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Volianskis R, Lundbye CJ, Petroff GN, Jane DE, Georgiou J, Collingridge GL. Cage effects on synaptic plasticity and its modulation in a mouse model of fragile X syndrome. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230484. [PMID: 38853552 DOI: 10.1098/rstb.2023.0484] [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: 02/01/2024] [Accepted: 04/08/2024] [Indexed: 06/11/2024] Open
Abstract
Fragile X syndrome (FXS) is characterized by impairments in executive function including different types of learning and memory. Long-term potentiation (LTP), thought to underlie the formation of memories, has been studied in the Fmr1 mouse model of FXS. However, there have been many discrepancies in the literature with inconsistent use of littermate and non-littermate Fmr1 knockout (KO) and wild-type (WT) control mice. Here, the influence of the breeding strategy (cage effect) on short-term potentiation (STP), LTP, contextual fear conditioning (CFC), expression of N-methyl-d-aspartate receptor (NMDAR) subunits and the modulation of NMDARs, were examined. The largest deficits in STP, LTP and CFC were found in KO mice compared with non-littermate WT. However, the expression of NMDAR subunits was unchanged in this comparison. Rather, NMDAR subunit (GluN1, 2A, 2B) expression was sensitive to the cage effect, with decreased expression in both WT and KO littermates compared with non-littermates. Interestingly, an NMDAR-positive allosteric modulator, UBP714, was only effective in potentiating the induction of LTP in non-littermate KO mice and not the littermate KO mice. These results suggest that commonly studied phenotypes in Fmr1 KOs are sensitive to the cage effect and therefore the breeding strategy may contribute to discrepancies in the literature.This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Rasa Volianskis
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Camilla J Lundbye
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Gillian N Petroff
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David E Jane
- Hello Bio Limited, Cabot Park, Avonmouth, Bristol BS11 0QL, UK
| | - John Georgiou
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Graham L Collingridge
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Barbour AJ, Gourmaud S, Lancaster E, Li X, Stewart DA, Hoag KF, Irwin DJ, Talos DM, Jensen FE. Seizures exacerbate excitatory: inhibitory imbalance in Alzheimer's disease and 5XFAD mice. Brain 2024; 147:2169-2184. [PMID: 38662500 PMCID: PMC11146435 DOI: 10.1093/brain/awae126] [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: 09/05/2023] [Revised: 03/02/2024] [Accepted: 03/24/2024] [Indexed: 05/14/2024] Open
Abstract
Approximately 22% of Alzheimer's disease (AD) patients suffer from seizures, and the co-occurrence of seizures and epileptiform activity exacerbates AD pathology and related cognitive deficits, suggesting that seizures may be a targetable component of AD progression. Given that alterations in neuronal excitatory:inhibitory (E:I) balance occur in epilepsy, we hypothesized that decreased markers of inhibition relative to those of excitation would be present in AD patients. We similarly hypothesized that in 5XFAD mice, the E:I imbalance would progress from an early stage (prodromal) to later symptomatic stages and be further exacerbated by pentylenetetrazol (PTZ) kindling. Post-mortem AD temporal cortical tissues from patients with or without seizure history were examined for changes in several markers of E:I balance, including levels of the inhibitory GABAA receptor, the sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2) and the excitatory NMDA and AMPA type glutamate receptors. We performed patch-clamp electrophysiological recordings from CA1 neurons in hippocampal slices and examined the same markers of E:I balance in prodromal 5XFAD mice. We next examined 5XFAD mice at chronic stages, after PTZ or control protocols, and in response to chronic mTORC1 inhibitor rapamycin, administered following kindled seizures, for markers of E:I balance. We found that AD patients with comorbid seizures had worsened cognitive and functional scores and decreased GABAA receptor subunit expression, as well as increased NKCC1/KCC2 ratios, indicative of depolarizing GABA responses. Patch clamp recordings of prodromal 5XFAD CA1 neurons showed increased intrinsic excitability, along with decreased GABAergic inhibitory transmission and altered glutamatergic neurotransmission, indicating that E:I imbalance may occur in early disease stages. Furthermore, seizure induction in prodromal 5XFAD mice led to later dysregulation of NKCC1/KCC2 and a reduction in GluA2 AMPA glutamate receptor subunit expression, indicative of depolarizing GABA receptors and calcium permeable AMPA receptors. Finally, we found that chronic treatment with the mTORC1 inhibitor, rapamycin, at doses we have previously shown to attenuate seizure-induced amyloid-β pathology and cognitive deficits, could also reverse elevations of the NKCC1/KCC2 ratio in these mice. Our data demonstrate novel mechanisms of interaction between AD and epilepsy and indicate that targeting E:I balance, potentially with US Food and Drug Administration-approved mTOR inhibitors, hold therapeutic promise for AD patients with a seizure history.
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Affiliation(s)
- Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eunjoo Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaofan Li
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - Keegan F Hoag
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Banke TG, Traynelis SF, Barria A. Early expression of GluN2A-containing NMDA receptors in a model of fragile X syndrome. J Neurophysiol 2024; 131:768-777. [PMID: 38380828 DOI: 10.1152/jn.00406.2023] [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: 11/02/2023] [Revised: 01/31/2024] [Accepted: 02/14/2024] [Indexed: 02/22/2024] Open
Abstract
NMDA-type glutamate receptors (NMDARs) play a crucial role in synaptogenesis, circuit development, and synaptic plasticity, serving as fundamental components in cellular models of learning and memory. Their dysregulation has been implicated in several neurological disorders and synaptopathies. NMDARs are heterotetrameric complexes composed of two GluN1 and two GluN2 subunits. The composition of GluN2 subunits determines the main biophysical properties of the channel, such as calcium permeability and gating kinetics, and influences the ability of the receptor to interact with postsynaptic proteins involved in normal synaptic physiology and plasticity, including scaffolding proteins and signaling molecules. During early development, NMDARs in the forebrain contain solely the GluN2B subunit, a necessary subunit for proper synaptogenesis and synaptic plasticity. As the animal matures, the expression of the GluN2A subunit increases, leading to a partial replacement of GluN2B-containing synaptic NMDARs with GluN2A-containing receptors. The switch in the synaptic GluN2A-to-GluN2B ratio has a significant impact on the kinetics of excitatory postsynaptic currents and diminishes the synaptic plasticity capacity. In this study, we present findings indicating that GluN2A expression occurs earlier in a mouse model of fragile X syndrome (FXS). This altered timing of GluN2A expression affects various important parameters of NMDAR-mediated excitatory postsynaptic currents, including maximal current amplitude, decay time, and response to consecutive stimuli delivered in close temporal proximity. These observations suggest that the early expression of GluN2A during a critical period when synapses and circuits are developing could be an underlying factor contributing to the formation of pathological circuits in the FXS mouse model.NEW & NOTEWORTHY NMDA receptors (NMDARs) play important roles in synaptic transmission and are involved in multiple neurological disorders. During development, GluN2A in the forebrain becomes incorporated into previously GluN2B-dominated NMDARs, leading to the "GluN2A/GluN2B ratio switch." This is a crucial step for normal brain development. Here we present findings indicating that GluN2A expression occurs earlier in the fragile X mouse and this could be an underlying factor contributing to the pathology found in the fragile X model.
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Affiliation(s)
- Tue G Banke
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, United States
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, United States
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, United States
| | - Andres Barria
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, United States
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Chojnacka M, Beroun A, Magnowska M, Stawikowska A, Cysewski D, Milek J, Dziembowska M, Kuzniewska B. Impaired synaptic incorporation of AMPA receptors in a mouse model of fragile X syndrome. Front Mol Neurosci 2023; 16:1258615. [PMID: 38025260 PMCID: PMC10665894 DOI: 10.3389/fnmol.2023.1258615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common monogenetic cause of inherited intellectual disability and autism in humans. One of the well-characterized molecular phenotypes of Fmr1 KO mice, a model of FXS, is increased translation of synaptic proteins. Although this upregulation stabilizes in adulthood, abnormalities during the critical period of plasticity have long-term effects on circuit formation and synaptic properties. Using high-resolution quantitative proteomics of synaptoneurosomes isolated from the adult, developed brains of Fmr1 KO mice, we show a differential abundance of proteins regulating the postsynaptic receptor activity of glutamatergic synapses. We investigated the AMPA receptor composition and shuttling in adult Fmr1 KO and WT mice using a variety of complementary experimental strategies such as surface protein crosslinking, immunostaining of surface receptors, and electrophysiology. We discovered that the activity-dependent synaptic delivery of AMPARs is impaired in adult Fmr1 KO mice. Furthermore, we show that Fmr1 KO synaptic AMPARs contain more GluA2 subunits that can be interpreted as a switch in the synaptic AMPAR subtype toward an increased number of Ca2+-impermeable receptors in adult Fmr1 KO synapses.
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Affiliation(s)
- Magdalena Chojnacka
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Anna Beroun
- Laboratory of Neuronal Plasticity, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Marta Magnowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Aleksandra Stawikowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Dominik Cysewski
- Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland
| | - Jacek Milek
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Magdalena Dziembowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Bozena Kuzniewska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
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Li X, Nie Y, Qiu Z, Wang S. Human MECP2 transgenic rats show increased anxiety, severe social deficits, and abnormal prefrontal neural oscillation stability. Biochem Biophys Res Commun 2023; 648:28-35. [PMID: 36724557 DOI: 10.1016/j.bbrc.2023.01.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Methylated CpG binding protein 2 (MeCP2) plays an important role in the development and normal function of the neural system. Abnormally high expression of MECP2 leads to a subtype of autism called MECP2 duplication syndrome and MECP2 is considered one of the key pathogenic genes for autism spectrum disorders. However, the effect of MECP2 overexpression on neural activity is still not fully understood. Thus, transgenic (TG) animals that abnormally overexpress MeCP2 are important disease models in research on neurological function and autism. To create an animal model with a stronger and more stable autism phenotype, this study established a human MECP2 TG rat model and evaluated its movement ability, anxiety, and social behavior through behavioral tests. The results showed that MECP2 TG rats had an abnormally increased anxiety phenotype and social deficits in terms of abnormal social approach and social novelty preference, but no movement disorder. These autism-like behavioral phenotypes suggest that human MECP2 TG rats are suitable models for studying autism as they show more severe social deficit phenotypes and without interference from movement disorders affecting other phenotypes, which is an issue for mouse models with MECP2 duplication. In addition, this study performed preliminary exploration of the influence of the human MECP2 transgene on neural oscillation stability of the medial prefrontal cortex (mPFC), which is an important brain region for social interactions. Oscillation stability in MECP2 TG rats showed abnormal responses to social conditions. Overall, the results of this study provide a new research tool for understanding the mechanism of social impairment and treatment of autism. The results also provide evidence for the influence of MECP2 duplication on mPFC neural activity.
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Affiliation(s)
- Xiao Li
- Institute of Intelligent Robotics, Academy for Engineering and Technology, Fudan University, Shanghai, China; Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China
| | - Yingnan Nie
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China
| | - Zilong Qiu
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
| | - Shouyan Wang
- Institute of Intelligent Robotics, Academy for Engineering and Technology, Fudan University, Shanghai, China; Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China; MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China.
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Svalina MN, Rio CACD, Kushner JK, Levy A, Baca SM, Guthman EM, Opendak M, Sullivan RM, Restrepo D, Huntsman MM. Basolateral Amygdala Hyperexcitability Is Associated with Precocious Developmental Emergence of Fear-Learning in Fragile X Syndrome. J Neurosci 2022; 42:7294-7308. [PMID: 35970562 PMCID: PMC9512574 DOI: 10.1523/jneurosci.1776-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 08/02/2022] [Accepted: 08/05/2022] [Indexed: 12/24/2022] Open
Abstract
Fragile X Syndrome is a neurodevelopmental disorder and the most common monogenic cause of intellectual disability, autism spectrum disorders, and anxiety disorders. Loss of fragile x mental retardation protein results in disruptions of synaptic development during a critical period of circuit formation in the BLA. However, it is unknown how these alterations impact microcircuit development and function. Using a combination of electrophysiologic and behavioral approaches in both male (Fmr1-/y) and female (Fmr1-/-) mice, we demonstrate that principal neurons in the Fmr1KO BLA exhibit hyperexcitability during a sensitive period in amygdala development. This hyperexcitability contributes to increased excitatory gain in fear-learning circuits. Further, synaptic plasticity is enhanced in the BLA of Fmr1KO mice. Behavioral correlation demonstrates that fear-learning emerges precociously in the Fmr1KO mouse. Early life 4,5,6,7-tetrahydroisoxazolo [5,4-c]pyridin-3ol intervention ameliorates fear-learning in Fmr1KO mice. These results suggest that critical period plasticity in the amygdala of the Fmr1KO mouse may be shifted to earlier developmental time points.SIGNIFICANCE STATEMENT In these studies, we identify early developmental alterations in principal neurons in the Fragile X syndrome BLA. We show that, as early as P14, excitability and feedforward excitation, and synaptic plasticity are enhanced in Fmr1KO lateral amygdala. This correlates with precocious emergence of fear-learning in the Fmr1KO mouse. Early life 4,5,6,7-tetrahydroisoxazolo [5,4-c]pyridin-3ol intervention restores critical period plasticity in WT mice and ameliorates fear-learning in the Fmr1KO mouse.
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Affiliation(s)
- Matthew N Svalina
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Christian A Cea-Del Rio
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- CIBAP, Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile 9170201
| | - J Keenan Kushner
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Abigail Levy
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Serapio M Baca
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - E Mae Guthman
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Maya Opendak
- Emotional Brain Institute, Nathan Kline Institute, Orangeburg, New York 10962
- Child Study Center, Child & Adolescent Psychiatry, New York University School of Medicine, New York, 10016
| | - Regina M Sullivan
- Emotional Brain Institute, Nathan Kline Institute, Orangeburg, New York 10962
- Child Study Center, Child & Adolescent Psychiatry, New York University School of Medicine, New York, 10016
| | - Diego Restrepo
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Molly M Huntsman
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
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Perez-Fernandez C, Matamala Montoya M, Morales-Navas M, Guardia-Escote L, Cabré M, Colomina MT, Giménez E, Sánchez-Santed F. Influence of Gestational Chlorpyrifos Exposure on ASD-like Behaviors in an fmr1-KO Rat Model. Mol Neurobiol 2022; 59:5835-5855. [PMID: 35802248 DOI: 10.1007/s12035-022-02933-0] [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: 03/07/2022] [Accepted: 06/17/2022] [Indexed: 11/26/2022]
Abstract
Based on previous reports, exposure to pesticides could be linked to the prevalence increase of autism spectrum disorders (ASD). Gestational exposure to chlorpyrifos (CPF) has been associated with ASD diagnosis in humans and ASD-like behaviors in rodents. However, ASD severity degree results from the complex relationship between genetic background and environmental factors. Thus, animals with a genetic vulnerability and prenatally exposed to CPF could have a more severe ASD-like phenotype. Fragile X syndrome is one of the most common monogenic causes of ASD, characterized by a mutation in the X chromosome which alters the expression of the fragile X mental retardation protein (FMRP). Based on this, some fmr1 knockout (KO) rodent models have been developed to study the physiological and genetic basis of ASD. Both fmr1-KO and wild-type male rats (F2 generation) were used in the present study. F1 pregnant females were randomly exposed to 1 mg/kg/mL/day of CPF (s.c.) from GD12.5-15.5 or vehicle. Different behavioral, developmental, and molecular variables were analyzed in F2 males. KO rats were heavier, emitted altered USVs, were socially inefficient, reacted more to a novel stimulus, were hyperactive when exploring a new context, but hypoactive when exploring anxiety-inducing environments, and had an upregulated hippocampal expression of the grin2c gene. When exposed to low doses of CPF during gestation, these KO rats showed decreased climbing capacity, dysfunctional social interaction, and increased hippocampal expression for kcc1 and 5ht2c genes. Gestational CPF exposure increased the ASD-like phenotype in those animals with a genetic vulnerability, although its effect was less generalized than expected. It is the first time that this additive effect of CPF exposure and the fmr1-KO genetic vulnerability model is explored concerning social traits or any other behavior.
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Affiliation(s)
- Cristian Perez-Fernandez
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - María Matamala Montoya
- Biomolecular Mass Spectrometry and Proteomics Group, Faculty of Science, Utrecht University, 3584 CS, Utrecht, The Netherlands
| | - Miguel Morales-Navas
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - Laia Guardia-Escote
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira I Virgili, Campus Sescelades, 43007, Tarragona, Spain
| | - María Cabré
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Biochemistry and Biotechnology, Universitat Rovira I Virgili, 43007, Tarragona, Spain
| | - María Teresa Colomina
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira I Virgili, 43007, Tarragona, Spain
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira I Virgili, Campus Sescelades, 43007, Tarragona, Spain
| | - Estela Giménez
- Department of Biology and Geology, University of Almería, Ctra. Sacramento, s/n, 04120, Almería, Spain
| | - Fernando Sánchez-Santed
- Department of Psychology and Health Research Center (CEINSA), Laboratory of Psychobiology, University of Almería CeiA3, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain.
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Chaudry S, Vasudevan N. mTOR-Dependent Spine Dynamics in Autism. Front Mol Neurosci 2022; 15:877609. [PMID: 35782388 PMCID: PMC9241970 DOI: 10.3389/fnmol.2022.877609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022] Open
Abstract
Autism Spectrum Conditions (ASC) are a group of neurodevelopmental disorders characterized by deficits in social communication and interaction as well as repetitive behaviors and restricted range of interests. ASC are complex genetic disorders with moderate to high heritability, and associated with atypical patterns of neural connectivity. Many of the genes implicated in ASC are involved in dendritic spine pruning and spine development, both of which can be mediated by the mammalian target of rapamycin (mTOR) signaling pathway. Consistent with this idea, human postmortem studies have shown increased spine density in ASC compared to controls suggesting that the balance between autophagy and spinogenesis is altered in ASC. However, murine models of ASC have shown inconsistent results for spine morphology, which may underlie functional connectivity. This review seeks to establish the relevance of changes in dendritic spines in ASC using data gathered from rodent models. Using a literature survey, we identify 20 genes that are linked to dendritic spine pruning or development in rodents that are also strongly implicated in ASC in humans. Furthermore, we show that all 20 genes are linked to the mTOR pathway and propose that the mTOR pathway regulating spine dynamics is a potential mechanism underlying the ASC signaling pathway in ASC. We show here that the direction of change in spine density was mostly correlated to the upstream positive or negative regulation of the mTOR pathway and most rodent models of mutant mTOR regulators show increases in immature spines, based on morphological analyses. We further explore the idea that these mutations in these genes result in aberrant social behavior in rodent models that is due to these altered spine dynamics. This review should therefore pave the way for further research on the specific genes outlined, their effect on spine morphology or density with an emphasis on understanding the functional role of these changes in ASC.
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Montanari M, Martella G, Bonsi P, Meringolo M. Autism Spectrum Disorder: Focus on Glutamatergic Neurotransmission. Int J Mol Sci 2022; 23:ijms23073861. [PMID: 35409220 PMCID: PMC8998955 DOI: 10.3390/ijms23073861] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/24/2022] [Accepted: 03/29/2022] [Indexed: 12/16/2022] Open
Abstract
Disturbances in the glutamatergic system have been increasingly documented in several neuropsychiatric disorders, including autism spectrum disorder (ASD). Glutamate-centered theories of ASD are based on evidence from patient samples and postmortem studies, as well as from studies documenting abnormalities in glutamatergic gene expression and metabolic pathways, including changes in the gut microbiota glutamate metabolism in patients with ASD. In addition, preclinical studies on animal models have demonstrated glutamatergic neurotransmission deficits and altered expression of glutamate synaptic proteins. At present, there are no approved glutamatergic drugs for ASD, but several ongoing clinical trials are currently focusing on evaluating in autistic patients glutamatergic pharmaceuticals already approved for other conditions. In this review, we provide an overview of the literature concerning the role of glutamatergic neurotransmission in the pathophysiology of ASD and as a potential target for novel treatments.
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Affiliation(s)
- Martina Montanari
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (M.M.); (G.M.)
- Department of Systems Neuroscience, University Tor Vergata, 00133 Rome, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (M.M.); (G.M.)
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (M.M.); (G.M.)
- Correspondence: (P.B.); (M.M.)
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (M.M.); (G.M.)
- Correspondence: (P.B.); (M.M.)
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Chater TE, Goda Y. The Shaping of AMPA Receptor Surface Distribution by Neuronal Activity. Front Synaptic Neurosci 2022; 14:833782. [PMID: 35387308 PMCID: PMC8979068 DOI: 10.3389/fnsyn.2022.833782] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 02/25/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotransmission is critically dependent on the number, position, and composition of receptor proteins on the postsynaptic neuron. Of these, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) are responsible for the majority of postsynaptic depolarization at excitatory mammalian synapses following glutamate release. AMPARs are continually trafficked to and from the cell surface, and once at the surface, AMPARs laterally diffuse in and out of synaptic domains. Moreover, the subcellular distribution of AMPARs is shaped by patterns of activity, as classically demonstrated by the synaptic insertion or removal of AMPARs following the induction of long-term potentiation (LTP) and long-term depression (LTD), respectively. Crucially, there are many subtleties in the regulation of AMPARs, and exactly how local and global synaptic activity drives the trafficking and retention of synaptic AMPARs of different subtypes continues to attract attention. Here we will review how activity can have differential effects on AMPAR distribution and trafficking along with its subunit composition and phosphorylation state, and we highlight some of the controversies and remaining questions. As the AMPAR field is extensive, to say the least, this review will focus primarily on cellular and molecular studies in the hippocampus. We apologise to authors whose work could not be cited directly owing to space limitations.
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Mohamad MHN, Abu IF, Fazel MF, Agarwal R, Iezhitsa I, Juliana N, Mellor IR, Franzyk H. Neuroprotection Against NMDA-Induced Retinal Damage by Philanthotoxin-343 Involves Reduced Nitrosative Stress. Front Pharmacol 2022; 12:798794. [PMID: 34970151 PMCID: PMC8714026 DOI: 10.3389/fphar.2021.798794] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/10/2021] [Indexed: 01/18/2023] Open
Abstract
N-methyl-D-aspartate receptor (NMDAR) overstimulation is known to mediate neurodegeneration, and hence represents a relevant therapeutic target for neurodegenerative disorders including glaucoma. This study examined the neuroprotective effects of philanthotoxin (PhTX)-343 against NMDA-induced retinal injury in rats. Male Sprague Dawley rats were divided into three groups; group 1 received phosphate buffer saline as the negative control, group 2 was injected with NMDA (160 nM) to induce retinal excitotoxic injury, and group 3 was pre-treated with PhTX-343 (160 nM) 24 h before NMDA exposure. All treatments were given intravitreally and bilaterally. Seven days post-treatment, rats were subjected to visual behaviour assessments using open field and colour recognition tests. Rats were then euthanized, and the retinas were harvested and subjected to haematoxylin and eosin (H&E) staining for morphometric analysis and 3-nitrotyrosine (3-NT) ELISA protocol as the nitrosative stress biomarker. PhTX-343 treatment prior to NMDA exposure improved the ability of rats to recognize visual cues and preserved visual functions (i.e., recognition of objects with different colours). Morphological examination of retinal tissues showed that the fractional ganglion cell layer thickness within the inner retina (IR) in the PhTX-343 treated group was greater by 1.28-fold as compared to NMDA-treated rats (p < 0.05) and was comparable to control rats (p > 0.05). Additionally, the number of retinal cell nuclei/100 μm2 in IR for the PhTX-343-treated group was greater by 1.82-fold compared to NMDA-treated rats (p < 0.05) and was comparable to control group (p > 0.05). PhTX-343 also reduced the retinal 3-NT levels by 1.74-fold compared to NMDA-treated rats (p < 0.05). In conclusion, PhTX-343 pretreatment protects against NMDA-induced retinal morphological changes and visual impairment by suppressing nitrosative stress as reflected by the reduced retinal 3-NT level.
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Affiliation(s)
| | - Izuddin Fahmy Abu
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Muhammad Fattah Fazel
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Renu Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Igor Iezhitsa
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia.,Department of Pharmacology and Bioinformatics, Volgograd State Medical University, Volgograd, Russian Federation
| | - Norsham Juliana
- Faculty of Medicine and Health Sciences, Universiti Sains Islam Malaysia, Negeri Sembilan, Malaysia
| | - Ian R Mellor
- School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zieger HL, Choquet D. Nanoscale synapse organization and dysfunction in neurodevelopmental disorders. Neurobiol Dis 2021; 158:105453. [PMID: 34314857 DOI: 10.1016/j.nbd.2021.105453] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 07/18/2021] [Accepted: 07/21/2021] [Indexed: 12/20/2022] Open
Abstract
Neurodevelopmental disorders such as those linked to intellectual disabilities or autism spectrum disorder are thought to originate in part from genetic defects in synaptic proteins. Single gene mutations linked to synapse dysfunction can broadly be separated in three categories: disorders of transcriptional regulation, disorders of synaptic signaling and disorders of synaptic scaffolding and structures. The recent developments in super-resolution imaging technologies and their application to synapses have unraveled a complex nanoscale organization of synaptic components. On the one hand, part of receptors, adhesion proteins, ion channels, scaffold elements and the pre-synaptic release machinery are partitioned in subsynaptic nanodomains, and the respective organization of these nanodomains has tremendous impact on synaptic function. For example, pre-synaptic neurotransmitter release sites are partly aligned with nanometer precision to postsynaptic receptor clusters. On the other hand, a large fraction of synaptic components is extremely dynamic and constantly exchanges between synaptic domains and extrasynaptic or intracellular compartments. It is largely the combination of the exquisitely precise nanoscale synaptic organization of synaptic components and their high dynamic that allows the rapid and profound regulation of synaptic function during synaptic plasticity processes that underlie adaptability of brain function, learning and memory. It is very tempting to speculate that genetic defects that lead to neurodevelopmental disorders and target synaptic scaffolds and structures mediate their deleterious impact on brain function through perturbing synapse nanoscale dynamic organization. We discuss here how applying super-resolution imaging methods in models of neurodevelopmental disorders could help in addressing this question.
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Affiliation(s)
- Hanna L Zieger
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000 Bordeaux, France
| | - Daniel Choquet
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000 Bordeaux, France; Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France.
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13
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Booker SA, Kind PC. Mechanisms regulating input-output function and plasticity of neurons in the absence of FMRP. Brain Res Bull 2021; 175:69-80. [PMID: 34245842 DOI: 10.1016/j.brainresbull.2021.06.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/13/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022]
Abstract
The function of brain circuits relies on high-fidelity information transfer within neurons. Synaptic inputs arrive primarily at dendrites, where they undergo integration and summation throughout the somatodendritic domain, ultimately leading to the generation of precise patterns of action potentials. Emerging evidence suggests that the ability of neurons to transfer synaptic information and modulate their output is impaired in a number of neurodevelopmental disorders including Fragile X Syndrome. In this review we summarise recent findings that have revealed the pathophysiological and plasticity mechanisms that alter the ability of neurons in sensory and limbic circuits to reliably code information in the absence of FMRP. We examine which aspects of this transform may result directly from the loss of FMRP and those that a result from compensatory or homeostatic alterations to neuronal function. Dissection of the mechanisms leading to altered input-output function of neurons in the absence of FMRP and their effects on regulating neuronal plasticity throughout development could have important implications for potential therapies for Fragile X Syndrome, including directing the timing and duration of different treatment options.
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Affiliation(s)
- Sam A Booker
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK; Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK; Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
| | - Peter C Kind
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK; Patrick Wild Centre for Autism Research, University of Edinburgh, Edinburgh, UK; Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK; National Centre for Biological Sciences (NCBS), Bangalore, India.
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