with DS with no evidence of cognitive decline. Theta–alpha activity (4–13 Hz) was characterized in relation to general cognitive ability (raw Kaufmann’s Brief Intelligence Test second Edition (KBIT-2) score). Higher KBIT-2 was associated with higher frontal alpha peak amplitude and higher theta–alpha band power across distributed regions. Modeling this association with DCM revealed intrinsic self-inhibition was the key network parameter underlying observed differences in 4–13 Hz power in relation to KBIT-2 and age. In particular, intrinsic self-inhibition in right V1 was negatively correlated with KBIT-2. Results suggest intrinsic self-inhibition within the alpha network is associated with individual differences in cognitive ability in adults with DS, and may provide a potential therapeutic target for cognitive enhancement.
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Affiliation(s)
- Sarah Hamburg
- Division of Psychiatry, Faculty of Brain Sciences, University College London, 149 Tottenham Court Road, London, UK.,Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.,The London Down Syndrome Consortium (LonDownS), London, UK
| | - Richard Rosch
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London, UK
| | - Carla Marie Startin
- Division of Psychiatry, Faculty of Brain Sciences, University College London, 149 Tottenham Court Road, London, UK.,Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.,The London Down Syndrome Consortium (LonDownS), London, UK
| | - Karl John Friston
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London, UK
| | - André Strydom
- Division of Psychiatry, Faculty of Brain Sciences, University College London, 149 Tottenham Court Road, London, UK.,Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.,The London Down Syndrome Consortium (LonDownS), London, UK
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11
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Interneuron deficits in neurodevelopmental disorders: Implications for disease pathology and interneuron-based therapies. Eur J Paediatr Neurol 2020; 24:81-88. [PMID: 31870698 PMCID: PMC7152321 DOI: 10.1016/j.ejpn.2019.12.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/06/2019] [Indexed: 12/16/2022]
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12
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Aziz NM, Klein JA, Brady MR, Olmos-Serrano JL, Gallo V, Haydar TF. Spatiotemporal development of spinal neuronal and glial populations in the Ts65Dn mouse model of Down syndrome. J Neurodev Disord 2019; 11:35. [PMID: 31839007 PMCID: PMC6913030 DOI: 10.1186/s11689-019-9294-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 11/11/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Down syndrome (DS), caused by the triplication of chromosome 21, results in a constellation of clinical features including changes in intellectual and motor function. Although altered neural development and function have been well described in people with DS, few studies have investigated the etiology underlying the observed motor phenotypes. Here, we examine the development, patterning, and organization of the spinal cord throughout life in the Ts65Dn mouse, a model that recapitulates many of the motor changes observed in people with DS. METHODS Spinal cords from embryonic to adult animals were processed for gene and protein expression (immunofluorescence) to track the spatiotemporal development of excitatory and inhibitory neurons and oligodendroglia. Postnatal analyses were focused on the lumbar region due to the reflex and gait abnormalities found in Ts65Dn mice and locomotive alterations seen in people with DS. RESULTS Between embryonic days E10.5 and E14.5, we found a larger motor neuron progenitor domain in Ts65Dn animals containing more OLIG2-expressing progenitor cells. These disturbed progenitors are delayed in motor neuron production but eventually generate a large number of ISL1+ migrating motor neurons. We found that higher numbers of PAX6+ and NKX2.2+ interneurons (INs) are also produced during this time frame. In the adult lumbar spinal cord, we found an increased level of Hb9 and a decreased level of Irx3 gene expression in trisomic animals. This was accompanied by an increase in Calretinin+ INs, but no changes in other neuronal populations. In aged Ts65Dn animals, both Calbindin+ and ChAT+ neurons were decreased compared to euploid controls. Additionally, in the dorsal corticospinal white matter tract, there were significantly fewer CC1+ mature OLs in 30- and 60-day old trisomic animals and this normalized to euploid levels at 10-11 months. In contrast, the mature OL population was increased in the lateral funiculus, an ascending white matter tract carrying sensory information. In 30-day old animals, we also found a decrease in the number of nodes of Ranvier in both tracts. This decrease normalized both in 60-day old and aged animals. CONCLUSIONS We show marked changes in both spinal white matter and neuronal composition that change regionally over the life span. In the embryonic Ts65Dn spinal cord, we observe alterations in motor neuron production and migration. In the adult spinal cord, we observe changes in oligodendrocyte maturation and motor neuron loss, the latter of which has also been observed in human spinal cord tissue samples. This work uncovers multiple cellular perturbations during Ts65Dn development and aging, many of which may underlie the motor deficits found in DS.
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Affiliation(s)
- Nadine M. Aziz
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Jenny A. Klein
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Morgan R. Brady
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Jose Luis Olmos-Serrano
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Vittorio Gallo
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Tarik F. Haydar
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
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13
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Unbalanced dendritic inhibition of CA1 neurons drives spatial-memory deficits in the Ts2Cje Down syndrome model. Nat Commun 2019; 10:4991. [PMID: 31676751 PMCID: PMC6825203 DOI: 10.1038/s41467-019-13004-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 10/15/2019] [Indexed: 12/21/2022] Open
Abstract
Overinhibition is assumed one of the main causes of cognitive deficits (e.g. memory impairment) in mouse models of Down syndrome (DS). Yet the mechanisms that drive such exaggerated synaptic inhibition and their behavioral effects remain unclear. Here we report the existence of bidirectional alterations to the synaptic inhibition on CA1 pyramidal cells in the Ts2Cje mouse model of DS which are associated to impaired spatial memory. Furthermore, we identify triplication of the kainate receptor (KAR) encoding gene Grik1 as the cause of these phenotypes. Normalization of Grik1 dosage in Ts2Cje mice specifically restored spatial memory and reversed the bidirectional alterations to CA1 inhibition, but not the changes in synaptic plasticity or the other behavioral modifications observed. We propose that modified information gating caused by disturbed inhibitory tone rather than generalized overinhibition underlies some of the characteristic cognitive deficits in DS. Exaggerated synaptic inhibition is hypothesised to be a main cause of cognitive deficits in Down syndrome models. The authors identify triplication of the kainate receptor encoding gene Grik1 as the cause of memory deficits due to a reorganization of synaptic inhibition along the CA1 dendritic tree.
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14
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Xu R, Brawner AT, Li S, Liu JJ, Kim H, Xue H, Pang ZP, Kim WY, Hart RP, Liu Y, Jiang P. OLIG2 Drives Abnormal Neurodevelopmental Phenotypes in Human iPSC-Based Organoid and Chimeric Mouse Models of Down Syndrome. Cell Stem Cell 2019; 24:908-926.e8. [PMID: 31130512 DOI: 10.1016/j.stem.2019.04.014] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 10/05/2018] [Accepted: 04/17/2019] [Indexed: 02/06/2023]
Abstract
Down syndrome (DS) is a common neurodevelopmental disorder, and cognitive defects in DS patients may arise from imbalances in excitatory and inhibitory neurotransmission. Understanding the mechanisms underlying such imbalances may provide opportunities for therapeutic intervention. Here, we show that human induced pluripotent stem cells (hiPSCs) derived from DS patients overproduce OLIG2+ ventral forebrain neural progenitors. As a result, DS hiPSC-derived cerebral organoids excessively produce specific subclasses of GABAergic interneurons and cause impaired recognition memory in neuronal chimeric mice. Increased OLIG2 expression in DS cells directly upregulates interneuron lineage-determining transcription factors. shRNA-mediated knockdown of OLIG2 largely reverses abnormal gene expression in early-stage DS neural progenitors, reduces interneuron production in DS organoids and chimeric mouse brains, and improves behavioral deficits in DS chimeric mice. Thus, altered OLIG2 expression may underlie neurodevelopmental abnormalities and cognitive defects in DS patients.
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Affiliation(s)
- Ranjie Xu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA; Department of Developmental Neuroscience, Munroe-Meyer Institute and Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Andrew T Brawner
- Department of Developmental Neuroscience, Munroe-Meyer Institute and Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Shenglan Li
- Department of Neurosurgery and Center for Stem Cell and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Jing-Jing Liu
- Department of Neuroscience and Cell Biology and Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Hyosung Kim
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Haipeng Xue
- Department of Neurosurgery and Center for Stem Cell and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Zhiping P Pang
- Department of Neuroscience and Cell Biology and Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Ronald P Hart
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Ying Liu
- Department of Neurosurgery and Center for Stem Cell and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Peng Jiang
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA; Department of Developmental Neuroscience, Munroe-Meyer Institute and Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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15
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Souchet B, Duchon A, Gu Y, Dairou J, Chevalier C, Daubigney F, Nalesso V, Créau N, Yu Y, Janel N, Herault Y, Delabar JM. Prenatal treatment with EGCG enriched green tea extract rescues GAD67 related developmental and cognitive defects in Down syndrome mouse models. Sci Rep 2019; 9:3914. [PMID: 30850713 PMCID: PMC6408590 DOI: 10.1038/s41598-019-40328-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 01/31/2019] [Indexed: 12/21/2022] Open
Abstract
Down syndrome is a common genetic disorder caused by trisomy of chromosome 21. Brain development in affected foetuses might be improved through prenatal treatment. One potential target is DYRK1A, a multifunctional kinase encoded by chromosome 21 that, when overexpressed, alters neuronal excitation-inhibition balance and increases GAD67 interneuron density. We used a green tea extract enriched in EGCG to inhibit DYRK1A function only during gestation of transgenic mice overexpressing Dyrk1a (mBACtgDyrk1a). Adult mice treated prenatally displayed reduced levels of inhibitory markers, restored VGAT1/VGLUT1 balance, and rescued density of GAD67 interneurons. Similar results for gabaergic and glutamatergic markers and interneuron density were obtained in Dp(16)1Yey mice, trisomic for 140 chromosome 21 orthologs; thus, prenatal EGCG exhibits efficacy in a more complex DS model. Finally, cognitive and behaviour testing showed that adult Dp(16)1Yey mice treated prenatally had improved novel object recognition memory but do not show improvement with Y maze paradigm. These findings provide empirical support for a prenatal intervention that targets specific neural circuitries.
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Affiliation(s)
- Benoit Souchet
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, Paris, France
| | - Arnaud Duchon
- Institut Génétique Biologie Moléculaire Cellulaire, CNRS, French National Institute of Health and Medical Research (INSERM), UMR 7104, UMR 964, Illkirch, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- INSERM, U964, Illkirch, France
- Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Yuchen Gu
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, Paris, France
| | - Julien Dairou
- CNRS, UMR 8601, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes-Sorbonne Paris Cité, 75270, Paris, France
| | - Claire Chevalier
- Institut Génétique Biologie Moléculaire Cellulaire, CNRS, French National Institute of Health and Medical Research (INSERM), UMR 7104, UMR 964, Illkirch, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- INSERM, U964, Illkirch, France
- Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Fabrice Daubigney
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, Paris, France
| | - Valérie Nalesso
- Institut Génétique Biologie Moléculaire Cellulaire, CNRS, French National Institute of Health and Medical Research (INSERM), UMR 7104, UMR 964, Illkirch, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- INSERM, U964, Illkirch, France
- Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Nicole Créau
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, Paris, France
| | - Yuejin Yu
- Children's Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Nathalie Janel
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, Paris, France
- Children's Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Yann Herault
- Institut Génétique Biologie Moléculaire Cellulaire, CNRS, French National Institute of Health and Medical Research (INSERM), UMR 7104, UMR 964, Illkirch, France.
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France.
- CNRS, UMR 7104, Illkirch, France.
- INSERM, U964, Illkirch, France.
- Université de Strasbourg, 1 rue Laurent Fries, 67404, Illkirch, France.
| | - Jean Maurice Delabar
- Université Paris-Diderot, Sorbonne Paris Cité, Adaptive Functional Biology, National Centre for Scientific Research (CNRS), UMR 8251, 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, Paris, France.
- Brain & Spine Institute (ICM) CNRS UMR7225, Inserm UMRS 975, Paris, France.
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16
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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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17
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Zorrilla de San Martin J, Delabar JM, Bacci A, Potier MC. GABAergic over-inhibition, a promising hypothesis for cognitive deficits in Down syndrome. Free Radic Biol Med 2018; 114:33-39. [PMID: 28993272 DOI: 10.1016/j.freeradbiomed.2017.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/01/2017] [Accepted: 10/04/2017] [Indexed: 12/31/2022]
Abstract
Down syndrome (DS), also known as trisomy 21, is the most common genetic cause of intellectual disability. It is also a model human disease for exploring consequences of gene dosage imbalance on complex phenotypes. Learning and memory impairments linked to intellectual disabilities in DS could result from synaptic plasticity deficits and excitatory-inhibitory alterations leading to changes in neuronal circuitry in the brain of affected individuals. Increasing number of studies in mouse and cellular models converge towards the assumption that excitatory-inhibitory imbalance occurs in DS, likely early during development. Thus increased inhibition appears to be a common trend that could explain synaptic and circuit disorganization. Interestingly using several potent pharmacological tools, preclinical studies strongly demonstrated that cognitive deficits could be restored in mouse models of DS. Clinical trials have not yet provided robust data for therapeutic application and additional studies are needed. Here we review the literature and our own published work emphasizing the over-inhibition hypothesis in DS and their links with gene dosage imbalance paving the way for future basic and clinical research.
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Affiliation(s)
- Javier Zorrilla de San Martin
- INSERM U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Jean-Maurice Delabar
- INSERM U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Alberto Bacci
- INSERM U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Marie-Claude Potier
- INSERM U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.
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18
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Ohtawa M, Krambis MJ, Cerne R, Schkeryantz JM, Witkin JM, Shenvi RA. Synthesis of (-)-11-O-Debenzoyltashironin: Neurotrophic Sesquiterpenes Cause Hyperexcitation. J Am Chem Soc 2017. [PMID: 28644021 DOI: 10.1021/jacs.7b04206] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
11-O-Debenzoyltashironin (1) is a member of the neurotrophic sesquiterpenes, trace plant metabolites that enhance neurite outgrowth in cultured neurons. We report its synthesis in six steps from a butenolide heterodimer via its likely biosynthetic precursor, 3,6-dideoxy-10-hydroxypseudoanisatin, here identified as the chain tautomer of 1. Access to the tashironin chemotype fills a gap in a comparison set of convulsive and neurotrophic sesquiterpenes, which we hypothesized to share a common target. Here we show that both classes mutually hyperexcite rat cortical neurons, consistent with antagonism of inhibitory channels and a mechanism of depolarization-induced neurite outgrowth.
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Affiliation(s)
- Masaki Ohtawa
- Department of Chemistry, The Scripps Research Institute , La Jolla, California 92037, United States
| | - Michael J Krambis
- Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Rok Cerne
- Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Jeffrey M Schkeryantz
- Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Jeffrey M Witkin
- Eli Lilly and Company , Lilly Corporate Center, Indianapolis, Indiana 46285, United States
| | - Ryan A Shenvi
- Department of Chemistry, The Scripps Research Institute , La Jolla, California 92037, United States
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19
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Contestabile A, Magara S, Cancedda L. The GABAergic Hypothesis for Cognitive Disabilities in Down Syndrome. Front Cell Neurosci 2017; 11:54. [PMID: 28326014 PMCID: PMC5339239 DOI: 10.3389/fncel.2017.00054] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/14/2017] [Indexed: 12/04/2022] Open
Abstract
Down syndrome (DS) is a genetic disorder caused by the presence of a third copy of chromosome 21. DS affects multiple organs, but it invariably results in altered brain development and diverse degrees of intellectual disability. A large body of evidence has shown that synaptic deficits and memory impairment are largely determined by altered GABAergic signaling in trisomic mouse models of DS. These alterations arise during brain development while extending into adulthood, and include genesis of GABAergic neurons, variation of the inhibitory drive and modifications in the control of neural-network excitability. Accordingly, different pharmacological interventions targeting GABAergic signaling have proven promising preclinical approaches to rescue cognitive impairment in DS mouse models. In this review, we will discuss recent data regarding the complex scenario of GABAergic dysfunctions in the trisomic brain of DS mice and patients, and we will evaluate the state of current clinical research targeting GABAergic signaling in individuals with DS.
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Affiliation(s)
- Andrea Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT) Genova, Italy
| | - Salvatore Magara
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT) Genova, Italy
| | - Laura Cancedda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT)Genova, Italy; Dulbecco Telethon InstituteGenova, Italy
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20
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De Giorgio A. The roles of motor activity and environmental enrichment in intellectual disability. Somatosens Mot Res 2017; 34:34-43. [PMID: 28140743 DOI: 10.1080/08990220.2016.1278204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In people with intellectual disabilities, an enriched environment can stimulate the acquisition of motor skills and could partially repair neuronal impairment thanks to exploration and motor activity. A deficit in environmental and motor stimulation leads to low scores in intelligence tests and can cause serious motor skill problems. Although studies in humans do not give much evidence for explaining basic mechanisms of intellectual disability and for highlighting improvements due to enriched environmental stimulation, animal models have been valuable in the investigation of these conditions. Here, we discuss the role of environmental enrichment in four intellectual disabilities: Foetal Alcohol Spectrum Disorder (FASD), Down, Rett, and Fragile X syndromes.
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Affiliation(s)
- Andrea De Giorgio
- a Department of Psychology , eCampus University , Novedrate , Italy.,b Department of Psychology , Universita Cattolica del Sacro Cuore , Milano , Italy
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21
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Mojabi FS, Fahimi A, Moghadam S, Moghadam S, Windy McNerneny M, Ponnusamy R, Kleschevnikov A, Mobley WC, Salehi A. GABAergic hyperinnervation of dentate granule cells in the Ts65Dn mouse model of down syndrome: Exploring the role of App. Hippocampus 2016; 26:1641-1654. [PMID: 27701794 DOI: 10.1002/hipo.22664] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2016] [Indexed: 12/20/2022]
Abstract
It has been suggested that increased GABAergic innervation in the hippocampus plays a significant role in cognitive dysfunction in Down syndrome (DS). Bolstering this notion, are studies linking hyper-innervation of the dentate gyrus (DG) by GABAergic terminals to failure in LTP induction in the Ts65Dn mouse model of DS. Here, we used extensive morphometrical methods to assess the status of GABAergic interneurons in the DG of young and old Ts65Dn mice and their 2N controls. We detected an age-dependent increase in GABAergic innervation of dentate granule cells (DGCs) in Ts65Dn mice. The primary source of GABAergic terminals to DGCs somata is basket cells (BCs). For this reason, we assessed the status of these cells and found a significant increase in the number of BCs in Ts65Dn mice compared with controls. Then we aimed to identify the gene/s whose overexpression could be linked to increased number of BCs in Ts65Dn and found that deleting the third copy of App gene in Ts65Dn mice led to normalization of the number of BCs in these mice. Our data suggest that App overexpression plays a major role in the pathophysiology of GABAergic hyperinnervation of the DG in Ts65Dn mice. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Fatemeh S Mojabi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | - Atoossa Fahimi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | | | | | - M Windy McNerneny
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | | | | | - William C Mobley
- Department of Neurosciences, University of California, San Diego, California
| | - Ahmad Salehi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
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22
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Zamboni V, Armentano M, Sarò G, Ciraolo E, Ghigo A, Germena G, Umbach A, Valnegri P, Passafaro M, Carabelli V, Gavello D, Bianchi V, D'Adamo P, de Curtis I, El-Assawi N, Mauro A, Priano L, Ferri N, Hirsch E, Merlo GR. Disruption of ArhGAP15 results in hyperactive Rac1, affects the architecture and function of hippocampal inhibitory neurons and causes cognitive deficits. Sci Rep 2016; 6:34877. [PMID: 27713499 PMCID: PMC5054378 DOI: 10.1038/srep34877] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/19/2016] [Indexed: 11/12/2022] Open
Abstract
During brain development, the small GTPases Rac1/Rac3 play key roles in neuronal migration, neuritogenesis, synaptic formation and plasticity, via control of actin cytoskeleton dynamic. Their activity is positively and negatively regulated by GEFs and GAPs molecules, respectively. However their in vivo roles are poorly known. The ArhGAP15 gene, coding for a Rac-specific GAP protein, is expressed in both excitatory and inhibitory neurons of the adult hippocampus, and its loss results in the hyperactivation of Rac1/Rac3. In the CA3 and dentate gyrus (DG) regions of the ArhGAP15 mutant hippocampus the CR+, PV+ and SST+ inhibitory neurons are reduced in number, due to reduced efficiency and directionality of their migration, while pyramidal neurons are unaffected. Loss of ArhGAP15 alters neuritogenesis and the balance between excitatory and inhibitory synapses, with a net functional result consisting in increased spike frequency and bursts, accompanied by poor synchronization. Thus, the loss of ArhGAP15 mainly impacts on interneuron-dependent inhibition. Adult ArhGAP15−/− mice showed defective hippocampus-dependent functions such as working and associative memories. These findings indicate that a normal architecture and function of hippocampal inhibitory neurons is essential for higher hippocampal functions, and is exquisitely sensitive to ArhGAP15-dependent modulation of Rac1/Rac3.
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Affiliation(s)
- Valentina Zamboni
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Maria Armentano
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Gabriella Sarò
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Elisa Ciraolo
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Alessandra Ghigo
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Giulia Germena
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Alessandro Umbach
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | | | | | | | | | - Veronica Bianchi
- IRCSS San Raffaele Scientific Institute and San Raffaele University, Division of Neuroscience, Milano, Italy
| | - Patrizia D'Adamo
- IRCSS San Raffaele Scientific Institute and San Raffaele University, Division of Neuroscience, Milano, Italy
| | - Ivan de Curtis
- IRCSS San Raffaele Scientific Institute and San Raffaele University, Division of Neuroscience, Milano, Italy
| | - Nadia El-Assawi
- Department of Neurosciences, University of Turin &Div. of Neurology and Neurorehabilitation, S.Giuseppe Hospital, Istituto Auxologico Italiano IRCCS, Piancavallo (VB), Italy
| | - Alessandro Mauro
- Department of Neurosciences, University of Turin &Div. of Neurology and Neurorehabilitation, S.Giuseppe Hospital, Istituto Auxologico Italiano IRCCS, Piancavallo (VB), Italy
| | - Lorenzo Priano
- Department of Neurosciences, University of Turin &Div. of Neurology and Neurorehabilitation, S.Giuseppe Hospital, Istituto Auxologico Italiano IRCCS, Piancavallo (VB), Italy
| | - Nicola Ferri
- Department of Pharmaceutical and Pharmacological Science, University of Padova, Italy
| | - Emilio Hirsch
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
| | - Giorgio R Merlo
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Italy
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23
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Rossato M, Dellagrana RA, da Costa RM, Bezerra EDS, Dos Santos JOL, Rech CR. The Accuracy of Anthropometric Equations to Assess Body Fat in Adults with Down Syndrome. JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES 2016; 31:193-199. [PMID: 27704678 DOI: 10.1111/jar.12290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND The aim of this study was to verify the accuracy of anthropometric equations to estimate the body density (BD) of adults with Down syndrome (DS), and propose new regression equations. MATERIALS AND METHODS Twenty-one males (30.5 ± 9.4 years) and 17 females (27.3 ± 7.7 years) with DS participated in this study. The reference method for BD was air displacement plethysmography (ADP). Also, the BD was estimated by anthropometric equations. The body fat percentage (BF %) was estimated by the Siri equation. RESULTS For females, the Durnin and Womersley equation showed no difference from the ADP, but a trend of underestimation was observed. For males, all equations were significantly different for the BF % from ADP. The equations developed in this study showed a high correlation and acceptable agreement with BF % from ADP in both genders. CONCLUSION All equations are not valid for DS adults. The new equations developed here were accurate in estimating the BF %.
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Affiliation(s)
- Mateus Rossato
- Human Performance Laboratory, Physical Education Faculty, Federal University of Amazonas, Manaus, Brazil.,Biomechanics Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Rodolfo André Dellagrana
- Biomechanics Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Rafael Martins da Costa
- Human Performance Laboratory, Physical Education Faculty, Federal University of Amazonas, Manaus, Brazil
| | - Ewertton de Souza Bezerra
- Human Performance Laboratory, Physical Education Faculty, Federal University of Amazonas, Manaus, Brazil.,Biomechanics Laboratory, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | - Cassiano Ricardo Rech
- Research Group on Physical Activity and Health, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil
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24
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López-Hidalgo R, Ballestín R, Vega J, Blasco-Ibáñez JM, Crespo C, Gilabert-Juan J, Nácher J, Varea E. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis. Front Neurosci 2016; 10:75. [PMID: 26973453 PMCID: PMC4773601 DOI: 10.3389/fnins.2016.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/17/2016] [Indexed: 01/08/2023] Open
Abstract
Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5'BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5'BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice.
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Affiliation(s)
- Rosa López-Hidalgo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Raul Ballestín
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Jessica Vega
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - José M. Blasco-Ibáñez
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Carlos Crespo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Javier Gilabert-Juan
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Juan Nácher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
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25
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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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