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Kat R, Linkenkaer-Hansen K, Koopmans MA, Houtman SJ, Bruining H, Kas MJH. Assessment of the excitation-inhibition ratio in the Fmr1 KO2 mouse using neuronal oscillation dynamics. Cereb Cortex 2024; 34:bhae201. [PMID: 38771240 PMCID: PMC11107376 DOI: 10.1093/cercor/bhae201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/19/2024] [Accepted: 05/01/2024] [Indexed: 05/22/2024] Open
Abstract
In vitro and ex vivo studies have shown consistent indications of hyperexcitability in the Fragile X Messenger Ribonucleoprotein 1 (Fmr1) knockout mouse model of autism spectrum disorder. We recently introduced a method to quantify network-level functional excitation-inhibition ratio from the neuronal oscillations. Here, we used this measure to study whether the implicated synaptic excitation-inhibition disturbances translate to disturbances in network physiology in the Fragile X Messenger Ribonucleoprotein 1 (Fmr1) gene knockout model. Vigilance-state scoring was used to extract segments of inactive wakefulness as an equivalent behavioral condition to the human resting-state and, subsequently, we performed high-frequency resolution analysis of the functional excitation-inhibition biomarker, long-range temporal correlations, and spectral power. We corroborated earlier studies showing increased high-frequency power in Fragile X Messenger Ribonucleoprotein 1 (Fmr1) knockout mice. Long-range temporal correlations were higher in the gamma frequency ranges. Contrary to expectations, functional excitation-inhibition was lower in the knockout mice in high frequency ranges, suggesting more inhibition-dominated networks. Exposure to the Gamma-aminobutyric acid (GABA)-agonist clonazepam decreased the functional excitation-inhibition in both genotypes, confirming that increasing inhibitory tone results in a reduction of functional excitation-inhibition. In addition, clonazepam decreased electroencephalogram power and increased long-range temporal correlations in both genotypes. These findings show applicability of these new resting-state electroencephalogram biomarkers to animal for translational studies and allow investigation of the effects of lower-level disturbances in excitation-inhibition balance.
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Affiliation(s)
- Renate Kat
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Klaus Linkenkaer-Hansen
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Marthe A Koopmans
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Simon J Houtman
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Hilgo Bruining
- Department of Child and Adolescent Psychiatry, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Martien J H Kas
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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2
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Westmark CJ. Toward an understanding of the role of the exposome on fragile X phenotypes. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 173:141-170. [PMID: 37993176 DOI: 10.1016/bs.irn.2023.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Fragile X syndrome (FXS) is the leading known monogenetic cause of autism with an estimated 21-50% of FXS individuals meeting autism diagnostic criteria. A critical gap in medical care for persons with autism is an understanding of how environmental exposures and gene-environment interactions affect disease outcomes. Our research indicates more severe neurological and metabolic outcomes (seizures, autism, increased body weight) in mouse and human models of autism spectrum disorders (ASD) as a function of diet. Thus, early-life exposure to chemicals in the diet could cause or exacerbate disease outcomes. Herein, we review the effects of potential dietary toxins, i.e., soy phytoestrogens, glyphosate, and polychlorinated biphenyls (PCB) in FXS and other autism models. The rationale is that potentially toxic chemicals in the diet, particularly infant formula, could contribute to the development and/or severity of ASD and that further study in this area has potential to improve ASD outcomes through dietary modification.
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Affiliation(s)
- Cara J Westmark
- Department of Neurology, University of Wisconsin-Madison, Medical Sciences Center, Room 3619, 1300 University Avenue, Madison, WI, United States; Molecular Environmental Toxicology Center, University of Wisconsin-Madison, Medical Sciences Center, Room 3619, 1300 University Avenue, Madison, WI, United States.
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3
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Abstract
The fragile X-related disorders are an important group of hereditary disorders that are caused by expanded CGG repeats in the 5' untranslated region of the FMR1 gene or by mutations in the coding sequence of this gene. Two categories of pathological CGG repeats are associated with these disorders, full mutation alleles and shorter premutation alleles. Individuals with full mutation alleles develop fragile X syndrome, which causes autism and intellectual disability, whereas those with premutation alleles, which have shorter CGG expansions, can develop fragile X-associated tremor/ataxia syndrome, a progressive neurodegenerative disease. Thus, fragile X-related disorders can manifest as neurodegenerative or neurodevelopmental disorders, depending on the size of the repeat expansion. Here, we review mouse models of fragile X-related disorders and discuss how they have informed our understanding of neurodegenerative and neurodevelopmental disorders. We also assess the translational value of these models for developing rational targeted therapies for intellectual disability and autism disorders.
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Affiliation(s)
- Rob Willemsen
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
| | - R. Frank Kooy
- Department of Clinical Genetics, Erasmus University Medical Center, 3015 CN Rotterdam, the Netherlands. Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
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4
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Katsuki F, Gerashchenko D, Brown RE. Alterations of sleep oscillations in Alzheimer's disease: A potential role for GABAergic neurons in the cortex, hippocampus, and thalamus. Brain Res Bull 2022; 187:181-198. [PMID: 35850189 DOI: 10.1016/j.brainresbull.2022.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/01/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023]
Abstract
Sleep abnormalities are widely reported in patients with Alzheimer's disease (AD) and are linked to cognitive impairments. Sleep abnormalities could be potential biomarkers to detect AD since they are often observed at the preclinical stage. Moreover, sleep could be a target for early intervention to prevent or slow AD progression. Thus, here we review changes in brain oscillations observed during sleep, their connection to AD pathophysiology and the role of specific brain circuits. Slow oscillations (0.1-1 Hz), sleep spindles (8-15 Hz) and their coupling during non-REM sleep are consistently reduced in studies of patients and in AD mouse models although the timing and magnitude of these alterations depends on the pathophysiological changes and the animal model studied. Changes in delta (1-4 Hz) activity are more variable. Animal studies suggest that hippocampal sharp-wave ripples (100-250 Hz) are also affected. Reductions in REM sleep amount and slower oscillations during REM are seen in patients but less consistently in animal models. Thus, changes in a variety of sleep oscillations could impact sleep-dependent memory consolidation or restorative functions of sleep. Recent mechanistic studies suggest that alterations in the activity of GABAergic neurons in the cortex, hippocampus and thalamic reticular nucleus mediate sleep oscillatory changes in AD and represent a potential target for intervention. Longitudinal studies of the timing of AD-related sleep abnormalities with respect to pathology and dysfunction of specific neural networks are needed to identify translationally relevant biomarkers and guide early intervention strategies to prevent or delay AD progression.
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Affiliation(s)
- Fumi Katsuki
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA.
| | - Dmitry Gerashchenko
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - Ritchie E Brown
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
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5
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Kenny A, Wright D, Stanfield AC. EEG as a translational biomarker and outcome measure in fragile X syndrome. Transl Psychiatry 2022; 12:34. [PMID: 35075104 PMCID: PMC8786970 DOI: 10.1038/s41398-022-01796-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 12/01/2021] [Accepted: 01/12/2022] [Indexed: 01/08/2023] Open
Abstract
Targeted treatments for fragile X syndrome (FXS) have frequently failed to show efficacy in clinical testing, despite success at the preclinical stages. This has highlighted the need for more effective translational outcome measures. EEG differences observed in FXS, including exaggerated N1 ERP amplitudes, increased resting gamma power and reduced gamma phase-locking in the sensory cortices, have been suggested as potential biomarkers of the syndrome. These abnormalities are thought to reflect cortical hyper excitability resulting from an excitatory (glutamate) and inhibitory (GABAergic) imbalance in FXS, which has been the target of several pharmaceutical remediation studies. EEG differences observed in humans also show similarities to those seen in laboratory models of FXS, which may allow for greater translational equivalence and better predict clinical success of putative therapeutics. There is some evidence from clinical trials showing that treatment related changes in EEG may be associated with clinical improvements, but these require replication and extension to other medications. Although the use of EEG characteristics as biomarkers is still in the early phases, and further research is needed to establish its utility in clinical trials, the current research is promising and signals the emergence of an effective translational biomarker.
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Affiliation(s)
- Aisling Kenny
- Patrick Wild Centre, Division of Psychiatry, Kennedy Tower, Royal Edinburgh Hospital, University of Edinburgh, EH10 5HF, Edinburgh, UK.
| | - Damien Wright
- grid.4305.20000 0004 1936 7988Patrick Wild Centre, Division of Psychiatry, Kennedy Tower, Royal Edinburgh Hospital, University of Edinburgh, EH10 5HF Edinburgh, UK
| | - Andrew C. Stanfield
- grid.4305.20000 0004 1936 7988Patrick Wild Centre, Division of Psychiatry, Kennedy Tower, Royal Edinburgh Hospital, University of Edinburgh, EH10 5HF Edinburgh, UK
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6
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Zerbi V, Pagani M, Markicevic M, Matteoli M, Pozzi D, Fagiolini M, Bozzi Y, Galbusera A, Scattoni ML, Provenzano G, Banerjee A, Helmchen F, Basson MA, Ellegood J, Lerch JP, Rudin M, Gozzi A, Wenderoth N. Brain mapping across 16 autism mouse models reveals a spectrum of functional connectivity subtypes. Mol Psychiatry 2021; 26:7610-7620. [PMID: 34381171 PMCID: PMC8873017 DOI: 10.1038/s41380-021-01245-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/30/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023]
Abstract
Autism Spectrum Disorder (ASD) is characterized by substantial, yet highly heterogeneous abnormalities in functional brain connectivity. However, the origin and significance of this phenomenon remain unclear. To unravel ASD connectopathy and relate it to underlying etiological heterogeneity, we carried out a bi-center cross-etiological investigation of fMRI-based connectivity in the mouse, in which specific ASD-relevant mutations can be isolated and modeled minimizing environmental contributions. By performing brain-wide connectivity mapping across 16 mouse mutants, we show that different ASD-associated etiologies cause a broad spectrum of connectional abnormalities in which diverse, often diverging, connectivity signatures are recognizable. Despite this heterogeneity, the identified connectivity alterations could be classified into four subtypes characterized by discrete signatures of network dysfunction. Our findings show that etiological variability is a key determinant of connectivity heterogeneity in ASD, hence reconciling conflicting findings in clinical populations. The identification of etiologically-relevant connectivity subtypes could improve diagnostic label accuracy in the non-syndromic ASD population and paves the way for personalized treatment approaches.
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Affiliation(s)
- V Zerbi
- Neural Control of Movement Lab, ETH Zurich, Zurich, Switzerland
| | - M Pagani
- Functional Neuroimaging Lab, Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems, Rovereto, Italy
| | - M Markicevic
- Neural Control of Movement Lab, ETH Zurich, Zurich, Switzerland
| | - M Matteoli
- Laboratory of Pharmacology and Brain Pathology, Neurocenter, Humanitas Clinical and Research Center - IRCCS, Rozzano, Mi, Italy
- CNR Institute of Neuroscience, Milano, Italy
| | - D Pozzi
- Laboratory of Pharmacology and Brain Pathology, Neurocenter, Humanitas Clinical and Research Center - IRCCS, Rozzano, Mi, Italy
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
| | - M Fagiolini
- F.M. Kirby Neurobiology Department, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Y Bozzi
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
| | - A Galbusera
- Functional Neuroimaging Lab, Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems, Rovereto, Italy
| | - M L Scattoni
- Research Coordination and Support Service, Istituto Superiore di Sanità, Rome, Italy
| | - G Provenzano
- Department of Cellular, Computational and Integrative Biology. (CIBIO), University of Trento, Trento, Italy
| | - A Banerjee
- Brain Research Institute, University of Zurich, Zurich, Switzerland
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - F Helmchen
- Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - M A Basson
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College, London, London, UK
| | - J Ellegood
- Mouse Imaging Ctr., Hosp. For Sick Children, Toronto, ON, Canada
| | - J P Lerch
- Mouse Imaging Ctr., Hosp. For Sick Children, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - M Rudin
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - A Gozzi
- Functional Neuroimaging Lab, Istituto Italiano di Tecnologia, Center for Neuroscience and Cognitive Systems, Rovereto, Italy.
| | - N Wenderoth
- Neural Control of Movement Lab, ETH Zurich, Zurich, Switzerland
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7
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Westmark PR, Garrone B, Ombrato R, Milanese C, Di Giorgio FP, Westmark CJ. Testing Fmr1 KO Phenotypes in Response to GSK3 Inhibitors: SB216763 versus AFC03127. Front Mol Neurosci 2021; 14:751307. [PMID: 34690696 PMCID: PMC8529056 DOI: 10.3389/fnmol.2021.751307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/15/2021] [Indexed: 11/15/2022] Open
Abstract
Glycogen synthase kinase 3 (GSK3) is a proline-directed serine-threonine kinase that is associated with several neurological disorders, including Alzheimer’s disease and fragile X syndrome (FXS). We tested the efficacy of a novel GSK3 inhibitor AFC03127, which was developed by Angelini Pharma, in comparison to the metabotropic glutamate receptor 5 inhibitor 2-Methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP) and the GSK3 inhibitor SB216763 in in vivo and in vitro assays in Fmr1KO mice, a mouse model useful for the study of FXS. The in vivo assay tested susceptibility to audiogenic-induced seizures (AGS) whereas the in vitro assays assessed biomarker expression and dendritic spine length and density in cultured primary neurons as a function of drug dose. MPEP and SB216763 attenuated AGS in Fmr1KO mice, whereas AFC03127 did not. MPEP and AFC03127 significantly reduced dendritic expression of amyloid-beta protein precursor (APP). All drugs rescued spine length and the ratio of mature dendritic spines. Spine density was not statistically different between vehicle and GSK3 inhibitor-treated cells. The drugs were tested over a wide concentration range in the in vitro assays to determine dose responses. A bell-shaped dose response decrease in APP expression was observed in response to AFC03127, which was more effective than SB216763. These findings confirm previous studies demonstrating differential effects of various GSK3 inhibitors on AGS propensity in Fmr1KO mice and confirm APP as a downstream biomarker that is responsive to GSK3 activity.
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Affiliation(s)
- Pamela R Westmark
- Department of Neurology, University of Wisconsin, Madison, WI, United States
| | | | | | | | | | - Cara J Westmark
- Department of Neurology, University of Wisconsin, Madison, WI, United States.,Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, United States
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8
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Filon MJ, Wallace E, Wright S, Douglas DJ, Steinberg LI, Verkuilen CL, Westmark PR, Maganti RK, Westmark CJ. Sleep and diurnal rest-activity rhythm disturbances in a mouse model of Alzheimer's disease. Sleep 2021; 43:5830779. [PMID: 32369586 DOI: 10.1093/sleep/zsaa087] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/07/2020] [Indexed: 01/08/2023] Open
Abstract
STUDY OBJECTIVES Accumulating evidence suggests a strong association between sleep, amyloid-beta (Aβ) deposition, and Alzheimer's disease (AD). We sought to determine if (1) deficits in rest-activity rhythms and sleep are significant phenotypes in J20 AD mice, (2) metabotropic glutamate receptor 5 inhibitors (mGluR5) could rescue deficits in rest-activity rhythms and sleep, and (3) Aβ levels are responsive to treatment with mGluR5 inhibitors. METHODS Diurnal rest-activity levels were measured by actigraphy and sleep-wake patterns by electroencephalography, while animals were chronically treated with mGluR5 inhibitors. Behavioral tests were performed, and Aβ levels measured in brain lysates. RESULTS J20 mice exhibited a 4.5-h delay in the acrophase of activity levels compared to wild-type littermates and spent less time in rapid eye movement (REM) sleep during the second half of the light period. J20 mice also exhibited decreased non-rapid eye movement (NREM) delta power but increased NREM sigma power. The mGluR5 inhibitor CTEP rescued the REM sleep deficit and improved NREM delta and sigma power but did not correct rest-activity rhythms. No statistically significant differences were observed in Aβ levels, rotarod performance, or the passive avoidance task following chronic mGluR5 inhibitor treatment. CONCLUSIONS J20 mice have disruptions in rest-activity rhythms and reduced homeostatic sleep pressure (reduced NREM delta power). NREM delta power was increased following treatment with a mGluR5 inhibitor. Drug bioavailability was poor. Further work is necessary to determine if mGluR5 is a viable target for treating sleep phenotypes in AD.
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Affiliation(s)
- Mikolaj J Filon
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | - Eli Wallace
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | - Samantha Wright
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | - Dylan J Douglas
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | | | | | - Pamela R Westmark
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | - Rama K Maganti
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
| | - Cara J Westmark
- Department of Neurology, University of Wisconsin-Madison, Madison, WI
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9
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Stoppel DC, McCamphill PK, Senter RK, Heynen AJ, Bear MF. mGluR5 Negative Modulators for Fragile X: Treatment Resistance and Persistence. Front Psychiatry 2021; 12:718953. [PMID: 34658956 PMCID: PMC8511445 DOI: 10.3389/fpsyt.2021.718953] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/08/2021] [Indexed: 11/13/2022] Open
Abstract
Fragile X syndrome (FXS) is caused by silencing of the human FMR1 gene and is the leading monogenic cause of intellectual disability and autism. Abundant preclinical data indicated that negative allosteric modulators (NAMs) of metabotropic glutamate receptor 5 (mGluR5) might be efficacious in treating FXS in humans. Initial attempts to translate these findings in clinical trials have failed, but these failures provide the opportunity for new discoveries that will improve future trials. The emergence of acquired treatment resistance ("tolerance") after chronic administration of mGluR5 NAMs is a potential factor in the lack of success. Here we confirm that FXS model mice display acquired treatment resistance after chronic treatment with the mGluR5 NAM CTEP in three assays commonly examined in the mouse model of FXS: (1) audiogenic seizure susceptibility, (2) sensory cortex hyperexcitability, and (3) hippocampal protein synthesis. Cross-tolerance experiments suggest that the mechanism of treatment resistance likely occurs at signaling nodes downstream of glycogen synthase kinase 3α (GSK3α), but upstream of protein synthesis. The rapid emergence of tolerance to CTEP begs the question of how previous studies showed an improvement in inhibitory avoidance (IA) cognitive performance after chronic treatment. We show here that this observation was likely explained by timely inhibition of mGluR5 during a critical period, as brief CTEP treatment in juvenile mice is sufficient to provide a persistent improvement of IA behavior measured many weeks later. These data will be important to consider when designing future fragile X clinical trials using compounds that target the mGluR5-to-protein synthesis signaling cascade.
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Affiliation(s)
- David C Stoppel
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Patrick K McCamphill
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Rebecca K Senter
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Arnold J Heynen
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Mark F Bear
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
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10
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Gregory KJ, Goudet C. International Union of Basic and Clinical Pharmacology. CXI. Pharmacology, Signaling, and Physiology of Metabotropic Glutamate Receptors. Pharmacol Rev 2020; 73:521-569. [PMID: 33361406 DOI: 10.1124/pr.119.019133] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabotropic glutamate (mGlu) receptors respond to glutamate, the major excitatory neurotransmitter in the mammalian brain, mediating a modulatory role that is critical for higher-order brain functions such as learning and memory. Since the first mGlu receptor was cloned in 1992, eight subtypes have been identified along with many isoforms and splice variants. The mGlu receptors are transmembrane-spanning proteins belonging to the class C G protein-coupled receptor family and represent attractive targets for a multitude of central nervous system disorders. Concerted drug discovery efforts over the past three decades have yielded a wealth of pharmacological tools including subtype-selective agents that competitively block or mimic the actions of glutamate or act allosterically via distinct sites to enhance or inhibit receptor activity. Herein, we review the physiologic and pathophysiological roles for individual mGlu receptor subtypes including the pleiotropic nature of intracellular signal transduction arising from each. We provide a comprehensive analysis of the in vitro and in vivo pharmacological properties of prototypical and commercially available orthosteric agonists and antagonists as well as allosteric modulators, including ligands that have entered clinical trials. Finally, we highlight emerging areas of research that hold promise to facilitate rational design of highly selective mGlu receptor-targeting therapeutics in the future. SIGNIFICANCE STATEMENT: The metabotropic glutamate receptors are attractive therapeutic targets for a range of psychiatric and neurological disorders. Over the past three decades, intense discovery efforts have yielded diverse pharmacological tools acting either competitively or allosterically, which have enabled dissection of fundamental biological process modulated by metabotropic glutamate receptors and established proof of concept for many therapeutic indications. We review metabotropic glutamate receptor molecular pharmacology and highlight emerging areas that are offering new avenues to selectively modulate neurotransmission.
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Affiliation(s)
- Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
| | - Cyril Goudet
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.) and Institut de Génomique Fonctionnelle (IGF), University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Montpellier, France (C.G.)
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11
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Arsova A, Møller TC, Vedel L, Hansen JL, Foster SR, Gregory KJ, Bräuner-Osborne H. Detailed In Vitro Pharmacological Characterization of Clinically Tested Negative Allosteric Modulators of the Metabotropic Glutamate Receptor 5. Mol Pharmacol 2020; 98:49-60. [PMID: 32358164 DOI: 10.1124/mol.119.119032] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 04/10/2020] [Indexed: 12/14/2022] Open
Abstract
Negative allosteric modulation of the metabotropic glutamate 5 (mGlu5) receptor has emerged as a potential strategy for the treatment of neurologic disorders. Despite the success in preclinical studies, many mGlu5 negative allosteric modulators (NAMs) that have reached clinical trials failed due to lack of efficacy. In this study, we provide a detailed in vitro pharmacological characterization of nine clinically and preclinically tested NAMs. We evaluated inhibition of l-glutamate-induced signaling with Ca2+ mobilization, inositol monophosphate (IP1) accumulation, extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, and real-time receptor internalization assays on rat mGlu5 expressed in HEK293A cells. Moreover, we determined association rates (kon) and dissociation rates (koff), as well as NAM affinities with [3H]methoxy-PEPy binding experiments. kon and koff values varied greatly between the nine NAMs (34- and 139-fold, respectively) resulting in long receptor residence times (>400 min) for basimglurant and mavoglurant, medium residence times (10-30 min) for AZD2066, remeglurant, and (RS)-remeglurant, and low residence times (<10 mins) for dipraglurant, F169521, F1699611, and STX107. We found that all NAMs inhibited l-glutamate-induced mGlu5 receptor internalization, generally with a similar potency to IP1 accumulation and ERK1/2 phosphorylation, whereas Ca2+ mobilization was less potently inhibited. Operational model of allosterism analyses revealed that dipraglurant and (RS)-remeglurant were biased toward (affinity) receptor internalization and away (cooperativity) from the ERK1/2 phosphorylation pathway, respectively. Our study is the first to measure mGlu5 NAM binding kinetics and negative allosteric modulation of mGlu5 receptor internalization and adds significant new knowledge about the molecular pharmacology of a diverse range of clinically relevant NAMs. SIGNIFICANCE STATEMENT: The metabotropic glutamate 5 (mGlu5) receptor is important in many brain functions and implicated in several neurological pathologies. Negative allosteric modulators (NAMs) have shown promising results in preclinical models but have so far failed in human clinical trials. Here we provide the most comprehensive and comparative molecular pharmacological study to date of nine preclinically/clinically tested NAMs at the mGlu5 receptor, which is also the first study to measure ligand binding kinetics and negative allosteric modulation of mGlu5 receptor internalization.
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Affiliation(s)
- Angela Arsova
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Thor C Møller
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Line Vedel
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Jakob Lerche Hansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Simon R Foster
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Karen J Gregory
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark (A.A., T.C.M., L.V., S.R.F., H.B.-O.); Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (K.J.G.); and Cardiovascular Research, Novo Nordisk A/S, Måløv, Denmark (J.L.H.)
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12
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Westmark PR, Gutierrez A, Gholston AK, Wilmer TM, Westmark CJ. Preclinical testing of the ketogenic diet in fragile X mice. Neurochem Int 2020; 134:104687. [PMID: 31958482 DOI: 10.1016/j.neuint.2020.104687] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/07/2020] [Accepted: 01/13/2020] [Indexed: 12/16/2022]
Abstract
The ketogenic diet is highly effective at attenuating seizures in refractory epilepsy, and accumulating evidence in the literature suggests that it may be beneficial in autism. To our knowledge, no one has studied the ketogenic diet in any fragile X syndrome (FXS) model. FXS is the leading known genetic cause of autism. Herein, we tested the effects of chronic ketogenic diet treatment on seizures, body weight, ketone and glucose levels, diurnal activity levels, learning and memory, and anxiety behaviors in Fmr1KO and littermate control mice as a function of age. The ketogenic diet selectively attenuates seizures in male but not female Fmr1KO mice and differentially affects weight gain and diurnal activity levels dependent on Fmr1 genotype, sex and age.
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Affiliation(s)
- Pamela R Westmark
- Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA
| | - Alejandra Gutierrez
- Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA; Molecular Environmental Toxicology Center, Summer Research Opportunities Program, University of Wisconsin, Madison, WI, USA
| | - Aaron K Gholston
- Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA; Molecular Environmental Toxicology Center, Summer Research Opportunities Program, University of Wisconsin, Madison, WI, USA
| | - Taralyn M Wilmer
- Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA
| | - Cara J Westmark
- Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA.
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13
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Gonzalez D, Tomasek M, Hays S, Sridhar V, Ammanuel S, Chang CW, Pawlowski K, Huber KM, Gibson JR. Audiogenic Seizures in the Fmr1 Knock-Out Mouse Are Induced by Fmr1 Deletion in Subcortical, VGlut2-Expressing Excitatory Neurons and Require Deletion in the Inferior Colliculus. J Neurosci 2019; 39:9852-9863. [PMID: 31666356 PMCID: PMC6891051 DOI: 10.1523/jneurosci.0886-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and the leading monogenetic cause of autism. One symptom of FXS and autism is sensory hypersensitivity (also called sensory over-responsivity). Perhaps related to this, the audiogenic seizure (AGS) is arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knock-out (KO) mouse. Therefore, the AGS may be considered a mouse model of sensory hypersensitivity. Hyperactive circuits are hypothesized to underlie dysfunction in a number of brain regions in patients with FXS and Fmr1 KO mice, and the AGS may be a result of this. But the specific cell types and brain regions underlying AGSs in the Fmr1 KO are unknown. We used conditional deletion or expression of Fmr1 in different cell populations to determine whether Fmr1 deletion in those cells was sufficient or necessary, respectively, for the AGS phenotype in males. Our data indicate that Fmr1 deletion in glutamatergic neurons that express vesicular glutamate transporter 2 (VGlut2) and are located in subcortical brain regions is sufficient and necessary to cause AGSs. Furthermore, the deletion of Fmr1 in glutamatergic neurons of the inferior colliculus is necessary for AGSs. When we demonstrate necessity, we show that Fmr1 expression in either the larger population of VGlut2-expressing glutamatergic neurons or the smaller population of inferior collicular glutamatergic neurons-in an otherwise Fmr1 KO mouse-eliminates AGSs. Therefore, targeting these neuronal populations in FXS and autism may be part of a therapeutic strategy to alleviate sensory hypersensitivity.SIGNIFICANCE STATEMENT Sensory hypersensitivity in fragile X syndrome (FXS) and autism patients significantly interferes with quality of life. Audiogenic seizures (AGSs) are arguably the most robust behavioral phenotype in the FXS mouse model-the Fmr1 knockout-and may be considered a model of sensory hypersensitivity in FXS. We provide the clearest and most precise genetic evidence to date for the cell types and brain regions involved in causing AGSs in the Fmr1 knockout and, more broadly, for any mouse mutant. The expression of Fmr1 in these same cell types in an otherwise Fmr1 knockout eliminates AGSs indicating possible cellular targets for alleviating sensory hypersensitivity in FXS and other forms of autism.
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Affiliation(s)
| | | | - Seth Hays
- Department of Neuroscience, Dallas, and
| | | | | | | | - Karen Pawlowski
- Department of Otolaryngology and Biomedical Engineering Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9035
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14
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Hyperexcitability and impaired intracortical inhibition in patients with fragile-X syndrome. Transl Psychiatry 2019; 9:312. [PMID: 31748507 PMCID: PMC6868148 DOI: 10.1038/s41398-019-0650-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/08/2019] [Accepted: 11/01/2019] [Indexed: 01/10/2023] Open
Abstract
Fragile-X syndrome (FXS) is characterized by neurological and psychiatric problems symptomatic of cortical hyperexcitability. Recent animal studies identified deficient γ-aminobutyricacid (GABA) inhibition as a key mechanism for hyperexcitability in FXS, but the GABA system remains largely unexplored in humans with the disorder. The primary objective of this study was to assess GABA-mediated inhibition and its relationship with hyperexcitability in patients with FXS. Transcranial magnetic stimulation (TMS) was used to assess cortical and corticospinal inhibitory and excitatory mechanisms in 18 patients with a molecular diagnosis of FXS and 18 healthy controls. GABA-mediated inhibition was measured with short-interval intracortical inhibition (GABAA), long-interval intracortical inhibition (GABAB), and the corticospinal silent period (GABAA+B). Net intracortical facilitation involving glutamate was assessed with intracortical facilitation, and corticospinal excitability was measured with the resting motor threshold. Results showed that FXS patients had significantly reduced short-interval intracortical inhibition, increased long-interval intracortical inhibition, and increased intracortical facilitation compared to healthy controls. In the FXS group, reduced short-interval intracortical inhibition was associated with heightened intracortical facilitation. Taken together, these results suggest that reduced GABAA inhibition is a plausible mechanism underlying cortical hyperexcitability in patients with FXS. These findings closely match those observed in animal models, supporting the translational validity of these markers for clinical research.
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15
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Crespi BJ. Comparative psychopharmacology of autism and psychotic-affective disorders suggests new targets for treatment. Evol Med Public Health 2019; 2019:149-168. [PMID: 31548888 PMCID: PMC6748779 DOI: 10.1093/emph/eoz022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/07/2019] [Indexed: 12/13/2022] Open
Abstract
The first treatments showing effectiveness for some psychiatric disorders, such as lithium for bipolar disorder and chlorpromazine for schizophrenia, were discovered by accident. Currently, psychiatric drug design is seen as a scientific enterprise, limited though it remains by the complexity of brain development and function. Relatively few novel and effective drugs have, however, been developed for many years. The purpose of this article is to demonstrate how evolutionary biology can provide a useful framework for psychiatric drug development. The framework is based on a diametrical nature of autism, compared with psychotic-affective disorders (mainly schizophrenia, bipolar disorder and depression). This paradigm follows from two inferences: (i) risks and phenotypes of human psychiatric disorders derive from phenotypes that have evolved along the human lineage and (ii) biological variation is bidirectional (e.g. higher vs lower, faster vs slower, etc.), such that dysregulation of psychological traits varies in two opposite ways. In this context, the author review the evidence salient to the hypothesis that autism and psychotic-affective disorders represent diametrical disorders in terms of current, proposed and potential psychopharmacological treatments. Studies of brain-derived neurotrophic factor, the PI3K pathway, the NMDA receptor, kynurenic acid metabolism, agmatine metabolism, levels of the endocannabinoid anandamide, antidepressants, anticonvulsants, antipsychotics, and other treatments, demonstrate evidence of diametric effects in autism spectrum disorders and phenotypes compared with psychotic-affective disorders and phenotypes. These findings yield insights into treatment mechanisms and the development of new pharmacological therapies, as well as providing an explanation for the longstanding puzzle of antagonism between epilepsy and psychosis. Lay Summary: Consideration of autism and schizophrenia as caused by opposite alterations to brain development and function leads to novel suggestions for pharmacological treatments.
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Affiliation(s)
- Bernard J Crespi
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
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16
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Westmark CJ. Fragile X and APP: a Decade in Review, a Vision for the Future. Mol Neurobiol 2019; 56:3904-3921. [PMID: 30225775 PMCID: PMC6421119 DOI: 10.1007/s12035-018-1344-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/05/2018] [Indexed: 10/28/2022]
Abstract
Fragile X syndrome (FXS) is a devastating developmental disability that has profound effects on cognition, behavior, and seizure susceptibility. There are currently no treatments that target the underlying cause of the disorder, and recent clinical trials have been unsuccessful. In 2007, seminal work demonstrated that amyloid-beta protein precursor (APP) is dysregulated in Fmr1KO mice through a metabotropic glutamate receptor 5 (mGluR5)-dependent pathway. These findings raise the hypotheses that: (1) APP and/or APP metabolites are potential therapeutic targets as well as biomarkers for FXS and (2) mGluR5 inhibitors may be beneficial in the treatment of Alzheimer's disease. Herein, advances in the field over the past decade that have reproduced and greatly expanded upon these original findings are reviewed, and required experimentation to validate APP metabolites as potential disease biomarkers as well as therapeutic targets for FXS are discussed.
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Affiliation(s)
- Cara J Westmark
- Department of Neurology, University of Wisconsin-Madison, Medical Sciences Center, Room 3619, 1300 University Avenue, Madison, WI, USA.
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Zerbi V, Markicevic M, Gasparini F, Schroeter A, Rudin M, Wenderoth N. Inhibiting mGluR5 activity by AFQ056/Mavoglurant rescues circuit-specific functional connectivity in Fmr1 knockout mice. Neuroimage 2019; 191:392-402. [DOI: 10.1016/j.neuroimage.2019.02.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 02/11/2019] [Accepted: 02/19/2019] [Indexed: 12/12/2022] Open
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