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Wither RG, Boehnke SE, Lablans A, Armitage-Brown B, Munoz DP. Behavioral shaping of rhesus macaques using the Cambridge neuropsychological automated testing battery. J Neurosci Methods 2020; 342:108803. [PMID: 32534008 DOI: 10.1016/j.jneumeth.2020.108803] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/29/2020] [Accepted: 06/03/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND The Cambridge neuropsychological test automated battery (CANTAB) is a set of computerized visuospatial tests used to probe cognition in humans. The non-human primate (NHP) version of the battery is a valuable translational research tool to quantify cognitive changes in NHP models of disease by allowing direct comparison with performance data from human patient populations. One limitation is the long training times required for NHPs to reach appropriate levels of task performance, which is prohibitive for high throughput experimental designs. NEW METHOD We report a new training regimen to teach NHPs a subset of CANTAB cognitive tasks using a method of successive approximations (shaping), where rewarded behaviors progressively approximate the goal behavior, and sequential task learning is used to build upon previously learned rules. Using this refined method, we taught 9 adult rhesus macaques to perform three tasks: the self-ordered spatial search (SOSS), delayed match-to-sample (DMTS), and paired associative learning (PAL) tasks. RESULTS AND COMPARISON WITH EXISTING METHODS NHPs learned all three cognitive tasks in approximately 130 training sessions, roughly 200 sessions faster than previously published training times. NHPs were able to perform each task to a stable level of performance (>80 % correct) enabling their use in future cognitive experiments. CONCLUSIONS Our approach of behavioral shaping reduced the time to train NHPs to performance criteria on SOSS, DMTS, and PAL tasks. This allows efficient use of the NHP-adapted CANTAB to compare cognitive changes in NHP models of neurological disease with those observed in human patient populations.
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Affiliation(s)
- Robert G Wither
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.
| | - Susan E Boehnke
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Ann Lablans
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | | | - Douglas P Munoz
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
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Boehnke SE, Robertson EL, Armitage‐Brown B, Wither RG, Lyra e Silva NM, Winterborn A, Levy R, Cook DJ, De Felice FG, Munoz DP. The effect of lumbar puncture on the neurodegeneration biomarker neurofilament light in macaque monkeys. Alzheimers Dement (Amst) 2020; 12:e12069. [PMID: 32695873 PMCID: PMC7366296 DOI: 10.1002/dad2.12069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Neurofilament light (NFL) in cerebrospinal fluid (CSF) is elevated in neurodegenerative disease patients, and may track disease progression and treatment. Macaque monkeys are emerging as important translational models of neurodegeneration, and NFL may be a useful biomarker. METHODS To determine the influence of a previous lumbar puncture (LP) on NFL, we collected CSF at multiple time points in macaque monkeys via LP or cisterna magna puncture. NFL, amyloid beta (Aβ40, Aβ42), and tau (tTau, pTau) in CSF were measured by standard enzyme-linked immunosorbent assay and multiplex. RESULTS NFL was significantly elevated at 14 to 23 days after an LP (median increase: 162%). Aβ and tau biomarkers remained stable. NFL peaked and decayed over 1 to 2 months after LP. NFL was not elevated after cisterna magna puncture. DISCUSSION Results suggest damage of the cauda equina during LP may increase NFL. Caution should be taken in interpreting NFL concentration in studies in which repeat LPs are performed.
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Affiliation(s)
- Susan E. Boehnke
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonOntarioCanada
| | - Emma L. Robertson
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
| | | | - Robert G. Wither
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
| | | | | | - Ron Levy
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
- Department of SurgeryKingston General HospitalKingstonOntarioCanada
| | - Douglas J. Cook
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
- Department of SurgeryKingston General HospitalKingstonOntarioCanada
| | - Fernanda G. De Felice
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
- Department of PsychiatryProvidence Care HospitalKingstonOntarioCanada
- Institute of Medical Biochemistry Leopoldo de MeisFederal University of Rio de JaneiroRio de JaneiroBrazil
| | - Douglas P. Munoz
- Centre for Neuroscience StudiesQueen's UniversityKingstonOntarioCanada
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonOntarioCanada
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Wither RG, Colic S, Bardakjian BL, Snead OC, Zhang L, Eubanks JH. Electrographic and pharmacological characterization of a progressive epilepsy phenotype in female MeCP2-deficient mice. Epilepsy Res 2018; 140:177-183. [PMID: 29414525 DOI: 10.1016/j.eplepsyres.2018.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 11/27/2022]
Abstract
Rett Syndrome is a neurodevelopmental disorder caused primarily by mutations in the gene encoding Methyl-CpG-binding protein 2 (MECP2). Spontaneous epileptiform activity is a common co-morbidity present in Rett syndrome, and hyper-excitable neural networks are present in MeCP2-deficient mouse models of Rett syndrome. In this study we conducted a longitudinal assessment of spontaneous cortical electrographic discharges in female MeCP2-deficient mice and defined the pharmacological responsiveness of these discharges to anti-convulsant drugs. Our data show that cortical discharge activity in female MeCP2-deficient mice progressively increases in severity as the mice age, with discharges being more frequent and of longer durations at 19-24 months of age compared to 3 months of age. Semiologically and pharmacologically, this basal discharge activity in female MeCP2-deficient mice displayed electroclinical properties consistent with absence epilepsy. Only rarely were convulsive seizures observed in these mice at any age. Since absence epilepsy is infrequently observed in Rett syndrome patients, these results indicate that the predominant spontaneous electroclinical phenotype of MeCP2-deficient mice we examined does not faithfully recapitulate the most prevalent seizure types observed in affected patients.
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Affiliation(s)
- Robert G Wither
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Berj L Bardakjian
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - O Carter Snead
- Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Liang Zhang
- Division of Fundamental Neurobiology, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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Wither RG, Borlot F, MacDonald A, Butcher NJ, Chow EWC, Bassett AS, Andrade DM. 22q11.2 deletion syndrome lowers seizure threshold in adult patients without epilepsy. Epilepsia 2017; 58:1095-1101. [PMID: 28448680 DOI: 10.1111/epi.13748] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2017] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Previous studies examining seizures in patients with 22q11.2 deletion syndrome (22q11.2DS) have focused primarily on children and adolescents. In this study we investigated the prevalence and characteristics of seizures and epilepsy in an adult 22q11.2DS population. METHODS The medical records of 202 adult patients with 22q11.2DS were retrospectively reviewed for documentation of seizures, electroencephalography (EEG) reports, and magnetic resonance imaging (MRI) findings. Epilepsy status was assigned in accordance with 2010 International League Against Epilepsy Classification. RESULTS Of 202 patients, 32 (15.8%) had a documented history of seizure. Of these 32, 23 (71.8%) had acute symptomatic seizures, usually associated with hypocalcemia and/or antipsychotic or antidepressant use. Nine patients (9/32, 28%; 9/202, 4%) met diagnostic criteria for epilepsy. Two patients had genetic generalized epilepsy; two patients had focal seizures of unknown etiology; two had epilepsy due to malformations of cortical development; in two the epilepsy was due to acquired structural changes; and in one patient the epilepsy could not be further classified. SIGNIFICANCE Similarly to children, the prevalence of epilepsy and acute symptomatic seizures in adults with 22q11.2DS is higher than in the general population. Hypocalcemia continues to be a risk factor for adults, but differently from kids, the main cause of seizures in adults with 22q11.2DS is exposure to antipsychotics and antidepressants. Further prospective studies are warranted to investigate how 22q11.2 microdeletion leads to an overall decreased seizure threshold.
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Affiliation(s)
- Robert G Wither
- Division of Neurology, Department of Medicine, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, Ontario, Canada
| | - Felippe Borlot
- Division of Neurology, Department of Medicine, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, Ontario, Canada.,Department of Neurology, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, U.S.A.,Krembil Neurosciences Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Alex MacDonald
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Nancy J Butcher
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Eva W C Chow
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Anne S Bassett
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Department of Medicine, Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Psychiatry, University Health Network, Toronto, Ontario, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Danielle M Andrade
- Division of Neurology, Department of Medicine, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, Ontario, Canada.,Krembil Neurosciences Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
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Abstract
OBJECTIVE Antiepileptic drug (AED) treatments produce inconsistent outcomes, often necessitating patients to go through several drug trials until a successful treatment can be found. This study proposes the use of machine learning techniques to predict epilepsy treatment outcomes of commonly used AEDs. APPROACH Machine learning algorithms were trained and evaluated using features obtained from intracranial electroencephalogram (iEEG) recordings of the epileptiform discharges observed in Mecp2-deficient mouse model of the Rett Syndrome. Previous work have linked the presence of cross-frequency coupling (I CFC) of the delta (2-5 Hz) rhythm with the fast ripple (400-600 Hz) rhythm in epileptiform discharges. Using the I CFC to label post-treatment outcomes we compared support vector machines (SVMs) and random forest (RF) machine learning classifiers for providing likelihood scores of successful treatment outcomes. MAIN RESULTS (a) There was heterogeneity in AED treatment outcomes, (b) machine learning techniques could be used to rank the efficacy of AEDs by estimating likelihood scores for successful treatment outcome, (c) I CFC features yielded the most effective a priori identification of appropriate AED treatment, and (d) both classifiers performed comparably. SIGNIFICANCE Machine learning approaches yielded predictions of successful drug treatment outcomes which in turn could reduce the burdens of drug trials and lead to substantial improvements in patient quality of life.
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Affiliation(s)
- Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S-3G4, Canada
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Zhang L, Wither RG, Lang M, Wu C, Sidorova-Darmos E, Netchev H, Matolcsy CB, Snead OC, Eubanks JH. A Role for Diminished GABA Transporter Activity in the Cortical Discharge Phenotype of MeCP2-Deficient Mice. Neuropsychopharmacology 2016; 41:1467-76. [PMID: 26499511 PMCID: PMC4832024 DOI: 10.1038/npp.2015.323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/13/2015] [Accepted: 10/01/2015] [Indexed: 12/14/2022]
Abstract
Cortical network hyper-excitability is a common phenotype in mouse models lacking the transcriptional regulator methyl-CPG-binding protein 2 (MeCP2). Here, we implicate enhanced GABAB receptor activity stemming from diminished cortical expression of the GABA transporter GAT-1 in the genesis of this network hyper-excitability. We found that administering the activity-dependent GABAB receptor allosteric modulator GS-39783 to female Mecp2(+/-) mice at doses producing no effect in wild-type mice strongly potentiated their basal rates of spontaneous cortical discharge activity. Consistently, administering the GABAB receptor antagonist CGP-35348 significantly decreased basal discharge activity in these mice. Expression analysis revealed that while GABAB or extra-synaptic GABAA receptor prevalence is preserved in the MeCP2-deficient cortex, the expression of GAT-1 is significantly reduced from wild-type levels. This decrease in GAT-1 expression is consequential, as low doses of the GAT-1 inhibitor NO-711 that had no effects in wild-type mice strongly exacerbated cortical discharge activity in female Mecp2(+/-) mice. Taken together, these data indicate that the absence of MeCP2 leads to decreased cortical levels of the GAT-1 GABA transporter, which facilitates cortical network hyper-excitability in MeCP2-deficient mice by increasing the activity of cortical GABAB receptors.
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Affiliation(s)
- Liang Zhang
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - Robert G Wither
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Min Lang
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Chiping Wu
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Elena Sidorova-Darmos
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hristo Netchev
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Catherine B Matolcsy
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Orlando Carter Snead
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - James H Eubanks
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada,Department of Surgery (Neurosurgery), University of Toronto, Toronto, ON, Canada,Toronto Western Hospital, 8KD-417, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada, Tel: +1 416 603 5800, ext. 2933, Fax: +1 416 603 5745, E-mail:
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7
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Colic S, Wither RG, Eubanks JH, Bardakjian BL. Support vector machines using EEG features of cross-frequency coupling can predict treatment outcome in Mecp2-deficient mice. Annu Int Conf IEEE Eng Med Biol Soc 2016; 2015:5606-9. [PMID: 26737563 DOI: 10.1109/embc.2015.7319663] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Anti-convulsive drug treatments of epilepsy typically produce varied outcomes from one patient to the next, often necessitating patients to go through several anticonvulsive drug trials until an appropriate treatment is found. The focus of this study is to predict treatment outcome using a priori electroencephalogram (EEG) features for a rare genetic model of epilepsy seen in patients with Rett Syndrome. Previous work on Mecp2-deficient mice, exhibiting the symptoms of Rett syndrome, have revealed EEG-based biomarkers that track the pathology well. Specifically the presence of cross-frequency coupling of the delta-like (3-6 Hz) frequency range phase with the fast ripple (400 - 600 Hz) frequency range amplitude in long duration discharges was found to track seizure pathology. Support Vector Machines (SVM) were trained with features generated from phase-amplitude comodulograms and tested on (n=6) Mecp2-deficient mice to predict treatment outcome to Midazolam, a commonly used anti-convulsive drug. Using SVMs it was shown that it is possible to generate a likelihood score to predict treatment outcomes on all of the animal subjects. Identifying the most appropriate treatment a priori would potentially lead to improved treatment outcomes.
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Colic S, Lang M, Wither RG, Liang Z, Eubanks JH, Bardakjian BL. Characterization of HFOs in short and long duration discharges recorded from in-vivo MeCP2-deficient mice. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:4603-6. [PMID: 25571017 DOI: 10.1109/embc.2014.6944649] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mutations in the X-linked gene encoding methyl CpG-binding protein 2 (MeCP2) have been linked to a neurodevelopmental disorder known as Rett syndrome. The disorder is associated with a number of symptoms, of which epileptic seizures are common. In this study we examined the presence of high frequency oscillations (HFOs) and their interactions with low frequency oscillations (LFOs) during epileptiform-like discharges using intracranial electroencephalogram (iEEG) recordings from male and female Mecp2-deficient mice. The study compared differences in mean HFO power levels normalized to baseline along with LFO-HFO modulation observed in short and long duration discharges. Short duration discharges, common to both male and female Mecp2-deficient mice, showed a decrease in mean HFO power levels compared to baseline levels. During the short duration discharges the theta (7-9 Hz) LFOs were found to modulate fast ripple (350-500 Hz) HFOs predominantly in the female Mecp2-deficient mice. Long duration discharges, predominantly observed in male Mecp2-deficient mice, were found to have elevated mean power levels in the ripple (80-200 Hz) and fast ripple (350-500 Hz) frequency ranges when compared to baseline. During the long duration discharges a lower frequency range theta LFO (4-6 Hz) modulated both the ripple (80-200 Hz) and fast ripple (350-500 Hz) HFOs. These findings suggest that the long duration discharges observed in male Mecp2-deficient mice share biomarkers indicative of seizure-like activity.
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Sidorova-Darmos E, Wither RG, Shulyakova N, Fisher C, Ratnam M, Aarts M, Lilge L, Monnier PP, Eubanks JH. Differential expression of sirtuin family members in the developing, adult, and aged rat brain. Front Aging Neurosci 2014; 6:333. [PMID: 25566066 PMCID: PMC4270178 DOI: 10.3389/fnagi.2014.00333] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/25/2014] [Indexed: 12/21/2022] Open
Abstract
The sirtuins are NAD+-dependent protein deacetylases and/or ADP-ribosyltransferases that play roles in metabolic homeostasis, stress response and potentially aging. This enzyme family resides in different subcellular compartments, and acts on a number of different targets in the nucleus, cytoplasm and in the mitochondria. Despite their recognized ability to regulate metabolic processes, the roles played by specific sirtuins in the brain—the most energy demanding tissue in the body—remains less well investigated and understood. In the present study, we examined the regional mRNA and protein expression patterns of individual sirtuin family members in the developing, adult, and aged rat brain. Our results show that while each sirtuin is expressed in the brain at each of these different stages, they display unique spatial and temporal expression patterns within the brain. Further, for specific members of the family, the protein expression profile did not coincide with their respective mRNA expression profile. Moreover, using primary cultures enriched for neurons and astrocytes respectively, we found that specific sirtuin members display preferential neural lineage expression. Collectively, these results provide the first composite illustration that sirtuin family members display differential expression patterns in the brain, and provide evidence that specific sirtuins could potentially be targeted to achieve cell-type selective effects within the brain.
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Affiliation(s)
- Elena Sidorova-Darmos
- Division of Genetics and Development, Toronto Western Research Institute Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
| | - Robert G Wither
- Division of Genetics and Development, Toronto Western Research Institute Toronto, ON, Canada
| | - Natalya Shulyakova
- Division of Genetics and Development, Toronto Western Research Institute Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
| | - Carl Fisher
- Department of Medical Biophysics, University of Toronto Toronto, ON, Canada
| | - Melanie Ratnam
- Department of Cell Systems Biology, University of Toronto Toronto, ON, Canada
| | - Michelle Aarts
- Department of Cell Systems Biology, University of Toronto Toronto, ON, Canada
| | - Lothar Lilge
- Department of Medical Biophysics, University of Toronto Toronto, ON, Canada
| | - Philippe P Monnier
- Division of Genetics and Development, Toronto Western Research Institute Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
| | - James H Eubanks
- Division of Genetics and Development, Toronto Western Research Institute Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada ; Institute of Medical Sciences, University of Toronto Toronto, ON, Canada ; Department of Surgery (Neurosurgery), University of Toronto Toronto, ON, Canada
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Lang M, Wither RG, Colic S, Wu C, Monnier PP, Bardakjian BL, Zhang L, Eubanks JH. Rescue of behavioral and EEG deficits in male and female Mecp2-deficient mice by delayed Mecp2 gene reactivation. Hum Mol Genet 2013; 23:303-18. [PMID: 24009314 PMCID: PMC3869352 DOI: 10.1093/hmg/ddt421] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mutations of the X-linked gene encoding methyl CpG binding protein type 2 (MECP2) are the predominant cause of Rett syndrome, a severe neurodevelopmental condition that affects primarily females. Previous studies have shown that major phenotypic deficits arising from MeCP2-deficiency may be reversible, as the delayed reactivation of the Mecp2 gene in Mecp2-deficient mice improved aspects of their Rett-like phenotype. While encouraging for prospective gene replacement treatments, it remains unclear whether additional Rett syndrome co-morbidities recapitulated in Mecp2-deficient mice will be similarly responsive to the delayed reintroduction of functional Mecp2. Here, we show that the delayed reactivation of Mecp2 in both male and female Mecp2-deficient mice rescues established deficits in motor and anxiety-like behavior, epileptiform activity, cortical and hippocampal electroencephalogram patterning and thermoregulation. These findings indicate that neural circuitry deficits arising from the deficiency in Mecp2 are not engrained, and provide further evidence that delayed restoration of Mecp2 function can improve a wide spectrum of the Rett-like deficits recapitulated by Mecp2-deficient mice.
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Affiliation(s)
- Min Lang
- Division of Genetics and Development and
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Colic S, Wither RG, Zhang L, Eubanks JH, Bardakjian BL. Characterization of seizure-like events recorded in vivo in a mouse model of Rett syndrome. Neural Netw 2013; 46:109-15. [PMID: 23727441 DOI: 10.1016/j.neunet.2013.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 05/01/2013] [Accepted: 05/05/2013] [Indexed: 10/26/2022]
Abstract
Rett syndrome is a neurodevelopmental disorder caused by mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MECP2). Spontaneous recurrent discharge episodes are displayed in Rett-related seizures as in other types of epilepsies. The aim of this paper is to investigate the seizure-like event (SLE) and inter-SLE states in a female MeCP2-deficient mouse model of Rett syndrome and compare them to those found in other spontaneous recurrent epilepsy models. The study was performed on a small population of female MeCP2-deficient mice using telemetric local field potential (LFP) recordings over a 24 h period. Durations of SLEs and inter-SLEs were extracted using a rule-based automated SLE detection system for both daytime and nighttime, as well as high and low power levels of the delta frequency range (0.5-4 Hz) of the recorded LFPs. The results suggest SLE occurrences are not influenced by circadian rhythms, but had a significantly greater association with delta power. Investigating inter-SLE and SLE states by fitting duration histograms to the gamma distribution showed that SLE initiation and termination were associated with random and deterministic mechanisms, respectively. These findings when compared to reported studies on epilepsy suggest that Rett-related seizures share many similarities with absence epilepsy.
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Affiliation(s)
- Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Canada.
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Colic S, Lang M, Wither RG, Eubanks JH, Liang Z, Bardakjian BL. Low frequency-modulated high frequency oscillations in seizure-like events recorded from in-vivo MeCP2-deficient mice. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:985-988. [PMID: 24109855 DOI: 10.1109/embc.2013.6609668] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Rett syndrome is a neurodevelopmental condition caused by mutations in the gene encoding methyl CpG-binding protein 2 (MeCP2). Seizures are often associated with Rett syndrome and can be observed in intracranial electroencephalogram (iEEG) recordings. To date most studies have focused on the low frequencies oscillations (LFOs), however recent findings in epilepsy studies link high frequency oscillations (HFOs) with epileptogenesis. In this study, we examine the presence of HFOs in the male and female MeCP2-deficient mouse models of Rett syndrome and their interaction with the LFOs present during seizure-like events (SLEs). Our findings indicate that HFOs (200-600 Hz) are present during the SLEs and in addition, we reveal strong phase-amplitude coupling between LFOs (6-10 Hz) and HFOs (200-600 Hz) during female SLEs in the MeCP2-deficient mouse model.
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Wither RG, Lang M, Zhang L, Eubanks JH. Regional MeCP2 expression levels in the female MeCP2-deficient mouse brain correlate with specific behavioral impairments. Exp Neurol 2013; 239:49-59. [DOI: 10.1016/j.expneurol.2012.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 09/13/2012] [Accepted: 09/20/2012] [Indexed: 11/25/2022]
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Lang M, Wither RG, Brotchie JM, Wu C, Zhang L, Eubanks JH. Selective preservation of MeCP2 in catecholaminergic cells is sufficient to improve the behavioral phenotype of male and female Mecp2-deficient mice. Hum Mol Genet 2012; 22:358-71. [PMID: 23077217 DOI: 10.1093/hmg/dds433] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused primarily by mutations of the X-linked MECP2 gene. Although the loss of MeCP2 function affects many neural systems, impairments of catecholaminergic function have been hypothesized to underlie several of the cardinal behavioral deficits of RTT patients and Mecp2-deficient mice. Although recent Mecp2 reactivation studies indicate that RTT may be a reversible condition, it remains unclear whether specifically preserving Mecp2 function within a specific system will be sufficient to convey beneficial effects. Here, we test whether the selective preservation of Mecp2 within catecholaminergic cells will improve the phenotype of Mecp2-deficient mice. Our results show that this targeted preservation of Mecp2 significantly improves the lifespan, phenotypic severity and cortical epileptiform discharge activity of both male and female Mecp2-deficient mice. Further, we found that the catecholaminergic preservation of Mecp2 also improves the ambulatory rate, rearing activity, motor coordination, anxiety and nest-building performances of Mecp2-deficient mice of each gender. Interestingly, our results also revealed a gender-specific improvement, as specific cortical and hippocampal electroencephalographic abnormalities were significantly improved in male, but not female, rescue mice. Collectively, these results support the role of the catecholaminergic system in the pathogenesis of RTT and provide proof-of-principle that restoring MeCP2 function within this specific system could represent a treatment strategy for RTT.
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Affiliation(s)
- Min Lang
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
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Wither RG, Colic S, Wu C, Bardakjian BL, Zhang L, Eubanks JH. Daily rhythmic behaviors and thermoregulatory patterns are disrupted in adult female MeCP2-deficient mice. PLoS One 2012; 7:e35396. [PMID: 22523589 PMCID: PMC3327685 DOI: 10.1371/journal.pone.0035396] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
Mutations in the X-linked gene encoding Methyl-CpG-binding protein 2 (MECP2) have been associated with neurodevelopmental and neuropsychiatric disorders including Rett Syndrome, X-linked mental retardation syndrome, severe neonatal encephalopathy, and Angelman syndrome. Although alterations in the performance of MeCP2-deficient mice in specific behavioral tasks have been documented, it remains unclear whether or not MeCP2 dysfunction affects patterns of periodic behavioral and electroencephalographic (EEG) activity. The aim of the current study was therefore to determine whether a deficiency in MeCP2 is sufficient to alter the normal daily rhythmic patterns of core body temperature, gross motor activity and cortical delta power. To address this, we monitored individual wild-type and MeCP2-deficient mice in their home cage environment via telemetric recording over 24 hour cycles. Our results show that the normal daily rhythmic behavioral patterning of cortical delta wave activity, core body temperature and mobility are disrupted in one-year old female MeCP2-deficient mice. Moreover, female MeCP2-deficient mice display diminished overall motor activity, lower average core body temperature, and significantly greater body temperature fluctuation than wild-type mice in their home-cage environment. Finally, we show that the epileptiform discharge activity in female MeCP2-deficient mice is more predominant during times of behavioral activity compared to inactivity. Collectively, these results indicate that MeCP2 deficiency is sufficient to disrupt the normal patterning of daily biological rhythmic activities.
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Affiliation(s)
- Robert G. Wither
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Chiping Wu
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario, Canada
| | - Berj L. Bardakjian
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Liang Zhang
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario, Canada
- Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
| | - James H. Eubanks
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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