Pubmed du 10/06/20

mercredi 10 juin 2020

1. Abdellatif B, McVeigh C, Bendriss G, Chaari A. The Promising Role of Probiotics in Managing the Altered Gut in Autism Spectrum Disorders. Int J Mol Sci ;2020 (Jun 10) ;21(11)

Gastrointestinal symptoms (GIS) have been reported repeatedly in people with autism spectrum disorder (ASD) and studies have reported interesting correlations between severity of behavioral and gastrointestinal symptoms. Growing evidence indicates that the gut microbiota in ASD is altered with various shifts described at different taxonomic levels, pointing to the importance of considering the gut-brain axis in treatment of these disorders. Probiotics are live beneficial bacteria that are ingested as food or customized pills. These beneficial bacteria, when added in sufficient amounts, can correct the dysbiosis. Because probiotics have shown success in treating irritable bowel syndrome (IBS), it is plausible to investigate whether they can induce alleviation of behavioral symptoms as well. Probiotics show, in some clinical studies, their potential benefits (1) in improving gastrointestinal dysfunction, (2) in correcting dysbiosis, (3) in consequently reducing the severity of ASD symptoms. This review compiles data from selected studies that investigate these benefits and the mechanisms that mediate these effects, which include the production of metabolites, hormones, and neurotransmitters and the regulation of pro-inflammatory and regulatory cytokines. Future research based on more randomized, controlled studies with a larger population size and standardized use of strains, concentration of probiotics, duration of treatments, and methods of DNA extraction is still needed in this area, which may lead to more robust results.

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2. Arnold Anteraper S, Guell X, Hollinshead M, D’Mello A, Whitfield-Gabrieli S, Biederman J, Joshi G. Functional Alterations Associated with Structural Abnormalities in Adults with High-Functioning Autism Spectrum Disorder. Brain Connect ;2020 (Jun 10)

BACKGROUND : The combination of structural and functional analyses is a biologically valid approach that offers methodological advantages in ASD neuroimaging science. The paucity of studies combining these methods constitutes an important knowledge gap. In this study, we investigate structural abnormalities and their associated functional differences in a developmentally homogeneous ASD cohort. 
 Methods : Whole-brain VBM analyses were performed on 28 ASD participants and 38 age-matched typically developing healthy controls (HC) to derive gray matter (GM) volume differences. The anatomically relevant clusters identified by voxel-based morphometry (VBM) served as seed regions of interest (ROI) for resting-state functional-connectivity (RsFc) analysis. RESULTS : Whole-brain VBM analyses revealed significant right lateralized GM volume abnormality in the ASD group with lower GM volumes in cerebellar lobules VIIb/VIIIa (cluster 1) and significantly higher GM volumes in posterior middle/superior temporal gyrii (BA 21/22, cluster 2) as compared to HC. Whole-brain RsFc analysis in HF-ASD revealed significant hypo-connectivity of the cerebellar VBM cluster with the right cerebral cortical regions of superior parietal lobule (BA7) and occipital pole (BA19) (overlapping with dorsal attention and visual networks, respectively). Cerebral cortical VBM cluster (cluster 2) revealed significant hypo-connectivity in HF-ASD with other task-positive cerebral cortical including the left lateral prefrontal cortex (frontoparietal network) and some aspects of the insula (ventral attention network) and ectopic positive connectivity (lack of anti-correlations) with posterior cingulate cortex and medial prefrontal cortex (default mode network). CONCLUSIONS : The cerebro-cerebellar intrinsic functional dysconnectivity based on the whole-brain VBM-derived ROIs may advance our understanding of the compensatory mechanisms associated with ASD and offer cerebellum as a potential target for diagnostic, predictive, prognostic, and therapeutic interventions in ASD. Our findings also provide additional support indicating that functional abnormalities as indexed by RsFc exist in ASD, and highlight that there is likely a relationship between structural and functional abnormalities in this disorder. 
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3. Bruining H, Hardstone R, Juarez-Martinez EL, Sprengers J, Avramiea AE, Simpraga S, Houtman SJ, Poil SS, Dallares E, Palva S, Oranje B, Matias Palva J, Mansvelder HD, Linkenkaer-Hansen K. Measurement of excitation-inhibition ratio in autism spectrum disorder using critical brain dynamics. Sci Rep ;2020 (Jun 8) ;10(1):9195.

Balance between excitation (E) and inhibition (I) is a key principle for neuronal network organization and information processing. Consistent with this notion, excitation-inhibition imbalances are considered a pathophysiological mechanism in many brain disorders including autism spectrum disorder (ASD). However, methods to measure E/I ratios in human brain networks are lacking. Here, we present a method to quantify a functional E/I ratio (fE/I) from neuronal oscillations, and validate it in healthy subjects and children with ASD. We define structural E/I ratio in an in silico neuronal network, investigate how it relates to power and long-range temporal correlations (LRTC) of the network’s activity, and use these relationships to design the fE/I algorithm. Application of this algorithm to the EEGs of healthy adults showed that fE/I is balanced at the population level and is decreased through GABAergic enforcement. In children with ASD, we observed larger fE/I variability and stronger LRTC compared to typically developing children (TDC). Interestingly, visual grading for EEG abnormalities that are thought to reflect E/I imbalances revealed elevated fE/I and LRTC in ASD children with normal EEG compared to TDC or ASD with abnormal EEG. We speculate that our approach will help understand physiological heterogeneity also in other brain disorders.

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4. Chan KKS, Leung DCK. Linking Child Autism to Parental Depression and Anxiety : Mediating the Roles of Enacted and Felt Stigma. J Autism Dev Disord ;2020 (Jun 10)

This study examined whether child autistic symptoms would heighten parental affective symptoms through evoking enacted stigma from the community (i.e., public and courtesy stigma) and felt stigma within the parents (i.e., vicarious and self-stigma). Cross-sectional questionnaire data were collected from 441 parents of children with autism spectrum disorder. Path analyses showed that social communication and interaction deficits and restricted and repetitive behaviors in child autism were positively associated with public and courtesy stigma. While public stigma was positively associated with parental vicarious stigma, courtesy stigma was positively associated with parental self-stigma. Both vicarious and self-stigma were positively associated with depressive and anxiety symptoms among parents. Findings revealed how child autism could compromise parental well-being through exacerbating the family’s stigmatizing experiences.

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5. Gudbrandsen M, Bletsch A, Mann C, Daly E, Murphy CM, Stoencheva V, Blackmore CE, Rogdaki M, Kushan L, Bearden CE, Murphy DGM, Craig MC, Ecker C. Neuroanatomical underpinnings of autism symptomatology in carriers and non-carriers of the 22q11.2 microdeletion. Mol Autism ;2020 (Jun 8) ;11(1):46.

BACKGROUND : A crucial step to understanding the mechanistic underpinnings of autism spectrum disorder (ASD), is to examine if the biological underpinnings of ASD in genetic high-risk conditions, like 22q11.2 deletion syndrome (22q11.2DS), are similar to those in idiopathic illness. This study aimed to examine if ASD symptomatology in 22q11.2DS is underpinned by the same-or distinct-neural systems that mediate these symptoms in non-deletion carriers. METHODS : We examined vertex-wise estimates of cortical volume (CV), surface area (SA), and cortical thickness across 131 individuals between 6 and 25 years of age including (1) 50 individuals with 22q11.2DS, out of which n = 25 had a diagnosis of ASD, (2) 40 non-carriers of the microdeletion with a diagnosis of ASD (i.e., idiopathic ASD), and (3) 41 typically developing (TD) controls. We employed a 2-by-2 factorial design to identify neuroanatomical variability associated with the main effects of 22q11.2DS and ASD, as well as their interaction. Further, using canonical correlation analysis (CCA), we compared neuroanatomical variability associated with the complex (i.e., multivariate) clinical phenotype of ASD between 22q11.2 deletion carriers and non-carriers. RESULTS : The set of brain regions associated with the main effect of 22q11.2DS was distinct from the neuroanatomical underpinnings of the main effect of ASD. Moreover, significant 22q11.2DS-by-ASD interactions were observed for CV and SA in the dorsolateral prefrontal cortex, precentral gyrus, and posterior cingulate cortex, suggesting that the neuroanatomy of ASD is significantly modulated by 22q11.2DS (p < 0.01). We further established that the multivariate patterns of neuroanatomical variability associated with differences in symptom profiles significantly differed between 22q11.2 deletion carriers and non-carriers. LIMITATIONS : We employed a multicenter design to overcome single-site recruitment limitations ; however, FreeSurfer-derived measures of surface anatomy have been shown to be highly reliable across scanner platforms and field strengths. Further, we controlled for gender to address the differing distribution between idiopathic ASD individuals and the other groups. Nonetheless, the gender distribution in our sample reflects that of the respective populations, adding to the generalizability of our results. Last, we included individuals with a relatively wide age range (i.e., 6-25 years). CONCLUSIONS : Our findings indicate that neuroanatomical correlates of ASD symptomatology in carriers of the 22q11.2 microdeletion diverge from those in idiopathic ASD.

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6. Jasoliya M, Bowling H, Petrasic IC, Durbin-Johnson B, Klann E, Bhattacharya A, Hagerman R, Tassone F. Blood-Based Biomarkers Predictive of Metformin Target Engagement in Fragile X Syndrome. Brain Sci ;2020 (Jun 10) ;10(6)

Recent advances in neurobiology have provided several molecular entrees for targeted treatments for Fragile X syndrome (FXS). However, the efficacy of these treatments has been demonstrated mainly in animal models and has not been consistently predictive of targeted drugs’ response in the preponderance of human clinical trials. Because of the heterogeneity of FXS at various levels, including the molecular level, phenotypic manifestation, and drug response, it is critically important to identify biomarkers that can help in patient stratification and prediction of therapeutic efficacy. The primary objective of this study was to assess the ability of molecular biomarkers to predict phenotypic subgroups, symptom severity, and treatment response to metformin in clinically treated patients with FXS. We specifically tested a triplex protein array comprising of hexokinase 1 (HK1), RAS (all isoforms), and Matrix Metalloproteinase 9 (MMP9) that we previously demonstrated were dysregulated in the FXS mouse model and in blood samples from patient with FXS. Seventeen participants with FXS, 12 males and 5 females, treated clinically with metformin were included in this study. The disruption in expression abundance of these proteins was normalized and associated with significant self-reported improvement in clinical phenotypes (CGI-I in addition to BMI) in a subset of participants with FXS. Our preliminary findings suggest that these proteins are of strong molecular relevance to the FXS pathology that could make them useful molecular biomarkers for this syndrome.

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7. Juybari KB, Sepehri G, Meymandi MS, Shahrbabaki SSV, Moslemizadeh A, Saeedi N, Aminzadeh A, Nozari M, Khaksari M, Haghpanah T, Bashiri H. Sex dependent alterations of resveratrol on social behaviors and nociceptive reactivity in VPA-induced autistic-like model in rats. Neurotoxicol Teratol ;2020 (Jun 10):106905.

INTRODUCTION : The present study was designed to clarify the effects of resveratrol (RSV) on social behavioral alterations and nociceptive reactivity in valproic acid (VPA)-induced autistic-like model in female and male rats. METHODS : Pregnant Wistar rats were randomly divided in five groups. Animals received saline, DMSO, VPA, RSV and RSV + VPA. VPA was administered (600 mg/kg, i. p.) on embryonic day 12.5 (E12.5) and pretreatment by resveratrol (3.6 mg/kg, s. c.) was applied on E6.5 until E18.5. All offspring were weaned on postnatal day 21 and the experiments were done in male and female rats on day 60. Social interaction, hot plate and tail flick tests were set out to assess social deficits and pain threshold, respectively. Sociability index (SI), Social novelty index (SNI) and latency time were calculated as the standard indices of social behaviors and pain threshold, respectively. RESULTS : The results indicated that systemic intraperitoneal administration of VPA (600 mg/kg) significantly decreased SI and SNI in social interaction test (SIT) especially in male rats, indicating the social impairments caused by VPA. RSV (3.6 mg/kg, s. c.) reversed VPA-induced social deficits in male rats, but not in female group. VPA administration resulted in significant increase in latency time in the hot plate and tail flick tests in male rats, whereas it had no such dramatic effect in females. RSV administration in combination with VPA had no significant effect on latency time compared to the valproic acid group in male rats. It is important to note that RSV by itself had no significant effect on SI, SNI and latency time in female and male rats. CONCLUSION : It can be concluded that valproic acid produces autistic-like behaviors and increases pain threshold in male rats which may be ameliorated at least in part by resveratrol administration. Further studies are needed to elucidate the molecular mechanisms involved in valproic acid and resveratrol-induced effects.

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8. Lu Y, Liang Y, Ning S, Deng G, Xie Y, Song J, Zuo N, Feng C, Qin Y. Rare partial trisomy and tetrasomy of 15q11-q13 associated with developmental delay and autism spectrum disorder. Mol Cytogenet ;2020 ;13:21.

BACKGROUND : Small supernumerary marker chromosomes (sSMCs), are additional abnormal chromosomes, which can’t be detected accurately by banding cytogenetic analysis. Abnormal phenotypes were observed in about 30% of SMC carriers. Duplication of chromosome 15 and related disorders, characterized by hypotonia motor delays, autism spectrum disorder (ASD), intellectual disability, and epilepsy including infantile spasms, might be account for 50% of the total sSMCs. CASE PRESENTATION : An 11-month-old infant with an sSMC found by banding cytogenetics was referred to our clinic because of developmental retardation and autism spectrum disorder. After several months of rehabilitation treatment, the progress of motor development was obvious, but the consciousness was still far from satisfied. High-resolution karyotype analysis, multiplex ligation-dependent probe amplification and copy number variation sequencing (CNV-Seq) were conducted to confirm the identity of the sSMC. A bisatellited dicentric sSMC was observed clearly in high-resolution karyotype analysis and a 10.16-Mb duplication of 15q11.1q13.2 (3.96 copies) together with a 1.84-Mb duplication of 15q13.2q13.3 (3 copies) was showed by CNV-Seq in the proband. It suggested that the molecular cytogenetic karyotype was 47,XY,+dic(15 ;15)(q13.2 ;q13.3). Furthermore, the clinical symptoms of the proband mostly fit 15q duplication related disorders which are characterized by hypotonia motor delays, autism spectrum disorder (ASD), and intellectual disability. CONCLUSION : We reported for the first time using CNV-Seq to detect sSMCs and find a partial trisomy and tetrasomy of 15q11-q13 associated with developmental delay and autism spectrum disorder. Our report indicates that CNV-seq is a useful and economical way for diagnosis of dup15q and related disorders.

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9. Lutz AK, Pfaender S, Incearap B, Ioannidis V, Ottonelli I, Föhr KJ, Cammerer J, Zoller M, Higelin J, Giona F, Stetter M, Stoecker N, Alami NO, Schön M, Orth M, Liebau S, Barbi G, Grabrucker AM, Delorme R, Fauler M, Mayer B, Jesse S, Roselli F, Ludolph AC, Bourgeron T, Verpelli C, Demestre M, Boeckers TM. Autism-associated SHANK3 mutations impair maturation of neuromuscular junctions and striated muscles. Sci Transl Med ;2020 (Jun 10) ;12(547)

Heterozygous mutations of the gene encoding the postsynaptic protein SHANK3 are associated with syndromic forms of autism spectrum disorders (ASDs). One of the earliest clinical symptoms in SHANK3-associated ASD is neonatal skeletal muscle hypotonia. This symptom can be critical for the early diagnosis of affected children ; however, the mechanism mediating hypotonia in ASD is not completely understood. Here, we used a combination of patient-derived human induced pluripotent stem cells (hiPSCs), Shank3Δ11(-/-) mice, and Phelan-McDermid syndrome (PMDS) muscle biopsies from patients of different ages to analyze the role of SHANK3 on motor unit development. Our results suggest that the hypotonia in SHANK3 deficiency might be caused by dysfunctions in all elements of the voluntary motor system : motoneurons, neuromuscular junctions (NMJs), and striated muscles. We found that SHANK3 localizes in Z-discs in the skeletal muscle sarcomere and co-immunoprecipitates with α-ACTININ. SHANK3 deficiency lead to shortened Z-discs and severe impairment of acetylcholine receptor clustering in hiPSC-derived myotubes and in muscle from Shank3Δ11(-/-) mice and patients with PMDS, indicating a crucial role for SHANK3 in the maturation of NMJs and striated muscle. Functional motor defects in Shank3Δ11(-/-) mice could be rescued with the troponin activator Tirasemtiv that sensitizes muscle fibers to calcium. Our observations give insight into the function of SHANK3 besides the central nervous system and imply potential treatment strategies for SHANK3-associated ASD.

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10. Matsuoka K, Makinodan M, Kitamura S, Takahashi M, Yoshikawa H, Yasuno F, Ishida R, Kishimoto N, Yasuda Y, Hashimoto R, Taoka T, Miyasaka T, Kichikawa K, Kishimoto T. Increased Dendritic Orientation Dispersion in the Left Occipital Gyrus is Associated with Atypical Visual Processing in Adults with Autism Spectrum Disorder. Cereb Cortex ;2020 (Jun 9)

In autism spectrum disorder (ASD), the complexity-specific hypothesis explains that atypical visual processing is attributable to selective functional changes in visual pathways. We investigated dendritic microstructures and their associations with functional connectivity (FC). Participants included 28 individuals with ASD and 29 typically developed persons. We explored changes in neurite orientation dispersion and density imaging (NODDI) and brain areas whose FC was significantly correlated with NODDI parameters in the explored regions of interests. Individuals with ASD showed significantly higher orientation dispersion index (ODI) values in the left occipital gyrus (OG) corresponding to the secondary visual cortex (V2). FC values between the left OG and the left middle temporal gyrus (MTG) were significantly negatively correlated with mean ODI values. The mean ODI values in the left OG were significantly positively associated with low registration of the visual quadrants of the Adolescent/Adult Sensory Profile (AASP), resulting in a significant positive correlation with passive behavioral responses of the AASP visual quadrants ; additionally, the FC values between the left OG and the left MTG were significantly negatively associated with reciprocal social interaction. Our results suggest that abnormal V2 dendritic arborization is associated with atypical visual processing by altered intermediation in the ventral visual pathway.

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11. Owji H, Eslami M, Nezafat N, Ghasemi Y. In Silico Elucidation of Deleterious Non-synonymous SNPs in SHANK3, the Autism Spectrum Disorder Gene. J Mol Neurosci ;2020 (Jun 10)

SHANK3, a member of SH3 and multiple ankyrin repeat domains (SHANK) proteins, plays a crucial role in synaptic development and functions. Mutations in SHANK3 have been linked to a number of neuropsychiatric and neurodevelopmental disorders, including autism spectrum disorder. In this study, the functional and structural impacts of non-synonymous single-nucleotide polymorphisms (SNPs) on SHANK3 were predicted. Various databases were used to extract 16,894 non-redundant SNPs, out of which 1179 were annotated as missense variants. Missense variants were categorized as deleterious or non-deleterious. Twenty-nine missense variants were unanimously recognized as deleterious and subjected to structural and stability analyses. Mutations, including L47P, G54W, G172D, G250C/D, and G627E, which posed drastic effects on the secondary structure of SHANK3, were modeled. Stability analyses introduced L47P, G54W, and G250D as the most destabilizing mutations, thus they were subjected to molecular dynamics simulation. Simulation revealed significant changes in intramolecular interactions and high fluctuations in residues of 1-350 that significantly affect the ANK functional domain. G250C/D and G635R consensus deleterious mutations were found in the first and second binding domains of SHANK3, and none were found in the post-translational modification sites. This study suggests L47P, G54W, and G250C/D deleterious mutations as priorities for future studies on SHANK3.

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12. Ozkul Y, Taheri S, Bayram KK, Sener EF, Mehmetbeyoglu E, Öztop DB, Aybuga F, Tufan E, Bayram A, Dolu N, Zararsiz G, Kianmehr L, Beyaz F, Doganyigit Z, Cuzin F, Rassoulzadegan M. A heritable profile of six miRNAs in autistic patients and mouse models. Sci Rep ;2020 (Jun 9) ;10(1):9011.

Autism spectrum disorder (ASD) is a group of developmental pathologies that impair social communication and cause repetitive behaviors. The suggested roles of noncoding RNAs in pathology led us to perform a comparative analysis of the microRNAs expressed in the serum of human ASD patients. The analysis of a cohort of 45 children with ASD revealed that six microRNAs (miR-19a-3p, miR-361-5p, miR-3613-3p, miR-150-5p, miR-126-3p, and miR-499a-5p) were expressed at low to very low levels compared to those in healthy controls. A similar but less pronounced decrease was registered in the clinically unaffected parents of the sick children and in their siblings but never in any genetically unrelated control. Results consistent with these observations were obtained in the blood, hypothalamus and sperm of two of the established mouse models of ASD : valproic acid-treated animals and Cc2d1a(+/-) heterozygotes. In both instances, the same characteristic miRNA profile was evidenced in the affected individuals and inherited together with disease symptoms in the progeny of crosses with healthy animals. The consistent association of these genetic regulatory changes with the disease provides a starting point for evaluating the changes in the activity of the target genes and, thus, the underlying mechanism(s). From the applied societal and medical perspectives, once properly confirmed in large cohorts, these observations provide tools for the very early identification of affected children and progenitors.

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13. Shield A, Wang X, Bone D, Narayanan S, Grossman RB. Conversational correlates of rapid social judgments of children and adolescents with and without ASD. Clin Linguist Phon ;2020 (Jun 10):1-13.

Autism spectrum disorder (ASD) is characterized by deficits in social communication, and even children with ASD with preserved language are often perceived as socially awkward. We ask if linguistic patterns are associated with social perceptions of speakers. Twenty-one adolescents with ASD participated in conversations with an adult ; each conversation was then rated for the social dimensions of likability, outgoingness, social skilfulness, responsiveness, and fluency. Conversations were analysed for responses to questions, pauses, and acoustic variables. Wide intonation ranges and more pauses within children’s own conversational turn were predictors of more positive social ratings while failure to respond to one’s conversational partner, faster syllable rate, and smaller quantity of speech were negative predictors of social perceptions.

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14. Sweigert JR, St John T, Begay KK, Davis GE, Munson J, Shankland E, Estes A, Dager SR, Kleinhans NM. Characterizing Olfactory Function in Children with Autism Spectrum Disorder and Children with Sensory Processing Dysfunction. Brain Sci ;2020 (Jun 10) ;10(6)

Abnormalities in olfactory function have been identified in a number of neurological and psychiatric disorders, including Parkinson’s disease and schizophrenia. However, little is known about olfactory function in autism spectrum disorder (ASD). The present study aims to assess the olfactory profiles of children with ASD, compared to an age- and sex-matched comparison group of typically developing children and a second clinical control group consisting of non-ASD children with sensory processing dysfunction (SPD). Participants completed a battery of sensory and behavioral assessments including olfactory tasks (Sniffin’ Sticks Threshold Test and self-reported valence ratings for two target odorants (phenylethyl alcohol and vanillin) and the University of Pennsylvania Smell Identification Test), and an autism evaluation (Autism Diagnostic Observation Schedule-2). Children with ASD showed intact odor detection with reduced odor identification ability. Poor odor identification was significantly correlated with autism symptom severity. Children with SPD demonstrated reduced odor detection and identification ability. These findings provide evidence for differential patterns of smell processing among ASD and non-ASD neurodevelopmental disorders. Future studies are needed to determine whether the association of impaired olfaction and increased autism symptoms is due to shared etiology.

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15. Sysoeva OV, Molholm S, Djukic A, Frey HP, Foxe JJ. Atypical processing of tones and phonemes in Rett Syndrome as biomarkers of disease progression. Transl Psychiatry ;2020 (Jun 10) ;10(1):188.

Due to severe motor impairments and the lack of expressive language abilities seen in most patients with Rett Syndrome (RTT), it has proven extremely difficult to obtain accurate measures of auditory processing capabilities in this population. Here, we examined early auditory cortical processing of pure tones and more complex phonemes in females with Rett Syndrome (RTT), by recording high-density auditory evoked potentials (AEP), which allow for objective evaluation of the timing and severity of processing deficits along the auditory processing hierarchy. We compared AEPs of 12 females with RTT to those of 21 typically developing (TD) peers aged 4-21 years, interrogating the first four major components of the AEP (P1 : 60-90 ms ; N1 : 100-130 ms ; P2 : 135-165 ms ; and N2 : 245-275 ms). Atypicalities were evident in RTT at the initial stage of processing. Whereas the P1 showed increased amplitude to phonemic inputs relative to tones in TD participants, this modulation by stimulus complexity was absent in RTT. Interestingly, the subsequent N1 did not differ between groups, whereas the following P2 was hugely diminished in RTT, regardless of stimulus complexity. The N2 was similarly smaller in RTT and did not differ as a function of stimulus type. The P2 effect was remarkably robust in differentiating between groups with near perfect separation between the two groups despite the wide age range of our samples. Given this robustness, along with the observation that P2 amplitude was significantly associated with RTT symptom severity, the P2 has the potential to serve as a monitoring, treatment response, or even surrogate endpoint biomarker. Compellingly, the reduction of P2 in patients with RTT mimics findings in animal models of RTT, providing a translational bridge between pre-clinical and human research.

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16. van Laarhoven T, Stekelenburg JJ, Eussen ML, Vroomen J. Atypical visual-auditory predictive coding in autism spectrum disorder : Electrophysiological evidence from stimulus omissions. Autism ;2020 (Jun 10):1362361320926061.

Many autistic individuals experience difficulties in processing sensory information (e.g. increased sensitivity to sound). Here we show that these difficulties may be related to an inability to process unexpected sensory stimulation. In this study, 29 older adolescents and young adults with autism and 29 age-matched individuals with typical development participated in an electroencephalography study. The electroencephalography study measured the participants’ brain activity during unexpected silences in a sequence of videos of a handclap. The results showed that the brain activity of autistic individuals during these silences was increased compared to individuals with typical development. This increased activity indicates that autistic individuals may have difficulties in processing unexpected incoming sensory information, and might explain why autistic individuals are often overwhelmed by sensory stimulation. Our findings contribute to a better understanding of the neural mechanisms underlying the different sensory perception experienced by autistic individuals.

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