Exploring the relationship between cortical GABA concentrations, auditory gamma-band responses and development in ASD: Evidence for an altered maturational trajectory in ASD / Russell G. PORT in Autism Research, 10-4 (April 2017)  

Public ISBD [article]  inAutism Research > 10-4 (April 2017) . - p.593-607 Titre : Exploring the relationship between cortical GABA concentrations, auditory gamma-band responses and development in ASD: Evidence for an altered maturational trajectory in ASD Type de document : Texte imprimé et/ou numérique Auteurs : Russell G. PORT, Auteur ; William GAETZ, Auteur ; Luke BLOY, Auteur ; Dah-Jyuu WANG, Auteur ; Lisa BLASKEY, Auteur ; Emily S. KUSCHNER, Auteur ; Susan E. LEVY, Auteur ; Edward S. BRODKIN, Auteur ; Timothy P. L. ROBERTS, Auteur Article en page(s) : p.593-607 Langues : Anglais (eng) Mots-clés : magnetoencephalography  gamma-band  GABA  MEGA-PRESS  magnetic resonance spectroscopy  auditory  autism spectrum disorder  excitatory/inhibitory Index. décimale : PER Périodiques Résumé : Autism spectrum disorder (ASD) is hypothesized to arise from imbalances between excitatory and inhibitory neurotransmission (E/I imbalance). Studies have demonstrated E/I imbalance in individuals with ASD and also corresponding rodent models. One neural process thought to be reliant on E/I balance is gamma-band activity (Gamma), with support arising from observed correlations between motor, as well as visual, Gamma and underlying GABA concentrations in healthy adults. Additionally, decreased Gamma has been observed in ASD individuals and relevant animal models, though the direct relationship between Gamma and GABA concentrations in ASD remains unexplored. This study combined magnetoencephalography (MEG) and edited magnetic resonance spectroscopy (MRS) in 27 typically developing individuals (TD) and 30 individuals with ASD. Auditory cortex localized phase-locked Gamma was compared to resting Superior Temporal Gyrus relative cortical GABA concentrations for both children/adolescents and adults. Children/adolescents with ASD exhibited significantly decreased GABA+/Creatine (Cr) levels, though typical Gamma. Additionally, these children/adolescents lacked the typical maturation of GABA+/Cr concentrations and gamma-band coherence. Furthermore, children/adolescents with ASD additionally failed to exhibit the typical GABA+/Cr to gamma-band coherence association. This altered coupling during childhood/adolescence may result in Gamma decreases observed in the adults with ASD. Therefore, individuals with ASD exhibit improper local neuronal circuitry maturation during a childhood/adolescence critical period, when GABA is involved in configuring of such circuit functioning. Provocatively a novel line of treatment is suggested (with a critical time window); by increasing neural GABA levels in children/adolescents with ASD, proper local circuitry maturation may be restored resulting in typical Gamma in adulthood. En ligne : http://dx.doi.org/10.1002/aur.1686 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=307 [article] Exploring the relationship between cortical GABA concentrations, auditory gamma-band responses and development in ASD: Evidence for an altered maturational trajectory in ASD [Texte imprimé et/ou numérique] / Russell G. PORT, Auteur ; William GAETZ, Auteur ; Luke BLOY, Auteur ; Dah-Jyuu WANG, Auteur ; Lisa BLASKEY, Auteur ; Emily S. KUSCHNER, Auteur ; Susan E. LEVY, Auteur ; Edward S. BRODKIN, Auteur ; Timothy P. L. ROBERTS, Auteur . - p.593-607. Langues : Anglais (eng) in Autism Research > 10-4 (April 2017) . - p.593-607 Mots-clés : magnetoencephalography  gamma-band  GABA  MEGA-PRESS  magnetic resonance spectroscopy  auditory  autism spectrum disorder  excitatory/inhibitory Index. décimale : PER Périodiques Résumé : Autism spectrum disorder (ASD) is hypothesized to arise from imbalances between excitatory and inhibitory neurotransmission (E/I imbalance). Studies have demonstrated E/I imbalance in individuals with ASD and also corresponding rodent models. One neural process thought to be reliant on E/I balance is gamma-band activity (Gamma), with support arising from observed correlations between motor, as well as visual, Gamma and underlying GABA concentrations in healthy adults. Additionally, decreased Gamma has been observed in ASD individuals and relevant animal models, though the direct relationship between Gamma and GABA concentrations in ASD remains unexplored. This study combined magnetoencephalography (MEG) and edited magnetic resonance spectroscopy (MRS) in 27 typically developing individuals (TD) and 30 individuals with ASD. Auditory cortex localized phase-locked Gamma was compared to resting Superior Temporal Gyrus relative cortical GABA concentrations for both children/adolescents and adults. Children/adolescents with ASD exhibited significantly decreased GABA+/Creatine (Cr) levels, though typical Gamma. Additionally, these children/adolescents lacked the typical maturation of GABA+/Cr concentrations and gamma-band coherence. Furthermore, children/adolescents with ASD additionally failed to exhibit the typical GABA+/Cr to gamma-band coherence association. This altered coupling during childhood/adolescence may result in Gamma decreases observed in the adults with ASD. Therefore, individuals with ASD exhibit improper local neuronal circuitry maturation during a childhood/adolescence critical period, when GABA is involved in configuring of such circuit functioning. Provocatively a novel line of treatment is suggested (with a critical time window); by increasing neural GABA levels in children/adolescents with ASD, proper local circuitry maturation may be restored resulting in typical Gamma in adulthood. En ligne : http://dx.doi.org/10.1002/aur.1686 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=307

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)  

Public ISBD [article]  inJournal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.395-405 Titre : Neuromagnetic Oscillations Predict Evoked-Response Latency Delays and Core Language Deficits in Autism Spectrum Disorders Type de document : Texte imprimé et/ou numérique Auteurs : J. Christopher EDGAR, Auteur ; Sarah Y. KHAN, Auteur ; Lisa BLASKEY, Auteur ; Vivian Y. CHOW, Auteur ; Michael REY, Auteur ; William GAETZ, Auteur ; Katelyn M. CANNON, Auteur ; Justin F. MONROE, Auteur ; Lauren CORNEW, Auteur ; Saba QASMIEH, Auteur ; Song LIU, Auteur ; John P. WELSH, Auteur ; Susan E. LEVY, Auteur ; Timothy P. L. ROBERTS, Auteur Article en page(s) : p.395-405 Langues : Anglais (eng) Mots-clés : Auditory  Autism spectrum disorders  M100  Gamma  Evoked  Inter-trial coherence  Phase-locking  Magnetoencephalography Index. décimale : PER Périodiques Résumé : Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a ‘core’ abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate ‘neural tone’ and an inability to rapidly return to a resting state prior to the next stimulus. En ligne : http://dx.doi.org/10.1007/s10803-013-1904-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258 [article] Neuromagnetic Oscillations Predict Evoked-Response Latency Delays and Core Language Deficits in Autism Spectrum Disorders [Texte imprimé et/ou numérique] / J. Christopher EDGAR, Auteur ; Sarah Y. KHAN, Auteur ; Lisa BLASKEY, Auteur ; Vivian Y. CHOW, Auteur ; Michael REY, Auteur ; William GAETZ, Auteur ; Katelyn M. CANNON, Auteur ; Justin F. MONROE, Auteur ; Lauren CORNEW, Auteur ; Saba QASMIEH, Auteur ; Song LIU, Auteur ; John P. WELSH, Auteur ; Susan E. LEVY, Auteur ; Timothy P. L. ROBERTS, Auteur . - p.395-405. Langues : Anglais (eng) in Journal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.395-405 Mots-clés : Auditory  Autism spectrum disorders  M100  Gamma  Evoked  Inter-trial coherence  Phase-locking  Magnetoencephalography Index. décimale : PER Périodiques Résumé : Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a ‘core’ abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate ‘neural tone’ and an inability to rapidly return to a resting state prior to the next stimulus. En ligne : http://dx.doi.org/10.1007/s10803-013-1904-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258

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