1. Bagni C, Zukin RS. {{A Synaptic Perspective of Fragile X Syndrome and Autism Spectrum Disorders}}. {Neuron};2019 (Mar 20);101(6):1070-1088.
Altered synaptic structure and function is a major hallmark of fragile X syndrome (FXS), autism spectrum disorders (ASDs), and other intellectual disabilities (IDs), which are therefore classified as synaptopathies. FXS and ASDs, while clinically and genetically distinct, share significant comorbidity, suggesting that there may be a common molecular and/or cellular basis, presumably at the synapse. In this article, we review brain architecture and synaptic pathways that are dysregulated in FXS and ASDs, including spine architecture, signaling in synaptic plasticity, local protein synthesis, (m)RNA modifications, and degradation. mRNA repression is a powerful mechanism for the regulation of synaptic structure and efficacy. We infer that there is no single pathway that explains most of the etiology and discuss new findings and the implications for future work directed at improving our understanding of the pathogenesis of FXS and related ASDs and the design of therapeutic strategies to ameliorate these disorders.
Lien vers le texte intégral (Open Access ou abonnement)
2. Baker EK, Richdale AL, Hazi A, Prendergast LA. {{Assessing a Hyperarousal Hypothesis of Insomnia in Adults with Autism Spectrum Disorder}}. {Autism Res};2019 (Mar 21)
This study aimed to investigate the relationship between sleep, psychopathology (anxiety, depression and presleep arousal) symptoms, and cortisol in adults with autism spectrum disorder (ASD). The sample composed of 29 adults with ASD (51.7% males) and 29 control adults (51.7% males) aged 21-44 years. Thirteen adults with ASD were medicated for a comorbid diagnosis of anxiety and/or depression (ASD-Med), while the remaining 16 adults with ASD were not medicated for such diagnoses (ASD-Only). Participants completed a questionnaire battery, 14-day sleep/wake diary and 14-day actigraphy assessment. On one day during the data collection period, participants collected five saliva samples, hourly, prior to sleep and two morning samples; immediately upon waking and 30 min thereafter for the analysis of cortisol. Cortisol 1 hr prior to habitual sleep onset time was associated with poorer sleep efficiency in both ASD groups and increased wake after sleep onset duration (ASD-Only). Higher subjective somatic arousal was also associated with increased sleep onset latency, regardless of group, and poorer sleep efficiency in the ASD-Only group. ASD-Only participants had significantly greater reductions in evening cortisol concentrations compared to both ASD-Med and control participants. No significant group differences were found for the cortisol awakening response. Findings suggest a hyperarousal hypothesis of insomnia in adults with ASD. Moreover, the low cortisol levels observed in ASD-Only adults suggest dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Longitudinal studies exploring the interplay between insomnia, anxiety and HPA axis regulation across the lifespan in those with ASD are warranted. LAY SUMMARY: Both objective (cortisol) and subjective (somatic) physiological arousal were associated with poor sleep quality in adults on the autism spectrum. Adults with autism spectrum disorder (ASD) who were not medicated for a comorbid diagnosis of anxiety and/or depression also had dampened cortisol secretion, suggesting a dysregulation of the hypothalamic pituitary axis. Longitudinal studies investigating the relationship between sleep, psychopathology symptoms and physiological arousal in autistic individuals are warranted. Autism Res 2019. (c) 2019 International Society for Autism Research, Wiley Periodicals, Inc.
Lien vers le texte intégral (Open Access ou abonnement)
3. Bakian AV, VanDerslice JA. {{Pesticides and autism}}. {Bmj};2019 (Mar 20);364:l1149.
Lien vers le texte intégral (Open Access ou abonnement)
4. Bishop SK, Moore JW, Dart EH, Radley K, Brewer R, Barker LK, Quintero L, Litten S, Gilfeather A, Newborne B, Toche C. {{Further investigation of increasing vocalizations of children with autism with a speech-generating device}}. {J Appl Behav Anal};2019 (Mar 22)
We replicated and extended the findings of Gervarter et al. (2016) by using prompting and reinforcement to produce increased vocal speech with 3 young children diagnosed with autism spectrum disorder (ASD) who used a speech generating device (SGD). We extended Gervarter et al. by adopting a more robust experimental design, conducting session-by-session preference assessments, and measuring the emergence of novel vocalizations. The frequency of vocalizations increased for all 3 participants after the introduction of an echoic prompt. These results suggest that SGD-based interventions may lead to increased vocal output for children with ASD.
Lien vers le texte intégral (Open Access ou abonnement)
5. Lavelle TA, Weinstein MC, Newhouse JP, Munir K, Kuhlthau KA, Prosser LA. {{Parent Preferences for Health Outcomes Associated with Autism Spectrum Disorders}}. {Pharmacoeconomics};2019 (Mar 21)
BACKGROUND: Few studies have used preference-based quality-of-life outcomes to assess how autism spectrum disorders (ASDs) affect children and parents, and none have examined variation by ASD severity. OBJECTIVE: Our objective was to derive parent valuations of child and parent health associated with varying ASD severity levels. METHODS: Parents of children aged 3-17 years with and without ASD were selected from a nationally representative research panel to complete a survey. We asked parents time trade-off (TTO) questions to value their own and their child’s current health. Parents of children with ASD were asked to report the severity of their child’s core ASD symptoms. We calculated utility values from each TTO amount, and used a two-part regression model to estimate the change in parent-reported child health utility, as well as parent health utility, associated with ASD diagnosis and increasing symptom severity, controlling for respondent and child characteristics. RESULTS: Sixty-nine percent of parents responded (final sample size was 135 in the ASD group and 120 in the comparison group). In adjusted analyses, there was a 0.12 (95% confidence interval [CI] 0.03-0.21) decrease in the parent-reported health utility of children with ASD, a 15% decrease from the mean health utility of children without ASD. On average, having a child with ASD was not significantly associated with a decrease in parent health utility, but there was a 0.14 (95% CI 0.01-0.26) reduction in health utility among parents of children with severe ASD, a 15% decrease from the comparison group mean. CONCLUSIONS: Overall, ASD had a significant impact on parent-reported child health utility, and the health utility of parents of children with severe ASD.
Lien vers le texte intégral (Open Access ou abonnement)
6. Ma B, Liang J, Dai M, Wang J, Luo J, Zhang Z, Jing J. {{Altered Gut Microbiota in Chinese Children With Autism Spectrum Disorders}}. {Front Cell Infect Microbiol};2019;9:40.
The link between gut microbes and autism spectrum disorders (ASD) has been already observed in some studies, but some bacterial families/species were found to be inconsistently up or down regulated. This issue has been rarely explored in the Chinese population. In this study, we assessed whether or not gut microbiota dysbiosis was associated with children with ASD in China. We enrolled 45 children with ASD (6-9 years of age; 39 boys and 6 girls) and 45 sex- and age-matched neurotypical children. Dietary and other socio-demographic information was obtained via questionnaires. We characterized the composition of the fecal microbiota using bacterial 16S ribosomal RNA (16S rRNA) gene sequencing. The ASD group showed less diversity and richness of gut microbiota than the neurotypical group, as estimated by the abundance-based coverage estimator index and the phylogenetic diversity index. The analysis of beta diversity showed an altered microbial community structure in the ASD group. After adjustment for confounders and multiple testing corrections, no significant group difference was found in the relative abundance of microbiota on the level of the phylum. At the family level, children with ASD had a lower relative abundance of Acidaminococcaceae than the healthy controls. Moreover, a decrease in the relative abundance of genera Lachnoclostridium, Tyzzerella subgroup 4, Flavonifractor, and unidentified Lachnospiraceae was observed in ASD group. This study provides further evidence of intestinal microbial dysbiosis in ASD and sheds light on the characteristics of the gut microbiome of autistic children in China.
Lien vers le texte intégral (Open Access ou abonnement)
7. Port RG, Dipiero MA, Ku M, Liu S, Blaskey L, Kuschner ES, Edgar JC, Roberts TPL, Berman J. {{Children with ASD demonstrate regionally specific altered resting-state phase-amplitude coupling}}. {Brain Connect};2019 (Mar 22)
Studies suggest that individuals with autism spectrum disorder (ASD) exhibit altered electrophysiological alpha to gamma phase-amplitude coupling (PAC). Preliminary reports with small samples report conflicting findings regarding the directionality of the alpha to gamma PAC alterations in ASD. The present study examined resting-state activity throughout the brain in a relatively large sample of 119 children with ASD and 47 typically developing (TD) children. Children with ASD demonstrated regionally specific abnormalities in alpha to low-gamma PAC, with increased alpha to low-gamma PAC for a central midline source and decreased PAC at lateral sources. Group differences in local gamma-band power did not account for the regional group differences in alpha to low-gamma PAC. Moreover, local alpha power did not significantly modulate alpha to low-gamma PAC estimates. Finally, PAC estimates were correlated with SRS indicating clinical relevance of the PAC metric. In conclusion, alpha to low-gamma PAC alterations in ASD demonstrate a heterogeneous spatial profile consistent with previous studies and were related to symptom severity.
Lien vers le texte intégral (Open Access ou abonnement)
8. Sapey-Triomphe LA, Leiros Costa T, Wagemans J. {{Sensory sensitivity in autism mostly depends on contextual predictions}}. {Cogn Neurosci};2019 (Mar 20):1-2.
A signal detection theory was elaborated in order to account for three types of sensory sensitivity (subjective, behavioral and neural) in neurotypical individuals and in autism. Here, we argue that the predictive coding framework could better account for the atypical pattern of sensory sensitivity in autism. We review the idea that sensory sensitivity should be considered as mostly depending on contextual predictions and that these account for the heterogeneous pattern of neural responses.
Lien vers le texte intégral (Open Access ou abonnement)
9. Singh NN, Lancioni GE, Karazsia BT, Myers RE, Hwang YS, Analayo B. {{Effects of Mindfulness-Based Positive Behavior Support (MBPBS) Training Are Equally Beneficial for Mothers and Their Children With Autism Spectrum Disorder or With Intellectual Disabilities}}. {Front Psychol};2019;10:385.
Parenting a child with autism spectrum disorder (ASD) or intellectual disabilities (IDs) can be stressful for many parents. Mindfulness-Based Positive Behavior Support (MBPBS) is a customized mindfulness program that enables parents and other caregivers to reduce their perceived psychological stress to normative levels through mindfulness procedures and to support children with ASD or ID to self-manage their challenging behaviors through positive behavior support (PBS). In this study, we evaluated whether MBPBS would have differential effects on the stress levels of mothers of adolescents with ASD (n = 47) or with ID (n = 45) and the effects of the program on the aggressive, disruptive, and compliance behaviors of their children. Both groups of mothers participated in the 40-week study (10 weeks control and 30 weeks MBPBS program), rated their own stress levels, and collected daily observational data on the adolescents’ behavior. Results showed significant reductions in the level of stress in both groups of mothers, but no differential effects on mothers of children with ASD or with ID. In addition, significant reductions in aggression and disruptive behavior and increases in compliance behaviors were observed in the adolescents in both groups. The results suggest that MBPBS is equally beneficial for mothers of adolescents with ASD or ID. In the present study, although the mothers of children with ID had slightly higher levels of stress at baseline and mothers of children with ASD had lower levels of stress following the MBPBS program, the program can be considered equally effective in reducing the stress levels of both groups of mothers. This suggests that the program may be effective regardless of baseline levels of mothers’ stress.
Lien vers le texte intégral (Open Access ou abonnement)
10. Van De Cruys S, Perrykkad K, Hohwy J. {{Explaining hyper-sensitivity and hypo-responsivity in autism with a common predictive coding-based mechanism}}. {Cogn Neurosci};2019 (Mar 21):1-2.
Ward’s signal detection theory-based framework elucidates some aspects of interindividual differences in sensitivity, but, we argue, obscures others. Specifically, it disregards the important challenge of inferring the meaning of sensory inputs. Within Bayesian predictive coding accounts, the meaning is given by inferences to more deeply hidden causes of sensory inputs and is generally the basis for initiating context-appropriate (e.g., social) behavior. As such, when inference of hierarchical causes is hampered, as accounts of autism based on deficient precision estimation imply, a form of hyporesponsivity can emerge (together with the hypersensitivity already highlighted by Ward).
Lien vers le texte intégral (Open Access ou abonnement)
11. von Ehrenstein OS, Ling C, Cui X, Cockburn M, Park AS, Yu F, Wu J, Ritz B. {{Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study}}. {Bmj};2019 (Mar 20);364:l962.
OBJECTIVE: To examine associations between early developmental exposure to ambient pesticides and autism spectrum disorder. DESIGN: Population based case-control study. SETTING: California’s main agricultural region, Central Valley, using 1998-2010 birth data from the Office of Vital Statistics. POPULATION: 2961 individuals with a diagnosis of autism spectrum disorder based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, revised (up to 31 December 2013), including 445 with intellectual disability comorbidity, were identified through records maintained at the California Department of Developmental Services and linked to their birth records. Controls derived from birth records were matched to cases 10:1 by sex and birth year. EXPOSURE: Data from California state mandated Pesticide Use Reporting were integrated into a geographic information system tool to estimate prenatal and infant exposures to pesticides (measured as pounds of pesticides applied per acre/month within 2000 m from the maternal residence). 11 high use pesticides were selected for examination a priori according to previous evidence of neurodevelopmental toxicity in vivo or in vitro (exposure defined as ever v never for each pesticide during specific developmental periods). MAIN OUTCOME MEASURE: Odds ratios and 95% confidence intervals using multivariable logistic regression were used to assess associations between pesticide exposure and autism spectrum disorder (with or without intellectual disabilities) in offspring, adjusting for confounders. RESULTS: Risk of autism spectrum disorder was associated with prenatal exposure to glyphosate (odds ratio 1.16, 95% confidence interval 1.06 to 1.27), chlorpyrifos (1.13, 1.05 to 1.23), diazinon (1.11, 1.01 to 1.21), malathion (1.11, 1.01 to 1.22), avermectin (1.12, 1.04 to 1.22), and permethrin (1.10, 1.01 to 1.20). For autism spectrum disorder with intellectual disability, estimated odds ratios were higher (by about 30%) for prenatal exposure to glyphosate (1.33, 1.05 to 1.69), chlorpyrifos (1.27, 1.04 to 1.56), diazinon (1.41, 1.15 to 1.73), permethrin (1.46, 1.20 to 1.78), methyl bromide (1.33, 1.07 to 1.64), and myclobutanil (1.32, 1.09 to 1.60); exposure in the first year of life increased the odds for the disorder with comorbid intellectual disability by up to 50% for some pesticide substances. CONCLUSION: Findings suggest that an offspring’s risk of autism spectrum disorder increases following prenatal exposure to ambient pesticides within 2000 m of their mother’s residence during pregnancy, compared with offspring of women from the same agricultural region without such exposure. Infant exposure could further increase risks for autism spectrum disorder with comorbid intellectual disability.
