Pubmed du 21/05/23
1. Duville MM, Ibarra-Zarate DI, Alonso-Valerdi LM. Autistic traits shape neuronal oscillations during emotion perception under attentional load modulation. Sci Rep;2023 (May 20);13(1):8178.
Emotional content is particularly salient, but situational factors such as cognitive load may disturb the attentional prioritization towards affective stimuli and interfere with their processing. In this study, 31 autistic and 31 typically developed children volunteered to assess their perception of affective prosodies via event-related spectral perturbations of neuronal oscillations recorded by electroencephalography under attentional load modulations induced by Multiple Object Tracking or neutral images. Although intermediate load optimized emotion processing by typically developed children, load and emotion did not interplay in children with autism. Results also outlined impaired emotional integration emphasized in theta, alpha and beta oscillations at early and late stages, and lower attentional ability indexed by the tracking capacity. Furthermore, both tracking capacity and neuronal patterns of emotion perception during task were predicted by daily-life autistic behaviors. These findings highlight that intermediate load may encourage emotion processing in typically developed children. However, autism aligns with impaired affective processing and selective attention, both insensitive to load modulations. Results were discussed within a Bayesian perspective that suggests atypical updating in precision between sensations and hidden states, towards poor contextual evaluations. For the first time, implicit emotion perception assessed by neuronal markers was integrated with environmental demands to characterize autism.
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2. Hadjikhani N, Åsberg Johnels J. Overwhelmed by the man in the moon? Pareidolic objects provoke increased amygdala activation in autism. Cortex;2023 (Apr 29);164:144-151.
An interesting feature of the primate face detection system results in the perception of illusory faces in objects, or pareidolia. These illusory faces do not per se contain social information, such as eye-gaze or specific identities, yet they activate the cortical brain face-processing network, possibly via the subcortical route, including the amygdala. In autism spectrum disorder (ASD), aversion to eye-contact is commonly reported, and so are alterations in face processing more generally, yet the underlying reasons are not clear. Here we show that in autistic participants (N=37), but not in non-autistic controls (N=34), pareidolic objects increase amygdala activation bilaterally (right amygdala peak: X = 26, Y = -6, Z = -16; left amygdala peak X = -24, Y = -6, Z = -20). In addition, illusory faces engage the face-processing cortical network significantly more in ASD than in controls. An early imbalance in the excitatory and inhibitory systems in autism, affecting typical brain maturation, may be at the basis of an overresponsive reaction to face configuration and to eye contact. Our data add to the evidence of an oversensitive subcortical face processing system in ASD.
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3. Lee HG, Imaichi S, Kraeutler E, Aguilar R, Lee YW, Sheridan SD, Lee JT. Site-specific R-loops induce CGG repeat contraction and fragile X gene reactivation. Cell;2023 (May 16)
Here, we describe an approach to correct the genetic defect in fragile X syndrome (FXS) via recruitment of endogenous repair mechanisms. A leading cause of autism spectrum disorders, FXS results from epigenetic silencing of FMR1 due to a congenital trinucleotide (CGG) repeat expansion. By investigating conditions favorable to FMR1 reactivation, we find MEK and BRAF inhibitors that induce a strong repeat contraction and full FMR1 reactivation in cellular models. We trace the mechanism to DNA demethylation and site-specific R-loops, which are necessary and sufficient for repeat contraction. A positive feedback cycle comprising demethylation, de novo FMR1 transcription, and R-loop formation results in the recruitment of endogenous DNA repair mechanisms that then drive excision of the long CGG repeat. Repeat contraction is specific to FMR1 and restores the production of FMRP protein. Our study therefore identifies a potential method of treating FXS in the future.
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4. Lipton BA, Oltean HN, Capron RB, Hamlet A, Montgomery SP, Chancey RJ, Konold VJL, Steffl KE. Baylisascaris procyonis Roundworm Infection in Child with Autism Spectrum Disorder, Washington, USA, 2022. Emerg Infect Dis;2023 (Jun);29(6):1232-1235.
We describe a case of Baylisascaris procyonis roundworm infection in a child in Washington, USA, with autism spectrum disorder. Environmental assessment confirmed nearby raccoon habitation and B. procyonis eggs. B. procyonis infections should be considered a potential cause of human eosinophilic meningitis, particularly among young children and persons with developmental delays.
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5. Peng Q, Liu Y, Yu L, Shen Y, Li F, Feng S, Chen F. Deletion of Arrb2 Down-regulates Autophagy in the Mouse Hippocampus via Akt-mTOR Pathway Activation. Neuroscience;2023 (May 21);519:120-130.
The cytoplasmic multifunctional adaptor protein β-arrestin 2 (Arrb2) is involved in the occurrence of various nervous system diseases, such as Alzheimer’s disease and Parkinson’s disease. Previous laboratory studies have shown that the expression and function of the Arrb2 gene was increased in valproic acid-induced autistic mice models. However, few reports have examined the possible role of Arrb2 in the pathogenesis of autism spectrum disorder. Therefore, Arrb2-deficient (Arrb2(-/-)) mice were further studied to uncover the physiological function of Arrb2 in the nervous system. In this study, we found that Arrb2(-/-) mice had normal behavioral characteristics compared with wild-type mice. The autophagy marker protein LC3B was decreased in the hippocampus of Arrb2(-/-) mice compared to wild-type mice. Western blot analysis revealed that deletion of Arrb2 caused hyperactivation of Akt-mTOR signaling in the hippocampus. In addition, abnormal mitochondrial dysfunction was observed in Arrb2(-/-) hippocampal neurons, which was characterized by a reduction in mitochondrial membrane potential and adenosine triphosphate production and an increase in reactive oxygen species levels. Therefore, this study elucidates the interaction between Arrb2 and the Akt-mTOR signaling pathway and provides insights into the role of Arrb2 in hippocampal neuron autophagy.
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6. Rieder AD, Viljoen M, Seris N, Shabalala N, Ndlovu M, Turner EL, Simmons R, de Vries PJ, Franz L. Improving access to early intervention for autism: findings from a proof-of-principle cascaded task-sharing naturalistic developmental behavioural intervention in South Africa. Child Adolesc Psychiatry Ment Health;2023 (May 20);17(1):64.
BACKGROUND: Despite the high number of children living with neurodevelopmental disabilities in sub-Saharan Africa, access to early intervention is almost non-existent. It is therefore important to develop feasible, scalable early autism intervention that can be integrated into systems of care. While Naturalistic Developmental Behavioural Intervention (NDBI) has emerged as an evidence-based intervention approach, implementation gaps exist globally, and task-sharing approaches may address access gaps. In this South African proof-of-principle pilot study, we set out to answer two questions about a 12-session cascaded task-sharing NDBI-whether the approach could be delivered with fidelity, and whether we could identify signals of change in child and caregiver outcomes. METHODS: We utilized a single-arm pre-post design. Fidelity (non-specialists, caregivers), caregiver outcomes (stress, sense of competence), and child outcomes (developmental, adaptive) were measured at baseline (T1) and follow-up (T2). Ten caregiver-child dyads and four non-specialists participated. Pre-to-post summary statistics were presented alongside individual trajectories. Non-parametric Wilcoxon signed rank test for paired samples was used to compare group medians between T1 and T2. RESULTS: Caregiver implementation fidelity increased in 10/10 participants. Non-specialists demonstrated a significant increase in coaching fidelity (increases in 7/10 dyads). Significant gains were seen on two Griffiths-III subscales (Language/Communication-9/10 improved, Foundations of Learning-10/10 improved) and on the General Developmental Quotient (9/10 improved). Significant gains were also seen on two Vineland Adaptive Behaviour Scales (Third Edition) subscales (Communication-9/10 improved, Socialization-6/10 improved) and in the Adaptive Behaviour Standard Score (9/10 improved). Caregiver sense of competence improved in 7/10 caregivers and caregiver stress in 6/10 caregivers. CONCLUSIONS: This proof-of-principle pilot study of the first cascaded task-sharing NDBI in Sub-Saharan Africa provided fidelity and intervention outcome data which supported the potential of such approaches in low-resource contexts. Larger studies are needed to expand on the evidence-base and answer questions on intervention effectiveness and implementation outcomes.
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7. Schembri-Mutch TM, McCrimmon AW, Zwiers ML. Understanding the Needs of Autistic Post-Secondary Students. J Autism Dev Disord;2023 (May 20)
Autistic students are a growing subgroup within post-secondary schooling; however, little is known about barriers to their success in that context. Research suggests autistic students face more challenges to completing post-secondary education than neurotypical students, but findings often rely on expert opinion and fail to incorporate first-hand perspectives. To address this gap, a qualitative inquiry into barriers to success for autistic post-secondary students was conducted. Thematic Analysis yielded 10 themes in three categories, while two separate cross-cutting themes emerged; themes interact with one another, intensifying concerns of autistic students. Findings can support post-secondary institutions to reflect on the extent to which these barriers are present for their autistic students and modify support services accordingly.
