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Medeiros D, Polepalli L, Li W, Pozzo-Miller L. Altered activity of mPFC pyramidal neurons and parvalbumin-expressing interneurons during social interactions in a Mecp2 mouse model for Rett syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.06.606882. [PMID: 39149275 PMCID: PMC11326302 DOI: 10.1101/2024.08.06.606882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Social memory impairments in Mecp2 knockout (KO) mice result from altered neuronal activity in the monosynaptic projection from the ventral hippocampus (vHIP) to the medial prefrontal cortex (mPFC). The hippocampal network is hyperactive in this model for Rett syndrome, and such atypically heightened neuronal activity propagates to the mPFC through this monosynaptic projection, resulting in altered mPFC network activity and social memory deficits. However, the underlying mechanism of cellular dysfunction within this projection between vHIP pyramidal neurons (PYR) and mPFC PYRs and parvalbumin interneurons (PV-IN) resulting in social memory impairments in Mecp2 KO mice has yet to be elucidated. We confirmed social memory (but not sociability) deficits in Mecp2 KO mice using a new 4-chamber social memory arena, designed to minimize the impact of the tethering to optical fibers required for simultaneous in vivo fiber photometry of Ca2+-sensor signals during social interactions. mPFC PYRs of wildtype (WT) mice showed increases in Ca2+ signal amplitude during explorations of a novel toy mouse and interactions with both familiar and novel mice, while PYRs of Mecp2 KO mice showed smaller Ca2+ signals during interactions only with live mice. On the other hand, mPFC PV-INs of Mecp2 KO mice showed larger Ca2+ signals during interactions with a familiar cage-mate compared to those signals in PYRs, a difference absent in the WT mice. These observations suggest atypically heightened inhibition and impaired excitation in the mPFC network of Mecp2 KO mice during social interactions, potentially driving their deficit in social memory.
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Affiliation(s)
- Destynie Medeiros
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Likhitha Polepalli
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wei Li
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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2
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Medina J, Zhou Z. Unlock the potential: Auditory-evoked event-related potential (ERP) as a treatment-responsive biomarker for Rett syndrome. Neurotherapeutics 2024; 21:e00389. [PMID: 38944637 PMCID: PMC11284539 DOI: 10.1016/j.neurot.2024.e00389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 07/01/2024] Open
Affiliation(s)
- Joanna Medina
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhaolan Zhou
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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3
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Deng J, Labarta-Bajo L, Brandebura AN, Kahn SB, Pinto AFM, Diedrich JK, Allen NJ. Suppression of astrocyte BMP signaling improves fragile X syndrome molecular signatures and functional deficits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.19.599752. [PMID: 38979341 PMCID: PMC11230279 DOI: 10.1101/2024.06.19.599752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Fragile X syndrome (FXS) is a monogenic neurodevelopmental disorder with manifestations spanning molecular, neuroanatomical, and behavioral changes. Astrocytes contribute to FXS pathogenesis and show hundreds of dysregulated genes and proteins; targeting upstream pathways mediating astrocyte changes in FXS could therefore be a point of intervention. To address this, we focused on the bone morphogenetic protein (BMP) pathway, which is upregulated in FXS astrocytes. We generated a conditional KO (cKO) of Smad4 in astrocytes to suppress BMP signaling, and found this lessens audiogenic seizure severity in FXS mice. To ask how this occurs on a molecular level, we performed in vivo transcriptomic and proteomic profiling of cortical astrocytes, finding upregulation of metabolic pathways, and downregulation of secretory machinery and secreted proteins in FXS astrocytes, with these alterations no longer present when BMP signaling is suppressed. Functionally, astrocyte Smad4 cKO restores deficits in inhibitory synapses present in FXS auditory cortex. Thus, astrocytes contribute to FXS molecular and functional phenotypes, and targeting astrocytes can mitigate FXS symptoms.
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Affiliation(s)
- James Deng
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
- Medical Scientist Training Program, University of California, San Diego, La Jolla, CA, USA
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Lara Labarta-Bajo
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Ashley N Brandebura
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Samuel B Kahn
- Department of Biology, University of California, San Diego, La Jolla, CA, USA
| | - Antonio F M Pinto
- Mass Spectrometry Core for Proteomics and Metabolomics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Jolene K Diedrich
- Mass Spectrometry Core for Proteomics and Metabolomics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
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Koster KP, Fyke Z, Nguyen TTA, Niqula A, Noriega-González LY, Woolfrey KM, Dell’Acqua ML, Cologna SM, Yoshii A. Akap5 links synaptic dysfunction to neuroinflammatory signaling in a mouse model of infantile neuronal ceroid lipofuscinosis. Front Synaptic Neurosci 2024; 16:1384625. [PMID: 38798824 PMCID: PMC11116793 DOI: 10.3389/fnsyn.2024.1384625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 04/23/2024] [Indexed: 05/29/2024] Open
Abstract
Palmitoylation and depalmitoylation represent dichotomic processes by which a labile posttranslational lipid modification regulates protein trafficking and degradation. The depalmitoylating enzyme, palmitoyl-protein thioesterase 1 (PPT1), is associated with the devastating pediatric neurodegenerative condition, infantile neuronal ceroid lipofuscinosis (CLN1). CLN1 is characterized by the accumulation of autofluorescent lysosomal storage material (AFSM) in neurons and robust neuroinflammation. Converging lines of evidence suggest that in addition to cellular waste accumulation, the symptomology of CLN1 corresponds with disruption of synaptic processes. Indeed, loss of Ppt1 function in cortical neurons dysregulates the synaptic incorporation of the GluA1 AMPA receptor (AMPAR) subunit during a type of synaptic plasticity called synaptic scaling. However, the mechanisms causing this aberration are unknown. Here, we used the Ppt1-/- mouse model (both sexes) to further investigate how Ppt1 regulates synaptic plasticity and how its disruption affects downstream signaling pathways. To this end, we performed a palmitoyl-proteomic screen, which provoked the discovery that Akap5 is excessively palmitoylated at Ppt1-/- synapses. Extending our previous data, in vivo induction of synaptic scaling, which is regulated by Akap5, caused an excessive upregulation of GluA1 in Ppt1-/- mice. This synaptic change was associated with exacerbated disease pathology. Furthermore, the Akap5- and inflammation-associated transcriptional regulator, nuclear factor of activated T cells (NFAT), was sensitized in Ppt1-/- cortical neurons. Suppressing the upstream regulator of NFAT activation, calcineurin, with the FDA-approved therapeutic FK506 (Tacrolimus) modestly improved neuroinflammation in Ppt1-/- mice. These findings indicate that the absence of depalmitoylation stifles synaptic protein trafficking and contributes to neuroinflammation via an Akap5-associated mechanism.
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Affiliation(s)
- Kevin P. Koster
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Zach Fyke
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Thu T. A. Nguyen
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Amanda Niqula
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | | | - Kevin M. Woolfrey
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Stephanie M. Cologna
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Akira Yoshii
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL, United States
- Department of Neurology, University of Illinois at Chicago, Chicago, IL, United States
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5
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Mykins M, Bridges B, Jo A, Krishnan K. Multidimensional Analysis of a Social Behavior Identifies Regression and Phenotypic Heterogeneity in a Female Mouse Model for Rett Syndrome. J Neurosci 2024; 44:e1078232023. [PMID: 38199865 PMCID: PMC10957218 DOI: 10.1523/jneurosci.1078-23.2023] [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: 06/09/2023] [Revised: 11/01/2023] [Accepted: 11/17/2023] [Indexed: 01/12/2024] Open
Abstract
Regression is a key feature of neurodevelopmental disorders such as autism spectrum disorder, Fragile X syndrome, and Rett syndrome (RTT). RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). It is characterized by an early period of typical development with subsequent regression of previously acquired motor and speech skills in girls. The syndromic phenotypes are individualistic and dynamic over time. Thus far, it has been difficult to capture these dynamics and syndromic heterogeneity in the preclinical Mecp2-heterozygous female mouse model (Het). The emergence of computational neuroethology tools allows for robust analysis of complex and dynamic behaviors to model endophenotypes in preclinical models. Toward this first step, we utilized DeepLabCut, a marker-less pose estimation software to quantify trajectory kinematics and multidimensional analysis to characterize behavioral heterogeneity in Het in the previously benchmarked, ethologically relevant social cognition task of pup retrieval. We report the identification of two distinct phenotypes of adult Het: Het that display a delay in efficiency in early days and then improve over days like wild-type mice and Het that regress and perform worse in later days. Furthermore, regression is dependent on age and behavioral context and can be detected in the initial days of retrieval. Together, the novel identification of two populations of Het suggests differential effects on neural circuitry, opens new avenues to investigate the underlying molecular and cellular mechanisms of heterogeneity, and designs better studies for stratifying therapeutics.
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Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Benjamin Bridges
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Angela Jo
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
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Li WK, Zhang SQ, Peng WL, Shi YH, Yuan B, Yuan YT, Xue ZY, Wang JC, Han WJ, Chen ZF, Shan SF, Xue BQ, Chen JL, Zhang C, Zhu SJ, Tai YL, Cheng TL, Qiu ZL. Whole-brain in vivo base editing reverses behavioral changes in Mef2c-mutant mice. Nat Neurosci 2024; 27:116-128. [PMID: 38012399 DOI: 10.1038/s41593-023-01499-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 10/16/2023] [Indexed: 11/29/2023]
Abstract
Whole-brain genome editing to correct single-base mutations and reduce or reverse behavioral changes in animal models of autism spectrum disorder (ASD) has not yet been achieved. We developed an apolipoprotein B messenger RNA-editing enzyme, catalytic polypeptide-embedded cytosine base editor (AeCBE) system for converting C·G to T·A base pairs. We demonstrate its effectiveness by targeting AeCBE to an ASD-associated mutation of the MEF2C gene (c.104T>C, p.L35P) in vivo in mice. We first constructed Mef2cL35P heterozygous mice. Male heterozygous mice exhibited hyperactivity, repetitive behavior and social abnormalities. We then programmed AeCBE to edit the mutated C·G base pairs of Mef2c in the mouse brain through the intravenous injection of blood-brain barrier-crossing adeno-associated virus. This treatment successfully restored Mef2c protein levels in several brain regions and reversed the behavioral abnormalities in Mef2c-mutant mice. Our work presents an in vivo base-editing paradigm that could potentially correct single-base genetic mutations in the brain.
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Affiliation(s)
- Wei-Ke Li
- Songjiang Research Institute, Songjiang Hospital & MOE-Shanghai Key Laboratory for Children's Environmental Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Institute of Pediatrics, National Children's Medical Center, Children's Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Shu-Qian Zhang
- Institute of Pediatrics, National Children's Medical Center, Children's Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Wan-Ling Peng
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yu-Han Shi
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Bo Yuan
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yi-Ting Yuan
- Songjiang Research Institute, Songjiang Hospital & MOE-Shanghai Key Laboratory for Children's Environmental Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen-Yu Xue
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin-Cheng Wang
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Wen-Jian Han
- Songjiang Research Institute, Songjiang Hospital & MOE-Shanghai Key Laboratory for Children's Environmental Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhi-Fang Chen
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Shi-Fang Shan
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Bi-Qing Xue
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Ministry of Education Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Jin-Long Chen
- Institute of Pediatrics, National Children's Medical Center, Children's Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Cheng Zhang
- Institute of Pediatrics, National Children's Medical Center, Children's Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Shu-Jia Zhu
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yi-Lin Tai
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Ministry of Education Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Tian-Lin Cheng
- Institute of Pediatrics, National Children's Medical Center, Children's Hospital, Institute for Translational Brain Research, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China.
| | - Zi-Long Qiu
- Songjiang Research Institute, Songjiang Hospital & MOE-Shanghai Key Laboratory for Children's Environmental Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.
- Clinical Neuroscience Center, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
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Farhoomand F, Delaney KR. Long-term cortical plasticity following sensory deprivation is reduced in male Rett model mice. Somatosens Mot Res 2023; 40:133-140. [PMID: 36565289 DOI: 10.1080/08990220.2022.2158799] [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: 03/01/2022] [Accepted: 12/08/2022] [Indexed: 12/25/2022]
Abstract
PURPOSE/AIM Rett (RTT) syndrome, a neurodevelopmental disorder, results from loss-of-function mutations in methyl-CpG-binding protein 2. We studied activity-dependent plasticity induced by sensory deprivation via whisker trimming in early symptomatic male mutant mice to assess neural rewiring capability. METHODS One whisker was trimmed for 0-14 days and intrinsic optical imaging of the transient reduction of brain blood oxygenation resulting from neural activation by 1 second of wiggling of the whisker stump was compared to that of an untrimmed control whisker. RESULTS Cortical evoked responses to wiggling a non-trimmed whisker were constant for 14 days, reduced for a trimmed whisker by 49.0 ± 4.3% in wild type (n = 14) but by only 22.7 ± 4.6% in mutant (n = 18, p = 0.001). CONCLUSION As the reduction in neural activation following sensory deprivation in whisker barrel cortex is known to be dependent upon evoked and basal neural activity, impairment of cortical re-wiring following whisker trimming provides a paradigm suitable to explore mechanisms underlying deficiencies in the establishment and maintenance of synapses in RTT, which can be potentially targeted by therapeutics.
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Affiliation(s)
| | - Kerry R Delaney
- Department of Biology, University of Victoria, Victoria, B.C, Canada
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Monday HR, Wang HC, Feldman DE. Circuit-level theories for sensory dysfunction in autism: convergence across mouse models. Front Neurol 2023; 14:1254297. [PMID: 37745660 PMCID: PMC10513044 DOI: 10.3389/fneur.2023.1254297] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/14/2023] [Indexed: 09/26/2023] Open
Abstract
Individuals with autism spectrum disorder (ASD) exhibit a diverse range of behavioral features and genetic backgrounds, but whether different genetic forms of autism involve convergent pathophysiology of brain function is unknown. Here, we analyze evidence for convergent deficits in neural circuit function across multiple transgenic mouse models of ASD. We focus on sensory areas of neocortex, where circuit differences may underlie atypical sensory processing, a central feature of autism. Many distinct circuit-level theories for ASD have been proposed, including increased excitation-inhibition (E-I) ratio and hyperexcitability, hypofunction of parvalbumin (PV) interneuron circuits, impaired homeostatic plasticity, degraded sensory coding, and others. We review these theories and assess the degree of convergence across ASD mouse models for each. Behaviorally, our analysis reveals that innate sensory detection behavior is heightened and sensory discrimination behavior is impaired across many ASD models. Neurophysiologically, PV hypofunction and increased E-I ratio are prevalent but only rarely generate hyperexcitability and excess spiking. Instead, sensory tuning and other aspects of neural coding are commonly degraded and may explain impaired discrimination behavior. Two distinct phenotypic clusters with opposing neural circuit signatures are evident across mouse models. Such clustering could suggest physiological subtypes of autism, which may facilitate the development of tailored therapeutic approaches.
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Affiliation(s)
- Hannah R. Monday
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | | | - Daniel E. Feldman
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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9
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Mykins M, Layo-Carris D, Dunn LR, Skinner DW, McBryar AH, Perez S, Shultz TR, Willems A, Lau BYB, Hong T, Krishnan K. Wild-type MECP2 expression coincides with age-dependent sensory phenotypes in a female mouse model for Rett syndrome. J Neurosci Res 2023; 101:1236-1258. [PMID: 37026482 PMCID: PMC10332853 DOI: 10.1002/jnr.25190] [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: 09/14/2022] [Revised: 02/07/2023] [Accepted: 03/12/2023] [Indexed: 04/08/2023]
Abstract
Rett syndrome is characterized by an early period of typical development and then, regression of learned motor and speech skills in girls. Loss of MECP2 protein is thought to cause Rett syndrome phenotypes. The specific underlying mechanisms from typical developmental trajectory to regression features throughout life are unclear. Lack of established timelines to study the molecular, cellular, and behavioral features of regression in female mouse models is a major contributing factor. Due to random X-chromosome inactivation, female patients with Rett syndrome and female mouse models for Rett syndrome (Mecp2Heterozygous , Het) express a functional copy of wild-type MECP2 protein in approximately half of all cells. As MECP2 expression is regulated during early postnatal development and experience, we characterized the expression of wild-type MECP2 in the primary somatosensory cortex of female Het mice. Here, we report increased MECP2 levels in non-parvalbumin-positive neurons of 6-week-old adolescent Het relative to age-matched wild-type controls, while also displaying typical levels of perineuronal net expression in the barrel field subregion of the primary somatosensory cortex, mild tactile sensory perception deficits, and efficient pup retrieval behavior. In contrast, 12-week-old adult Het express MECP2 at levels similar to age-matched wild-type mice, show increased perineuronal net expression in the cortex, and display significant tactile sensory perception deficits. Thus, we have identified a set of behavioral metrics and the cellular substrates to study regression during a specific time in the female Het mouse model, which coincides with changes in wild-type MECP2 expression. We speculate that the precocious increase in MECP2 expression within specific cell types of adolescent Het may provide compensatory benefits at the behavioral level, while the inability to further increase MECP2 levels leads to regressive behavioral phenotypes over time.
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Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Dana Layo-Carris
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Logan Reid Dunn
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - David Wilson Skinner
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Alexandra Hart McBryar
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Sarah Perez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Trinity Rose Shultz
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Andrew Willems
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Billy You Bun Lau
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Tian Hong
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
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10
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Gonda S, Köhler I, Haase A, Czubay K, Räk A, Riedel C, Wahle P. Optogenetic stimulation shapes dendritic trees of infragranular cortical pyramidal cells. Front Cell Neurosci 2023; 17:1212483. [PMID: 37587917 PMCID: PMC10427221 DOI: 10.3389/fncel.2023.1212483] [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: 04/26/2023] [Accepted: 06/09/2023] [Indexed: 08/18/2023] Open
Abstract
Spontaneous or experimentally evoked activity can lead to changes in length and/or branching of neocortical pyramidal cell dendrites. For instance, an early postnatal overexpression of certain AMPA or kainate glutamate receptor subunits leads to larger amplitudes of depolarizing events driven by spontaneous activity, and this increases apical dendritic complexity. Whether stimulation frequency has a role is less clear. In this study, we report that the expression of channelrhodopsin2-eYFP was followed by a 5-day optogenetic stimulation from DIV 5-10 or 11-15 in organotypic cultures of rat visual cortex-evoked dendritic remodeling. Stimulation at 0.05 Hz, at a frequency range of spontaneous calcium oscillations known to occur in the early postnatal neocortex in vivo until eye opening, had no effect. Stimulation with 0.5 Hz, a frequency at which the cortex in vivo adopts after eye opening, unexpectedly caused shorter and somewhat less branched apical dendrites of infragranular pyramidal neurons. The outcome resembles the remodeling of corticothalamic and callosal projection neurons of layers VI and V, which in the adult have apical dendrites no longer terminating in layer I. Exposure to 2.5 Hz, a frequency not occurring naturally during the time windows, evoked dendritic damage. The results suggested that optogenetic stimulation at a biologically meaningful frequency for the selected developmental stage can influence dendrite growth, but contrary to expectation, the optogenetic stimulation decreased dendritic growth.
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11
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Oluigbo DC. Rett Syndrome: A Tale of Altered Genetics, Synaptic Plasticity, and Neurodevelopmental Dynamics. Cureus 2023; 15:e41555. [PMID: 37554594 PMCID: PMC10405636 DOI: 10.7759/cureus.41555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2023] [Indexed: 08/10/2023] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder that is a leading cause of severe cognitive and physical impairment. RTT typically occurs in females, although rare cases of males with the disease exist. Its genetic cause, symptoms, and clinical progression timeline have also become well-documented since its initial discovery. However, a relatively late diagnosis and lack of an available cure signify that our understanding of the disease is incomplete. Innovative research methods and tools are thereby helping to fill gaps in our knowledge of RTT. Specifically, mouse models of RTT, video analysis, and retrospective parental analysis are well-established tools that provide valuable insights into RTT. Moreover, current and anticipated treatment options are improving the quality of life of the RTT patient population. Collectively, these developments are creating optimistic future perspectives for RTT.
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Affiliation(s)
- David C Oluigbo
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, USA
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12
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Scaffei E, Mazziotti R, Conti E, Costanzo V, Calderoni S, Stoccoro A, Carmassi C, Tancredi R, Baroncelli L, Battini R. A Potential Biomarker of Brain Activity in Autism Spectrum Disorders: A Pilot fNIRS Study in Female Preschoolers. Brain Sci 2023; 13:951. [PMID: 37371429 DOI: 10.3390/brainsci13060951] [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: 05/07/2023] [Revised: 05/29/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023] Open
Abstract
Autism spectrum disorder (ASD) refers to a neurodevelopmental condition whose detection still remains challenging in young females due to the heterogeneity of the behavioral phenotype and the capacity of camouflage. The availability of quantitative biomarkers to assess brain function may support in the assessment of ASD. Functional Near-infrared Spectroscopy (fNIRS) is a non-invasive and flexible tool that quantifies cortical hemodynamic responses (HDR) that can be easily employed to describe brain activity. Since the study of the visual phenotype is a paradigmatic model to evaluate cerebral processing in many neurodevelopmental conditions, we hypothesized that visually-evoked HDR (vHDR) might represent a potential biomarker in ASD females. We performed a case-control study comparing vHDR in a cohort of high-functioning preschooler females with ASD (fASD) and sex/age matched peers. We demonstrated the feasibility of visual fNIRS measurements in fASD, and the possibility to discriminate between fASD and typical subjects using different signal features, such as the amplitude and lateralization of vHDR. Moreover, the level of response lateralization was correlated to the severity of autistic traits. These results corroborate the cruciality of sensory symptoms in ASD, paving the way for the validation of the fNIRS analytical tool for diagnosis and treatment outcome monitoring in the ASD population.
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Affiliation(s)
- Elena Scaffei
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, 50135 Florence, Italy
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
| | - Raffaele Mazziotti
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, 56124 Pisa, Italy
| | - Eugenia Conti
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
| | - Valeria Costanzo
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
| | - Sara Calderoni
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy
| | - Andrea Stoccoro
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56100 Pisa, Italy
| | - Claudia Carmassi
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy
| | | | - Laura Baroncelli
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, 56124 Pisa, Italy
| | - Roberta Battini
- IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy
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13
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He JL, Williams ZJ, Harris A, Powell H, Schaaf R, Tavassoli T, Puts NAJ. A working taxonomy for describing the sensory differences of autism. Mol Autism 2023; 14:15. [PMID: 37041612 PMCID: PMC10091684 DOI: 10.1186/s13229-022-00534-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 12/14/2022] [Indexed: 04/13/2023] Open
Abstract
BACKGROUND Individuals on the autism spectrum have been long described to process sensory information differently than neurotypical individuals. While much effort has been leveraged towards characterizing and investigating the neurobiology underlying the sensory differences of autism, there has been a notable lack of consistency in the terms being used to describe the nature of those differences. MAIN BODY We argue that inconsistent and interchangeable terminology-use when describing the sensory differences of autism has become problematic beyond mere pedantry and inconvenience. We begin by highlighting popular terms that are currently being used to describe the sensory differences of autism (e.g. "sensitivity", "reactivity" and "responsivity") and discuss why poor nomenclature may hamper efforts towards understanding the aetiology of sensory differences in autism. We then provide a solution to poor terminology-use by proposing a hierarchical taxonomy for describing and referring to various sensory features. CONCLUSION Inconsistent terminology-use when describing the sensory features of autism has stifled discussion and scientific understanding of the sensory differences of autism. The hierarchical taxonomy proposed was developed to help resolve lack of clarity when discussing the sensory differences of autism and to place future research targets at appropriate levels of analysis.
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Affiliation(s)
- Jason L He
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK.
| | - Zachary J Williams
- Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
- Frist Center for Autism and Innovation, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ashley Harris
- Department of Radiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Helen Powell
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Roseann Schaaf
- Department of Occupational Therapy, Thomas Jefferson University, Philadelphia, PA, USA
| | - Teresa Tavassoli
- School of Psychology and Clinical Language Sciences, University of Reading, Reading, RG6 6AL, UK
| | - Nicolaas A J Puts
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
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14
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Durand S, Heller GR, Ramirez TK, Luviano JA, Williford A, Sullivan DT, Cahoon AJ, Farrell C, Groblewski PA, Bennett C, Siegle JH, Olsen SR. Acute head-fixed recordings in awake mice with multiple Neuropixels probes. Nat Protoc 2023; 18:424-457. [PMID: 36477710 DOI: 10.1038/s41596-022-00768-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 08/09/2022] [Indexed: 12/12/2022]
Abstract
Multi-electrode arrays such as Neuropixels probes enable electrophysiological recordings from large populations of single neurons with high temporal resolution. By using such probes, the activity from functionally interacting, yet distinct, brain regions can be measured simultaneously by inserting multiple probes into the same subject. However, the use of multiple probes in small animals such as mice requires the removal of a sizable fraction of the skull, while also minimizing tissue damage and keeping the brain stable during the recordings. Here, we describe a step-by-step process designed to facilitate reliable recordings from up to six Neuropixels probes simultaneously in awake, head-fixed mice. The procedure involves four stages: the implantation of a headframe and a removable glass coverslip, the precise positioning of the Neuropixels probes at targeted points on the brain surface, the placement of a perforated plastic imaging window and the insertion of the probes into the brain of an awake mouse. The approach provides access to multiple brain regions and has been successfully applied across hundreds of mice. The procedure has been optimized for dense recordings from the mouse visual system, but it can be adapted for alternative recording configurations to target multiple probes in other brain areas. The protocol is suitable for users with experience in stereotaxic surgery in mice.
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Affiliation(s)
| | - Greggory R Heller
- Allen Institute, Seattle, WA, USA.,Department of Brain and Cognitive Sciences, Massachussetts Institute of Technology, Cambridge, MA, USA
| | - Tamina K Ramirez
- Allen Institute, Seattle, WA, USA.,Department of Neurobiology and Behavior, Columbia University, New York, NY, USA
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15
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Abstract
Recent advances in genomics have revealed a wide spectrum of genetic variants associated with neurodevelopmental disorders at an unprecedented scale. An increasing number of studies have consistently identified mutations-both inherited and de novo-impacting the function of specific brain circuits. This suggests that, during brain development, alterations in distinct neural circuits, cell types, or broad regulatory pathways ultimately shaping synapses might be a dysfunctional process underlying these disorders. Here, we review findings from human studies and animal model research to provide a comprehensive description of synaptic and circuit mechanisms implicated in neurodevelopmental disorders. We discuss how specific synaptic connections might be commonly disrupted in different disorders and the alterations in cognition and behaviors emerging from imbalances in neuronal circuits. Moreover, we review new approaches that have been shown to restore or mitigate dysfunctional processes during specific critical windows of brain development. Considering the heterogeneity of neurodevelopmental disorders, we also highlight the recent progress in developing improved clinical biomarkers and strategies that will help to identify novel therapeutic compounds and opportunities for early intervention.
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Affiliation(s)
- David Exposito-Alonso
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom;
- Current affiliation: Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA;
| | - Beatriz Rico
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom;
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16
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Groves Kuhnle C, Grimes M, Suárez Casanova VM, Turrigiano GG, Van Hooser SD. Juvenile Shank3 KO Mice Adopt Distinct Hunting Strategies during Prey Capture Learning. eNeuro 2022; 9:ENEURO.0230-22.2022. [PMID: 36446569 PMCID: PMC9768843 DOI: 10.1523/eneuro.0230-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 10/11/2022] [Accepted: 10/23/2022] [Indexed: 12/02/2022] Open
Abstract
Mice are opportunistic omnivores that readily learn to hunt and eat insects such as crickets. The details of how mice learn these behaviors and how these behaviors may differ in strains with altered neuroplasticity are unclear. We quantified the behavior of juvenile wild-type (WT) and Shank3 knock-out (KO) mice as they learned to hunt crickets during the critical period for ocular dominance plasticity. This stage involves heightened cortical plasticity including homeostatic synaptic scaling, which requires Shank3, a glutamatergic synaptic protein that, when mutated, produces Phelan-McDermid syndrome and is often comorbid with autism spectrum disorder (ASD). Both strains showed interest in examining live and dead crickets and learned to hunt. Shank3 knock-out mice took longer to become proficient, and, after 5 d, did not achieve the efficiency of wild-type mice in either time-to-capture or distance-to-capture. Shank3 knock-out mice also exhibited different characteristics when pursuing crickets that could not be explained by a simple motor deficit. Although both genotypes moved at the same average speed when approaching a cricket, Shank3 KO mice paused more often, did not begin final accelerations toward crickets as early, and did not close the distance gap to the cricket as quickly as wild-type mice. These differences in Shank3 KO mice are reminiscent of some behavioral characteristics of individuals with ASD as they perform complex tasks, such as slower action initiation and completion. This paradigm will be useful for exploring the neural circuit mechanisms that underlie these learning and performance differences in monogenic ASD rodent models.
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Affiliation(s)
| | - Micaela Grimes
- Department of Biology, Brandeis University, Waltham, MA 02453
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17
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A Global Multiregional Proteomic Map of the Human Cerebral Cortex. GENOMICS, PROTEOMICS & BIOINFORMATICS 2022; 20:614-632. [PMID: 34763096 PMCID: PMC9880820 DOI: 10.1016/j.gpb.2021.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 06/25/2021] [Accepted: 09/27/2021] [Indexed: 01/31/2023]
Abstract
The Brodmann area (BA)-based map is one of the most widely used cortical maps for studies of human brain functions and in clinical practice; however, the molecular architecture of BAs remains unknown. The present study provided a global multiregional proteomic map of the human cerebral cortex by analyzing 29 BAs. These 29 BAs were grouped into 6 clusters based on similarities in proteomic patterns: the motor and sensory cluster, vision cluster, auditory and Broca's area cluster, Wernicke's area cluster, cingulate cortex cluster, and heterogeneous function cluster. We identified 474 cluster-specific and 134 BA-specific signature proteins whose functions are closely associated with specialized functions and disease vulnerability of the corresponding cluster or BA. The findings of the present study could provide explanations for the functional connections between the anterior cingulate cortex and sensorimotor cortex and for anxiety-related function in the sensorimotor cortex. The brain transcriptome and proteome comparison indicates that they both could reflect the function of cerebral cortex, but show different characteristics. These proteomic data are publicly available at the Human Brain Proteome Atlas (www.brain-omics.com). Our results may enhance our understanding of the molecular basis of brain functions and provide an important resource to support human brain research.
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18
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Smith M, Arthur B, Cikowski J, Holt C, Gonzalez S, Fisher NM, Vermudez SAD, Lindsley CW, Niswender CM, Gogliotti RG. Clinical and Preclinical Evidence for M 1 Muscarinic Acetylcholine Receptor Potentiation as a Therapeutic Approach for Rett Syndrome. Neurotherapeutics 2022; 19:1340-1352. [PMID: 35670902 PMCID: PMC9587166 DOI: 10.1007/s13311-022-01254-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2022] [Indexed: 12/04/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder that is characterized by developmental regression, loss of communicative ability, stereotyped hand wringing, cognitive impairment, and central apneas, among many other symptoms. RTT is caused by loss-of-function mutations in a methyl-reader known as methyl-CpG-binding protein 2 (MeCP2), a protein that links epigenetic changes on DNA to larger chromatin structure. Historically, target identification for RTT has relied heavily on Mecp2 knockout mice; however, we recently adopted the alternative approach of performing transcriptional profiling in autopsy samples from RTT patients. Through this mechanism, we identified muscarinic acetylcholine receptors (mAChRs) as potential therapeutic targets. Here, we characterized a cohort of 40 temporal cortex samples from individuals with RTT and quantified significantly decreased levels of the M1, M2, M3, and M5 mAChRs subtypes relative to neurotypical controls. Of these four subtypes, M1 expression demonstrated a linear relationship with MeCP2 expression, such that M1 levels were only diminished in contexts where MeCP2 was also significantly decreased. Further, we show that M1 potentiation with the positive allosteric modulator (PAM) VU0453595 (VU595) rescued social preference, spatial memory, and associative memory deficits, as well as decreased apneas in Mecp2+/- mice. VU595's efficacy on apneas in Mecp2+/- mice was mediated by the facilitation of the transition from inspiration to expiration. Molecular analysis correlated rescue with normalized global gene expression patterns in the brainstem and hippocampus, as well as increased Gsk3β inhibition and NMDA receptor trafficking. Together, these data suggest that M1 PAMs could represent a new class of RTT therapeutics.
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Affiliation(s)
- Mackenzie Smith
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL, 60153, USA
- Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA
| | - Bright Arthur
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Jakub Cikowski
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL, 60153, USA
- Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA
| | - Calista Holt
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL, 60153, USA
- Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA
| | - Sonia Gonzalez
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL, 60153, USA
- Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA
| | - Nicole M Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Sheryl Anne D Vermudez
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, USA
| | - Rocco G Gogliotti
- Department of Molecular Pharmacology and Neuroscience, Loyola University Chicago, Maywood, IL, 60153, USA.
- Edward Hines Jr. VA Hospital, Hines, IL, 60141, USA.
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, USA.
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19
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Li W. Excitation and Inhibition Imbalance in Rett Syndrome. Front Neurosci 2022; 16:825063. [PMID: 35250460 PMCID: PMC8894599 DOI: 10.3389/fnins.2022.825063] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
A loss of the excitation/inhibition (E/I) balance in the neural circuit has emerged as a common neuropathological feature in many neurodevelopmental disorders. Rett syndrome (RTT), a prevalent neurodevelopmental disorder that affects 1:10,000-15,000 women globally, is caused by loss-of-function mutations in the Methyl-CpG-binding Protein-2 (Mecp2) gene. E/I imbalance is recognized as the leading cellular and synaptic hallmark that is fundamental to diverse RTT neurological symptoms, including stereotypic hand movements, impaired motor coordination, breathing irregularities, seizures, and learning/memory dysfunctions. E/I balance in RTT is not homogeneously altered but demonstrates brain region and cell type specificity instead. In this review, I elaborate on the current understanding of the loss of E/I balance in a range of brain areas at molecular and cellular levels. I further describe how the underlying cellular mechanisms contribute to the disturbance of the proper E/I ratio. Last, I discuss current pharmacologic innervations for RTT and their role in modifying the E/I balance.
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Affiliation(s)
- Wei Li
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
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20
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The amplitude of fNIRS hemodynamic response in the visual cortex unmasks autistic traits in typically developing children. Transl Psychiatry 2022; 12:53. [PMID: 35136021 PMCID: PMC8826368 DOI: 10.1038/s41398-022-01820-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 12/21/2022] Open
Abstract
Autistic traits represent a continuum dimension across the population, with autism spectrum disorder (ASD) being the extreme end of the distribution. Accumulating evidence shows that neuroanatomical and neurofunctional profiles described in relatives of ASD individuals reflect an intermediate neurobiological pattern between the clinical population and healthy controls. This suggests that quantitative measures detecting autistic traits in the general population represent potential candidates for the development of biomarkers identifying early pathophysiological processes associated with ASD. Functional near-infrared spectroscopy (fNIRS) has been extensively employed to investigate neural development and function. In contrast, the potential of fNIRS to define reliable biomarkers of brain activity has been barely explored. Features of non-invasiveness, portability, ease of administration, and low-operating costs make fNIRS a suitable instrument to assess brain function for differential diagnosis, follow-up, analysis of treatment outcomes, and personalized medicine in several neurological conditions. Here, we introduce a novel standardized procedure with high entertaining value to measure hemodynamic responses (HDR) in the occipital cortex of adult subjects and children. We found that the variability of evoked HDR correlates with the autistic traits of children, assessed by the Autism-Spectrum Quotient. Interestingly, HDR amplitude was especially linked to social and communication features, representing the core symptoms of ASD. These findings establish a quick and easy strategy for measuring visually-evoked cortical activity with fNIRS that optimize the compliance of young subjects, setting the background for testing the diagnostic value of fNIRS visual measurements in the ASD clinical population.
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21
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Abstract
SUMMARY The field of clinical EEG has had an uneasy relationship with the use of this technology for clinical cognitive applications and often for good reason. However, apart from its clinical use, EEG has had a tradition as a major tool in cognitive psychology and cognitive neuroscience dating back at least to the 1960s. Based on accumulated knowledge from its research application, EEG-based biomarkers are beginning to see applications in clinical trials and may eventually enter clinical care. We address concerns surrounding quality control, the treatment of artifact, and normal variants and how developments in engineering, biomarker validation, and implementation science rigorously applied to these tools can lead to well-justified approaches.
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Affiliation(s)
- Joshua B. Ewen
- Kennedy Krieger Institute, Baltimore, MD
- Johns Hopkins University, Baltimore, MD
| | - April R. Levin
- Harvard Medical School, Boston, MA
- Boston Children’s Hospital, Boston, MA
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22
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Bach S, Shovlin S, Moriarty M, Bardoni B, Tropea D. Rett Syndrome and Fragile X Syndrome: Different Etiology With Common Molecular Dysfunctions. Front Cell Neurosci 2021; 15:764761. [PMID: 34867203 PMCID: PMC8640214 DOI: 10.3389/fncel.2021.764761] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/27/2021] [Indexed: 01/04/2023] Open
Abstract
Rett syndrome (RTT) and Fragile X syndrome (FXS) are two monogenetic neurodevelopmental disorders with complex clinical presentations. RTT is caused by mutations in the Methyl-CpG binding protein 2 gene (MECP2) altering the function of its protein product MeCP2. MeCP2 modulates gene expression by binding methylated CpG dinucleotides, and by interacting with transcription factors. FXS is caused by the silencing of the FMR1 gene encoding the Fragile X Mental Retardation Protein (FMRP), a RNA binding protein involved in multiple steps of RNA metabolism, and modulating the translation of thousands of proteins including a large set of synaptic proteins. Despite differences in genetic etiology, there are overlapping features in RTT and FXS, possibly due to interactions between MeCP2 and FMRP, and to the regulation of pathways resulting in dysregulation of common molecular signaling. Furthermore, basic physiological mechanisms are regulated by these proteins and might concur to the pathophysiology of both syndromes. Considering that RTT and FXS are disorders affecting brain development, and that most of the common targets of MeCP2 and FMRP are involved in brain activity, we discuss the mechanisms of synaptic function and plasticity altered in RTT and FXS, and we consider the similarities and the differences between these two disorders.
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Affiliation(s)
- Snow Bach
- School of Mathematical Sciences, Dublin City University, Dublin, Ireland.,Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland
| | - Stephen Shovlin
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland
| | | | - Barbara Bardoni
- Inserm, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Université Côte d'Azur, Valbonne, France
| | - Daniela Tropea
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland.,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland
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23
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Ciptasari U, van Bokhoven H. The phenomenal epigenome in neurodevelopmental disorders. Hum Mol Genet 2021; 29:R42-R50. [PMID: 32766754 PMCID: PMC7530535 DOI: 10.1093/hmg/ddaa175] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/16/2020] [Accepted: 07/30/2020] [Indexed: 12/12/2022] Open
Abstract
Disruption of chromatin structure due to epimutations is a leading genetic etiology of neurodevelopmental disorders, collectively known as chromatinopathies. We show that there is an increasing level of convergence from the high diversity of genes that are affected by mutations to the molecular networks and pathways involving the respective proteins, the disrupted cellular and subcellular processes, and their consequence for higher order cellular network function. This convergence is ultimately reflected by specific phenotypic features shared across the various chromatinopathies. Based on these observations, we propose that the commonly disrupted molecular and cellular anomalies might provide a rational target for the development of symptomatic interventions for defined groups of genetically distinct neurodevelopmental disorders.
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Affiliation(s)
- Ummi Ciptasari
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud university medical center, 6500 HB Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud university medical center, 6500 HB Nijmegen, The Netherlands.,Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud university medical center, 6500 HB Nijmegen, The Netherlands
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24
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Carstens KE, Lustberg DJ, Shaughnessy EK, McCann KE, Alexander GM, Dudek SM. Perineuronal net degradation rescues CA2 plasticity in a mouse model of Rett syndrome. J Clin Invest 2021; 131:e137221. [PMID: 34228646 DOI: 10.1172/jci137221] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/25/2021] [Indexed: 12/14/2022] Open
Abstract
Perineuronal nets (PNNs), a specialized form of extracellular matrix, are abnormal in the brains of people with Rett syndrome (RTT). We previously reported that PNNs function to restrict synaptic plasticity in hippocampal area CA2, which is unusually resistant to long-term potentiation (LTP) and has been linked to social learning in mice. Here we report that PNNs appear elevated in area CA2 of the hippocampus of an individual with RTT and that PNNs develop precociously and remain elevated in area CA2 of a mouse model of RTT (Mecp2-null). Further, we provide evidence that LTP could be induced at CA2 synapses prior to PNN maturation (postnatal day 8-11) in wild-type mice and that this window of plasticity was prematurely restricted at CA2 synapses in Mecp2-null mice. Degrading PNNs in Mecp2-null hippocampus was sufficient to rescue the premature disruption of CA2 plasticity. We identified several molecular targets that were altered in the developing Mecp2-null hippocampus that may explain aberrant PNNs and CA2 plasticity, and we discovered that CA2 PNNs are negatively regulated by neuronal activity. Collectively, our findings demonstrate that CA2 PNN development is regulated by Mecp2 and identify a window of hippocampal plasticity that is disrupted in a mouse model of RTT.
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25
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Scaramuzza L, De Rocco G, Desiato G, Cobolli Gigli C, Chiacchiaretta M, Mirabella F, Pozzi D, De Simone M, Conforti P, Pagani M, Benfenati F, Cesca F, Bedogni F, Landsberger N. The enhancement of activity rescues the establishment of Mecp2 null neuronal phenotypes. EMBO Mol Med 2021; 13:e12433. [PMID: 33665914 PMCID: PMC8033520 DOI: 10.15252/emmm.202012433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 01/29/2023] Open
Abstract
MECP2 mutations cause Rett syndrome (RTT), a severe and progressive neurodevelopmental disorder mainly affecting females. Although RTT patients exhibit delayed onset of symptoms, several evidences demonstrate that MeCP2 deficiency alters early development of the brain. Indeed, during early maturation, Mecp2 null cortical neurons display widespread transcriptional changes, reduced activity, and defective morphology. It has been proposed that during brain development these elements are linked in a feed-forward cycle where neuronal activity drives transcriptional and morphological changes that further increase network maturity. We hypothesized that the enhancement of neuronal activity during early maturation might prevent the onset of RTT-typical molecular and cellular phenotypes. Accordingly, we show that the enhancement of excitability, obtained by adding to neuronal cultures Ampakine CX546, rescues transcription of several genes, neuronal morphology, and responsiveness to stimuli. Greater effects are achieved in response to earlier treatments. In vivo, short and early administration of CX546 to Mecp2 null mice prolongs lifespan, delays the disease progression, and rescues motor abilities and spatial memory, thus confirming the value for RTT of an early restoration of neuronal activity.
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Affiliation(s)
- Linda Scaramuzza
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Department of Bioscience, University of Milan, Milan, Italy; Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Giuseppina De Rocco
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Genni Desiato
- IRCCS Humanitas Research HospitalMilanItaly
- CNR Institute of NeuroscienceMilanItaly
| | - Clementina Cobolli Gigli
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Martina Chiacchiaretta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Present address:
Department of NeuroscienceTufts University School of MedicineBostonMAUSA
| | - Filippo Mirabella
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Davide Pozzi
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Marco De Simone
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Paola Conforti
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Department of BiosciencesUniversity of MilanMilanItaly
| | - Massimiliano Pagani
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- IRCCS Ospedale Policlinico San MartinoGenovaItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Department of Life SciencesUniversity of TriesteTriesteItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Francesco Bedogni
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Neuroscience and Mental Health Research Institute (NMHRI)Division of NeuroscienceSchool of BiosciencesCardiffUK
| | - Nicoletta Landsberger
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
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26
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Saby JN, Benke TA, Peters SU, Standridge SM, Matsuzaki J, Cutri-French C, Swanson LC, Lieberman DN, Key AP, Percy AK, Neul JL, Nelson CA, Roberts TP, Marsh ED. Multisite Study of Evoked Potentials in Rett Syndrome. Ann Neurol 2021; 89:790-802. [PMID: 33480039 PMCID: PMC8882338 DOI: 10.1002/ana.26029] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 01/04/2023]
Abstract
OBJECTIVE The aim of the current study was to evaluate the utility of evoked potentials as a biomarker of cortical function in Rett syndrome (RTT). As a number of disease-modifying therapeutics are currently under development, there is a pressing need for biomarkers to objectively and precisely assess the effectiveness of these treatments. METHOD Yearly visual evoked potentials (VEPs) and auditory evoked potentials (AEPs) were acquired from individuals with RTT, aged 2 to 37 years, and control participants across 5 sites as part of the Rett Syndrome and Related Disorders Natural History Study. Baseline and year 1 data, when available, were analyzed and the repeatability of the results was tested. Two syndrome-specific measures from the Natural History Study were used for evaluating the clinical relevance of the VEP and AEP parameters. RESULTS At the baseline study, group level comparisons revealed reduced VEP and AEP amplitude in RTT compared to control participants. Further analyses within the RTT group indicated that this reduction was associated with RTT-related symptoms, with greater severity associated with lower VEP and AEP amplitude. In participants with RTT, VEP and AEP amplitude was also negatively associated with age. Year 1 follow-up data analyses yielded similar findings and evidence of repeatability of EPs at the individual level. INTERPRETATION The present findings indicate the promise of evoked potentials (EPs) as an objective measure of disease severity in individuals with RTT. Our multisite approach demonstrates potential research and clinical applications to provide unbiased assessment of disease staging, prognosis, and response to therapy. ANN NEUROL 2021;89:790-802.
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Affiliation(s)
- Joni N. Saby
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Timothy A. Benke
- Department of Pediatrics, Neurology, Pharmacology and Otolaryngology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, Colorado
| | - Sarika U. Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Shannon M. Standridge
- Cincinnati Children’s Hospital Medical Center, Division of Neurology and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Junko Matsuzaki
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Clare Cutri-French
- Division of Child Neurology, Children’s Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lindsay C. Swanson
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - David N. Lieberman
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - Alexandra P. Key
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Alan K. Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jeffrey L. Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Vanderbilt Kennedy Center, Nashville, Tennessee
| | - Charles A. Nelson
- Laboratories of Cognitive Neuroscience, Boston Children’s Hospital, Boston, Massachusetts; Department of Pediatrics, Harvard Medical School
| | - Timothy P.L. Roberts
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eric D. Marsh
- Division of Child Neurology, Children’s Hospital of Philadelphia, Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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27
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Patrizi A, Awad PN, Chattopadhyaya B, Li C, Di Cristo G, Fagiolini M. Accelerated Hyper-Maturation of Parvalbumin Circuits in the Absence of MeCP2. Cereb Cortex 2021; 30:256-268. [PMID: 31038696 DOI: 10.1093/cercor/bhz085] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 02/21/2019] [Accepted: 03/29/2019] [Indexed: 12/27/2022] Open
Abstract
Methyl-CpG-binding protein 2 (MeCP2) mutations are the primary cause of Rett syndrome, a severe neurodevelopmental disorder. Cortical parvalbumin GABAergic interneurons (PV) make exuberant somatic connections onto pyramidal cells in the visual cortex of Mecp2-deficient mice, which contributes to silencing neuronal cortical circuits. This phenotype can be rescued independently of Mecp2 by environmental, pharmacological, and genetic manipulation. It remains unknown how Mecp2 mutation can result in abnormal inhibitory circuit refinement. In the present manuscript, we examined the development of GABAergic circuits in the primary visual cortex of Mecp2-deficient mice. We identified that PV circuits were the only GABAergic interneurons to be upregulated, while other interneurons were downregulated. Acceleration of PV cell maturation was accompanied by increased PV cells engulfment by perineuronal nets (PNNs) and by an increase of PV cellular and PNN structural complexity. Interestingly, selective deletion of Mecp2 from PV cells was sufficient to drive increased structure complexity of PNN. Moreover, the accelerated PV and PNN maturation was recapitulated in organotypic cultures. Our results identify a specific timeline of disruption of GABAergic circuits in the absence of Mecp2, indicating a possible cell-autonomous role of MeCP2 in the formation of PV cellular arbors and PNN structures in the visual cortex.
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Affiliation(s)
- Annarita Patrizi
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,Schaller Research Group Leader at the German Cancer Research Center (DKFZ), Heildeberg, Germany
| | - Patricia N Awad
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Chloe Li
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Graziella Di Cristo
- Department of Neurosciences, Université de Montréal, Montreal, Canada.,CHU Ste Justine Research Center, Montreal, QC Canada
| | - Michela Fagiolini
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,International Research Center for Neurointelligence, University of Tokyo Institutes for Advanced Study, Tokyo, Japan
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Mossink B, Negwer M, Schubert D, Nadif Kasri N. The emerging role of chromatin remodelers in neurodevelopmental disorders: a developmental perspective. Cell Mol Life Sci 2021; 78:2517-2563. [PMID: 33263776 PMCID: PMC8004494 DOI: 10.1007/s00018-020-03714-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/04/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022]
Abstract
Neurodevelopmental disorders (NDDs), including intellectual disability (ID) and autism spectrum disorders (ASD), are a large group of disorders in which early insults during brain development result in a wide and heterogeneous spectrum of clinical diagnoses. Mutations in genes coding for chromatin remodelers are overrepresented in NDD cohorts, pointing towards epigenetics as a convergent pathogenic pathway between these disorders. In this review we detail the role of NDD-associated chromatin remodelers during the developmental continuum of progenitor expansion, differentiation, cell-type specification, migration and maturation. We discuss how defects in chromatin remodelling during these early developmental time points compound over time and result in impaired brain circuit establishment. In particular, we focus on their role in the three largest cell populations: glutamatergic neurons, GABAergic neurons, and glia cells. An in-depth understanding of the spatiotemporal role of chromatin remodelers during neurodevelopment can contribute to the identification of molecular targets for treatment strategies.
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Affiliation(s)
- Britt Mossink
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Geert Grooteplein 10, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Moritz Negwer
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Geert Grooteplein 10, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Geert Grooteplein 10, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands.
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29
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Yang D, Robertson HL, Condliffe EG, Carter MT, Dewan T, Gnanakumar V. Rehabilitation therapies in Rett syndrome across the lifespan: A scoping review of human and animal studies. J Pediatr Rehabil Med 2021; 14:69-96. [PMID: 32894256 DOI: 10.3233/prm-200683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
PURPOSE To perform a scoping review of the evidence for therapeutic interventions to manage functional impairments associated with Rett syndrome (RTT) throughout the lifespan. METHODS MEDLINE, EMBASE, PsycINFO, CENTRAL, CINAHL, Scopus and Index to Chiropractic Literature were searched systematically up to December 2019. Two investigators independently reviewed all search results and extracted those that met the inclusion criteria. Human and animal model studies pertaining to therapies that increase functional ability or treat RTT-associated symptoms in all age groups were included. Relevant studies were grouped into intervention categories and rated using the Oxford Centre of Evidence Based Medicine Levels of Evidence. Demographics of participants, interventions, and outcomes were summarized. RESULTS Ninety-one articles representing 88 studies met the inclusion criteria, of which 80 were human clinical studies and eight were studies using animal models. Study designs were primarily case series and only six studies involved participants above the age of 40. CONCLUSION A small number of rigorously studied rehabilitation interventions have been published. Published studies aim to address a wide variety of functional impairments. Research regarding implementation of therapies for older patients with RTT is lacking and requires further exploration.
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Affiliation(s)
- David Yang
- University of Calgary Cumming School of Medicine, Calgary, AB, Canada
| | - Helen Lee Robertson
- Liaison Librarian, Clinical Medicine, Health Sciences Library, University of Calgary, Calgary, AB, Canada
| | - Elizabeth G Condliffe
- Departments of Clinical Neurosciences and Pediatrics, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
| | - Melissa T Carter
- Department of Pediatrics, University of Ottawa, Ottawa, ON, Canada
| | - Tammie Dewan
- Department of Pediatrics, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
| | - Vithya Gnanakumar
- Departments of Clinical Neurosciences and Pediatrics, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
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30
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Filice F, Janickova L, Henzi T, Bilella A, Schwaller B. The Parvalbumin Hypothesis of Autism Spectrum Disorder. Front Cell Neurosci 2020; 14:577525. [PMID: 33390904 PMCID: PMC7775315 DOI: 10.3389/fncel.2020.577525] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
The prevalence of autism spectrum disorder (ASD)-a type of neurodevelopmental disorder-is increasing and is around 2% in North America, Asia, and Europe. Besides the known genetic link, environmental, epigenetic, and metabolic factors have been implicated in ASD etiology. Although highly heterogeneous at the behavioral level, ASD comprises a set of core symptoms including impaired communication and social interaction skills as well as stereotyped and repetitive behaviors. This has led to the suggestion that a large part of the ASD phenotype is caused by changes in a few and common set of signaling pathways, the identification of which is a fundamental aim of autism research. Using advanced bioinformatics tools and the abundantly available genetic data, it is possible to classify the large number of ASD-associated genes according to cellular function and pathways. Cellular processes known to be impaired in ASD include gene regulation, synaptic transmission affecting the excitation/inhibition balance, neuronal Ca2+ signaling, development of short-/long-range connectivity (circuits and networks), and mitochondrial function. Such alterations often occur during early postnatal neurodevelopment. Among the neurons most affected in ASD as well as in schizophrenia are those expressing the Ca2+-binding protein parvalbumin (PV). These mainly inhibitory interneurons present in many different brain regions in humans and rodents are characterized by rapid, non-adaptive firing and have a high energy requirement. PV expression is often reduced at both messenger RNA (mRNA) and protein levels in human ASD brain samples and mouse ASD (and schizophrenia) models. Although the human PVALB gene is not a high-ranking susceptibility/risk gene for either disorder and is currently only listed in the SFARI Gene Archive, we propose and present supporting evidence for the Parvalbumin Hypothesis, which posits that decreased PV level is causally related to the etiology of ASD (and possibly schizophrenia).
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Affiliation(s)
| | | | | | | | - Beat Schwaller
- Section of Medicine, Anatomy, University of Fribourg, Fribourg, Switzerland
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31
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Negwer M, Piera K, Hesen R, Lütje L, Aarts L, Schubert D, Nadif Kasri N. EHMT1 regulates Parvalbumin-positive interneuron development and GABAergic input in sensory cortical areas. Brain Struct Funct 2020; 225:2701-2716. [PMID: 32975655 PMCID: PMC7674571 DOI: 10.1007/s00429-020-02149-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 09/10/2020] [Indexed: 02/08/2023]
Abstract
Mutations in the Euchromatic Histone Methyltransferase 1 (EHMT1) gene cause Kleefstra syndrome, a rare form of intellectual disability (ID) with strong autistic traits and sensory processing deficits. Proper development of inhibitory interneurons is crucial for sensory function. Here we report a timeline of Parvalbumin-positive (PV+) interneuron development in the three most important sensory cortical areas in the Ehmt1+/- mouse. We find a hitherto unreported delay of PV+ neuron maturation early in sensory development, with layer- and region-specific variability later in development. The delayed PV+ maturation is also reflected in a delayed maturation of GABAergic transmission in Ehmt1+/- auditory cortex, where we find a reduced GABA release probability specifically in putative PV+ synapses. Together with earlier reports of excitatory impairments in Ehmt1+/- neurons, we propose a shift in excitatory-inhibitory balance towards overexcitability in Ehmt1+/- sensory cortices as a consequence of early deficits in inhibitory maturation.
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Affiliation(s)
- Moritz Negwer
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Karol Piera
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Rick Hesen
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lukas Lütje
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lynn Aarts
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands.
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32
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Balsor JL, Ahuja D, Jones DG, Murphy KM. A Primer on Constructing Plasticity Phenotypes to Classify Experience-Dependent Development of the Visual Cortex. Front Cell Neurosci 2020; 14:245. [PMID: 33192303 PMCID: PMC7482673 DOI: 10.3389/fncel.2020.00245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 07/15/2020] [Indexed: 11/20/2022] Open
Abstract
Many neural mechanisms regulate experience-dependent plasticity in the visual cortex (V1), and new techniques for quantifying large numbers of proteins or genes are transforming how plasticity is studied into the era of big data. With those large data sets comes the challenge of extracting biologically meaningful results about visual plasticity from data-driven analytical methods designed for high-dimensional data. In other areas of neuroscience, high-information content methodologies are revealing more subtle aspects of neural development and individual variations that give rise to a richer picture of brain disorders. We have developed an approach for studying V1 plasticity that takes advantage of the known functions of many synaptic proteins for regulating visual plasticity. We use that knowledge to rebrand protein measurements into plasticity features and combine those into a plasticity phenotype. Here, we provide a primer for analyzing experience-dependent plasticity in V1 using example R code to identify high-dimensional changes in a group of proteins. We describe using PCA to classify high-dimensional plasticity features and use them to construct a plasticity phenotype. In the examples, we show how to use this analytical framework to study and compare experience-dependent development and plasticity of V1 and apply the plasticity phenotype to translational research questions. We include an R package “PlasticityPhenotypes” that aggregates the coding packages and custom code written in RStudio to construct and analyze plasticity phenotypes.
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Affiliation(s)
- Justin L Balsor
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada
| | - Dezi Ahuja
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
| | | | - Kathryn M Murphy
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada.,Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
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33
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Apulei J, Kim N, Testa D, Ribot J, Morizet D, Bernard C, Jourdren L, Blugeon C, Di Nardo AA, Prochiantz A. Non-cell Autonomous OTX2 Homeoprotein Regulates Visual Cortex Plasticity Through Gadd45b/g. Cereb Cortex 2020; 29:2384-2395. [PMID: 29771284 DOI: 10.1093/cercor/bhy108] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/19/2018] [Indexed: 11/14/2022] Open
Abstract
The non-cell autonomous transfer of OTX2 homeoprotein transcription factor into juvenile mouse cerebral cortex regulates parvalbumin interneuron maturation and critical period timing. By analyzing gene expression in primary visual cortex of wild-type and Otx2+/GFP mice at plastic and nonplastic ages, we identified several putative genes implicated in Otx2-dependent visual cortex plasticity for ocular dominance. Cortical OTX2 infusion in juvenile mice induced Gadd45b/g expression through direct regulation of transcription. Intriguingly, a reverse effect was found in the adult, where reducing cortical OTX2 resulted in Gadd45b/g upregulation. Viral expression of Gadd45b in adult visual cortex directly induced ocular dominance plasticity with concomitant changes in MeCP2 foci within parvalbumin interneurons and in methylation states of several plasticity gene promoters, suggesting epigenetic regulation. This interaction provides a molecular mechanism for OTX2 to trigger critical period plasticity yet suppress adult plasticity.
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Affiliation(s)
- Jessica Apulei
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Namsuk Kim
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Damien Testa
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Jérôme Ribot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - David Morizet
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Clémence Bernard
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Laurent Jourdren
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Corinne Blugeon
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
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34
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Dong HW, Erickson K, Lee JR, Merritt J, Fu C, Neul JL. Detection of neurophysiological features in female R255X MeCP2 mutation mice. Neurobiol Dis 2020; 145:105083. [PMID: 32927061 PMCID: PMC7572861 DOI: 10.1016/j.nbd.2020.105083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/11/2020] [Accepted: 09/08/2020] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder (NDD) that is nearly always caused by loss of function mutations in Methyl-CpG-binding Protein 2 (MECP2) and shares many clinical features with other NDD. Genetic restoration of Mecp2 in symptomatic mice lacking MeCP2 expression can reverse symptoms, providing hope that disease modifying therapies can be identified for RTT. Effective and rapid clinical trial completion relies on well-defined clinical outcome measures and robust biomarkers of treatment responses. Studies on other NDD have found evidence of differences in neurophysiological measures that correlate with disease severity. However, currently there are no well-validated biomarkers in RTT to predict disease prognosis or treatment responses. To address this, we characterized neurophysiological features in a mouse model of RTT containing a knock-in nonsense mutation (p.R255X) in the Mecp2 locus. We found a variety of changes in heterozygous female Mecp2R255X/X mice including age-related changes in sleep/wake architecture, alterations in baseline EEG power, increased incidence of spontaneous epileptiform discharges, and changes in auditory evoked potentials. Furthermore, we identified association of some neurophysiological features with disease severity. These findings provide a set of potential non-invasive and translatable biomarkers that can be utilized in preclinical therapy trials in animal models of RTT and eventually within the context of clinical trials.
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Affiliation(s)
- Hong-Wei Dong
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Kirsty Erickson
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jessica R Lee
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jonathan Merritt
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Cary Fu
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
| | - Jeffrey L Neul
- Department of Pediatrics, Division of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37203, USA.
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35
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Dehorter N, Del Pino I. Shifting Developmental Trajectories During Critical Periods of Brain Formation. Front Cell Neurosci 2020; 14:283. [PMID: 33132842 PMCID: PMC7513795 DOI: 10.3389/fncel.2020.00283] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Critical periods of brain development are epochs of heightened plasticity driven by environmental influence necessary for normal brain function. Recent studies are beginning to shed light on the possibility that timely interventions during critical periods hold potential to reorient abnormal developmental trajectories in animal models of neurological and neuropsychiatric disorders. In this review, we re-examine the criteria defining critical periods, highlighting the recently discovered mechanisms of developmental plasticity in health and disease. In addition, we touch upon technological improvements for modeling critical periods in human-derived neural networks in vitro. These scientific advances associated with the use of developmental manipulations in the immature brain of animal models are the basic preclinical systems that will allow the future translatability of timely interventions into clinical applications for neurodevelopmental disorders such as intellectual disability, autism spectrum disorders (ASD) and schizophrenia.
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Affiliation(s)
- Nathalie Dehorter
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Isabel Del Pino
- Principe Felipe Research Center (Centro de Investigación Principe Felipe, CIPF), Valencia, Spain
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36
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Thion MS, Garel S. Microglial ontogeny, diversity and neurodevelopmental functions. Curr Opin Genet Dev 2020; 65:186-194. [PMID: 32823206 DOI: 10.1016/j.gde.2020.06.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/05/2020] [Accepted: 06/30/2020] [Indexed: 12/29/2022]
Abstract
Microglia are instrumental to the development, function, homeostasis and pathologies of the central nervous system. These brain-resident macrophages arise early in embryogenesis and seed the developing brain, where they differentiate in response to cues provided by their neural niche. Throughout life, microglia regulate the neural tissue through a variety of cellular functions influenced by intrinsic and extrinsic factors. Despite their importance, we are only starting to uncover how microglia colonize the brain, adopt distinct functional states during development and the long-term impact of early alteration of their functions. This review highlights the latest knowledge on the ontogeny of microglia, their developmental trajectory and emerging roles. Characterizing these processes will be critical for our understanding of both brain physiology and pathologies.
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Affiliation(s)
- Morgane Sonia Thion
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France.
| | - Sonia Garel
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France.
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37
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Hooks BM, Chen C. Circuitry Underlying Experience-Dependent Plasticity in the Mouse Visual System. Neuron 2020; 106:21-36. [PMID: 32272065 DOI: 10.1016/j.neuron.2020.01.031] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/13/2020] [Accepted: 01/23/2020] [Indexed: 12/15/2022]
Abstract
Since the discovery of ocular dominance plasticity, neuroscientists have understood that changes in visual experience during a discrete developmental time, the critical period, trigger robust changes in the visual cortex. State-of-the-art tools used to probe connectivity with cell-type-specific resolution have expanded the understanding of circuit changes underlying experience-dependent plasticity. Here, we review the visual circuitry of the mouse, describing projections from retina to thalamus, between thalamus and cortex, and within cortex. We discuss how visual circuit development leads to precise connectivity and identify synaptic loci, which can be altered by activity or experience. Plasticity extends to visual features beyond ocular dominance, involving subcortical and cortical regions, and connections between cortical inhibitory interneurons. Experience-dependent plasticity contributes to the alignment of networks spanning retina to thalamus to cortex. Disruption of this plasticity may underlie aberrant sensory processing in some neurodevelopmental disorders.
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Affiliation(s)
- Bryan M Hooks
- Department of Neurobiology, University of Pittsburgh School of Medicine, W1458 BSTWR, 203 Lothrop Street, Pittsburgh, PA 15213, USA.
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital, Boston, 300 Longwood Avenue, Boston, MA 02115, USA.
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38
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Mazziotti R, Cacciante F, Sagona G, Lupori L, Gennaro M, Putignano E, Alessandrì MG, Ferrari A, Battini R, Cioni G, Pizzorusso T, Baroncelli L. Novel translational phenotypes and biomarkers for creatine transporter deficiency. Brain Commun 2020; 2:fcaa089. [PMID: 32954336 PMCID: PMC7472907 DOI: 10.1093/braincomms/fcaa089] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/20/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Creatine transporter deficiency is a metabolic disorder characterized by intellectual disability, autistic-like behaviour and epilepsy. There is currently no cure for creatine transporter deficiency, and reliable biomarkers of translational value for monitoring disease progression and response to therapeutics are sorely lacking. Here, we found that mice lacking functional creatine transporter display a significant alteration of neural oscillations in the EEG and a severe epileptic phenotype that are recapitulated in patients with creatine transporter deficiency. In-depth examination of knockout mice for creatine transporter also revealed that a decrease in EEG theta power is predictive of the manifestation of spontaneous seizures, a frequency that is similarly affected in patients compared to healthy controls. In addition, knockout mice have a highly specific increase in haemodynamic responses in the cerebral cortex following sensory stimuli. Principal component and Random Forest analyses highlighted that these functional variables exhibit a high performance in discriminating between pathological and healthy phenotype. Overall, our findings identify novel, translational and non-invasive biomarkers for the analysis of brain function in creatine transporter deficiency, providing a very reliable protocol to longitudinally monitor the efficacy of potential therapeutic strategies in preclinical, and possibly clinical, studies.
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Affiliation(s)
- Raffaele Mazziotti
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | | | - Giulia Sagona
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Leonardo Lupori
- BIO@SNS Lab, Scuola Normale Superiore di Pisa, Pisa I-56125, Italy
| | - Mariangela Gennaro
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Maria Grazia Alessandrì
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Annarita Ferrari
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa I-56126, Italy
| | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence I-50135, Italy.,Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy
| | - Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), Pisa I-56124, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa I-56128, Italy
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39
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An Astrocytic Influence on Impaired Tonic Inhibition in Hippocampal CA1 Pyramidal Neurons in a Mouse Model of Rett Syndrome. J Neurosci 2020; 40:6250-6261. [PMID: 32616668 DOI: 10.1523/jneurosci.3042-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 05/13/2020] [Accepted: 06/10/2020] [Indexed: 01/28/2023] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disease caused by mutations in the methyl-CpG binding protein 2 (MECP2) gene. Although altered interneuron development and function are clearly demonstrated in RTT mice, a particular mode of inhibition, tonic inhibition, has not been carefully examined. We report here that tonic inhibition is significantly reduced in pyramidal neurons in the CA1 region of the hippocampus in mice where Mecp2 is deleted either in all cells or specifically in astrocytes. Since no change is detected in the level of GABA receptors, such a reduction in tonic inhibition is likely a result of decreased ambient GABA level in the extracellular space. Consistent with this explanation, we observed increased expression of a GABA transporter, GABA transporter 3 (GAT3), in the hippocampus of the Mecp2 KO mice, as well as a corresponding increase of GAT3 current in hippocampal astrocytes. These phenotypes are relevant to RTT because pharmacological blockage of GAT3 can normalize tonic inhibition and intrinsic excitability in CA1 pyramidal neurons, and rescue the phenotype of increased network excitability in acute hippocampal slices from the Mecp2 KO mice. Finally, chronic administration of a GAT3 antagonist improved a composite symptom score and extended lifespan in the Mecp2 KO mice. Only male mice were used in this study. These results not only advance our understanding of RTT etiology by defining a new neuronal phenotype and revealing how it can be influenced by astrocytic alterations, but also reveal potential targets for intervention.SIGNIFICANCE STATEMENT Our study reports a novel phenotype of reduced tonic inhibition in hippocampal CA1 pyramidal neurons in the Rett syndrome mice, reveal a potential mechanism of increased GABA transporter expression/activity in the neighboring astrocytes, describe a disease-relevant consequence in hyperexcitability, and provide preliminary evidence that targeting this phenotype may slow down disease progression in Rett syndrome mice. These results help our understanding of the disease etiology and identify a new therapeutic target for treating Rett syndrome.
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40
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Lateralized Expression of Cortical Perineuronal Nets during Maternal Experience is Dependent on MECP2. eNeuro 2020; 7:ENEURO.0500-19.2020. [PMID: 32332080 PMCID: PMC7294466 DOI: 10.1523/eneuro.0500-19.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023] Open
Abstract
Cortical neuronal circuits along the sensorimotor pathways are shaped by experience during critical periods of heightened plasticity in early postnatal development. After closure of critical periods, measured histologically by the formation and maintenance of extracellular matrix structures called perineuronal nets (PNNs), the adult mouse brain exhibits restricted plasticity and maturity. Mature PNNs are typically considered to be stable structures that restrict synaptic plasticity on cortical parvalbumin+ (PV+) GABAergic neurons. Changes in environment (i.e., novel behavioral training) or social contexts (i.e., motherhood) are known to elicit synaptic plasticity in relevant neural circuitry. However, little is known about concomitant changes in the PNNs surrounding the cortical PV+ GABAergic neurons. Here, we show novel changes in PNN density in the primary somatosensory cortex (SS1) of adult female mice after maternal experience [called surrogate (Sur)], using systematic microscopy analysis of a whole brain region. On average, PNNs were increased in the right barrel field and decreased in the left forelimb regions. Individual mice had left hemisphere dominance in PNN density. Using adult female mice deficient in methyl-CpG-binding protein 2 (MECP2), an epigenetic regulator involved in regulating experience-dependent plasticity, we found that MECP2 is critical for this precise and dynamic expression of PNN. Adult naive Mecp2-heterozygous (Het) females had increased PNN density in specific subregions in both hemispheres before maternal experience, compared with wild-type (WT) littermate controls. The laterality in PNN expression seen in naive Het (NH) was lost after maternal experience in Sur Het (SH) mice, suggesting possible intact mechanisms for plasticity. Together, our results identify subregion and hemisphere-specific alterations in PNN expression in adult females, suggesting extracellular matrix plasticity as a possible neurobiological mechanism for adult behaviors in rodents.
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41
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Disruption of Critical Period Plasticity in a Mouse Model of Neurofibromatosis Type 1. J Neurosci 2020; 40:5495-5509. [PMID: 32527982 DOI: 10.1523/jneurosci.2235-19.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 11/21/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is a common monogenic neurodevelopmental disorder associated with physical and cognitive problems. The cognitive issues are thought to arise from increased release of the neurotransmitter GABA. Modulating the signaling pathways causing increased GABA release in a mouse model of NF1 reverts deficits in hippocampal learning. However, clinical trials based on these approaches have so far been unsuccessful. We therefore used a combination of slice electrophysiology, in vivo two-photon calcium imaging, and optical imaging of intrinsic signal in a mouse model of NF1 to investigate whether cortical development is affected in NF1, possibly causing lifelong consequences that cannot be rescued by reducing inhibition later in life. We find that, in NF1 mice of both sexes, inhibition increases strongly during the development of the visual cortex and remains high. While this increase in cortical inhibition does not affect spontaneous cortical activity patterns during early cortical development, the critical period for ocular dominance plasticity is shortened in NF1 mice due to its early closure but unaltered onset. Notably, after environmental enrichment, differences in inhibitory innervation and ocular dominance plasticity between NF1 mice and WT littermates disappear. These results provide the first evidence for critical period dysregulation in NF1 and suggest that treatments aimed at normalizing levels of inhibition will need to start at early stages of development.SIGNIFICANCE STATEMENT Neurofibromatosis type 1 is associated with cognitive problems for which no treatment is currently available. This study shows that, in a mouse model of neurofibromatosis type 1, cortical inhibition is increased during development and critical period regulation is disturbed. Rearing the mice in an environment that stimulates cognitive function overcomes these deficits. These results uncover critical period dysregulation as a novel mechanism in the pathogenesis of neurofibromatosis type 1. This suggests that targeting the affected signaling pathways in neurofibromatosis type 1 for the treatment of cognitive disabilities may have to start at a much younger age than has so far been tested in clinical trials.
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42
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Razak KA, Dominick KC, Erickson CA. Developmental studies in fragile X syndrome. J Neurodev Disord 2020; 12:13. [PMID: 32359368 PMCID: PMC7196229 DOI: 10.1186/s11689-020-09310-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 02/13/2020] [Indexed: 01/27/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common single gene cause of autism and intellectual disabilities. Humans with FXS exhibit increased anxiety, sensory hypersensitivity, seizures, repetitive behaviors, cognitive inflexibility, and social behavioral impairments. The main purpose of this review is to summarize developmental studies of FXS in humans and in the mouse model, the Fmr1 knockout mouse. The literature presents considerable evidence that a number of early developmental deficits can be identified and that these early deficits chart a course of altered developmental experience leading to symptoms well characterized in adolescents and adults. Nevertheless, a number of critical issues remain unclear or untested regarding the development of symptomology and underlying mechanisms. First, what is the role of FMRP, the protein product of Fmr1 gene, during different developmental ages? Does the absence of FMRP during early development lead to irreversible changes, or could reintroduction of FMRP or therapeutics aimed at FMRP-interacting proteins/pathways hold promise when provided in adults? These questions have implications for clinical trial designs in terms of optimal treatment windows, but few studies have systematically addressed these issues in preclinical and clinical work. Published studies also point to complex trajectories of symptom development, leading to the conclusion that single developmental time point studies are unlikely to disambiguate effects of genetic mutation from effects of altered developmental experience and compensatory plasticity. We conclude by suggesting a number of experiments needed to address these major gaps in the field.
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Affiliation(s)
- Khaleel A Razak
- Department of Psychology and Graduate Neuroscience Program, University of California, Riverside, USA
| | - Kelli C Dominick
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA.,Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH, 45229, USA
| | - Craig A Erickson
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA. .,Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH, 45229, USA.
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43
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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44
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Ribic A. Stability in the Face of Change: Lifelong Experience-Dependent Plasticity in the Sensory Cortex. Front Cell Neurosci 2020; 14:76. [PMID: 32372915 PMCID: PMC7186337 DOI: 10.3389/fncel.2020.00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/17/2020] [Indexed: 11/13/2022] Open
Abstract
Plasticity is a fundamental property of the nervous system that enables its adaptations to the ever-changing environment. Heightened plasticity typical for developing circuits facilitates their robust experience-dependent functional maturation. This plasticity wanes during adolescence to permit the stabilization of mature brain function, but abundant evidence supports that adult circuits exhibit both transient and long-term experience-induced plasticity. Cortical plasticity has been extensively studied throughout the life span in sensory systems and the main distinction between development and adulthood arising from these studies is the concept that passive exposure to relevant information is sufficient to drive robust plasticity early in life, while higher-order attentional mechanisms are necessary to drive plastic changes in adults. Recent work in the primary visual and auditory cortices began to define the circuit mechanisms that govern these processes and enable continuous adaptation to the environment, with transient circuit disinhibition emerging as a common prerequisite for both developmental and adult plasticity. Drawing from studies in visual and auditory systems, this review article summarizes recent reports on the circuit and cellular mechanisms of experience-driven plasticity in the developing and adult brains and emphasizes the similarities and differences between them. The benefits of distinct plasticity mechanisms used at different ages are discussed in the context of sensory learning, as well as their relationship to maladaptive plasticity and neurodevelopmental brain disorders. Knowledge gaps and avenues for future work are highlighted, and these will hopefully motivate future research in these areas, particularly those about the learning of complex skills during development.
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Affiliation(s)
- Adema Ribic
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
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45
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Persic D, Thomas ME, Pelekanos V, Ryugo DK, Takesian AE, Krumbholz K, Pyott SJ. Regulation of auditory plasticity during critical periods and following hearing loss. Hear Res 2020; 397:107976. [PMID: 32591097 PMCID: PMC8546402 DOI: 10.1016/j.heares.2020.107976] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/15/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023]
Abstract
Sensory input has profound effects on neuronal organization and sensory maps in the brain. The mechanisms regulating plasticity of the auditory pathway have been revealed by examining the consequences of altered auditory input during both developmental critical periods—when plasticity facilitates the optimization of neural circuits in concert with the external environment—and in adulthood—when hearing loss is linked to the generation of tinnitus. In this review, we summarize research identifying the molecular, cellular, and circuit-level mechanisms regulating neuronal organization and tonotopic map plasticity during developmental critical periods and in adulthood. These mechanisms are shared in both the juvenile and adult brain and along the length of the auditory pathway, where they serve to regulate disinhibitory networks, synaptic structure and function, as well as structural barriers to plasticity. Regulation of plasticity also involves both neuromodulatory circuits, which link plasticity with learning and attention, as well as ascending and descending auditory circuits, which link the auditory cortex and lower structures. Further work identifying the interplay of molecular and cellular mechanisms associating hearing loss-induced plasticity with tinnitus will continue to advance our understanding of this disorder and lead to new approaches to its treatment. During CPs, brain plasticity is enhanced and sensitive to acoustic experience. Enhanced plasticity can be reinstated in the adult brain following hearing loss. Molecular, cellular, and circuit-level mechanisms regulate CP and adult plasticity. Plasticity resulting from hearing loss may contribute to the emergence of tinnitus. Modifying plasticity in the adult brain may offer new treatments for tinnitus.
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Affiliation(s)
- Dora Persic
- University of Groningen, University Medical Center Groningen, Groningen, Department of Otorhinolaryngology and Head/Neck Surgery, 9713, GZ, Groningen, the Netherlands
| | - Maryse E Thomas
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear and Department of Otorhinolaryngology and Head/Neck Surgery, Harvard Medical School, Boston, MA, USA
| | - Vassilis Pelekanos
- Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, University Park, Nottingham, UK
| | - David K Ryugo
- Hearing Research, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia; School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia; Department of Otolaryngology, Head, Neck & Skull Base Surgery, St Vincent's Hospital, Sydney, NSW, 2010, Australia
| | - Anne E Takesian
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear and Department of Otorhinolaryngology and Head/Neck Surgery, Harvard Medical School, Boston, MA, USA
| | - Katrin Krumbholz
- Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, University Park, Nottingham, UK
| | - Sonja J Pyott
- University of Groningen, University Medical Center Groningen, Groningen, Department of Otorhinolaryngology and Head/Neck Surgery, 9713, GZ, Groningen, the Netherlands.
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46
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Luoni M, Giannelli S, Indrigo MT, Niro A, Massimino L, Iannielli A, Passeri L, Russo F, Morabito G, Calamita P, Gregori S, Deverman B, Broccoli V. Whole brain delivery of an instability-prone Mecp2 transgene improves behavioral and molecular pathological defects in mouse models of Rett syndrome. eLife 2020; 9:52629. [PMID: 32207685 PMCID: PMC7117907 DOI: 10.7554/elife.52629] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/23/2020] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome is an incurable neurodevelopmental disorder caused by mutations in the gene encoding for methyl-CpG binding-protein 2 (MeCP2). Gene therapy for this disease presents inherent hurdles since MECP2 is expressed throughout the brain and its duplication leads to severe neurological conditions as well. Herein, we use the AAV-PHP.eB to deliver an instability-prone Mecp2 (iMecp2) transgene cassette which, increasing RNA destabilization and inefficient protein translation of the viral Mecp2 transgene, limits supraphysiological Mecp2 protein levels. Intravenous injections of the PHP.eB-iMecp2 virus in symptomatic Mecp2 mutant mice significantly improved locomotor activity, lifespan and gene expression normalization. Remarkably, PHP.eB-iMecp2 administration was well tolerated in female Mecp2 mutant or in wild-type animals. In contrast, we observed a strong immune response to the transgene in treated male Mecp2 mutant mice that was overcome by immunosuppression. Overall, PHP.eB-mediated delivery of iMecp2 provided widespread and efficient gene transfer maintaining physiological Mecp2 protein levels in the brain.
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Affiliation(s)
- Mirko Luoni
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Serena Giannelli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Marzia Tina Indrigo
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Antonio Niro
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Luca Massimino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Angelo Iannielli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
| | - Laura Passeri
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Fabio Russo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Giuseppe Morabito
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Piera Calamita
- National Institute of Molecular Genetics (INGM), Milan, Italy
| | - Silvia Gregori
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute IRCCS, Via Olgettina, Milan, Italy
| | - Benjamin Deverman
- Stanley Center for Psychiatric Research at Broad Institute, Cambridge, United States
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,CNR Institute of Neuroscience, Milan, Italy
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Lupori L, Sagona G, Fuchs C, Mazziotti R, Stefanov A, Putignano E, Napoli D, Strettoi E, Ciani E, Pizzorusso T. Site-specific abnormalities in the visual system of a mouse model of CDKL5 deficiency disorder. Hum Mol Genet 2020; 28:2851-2861. [PMID: 31108505 PMCID: PMC6736061 DOI: 10.1093/hmg/ddz102] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/12/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is a neurodevelopmental disorder characterized by a severe global developmental delay and early-onset seizures. Notably, patients show distinctive visual abnormalities often clinically diagnosed as cortical visual impairment. However, the involvement of cerebral cortical dysfunctions in the origin of the symptoms is poorly understood. CDD mouse models also display visual deficits, and cortical visual responses can be used as a robust biomarker in CDKL5 mutant mice. A deeper understanding of the circuits underlying the described visual deficits is essential for directing preclinical research and translational approaches. Here, we addressed this question in two ways: first, we performed an in-depth morphological analysis of the visual pathway, from the retina to the primary visual cortex (V1), of CDKL5 null mice. We found that the lack of CDKL5 produced no alteration in the organization of retinal circuits. Conversely, CDKL5 mutants showed reduced density and altered morphology of spines and decreased excitatory synapse marker PSD95 in the dorsal lateral geniculate nucleus and in V1. An increase in the inhibitory marker VGAT was selectively present in V1. Second, using a conditional CDKL5 knockout model, we showed that selective cortical deletion of CDKL5 from excitatory cells is sufficient to produce abnormalities of visual cortical responses, demonstrating that the normal function of cortical circuits is dependent on CDKL5. Intriguingly, these deficits were associated with morphological alterations of V1 excitatory and inhibitory synaptic contacts. In summary, this work proposes cortical circuit structure and function as a critically important target for studying CDD.
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Affiliation(s)
- Leonardo Lupori
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Giulia Sagona
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa 56128, Italy
| | - Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40126, Italy
| | - Raffaele Mazziotti
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy
| | - Antonia Stefanov
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Debora Napoli
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Enrica Strettoi
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40126, Italy
| | - Tommaso Pizzorusso
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy
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48
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Maternal Experience-Dependent Cortical Plasticity in Mice Is Circuit- and Stimulus-Specific and Requires MECP2. J Neurosci 2020; 40:1514-1526. [PMID: 31911459 DOI: 10.1523/jneurosci.1964-19.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/12/2019] [Accepted: 12/20/2019] [Indexed: 01/26/2023] Open
Abstract
The neurodevelopmental disorder Rett syndrome is caused by mutations in the gene Mecp2 Misexpression of the protein MECP2 is thought to contribute to neuropathology by causing dysregulation of plasticity. Female heterozygous Mecp2 mutants (Mecp2het ) failed to acquire a learned maternal retrieval behavior when exposed to pups, an effect linked to disruption of parvalbumin-expressing inhibitory interneurons (PV) in the auditory cortex. Nevertheless, how dysregulated PV networks affect the neural activity dynamics that underlie auditory cortical plasticity during early maternal experience is unknown. Here we show that maternal experience in WT adult female mice (WT) triggers suppression of PV auditory responses. We also observe concomitant disinhibition of auditory responses in deep-layer pyramidal neurons that is selective for behaviorally relevant pup vocalizations. These neurons further exhibit sharpened tuning for pup vocalizations following maternal experience. All of these neuronal changes are abolished in Mecp2het , suggesting that they are an essential component of maternal learning. This is further supported by our finding that genetic manipulation of GABAergic networks that restores accurate retrieval behavior in Mecp2het also restores maternal experience-dependent plasticity of PV. Our data are consistent with a growing body of evidence that cortical networks are particularly vulnerable to mutations of Mecp2 in PV neurons. Moreover, our work links, for the first time, impaired in vivo cortical plasticity in awake Mecp2 mutant animals to a natural, ethologically relevant behavior.SIGNIFICANCE STATEMENT Rett syndrome is a genetic disorder that includes language communication problems. Nearly all Rett syndrome is caused by mutations in the gene that produces the protein MECP2, which is important for changes in brain connectivity believed to underlie learning. We previously showed that female Mecp2 mutants fail to learn a simple maternal care behavior performed in response to their pups' distress cries. This impairment appeared to critically involve inhibitory neurons in the auditory cortex called parvalbumin neurons. Here we record from these neurons before and after maternal experience, and we show that they adapt their response to pup calls during maternal learning in nonmutants, but not in mutants. This adaptation is partially restored by a manipulation that improves learning.
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Sysoeva OV, Smirnov K, Stroganova TA. Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review. Clin Neurophysiol 2019; 131:213-224. [PMID: 31812082 DOI: 10.1016/j.clinph.2019.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Systematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations). METHODS Pubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards. RESULTS ERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients. CONCLUSIONS While there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms. SIGNIFICANCE The review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.
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Affiliation(s)
- Olga V Sysoeva
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA; The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; The Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | - Kirill Smirnov
- Department of Neuroontogenesis, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Moscow, Russia.
| | - Tatiana A Stroganova
- Center for Neurocognitive Research (MEG-Center), Moscow State University of Psychology and Education (MSUPE), Moscow, Russia; Autism Research Laboratory, Moscow State University of Psychology and Education (MSUPE), Moscow, Russia.
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50
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Smith ES, Smith DR, Eyring C, Braileanu M, Smith-Connor KS, Ei Tan Y, Fowler AY, Hoffman GE, Johnston MV, Kannan S, Blue ME. Altered trajectories of neurodevelopment and behavior in mouse models of Rett syndrome. Neurobiol Learn Mem 2019; 165:106962. [PMID: 30502397 PMCID: PMC8040058 DOI: 10.1016/j.nlm.2018.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 10/17/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022]
Abstract
Rett Syndrome (RTT) is a genetic disorder that is caused by mutations in the x-linked gene coding for methyl-CpG-biding-protein 2 (MECP2) and that mainly affects females. Male and female transgenic mouse models of RTT have been studied extensively, and we have learned a great deal regarding RTT neuropathology and how MeCP2 deficiency may be influencing brain function and maturation. In this manuscript we review what is known concerning structural and coinciding functional and behavioral deficits in RTT and in mouse models of MeCP2 deficiency. We also introduce our own corroborating data regarding behavioral phenotype and morphological alterations in volume of the cortex and striatum and the density of neurons, aberrations in experience-dependent plasticity within the barrel cortex and the impact of MeCP2 loss on glial structure. We conclude that regional structural changes in genetic models of RTT show great similarity to the alterations in brain structure of patients with RTT. These region-specific modifications often coincide with phenotype onset and contribute to larger issues of circuit connectivity, progression, and severity. Although the alterations seen in mouse models of RTT appear to be primarily due to cell-autonomous effects, there are also non-cell autonomous mechanisms including those caused by MeCP2-deficient glia that negatively impact healthy neuronal function. Collectively, this body of work has provided a solid foundation on which to continue to build our understanding of the role of MeCP2 on neuronal and glial structure and function, its greater impact on neural development, and potential new therapeutic avenues.
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Affiliation(s)
- Elizabeth S Smith
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Dani R Smith
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Charlotte Eyring
- The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Maria Braileanu
- Undergraduate Program in Neuroscience, The Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Karen S Smith-Connor
- The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Yew Ei Tan
- Perdana University Graduate School of Medicine, Kuala Lumpur, Malaysia
| | - Amanda Y Fowler
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
| | - Gloria E Hoffman
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
| | - Michael V Johnston
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA
| | - Mary E Blue
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Hugo W. Moser Research Institute at Kennedy Krieger, Inc., Baltimore, MD 21205, USA.
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