11 recherche sur le mot-clé 'gamma'

Atypical Laterality of Resting Gamma Oscillations in Autism Spectrum Disorders / Christina R. MAXWELL in Journal of Autism and Developmental Disorders, 45-2 (February 2015)  

Public ISBD [article]  inJournal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.292-297 Titre : Atypical Laterality of Resting Gamma Oscillations in Autism Spectrum Disorders Type de document : Texte imprimé et/ou numérique Auteurs : Christina R. MAXWELL, Auteur ; Michele E. VILLALOBOS, Auteur ; Robert T. SCHULTZ, Auteur ; Beate HERPERTZ-DAHLMANN, Auteur ; Kerstin KONRAD, Auteur ; Gregor KOHLS, Auteur Article en page(s) : p.292-297 Langues : Anglais (eng) Mots-clés : Autism  Gamma  EEG  SRS  Resting state  Laterality Index. décimale : PER Périodiques Résumé : Abnormal brain oscillatory activity has been found in autism spectrum disorders (ASD) and proposed as a potential biomarker. While several studies have investigated gamma oscillations in ASD, none have examined resting gamma power across multiple brain regions. This study investigated resting gamma power using EEG in 15 boys with ASD and 18 age and intelligence quotient matched typically developing controls. We found a decrease in resting gamma power at right lateral electrodes in ASD. We further explored associations between gamma and ASD severity as measured by the Social Responsiveness Scale (SRS) and found a negative correlation between SRS and gamma power. We believe that our findings give further support of gamma oscillations as a potential biomarker for ASD. En ligne : http://dx.doi.org/10.1007/s10803-013-1842-7 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258 [article] Atypical Laterality of Resting Gamma Oscillations in Autism Spectrum Disorders [Texte imprimé et/ou numérique] / Christina R. MAXWELL, Auteur ; Michele E. VILLALOBOS, Auteur ; Robert T. SCHULTZ, Auteur ; Beate HERPERTZ-DAHLMANN, Auteur ; Kerstin KONRAD, Auteur ; Gregor KOHLS, Auteur . - p.292-297. Langues : Anglais (eng) in Journal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.292-297 Mots-clés : Autism  Gamma  EEG  SRS  Resting state  Laterality Index. décimale : PER Périodiques Résumé : Abnormal brain oscillatory activity has been found in autism spectrum disorders (ASD) and proposed as a potential biomarker. While several studies have investigated gamma oscillations in ASD, none have examined resting gamma power across multiple brain regions. This study investigated resting gamma power using EEG in 15 boys with ASD and 18 age and intelligence quotient matched typically developing controls. We found a decrease in resting gamma power at right lateral electrodes in ASD. We further explored associations between gamma and ASD severity as measured by the Social Responsiveness Scale (SRS) and found a negative correlation between SRS and gamma power. We believe that our findings give further support of gamma oscillations as a potential biomarker for ASD. En ligne : http://dx.doi.org/10.1007/s10803-013-1842-7 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258

Increased aperiodic gamma power in young boys with Fragile X Syndrome is associated with better language ability / C. L. WILKINSON in Molecular Autism, 12 (2021)  

Public ISBD [article]  inMolecular Autism > 12 (2021) . - 17 p. Titre : Increased aperiodic gamma power in young boys with Fragile X Syndrome is associated with better language ability Type de document : Texte imprimé et/ou numérique Auteurs : C. L. WILKINSON, Auteur ; C. A. NELSON, Auteur Article en page(s) : 17 p. Langues : Anglais (eng) Mots-clés : Brain/physiopathology  Child  Child Language  Child, Preschool  Electroencephalography  Fragile X Mental Retardation Protein/genetics  Fragile X Syndrome/genetics/physiopathology/psychology  Humans  Male  Biomarker  E:I ratio  Fragile X Syndrome  Gamma  Language  Outcome measures Index. décimale : PER Périodiques Résumé : BACKGROUND: The lack of robust and reliable clinical biomarkers in Fragile X Syndrome (FXS), the most common inherited form of intellectual disability, has limited the successful translation of bench-to-bedside therapeutics. While numerous drugs have shown promise in reversing synaptic and behavioral phenotypes in mouse models of FXS, none have demonstrated clinical efficacy in humans. Electroencephalographic (EEG) measures have been identified as candidate biomarkers as EEG recordings of both adults with FXS and mouse models of FXS consistently exhibit alterations in resting state and task-related activity. However, the developmental timing of these EEG differences is not known as thus far EEG studies have not focused on young children with FXS. Further, understanding how EEG differences are associated with core symptoms of FXS is crucial to successful use of EEG as a biomarker, and may improve our understanding of the disorder. METHODS: Resting-state EEG was collected from FXS boys with full mutation of Fmr1 (2.5-7 years old, n?=?11) and compared with both age-matched (n?=?12) and cognitive-matched (n?=?12) typically developing boys. Power spectra (including aperiodic and periodic components) were compared using non-parametric cluster-based permutation testing. Associations between 30 and 50 Hz gamma power and cognitive, language, and behavioral measures were evaluated using Pearson correlation and linear regression with age as a covariate. RESULTS: FXS participants showed increased power in the beta/gamma range (~?25-50 Hz) across multiple brain regions. Both a reduction in the aperiodic (1/f) slope and increase in beta/gamma periodic activity contributed to the significant increase in high-frequency power. Increased gamma power, driven by the aperiodic component, was associated with better language ability in the FXS group. No association was observed between gamma power and parent report measures of behavioral challenges, sensory hypersensitivities, or adaptive behaviors. LIMITATIONS: The study sample size was small, although comparable to other human studies in rare-genetic disorders. Findings are also limited to males in the age range studied. CONCLUSIONS: Resting-state EEG measures from this study in young boys with FXS identified similar increases in gamma power previously reported in adults and mouse models. The observed positive association between resting state aperiodic gamma power and language development supports hypotheses that alterations in some EEG measures may reflect ongoing compensatory mechanisms. En ligne : http://dx.doi.org/10.1186/s13229-021-00425-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459 [article] Increased aperiodic gamma power in young boys with Fragile X Syndrome is associated with better language ability [Texte imprimé et/ou numérique] / C. L. WILKINSON, Auteur ; C. A. NELSON, Auteur . - 17 p. Langues : Anglais (eng) in Molecular Autism > 12 (2021) . - 17 p. Mots-clés : Brain/physiopathology  Child  Child Language  Child, Preschool  Electroencephalography  Fragile X Mental Retardation Protein/genetics  Fragile X Syndrome/genetics/physiopathology/psychology  Humans  Male  Biomarker  E:I ratio  Fragile X Syndrome  Gamma  Language  Outcome measures Index. décimale : PER Périodiques Résumé : BACKGROUND: The lack of robust and reliable clinical biomarkers in Fragile X Syndrome (FXS), the most common inherited form of intellectual disability, has limited the successful translation of bench-to-bedside therapeutics. While numerous drugs have shown promise in reversing synaptic and behavioral phenotypes in mouse models of FXS, none have demonstrated clinical efficacy in humans. Electroencephalographic (EEG) measures have been identified as candidate biomarkers as EEG recordings of both adults with FXS and mouse models of FXS consistently exhibit alterations in resting state and task-related activity. However, the developmental timing of these EEG differences is not known as thus far EEG studies have not focused on young children with FXS. Further, understanding how EEG differences are associated with core symptoms of FXS is crucial to successful use of EEG as a biomarker, and may improve our understanding of the disorder. METHODS: Resting-state EEG was collected from FXS boys with full mutation of Fmr1 (2.5-7 years old, n?=?11) and compared with both age-matched (n?=?12) and cognitive-matched (n?=?12) typically developing boys. Power spectra (including aperiodic and periodic components) were compared using non-parametric cluster-based permutation testing. Associations between 30 and 50 Hz gamma power and cognitive, language, and behavioral measures were evaluated using Pearson correlation and linear regression with age as a covariate. RESULTS: FXS participants showed increased power in the beta/gamma range (~?25-50 Hz) across multiple brain regions. Both a reduction in the aperiodic (1/f) slope and increase in beta/gamma periodic activity contributed to the significant increase in high-frequency power. Increased gamma power, driven by the aperiodic component, was associated with better language ability in the FXS group. No association was observed between gamma power and parent report measures of behavioral challenges, sensory hypersensitivities, or adaptive behaviors. LIMITATIONS: The study sample size was small, although comparable to other human studies in rare-genetic disorders. Findings are also limited to males in the age range studied. CONCLUSIONS: Resting-state EEG measures from this study in young boys with FXS identified similar increases in gamma power previously reported in adults and mouse models. The observed positive association between resting state aperiodic gamma power and language development supports hypotheses that alterations in some EEG measures may reflect ongoing compensatory mechanisms. En ligne : http://dx.doi.org/10.1186/s13229-021-00425-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459

Targeting Gamma-Related Pathophysiology in Autism Spectrum Disorder Using Transcranial Electrical Stimulation: Opportunities and Challenges / Fae B. KAYARIAN in Autism Research, 13-7 (July 2020)  

Public ISBD [article]  inAutism Research > 13-7 (July 2020) . - p.1051-1071 Titre : Targeting Gamma-Related Pathophysiology in Autism Spectrum Disorder Using Transcranial Electrical Stimulation: Opportunities and Challenges Type de document : Texte imprimé et/ou numérique Auteurs : Fae B. KAYARIAN, Auteur ; Ali JANNATI, Auteur ; Alexander ROTENBERG, Auteur ; Emiliano SANTARNECCHI, Auteur Article en page(s) : p.1051-1071 Langues : Anglais (eng) Mots-clés : autism spectrum disorder  gamma  transcranial alternating current stimulation  transcranial direct current stimulation  transcranial electrical stimulation Index. décimale : PER Périodiques Résumé : A range of scalp electroencephalogram (EEG) abnormalities correlates with the core symptoms of autism spectrum disorder (ASD). Among these are alterations of brain oscillations in the gamma-frequency EEG band in adults and children with ASD, whose origin has been linked to dysfunctions of inhibitory interneuron signaling. While therapeutic interventions aimed to modulate gamma oscillations are being tested for neuropsychiatric disorders such as schizophrenia, Alzheimer's disease, and frontotemporal dementia, the prospects for therapeutic gamma modulation in ASD have not been extensively studied. Accordingly, we discuss gamma-related alterations in the setting of ASD pathophysiology, as well as potential interventions that can enhance gamma oscillations in patients with ASD. Ultimately, we argue that transcranial electrical stimulation modalities capable of entraining gamma oscillations, and thereby potentially modulating inhibitory interneuron circuitry, are promising methods to study and mitigate gamma alterations in ASD. Autism Res 2020, 13: 1051-1071. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Brain functions are mediated by various oscillatory waves of neuronal activity, ranging in amplitude and frequency. In certain neuropsychiatric disorders, such as schizophrenia and Alzheimer's disease, reduced high-frequency oscillations in the "gamma" band have been observed, and therapeutic interventions to enhance such activity are being explored. Here, we review and comment on evidence of reduced gamma activity in ASD, arguing that modalities used in other disorders may benefit individuals with ASD as well. En ligne : http://dx.doi.org/10.1002/aur.2312 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=429 [article] Targeting Gamma-Related Pathophysiology in Autism Spectrum Disorder Using Transcranial Electrical Stimulation: Opportunities and Challenges [Texte imprimé et/ou numérique] / Fae B. KAYARIAN, Auteur ; Ali JANNATI, Auteur ; Alexander ROTENBERG, Auteur ; Emiliano SANTARNECCHI, Auteur . - p.1051-1071. Langues : Anglais (eng) in Autism Research > 13-7 (July 2020) . - p.1051-1071 Mots-clés : autism spectrum disorder  gamma  transcranial alternating current stimulation  transcranial direct current stimulation  transcranial electrical stimulation Index. décimale : PER Périodiques Résumé : A range of scalp electroencephalogram (EEG) abnormalities correlates with the core symptoms of autism spectrum disorder (ASD). Among these are alterations of brain oscillations in the gamma-frequency EEG band in adults and children with ASD, whose origin has been linked to dysfunctions of inhibitory interneuron signaling. While therapeutic interventions aimed to modulate gamma oscillations are being tested for neuropsychiatric disorders such as schizophrenia, Alzheimer's disease, and frontotemporal dementia, the prospects for therapeutic gamma modulation in ASD have not been extensively studied. Accordingly, we discuss gamma-related alterations in the setting of ASD pathophysiology, as well as potential interventions that can enhance gamma oscillations in patients with ASD. Ultimately, we argue that transcranial electrical stimulation modalities capable of entraining gamma oscillations, and thereby potentially modulating inhibitory interneuron circuitry, are promising methods to study and mitigate gamma alterations in ASD. Autism Res 2020, 13: 1051-1071. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Brain functions are mediated by various oscillatory waves of neuronal activity, ranging in amplitude and frequency. In certain neuropsychiatric disorders, such as schizophrenia and Alzheimer's disease, reduced high-frequency oscillations in the "gamma" band have been observed, and therapeutic interventions to enhance such activity are being explored. Here, we review and comment on evidence of reduced gamma activity in ASD, arguing that modalities used in other disorders may benefit individuals with ASD as well. En ligne : http://dx.doi.org/10.1002/aur.2312 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=429

Atypical Hemispheric Specialization for Faces in Infants at Risk for Autism Spectrum Disorder / Brandon KEEHN in Autism Research, 8-2 (April 2015)  

Public ISBD [article]  inAutism Research > 8-2 (April 2015) . - p.187-198 Titre : Atypical Hemispheric Specialization for Faces in Infants at Risk for Autism Spectrum Disorder Type de document : Texte imprimé et/ou numérique Auteurs : Brandon KEEHN, Auteur ; Vanessa VOGEL-FARLEY, Auteur ; Helen TAGER-FLUSBERG, Auteur ; Charles A. NELSON, Auteur Article en page(s) : p.187-198 Langues : Anglais (eng) Mots-clés : autism  EEG coherence  face processing  hemispheric specialization  endophenotype  gamma  infancy Index. décimale : PER Périodiques Résumé : Among the many experimental findings that tend to distinguish those with and without autism spectrum disorder (ASD) are face processing deficits, reduced hemispheric specialization, and atypical neurostructural and functional connectivity. To investigate the earliest manifestations of these features, we examined lateralization of event-related gamma-band coherence to faces during the first year of life in infants at high risk for autism (HRA; defined as having an older sibling with ASD) who were compared with low-risk comparison (LRC) infants, defined as having no family history of ASD. Participants included 49 HRA and 46 LRC infants who contributed a total of 127 data sets at 6 and 12 months. Electroencephalography was recorded while infants viewed images of familiar/unfamiliar faces. Event-related gamma-band (30–50?Hz) phase coherence between anterior–posterior electrode pairs for left and right hemispheres was computed. Developmental trajectories for lateralization of intra-hemispheric coherence were significantly different in HRA and LRC infants: by 12 months, HRA infants showed significantly greater leftward lateralization compared with LRC infants who showed rightward lateralization. Preliminary results indicate that infants who later met criteria for ASD were those that showed the greatest leftward lateralization. HRA infants demonstrate an aberrant pattern of leftward lateralization of intra-hemispheric coherence by the end of the first year of life, suggesting that the network specialized for face processing may develop atypically. Further, infants with the greatest leftward asymmetry at 12 months where those that later met criteria for ASD, providing support to the growing body of evidence that atypical hemispheric specialization may be an early neurobiological marker for ASD. En ligne : http://dx.doi.org/10.1002/aur.1438 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=256 [article] Atypical Hemispheric Specialization for Faces in Infants at Risk for Autism Spectrum Disorder [Texte imprimé et/ou numérique] / Brandon KEEHN, Auteur ; Vanessa VOGEL-FARLEY, Auteur ; Helen TAGER-FLUSBERG, Auteur ; Charles A. NELSON, Auteur . - p.187-198. Langues : Anglais (eng) in Autism Research > 8-2 (April 2015) . - p.187-198 Mots-clés : autism  EEG coherence  face processing  hemispheric specialization  endophenotype  gamma  infancy Index. décimale : PER Périodiques Résumé : Among the many experimental findings that tend to distinguish those with and without autism spectrum disorder (ASD) are face processing deficits, reduced hemispheric specialization, and atypical neurostructural and functional connectivity. To investigate the earliest manifestations of these features, we examined lateralization of event-related gamma-band coherence to faces during the first year of life in infants at high risk for autism (HRA; defined as having an older sibling with ASD) who were compared with low-risk comparison (LRC) infants, defined as having no family history of ASD. Participants included 49 HRA and 46 LRC infants who contributed a total of 127 data sets at 6 and 12 months. Electroencephalography was recorded while infants viewed images of familiar/unfamiliar faces. Event-related gamma-band (30–50?Hz) phase coherence between anterior–posterior electrode pairs for left and right hemispheres was computed. Developmental trajectories for lateralization of intra-hemispheric coherence were significantly different in HRA and LRC infants: by 12 months, HRA infants showed significantly greater leftward lateralization compared with LRC infants who showed rightward lateralization. Preliminary results indicate that infants who later met criteria for ASD were those that showed the greatest leftward lateralization. HRA infants demonstrate an aberrant pattern of leftward lateralization of intra-hemispheric coherence by the end of the first year of life, suggesting that the network specialized for face processing may develop atypically. Further, infants with the greatest leftward asymmetry at 12 months where those that later met criteria for ASD, providing support to the growing body of evidence that atypical hemispheric specialization may be an early neurobiological marker for ASD. En ligne : http://dx.doi.org/10.1002/aur.1438 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=256

Neural synchronization deficits linked to cortical hyper-excitability and auditory hypersensitivity in fragile X syndrome / L. E. ETHRIDGE in Molecular Autism, 8 (2017)  

Public ISBD [article]  inMolecular Autism > 8 (2017) . - 22p. Titre : Neural synchronization deficits linked to cortical hyper-excitability and auditory hypersensitivity in fragile X syndrome Type de document : Texte imprimé et/ou numérique Auteurs : L. E. ETHRIDGE, Auteur ; S. P. WHITE, Auteur ; M. W. MOSCONI, Auteur ; J. WANG, Auteur ; Ernest V. PEDAPATI, Auteur ; C. A. ERICKSON, Auteur ; M. J. BYERLY, Auteur ; J. A. SWEENEY, Auteur Article en page(s) : 22p. Langues : Anglais (eng) Mots-clés : Chirp  Eeg  Fragile X syndrome  Gamma  Sensory Index. décimale : PER Périodiques Résumé : BACKGROUND: Studies in the fmr1 KO mouse demonstrate hyper-excitability and increased high-frequency neuronal activity in sensory cortex. These abnormalities may contribute to prominent and distressing sensory hypersensitivities in patients with fragile X syndrome (FXS). The current study investigated functional properties of auditory cortex using a sensory entrainment task in FXS. METHODS: EEG recordings were obtained from 17 adolescents and adults with FXS and 17 age- and sex-matched healthy controls. Participants heard an auditory chirp stimulus generated using a 1000-Hz tone that was amplitude modulated by a sinusoid linearly increasing in frequency from 0-100 Hz over 2 s. RESULTS: Single trial time-frequency analyses revealed decreased gamma band phase-locking to the chirp stimulus in FXS, which was strongly coupled with broadband increases in gamma power. Abnormalities in gamma phase-locking and power were also associated with theta-gamma amplitude-amplitude coupling during the pre-stimulus period and with parent reports of heightened sensory sensitivities and social communication deficits. CONCLUSIONS: This represents the first demonstration of neural entrainment alterations in FXS patients and suggests that fast-spiking interneurons regulating synchronous high-frequency neural activity have reduced functionality. This reduced ability to synchronize high-frequency neural activity was related to the total power of background gamma band activity. These observations extend findings from fmr1 KO models of FXS, characterize a core pathophysiological aspect of FXS, and may provide a translational biomarker strategy for evaluating promising therapeutics. En ligne : http://dx.doi.org/10.1186/s13229-017-0140-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=330 [article] Neural synchronization deficits linked to cortical hyper-excitability and auditory hypersensitivity in fragile X syndrome [Texte imprimé et/ou numérique] / L. E. ETHRIDGE, Auteur ; S. P. WHITE, Auteur ; M. W. MOSCONI, Auteur ; J. WANG, Auteur ; Ernest V. PEDAPATI, Auteur ; C. A. ERICKSON, Auteur ; M. J. BYERLY, Auteur ; J. A. SWEENEY, Auteur . - 22p. Langues : Anglais (eng) in Molecular Autism > 8 (2017) . - 22p. Mots-clés : Chirp  Eeg  Fragile X syndrome  Gamma  Sensory Index. décimale : PER Périodiques Résumé : BACKGROUND: Studies in the fmr1 KO mouse demonstrate hyper-excitability and increased high-frequency neuronal activity in sensory cortex. These abnormalities may contribute to prominent and distressing sensory hypersensitivities in patients with fragile X syndrome (FXS). The current study investigated functional properties of auditory cortex using a sensory entrainment task in FXS. METHODS: EEG recordings were obtained from 17 adolescents and adults with FXS and 17 age- and sex-matched healthy controls. Participants heard an auditory chirp stimulus generated using a 1000-Hz tone that was amplitude modulated by a sinusoid linearly increasing in frequency from 0-100 Hz over 2 s. RESULTS: Single trial time-frequency analyses revealed decreased gamma band phase-locking to the chirp stimulus in FXS, which was strongly coupled with broadband increases in gamma power. Abnormalities in gamma phase-locking and power were also associated with theta-gamma amplitude-amplitude coupling during the pre-stimulus period and with parent reports of heightened sensory sensitivities and social communication deficits. CONCLUSIONS: This represents the first demonstration of neural entrainment alterations in FXS patients and suggests that fast-spiking interneurons regulating synchronous high-frequency neural activity have reduced functionality. This reduced ability to synchronize high-frequency neural activity was related to the total power of background gamma band activity. These observations extend findings from fmr1 KO models of FXS, characterize a core pathophysiological aspect of FXS, and may provide a translational biomarker strategy for evaluating promising therapeutics. En ligne : http://dx.doi.org/10.1186/s13229-017-0140-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=330

Neuromagnetic Oscillations Predict Evoked-Response Latency Delays and Core Language Deficits in Autism Spectrum Disorders / J. Christopher EDGAR in Journal of Autism and Developmental Disorders, 45-2 (February 2015)  

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Oxytocin impacts top-down and bottom-up social perception in adolescents with ASD: a MEG study of neural connectivity / Adi KORISKY in Molecular Autism, 13 (2022)  

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Patterns of altered neural synchrony in the default mode network in autism spectrum disorder revealed with magnetoencephalography (MEG): Relationship to clinical symptomatology / R. LAJINESS-O'NEILL in Autism Research, 11-3 (March 2018)  

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Reduced auditory steady state responses in autism spectrum disorder / R. A. SEYMOUR in Molecular Autism, 11 (2020)  

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A resting EEG study of neocortical hyperexcitability and altered functional connectivity in fragile X syndrome / J. WANG in Journal of Neurodevelopmental Disorders, 9-1 (December 2017)  

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