Autism spectrum disorder: psychological and functional assessment, and behavioral treatment approaches

Autism spectrum disorder and various mechanisms behind it

Autism Spectrum Disorder (ASD) is a complex and heterogeneous neurodevelopmental condition characterized by a range of social, communicative, and behavioral challenges. This comprehensive review delves into key aspects of ASD. Clinical Overview and genetic features provide a foundational understanding of ASD, highlighting the clinical presentation and genetic underpinnings that contribute to its complexity. We explore the intricate neurobiological mechanisms at play in ASD, including structural and functional differences that may underlie the condition's hallmark traits. Emerging research has shed light on the role of the immune system and neuroinflammation in ASD. This section investigates the potential links between immunological factors and ASD, offering insights into the condition's pathophysiology. We examine how atypical functional connectivity and alterations in neurotransmitter systems may contribute to the unique cognitive and behavioral features of ASD. In the pursuit of effective interventions, this section reviews current therapeutic strategies, ranging from behavioral and educational interventions to pharmacological approaches, providing a glimpse into the diverse and evolving landscape of ASD treatment. This holistic exploration of mechanisms in ASD aims to contribute to our evolving understanding of the condition and to guide the development of more targeted and personalized interventions for individuals living with ASD.

Probiotics for autism spectrum disorder: An updated systematic review and meta-analysis of effects on symptoms

BACKGROUND

Recent researches highlighted the significant role of the gut-brain axis and gut microbiota in autism spectrum disorder (ASD), a neurobehavioral developmental disorder characterized by a variety of neuropsychiatric and gastrointestinal symptoms, suggesting that alterations in the gut microbiota may correlate with the severity of ASD symptoms. Therefore, this study was designed to conduct a comprehensive systematic review and meta-analysis of the effectiveness of probiotic interventions in ameliorating behavioral symptoms in individuals with ASD.

METHODS

This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A comprehensive literature search was performed across multiple databases including the Cochrane Library, PubMed, Web of Science, and Google Scholar up until June 2024. Inclusion criteria encompassed published randomized clinical trials (RCTs), focusing on probiotic interventions and evaluating outcomes related to ASD behavior symptoms. The study utilized Cochrane's Risk of Bias 2 for bias assessment and applied random effect models with inverse variance method for statistical analysis, also addressing publication bias and conducting subgroup analyses through Begg's and Egger's tests to explore the effects of various factors on the outcomes.

RESULTS

Our meta-analysis, which looked at eight studies with a total of 318 samples from ASD patients aged 1.5-20 years, showed that the probiotic intervention group had significantly better behavioral symptoms compared to the control group. This was shown by a pooled standardized mean difference (SMD) of -0.38 (95% CI: 0.58 to -0.18, p < 0.01). Subgroup analyses revealed significant findings across a variety of factors: studies conducted in the European region showed a notable improvement with an SMD of -0.44 (95%CI: 0.72 to -0.15); interventions lasting longer than three months exhibited a significant improvement with an SMD of -0.43 (95%CI: 0.65 to -0.21); and studies focusing on both participants under and greater than 10 years found significant benefits with an SMDs of -0.37 and -0.40, respectively (95%CI: 0.65 to -0.09, and 95%CI: 0.69 to -0.11, respectively). Moreover, both multi-strain probiotics and single-strain interventions showed an overall significant improvement with a SMD of -0.53 (95%CI: 0.85 to -0.22) and -0.28 (95%CI: 0.54 to -0.02), respectively. Also, the analysis confirmed the low likelihood of publication bias and the robustness of these findings.

CONCLUSION

Our study highlighted the significant improvement in ASD behavioral symptoms through probiotic supplementation. The need for personalized treatment approaches and further research to confirm efficacy and safety of probiotics in ASD management is emphasized.

Feasibility, acceptability, and effects of a web-delivered behavioral parent training intervention for rural parents of children with autism spectrum disorder: A protocol

Caregivers of children with autism spectrum disorder (ASD) often report higher levels of stress and mental health issues. Support services and parent training programs may help buffer the effects of caring for a child with ASD. However, due to the national lack of trained ASD providers and disparity of ASD support resources available in rural areas, caregivers often go without support. A possible solution to reach caregivers in rural areas is web-based interventions. This paper describes an ongoing pilot study examining the feasibility, acceptability, and preliminary effects on caregiver well-being and disruptive child behaviors for a web-based parent training program (Attend Behavior) for caregivers of young children (ages 2-11 years old) with autism spectrum disorder (ASD) living in rural areas (trial registration NCT05554198). The intervention is available on the internet as well as a downloadable app for mobile phones. Participants will be invited to use the intervention program for 12-weeks. Prior to using the program, participants will be asked to take a baseline survey assessing depressive symptoms (PROMIS Depression Short Form-6a), caregiver stress (Parenting Stress Index-Short Form), child disruptive behaviors (Home Situations Questionnaire-ASD and Aberrant Behavior Checklist). After 12-weeks, participants will be asked to complete a post-intervention survey with the same measurement scales plus questions regarding intervention acceptability, appropriateness, and feasibility (Acceptability of Intervention, Intervention Appropriateness Measure, and the Feasibility of Intervention Measure). Participants are also invited to partake in a brief 1:1 interview with a study team member to give further feedback regarding the intervention. Study retention and participant app usage data will be examined. Information generated from this pilot study will be used to inform a future larger scale randomized control trial of Attend Behavior.

Transcranial photobiomodulation for neurodevelopmental disorders: a narrative review

BACKGROUND

Neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Down syndrome (DS) significantly impact social, communicative, and behavioral functioning. Transcranial photobiomodulation (t-PBM) with near-infrared light is a promising non-invasive neurostimulation technique for neuropsychiatric disorders, including NDDs. This narrative review aimed to examine the preclinical and clinical evidence of photobiomodulation (PBM) in treating NDDs.

METHODS

A comprehensive search across six databases was conducted, using a combination of MeSH terms and title/abstract keywords: "photobiomodulation", "PBM", "neurodevelopmental disorders", "NDD", and others. Studies applying PBM to diagnosed NDD cases or animal models replicating NDDs were included. Protocols, reviews, studies published in languages other than English, and studies not evaluating clinical or cognitive outcomes were excluded.

RESULTS

Nine studies were identified, including one preclinical and eight clinical studies (five on ASD, two on ADHD, and one on DS). The reviewed studies encompassed various t-PBM parameters (wavelengths: 635-905 nm) and targeted primarily frontal cortex areas. t-PBM showed efficacy in improving disruptive behavior, social communication, cognitive rigidity, sleep quality, and attention in ASD; in enhancing attention in ADHD; and in improving motor skills and verbal fluency in DS. Minimal adverse effects were reported. Proposed mechanisms involve enhanced mitochondrial function, modulated oxidative stress, and reduced neuroinflammation.

CONCLUSIONS

t-PBM emerges as a promising intervention for NDDs, with potential therapeutic effects across ASD, ADHD, and DS. These findings underscore the need for further research, including larger-scale, randomized sham-controlled clinical trials with comprehensive biomarker analyses, to optimize treatment parameters and understand the underlying mechanisms associated with the effects of t-PBM.

Impact of Gluten-Free and Casein-Free Diet on Behavioural Outcomes and Quality of Life of Autistic Children and Adolescents: A Scoping Review

BACKGROUND

Gluten- and casein-containing foods could aggravate the symptoms of children and adolescents with autism spectrum disorder (ASD), and subsequently impact their quality of life. However, there is a mixed opinion among researchers concerning the impact of alternative diet on reducing ASD symptoms.

OBJECTIVE

This scoping review aimed at examining the impact of the "gluten-free, casein-free" (GFCF) diet on health outcomes and the quality of life among autistic children and adolescents.

METHODS

A scoping review of the literature was performed following the Joanna Briggs Institute (JBI) guidelines. Four databases, including EbscoHost, Medline, CINAHL, and ProQuest, were used to obtain subject-specific studies relevant to the research question and published between July 2013 and March 2024. A comprehensive search using keywords such as "autism spectrum disorder", "gluten-free diet", and "casein-free diet" was conducted to obtain articles related to the research focus area. Only full-text, peer-reviewed, written in English articles were selected. Data extraction and data analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-extension to Scoping Review (PRISMA-ScR) protocol.

RESULTS

From the initial 586 studies, a total of 27 articles were included in the final analysis of the review. The thematic analysis included "GFCF diet and improvement of the core autistic symptoms", "the gut-brain link", "dietary interventions and autism", "possible side effects due to the GCFC diet", and "inconclusive studies and mixed opinions". A majority of the studies showed a positive effect of the GFCF diet on a variety of autistic symptoms, including positive changes in cognitive skills, behaviour, and gastrointestinal symptoms, while some showed conflicting evidence.

CONCLUSIONS

The currently available evidence on the impact of the "GFCF" diet on the quality of life of autistic children and adolescents may warrant potentially effective interventions for alleviating symptoms of autism spectrum disorders. However, this scoping review highlights the need for more research to provide more reliable evidence on the health outcomes and quality of life of ASD sufferers to guide practice.

Transcranial photobiomodulation in children aged 2-6 years: a randomized sham-controlled clinical trial assessing safety, efficacy, and impact on autism spectrum disorder symptoms and brain electrophysiology

Background

Small pilot studies have suggested that transcranial photobiomodulation (tPBM) could help reduce symptoms of neurological conditions, such as depression, traumatic brain injury, and autism spectrum disorder (ASD).

Objective

To examine the impact of tPBM on the symptoms of ASD in children aged two to six years.

Method

We conducted a randomized, sham-controlled clinical trial involving thirty children aged two to six years with a prior diagnosis of ASD. We delivered pulses of near-infrared light (40 Hz, 850 nm) noninvasively to selected brain areas twice a week for eight weeks, using an investigational medical device designed for this purpose (Cognilum™, JelikaLite Corp., New York, United States). We used the Childhood Autism Rating Scale (CARS, 2nd Edition) to assess and compare the ASD symptoms of participants before and after the treatment course. We collected electroencephalogram (EEG) data during each session from those participants who tolerated wearing the EEG cap.

Results

The difference in the change in CARS scores between the two groups was 7.23 (95% CI 2.357 to 12.107, p = 0.011). Seventeen of the thirty participants completed at least two EEGs and time-dependent trends were detected. In addition, an interaction between Active versus Sham and Scaled Time was observed in delta power (Coefficient = 7.521, 95% CI -0.517 to 15.559, p = 0.07) and theta power (Coefficient = -8.287, 95% CI -17.199 to 0.626, p = 0.07), indicating a potential trend towards a greater reduction in delta power and an increase in theta power over time with treatment in the Active group, compared to the Sham group. Furthermore, there was a significant difference in the condition (Treatment vs. Sham) in the power of theta waves (net_theta) (Coefficient = 9.547, 95% CI 0.027 to 19.067, p = 0.049). No moderate or severe side effects or adverse effects were reported or observed during the trial.

Conclusion

These results indicate that tPBM may be a safe and effective treatment for ASD and should be studied in more depth in larger studies.Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT04660552, identifier NCT04660552.

A hybrid model for the classification of Autism Spectrum Disorder using Mu rhythm in EEG

BACKGROUND

Autism Spectrum Disorder (ASD) is a condition with social interaction, communication, and behavioral difficulties. Diagnostic methods mostly rely on subjective evaluations and can lack objectivity. In this research Machine learning (ML) and deep learning (DL) techniques are used to enhance ASD classification.

OBJECTIVE

This study focuses on improving ASD and TD classification accuracy with a minimal number of EEG channels. ML and DL models are used with EEG data, including Mu Rhythm from the Sensory Motor Cortex (SMC) for classification.

METHODS

Non-linear features in time and frequency domains are extracted and ML models are applied for classification. The EEG 1D data is transformed into images using Independent Component Analysis-Second Order Blind Identification (ICA-SOBI), Spectrogram, and Continuous Wavelet Transform (CWT).

RESULTS

Stacking Classifier employed with non-linear features yields precision, recall, F1-score, and accuracy rates of 78%, 79%, 78%, and 78% respectively. Including entropy and fuzzy entropy features further improves accuracy to 81.4%. In addition, DL models, employing SOBI, CWT, and spectrogram plots, achieve precision, recall, F1-score, and accuracy of 75%, 75%, 74%, and 75% respectively. The hybrid model, which combined deep learning features from spectrogram and CWT with machine learning, exhibits prominent improvement, attained precision, recall, F1-score, and accuracy of 94%, 94%, 94%, and 94% respectively. Incorporating entropy and fuzzy entropy features further improved the accuracy to 96.9%.

CONCLUSIONS

This study underscores the potential of ML and DL techniques in improving the classification of ASD and TD individuals, particularly when utilizing a minimal set of EEG channels.

Beyond Clinical Care: The Role of Pediatric Psychology in Supporting Postpartum Depression Screening in Primary Care

Maternal health is a critical component of optimal child health and development. Consequently, the American Academy of Pediatrics added postpartum depression (PPD) screening to their psychosocial screening guidelines in 2017. The Healthy Mothers, Healthy Children Project (HMHCP) was an interprofessional initiative aimed at preparing for, then implementing and maintaining pediatrician-completed PPD screening at 1-month well visits in a pediatric primary care clinic. Roles of pediatric psychology and rates of PPD screening were examined. Pediatric psychologists actively participated as leaders and collaborators in a variety of non-clinical roles from HMHCP preparation through maintenance. The clinic achieved high and continuously improving PPD screening rates following HMHCP implementation. Importantly, PPD screening rates were equitable across race and gender. The current study outlines feasible non-clinical roles that pediatric psychologists can fulfill in support of routine PPD screening within pediatric primary care. It also highlights associated benefits and outcomes for the clinic, providers, and patients.

Neuroanatomical Alterations in the CNTNAP2 Mouse Model of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is associated with neurodevelopmental alterations, including atypical forebrain cellular organization. Mutations in several ASD-related genes often result in cerebral cortical anomalies, such as the abnormal developmental migration of excitatory pyramidal cells and the malformation of inhibitory neuronal circuitry. Notably here, mutations in the CNTNAP2 gene result in ectopic superficial cortical neurons stalled in lower cortical layers and alterations to the balance of cortical excitation and inhibition. However, the broader circuit-level implications of these findings have not been previously investigated. Therefore, we assessed whether ectopic cortical neurons in CNTNAP2 mutant mice form aberrant connections with higher-order thalamic nuclei, potentially accounting for some autistic behaviors, such as repetitive and hyperactive behaviors. Furthermore, we assessed whether the development of parvalbumin-positive (PV) cortical interneurons and their specialized matrix support structures, called perineuronal nets (PNNs), were altered in these mutant mice. We found alterations in both ectopic neuronal connectivity and in the development of PNNs, PV neurons and PNNs enwrapping PV neurons in various sensory cortical regions and at different postnatal ages in the CNTNAP2 mutant mice, which likely lead to some of the cortical excitation/inhibition (E/I) imbalance associated with ASD. These findings suggest neuroanatomical alterations in cortical regions that underlie the emergence of ASD-related behaviors in this mouse model of the disorder.

Behavioral regulation by perineuronal nets in the prefrontal cortex of the CNTNAP2 mouse model of autism spectrum disorder

Autism spectrum disorders (ASDs) arise from altered development of the central nervous system, and manifest behaviorally as social interaction deficits and restricted and repetitive behaviors. Alterations to parvalbumin (PV) expressing interneurons have been implicated in the neuropathological and behavioral deficits in autism. In addition, perineuronal nets (PNNs), specialized extracellular matrix structures that enwrap the PV-expressing neurons, also may be altered, which compromises neuronal function and susceptibility to oxidative stress. In particular, the prefrontal cortex (PFC), which regulates several core autistic traits, relies on the normal organization of PNNs and PV-expressing cells, as well as other neural circuit elements. Consequently, we investigated whether PNNs and PV-expressing cells were altered in the PFC of the CNTNAP2 knockout mouse model of ASD and whether these contributed to core autistic-like behaviors in this model system. We observed an overexpression of PNNs, PV-expressing cells, and PNNs enwrapping PV-expressing cells in adult CNTNAP2 mice. Transient digestion of PNNs from the prefrontal cortex (PFC) by injection of chondroitinase ABC in CNTNAP2 mutant mice rescued some of the social interaction deficits, but not the restricted and repetitive behaviors. These findings suggest that the neurobiological regulation of PNNs and PVs in the PFC contribute to social interaction behaviors in neurological disorders including autism.

Development and validation of the social-emotional rating scale for autism spectrum disorder (SERA) in an Indian sample

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that occurs during the developmental period and affects overall cognitive, emotional, social, and physical health. Comprehensive screening for ASD can assist in diagnosis and intervention planning. The primary aim of this study was to develop and validate a screening tool for ASD based on the diagnostic guidelines of the International Classification of Diseases (ICD-11). The Social-Emotional Rating Scale for Autism Spectrum Disorder (SERA) was validated with 504 participants, including healthcare professionals who have worked with individuals with ASD and parents/primary caregivers of children with ASD. A confirmatory factor analysis on 78 participants with ASD and 27 participants without ASD indicated a good fit for the data. As an intervention planning tool, the developed SERA appears promising for identifying a person's social-emotional functioning level in line with autistic characteristics.

The Management of Toe Walking in Children with Autism Spectrum Disorder: "Cast and Go"

Background: Toe walking is associated with autism spectrum disorders (ASD). Correction of this “behavior” is a health challenge. The toe walker is affected by the contact refusal with the outside world: touching the ground as little as possible, trying to avoid any contact. A structured equines foot is a possible consequence. Method: We present the “Cast and Go” protocol, used in 22 idiopathic toe walker children with ASD treated from 2015 to 2020. The treatment was performed by a single senior experienced doctor with botulinum injection, ankle casts and rehabilitative therapies. All patients underwent pre- and post-treatment clinical evaluation using ankle dorsiflexion angle and casting number as treatment. We aimed to identify the intervention with the shortest acquisition time for the management of toe walking. Results: Our findings demonstrated the baseline ankle dorsiflexion angle influenced the casting number (p < 0.01) and male patients had a higher baseline ankle dorsiflexion angle than female patients (p < 0.01). No adverse events were observed. Conclusions: These findings suggested that the “Cast and Go” protocol could be a promising, dynamic and effective practice for toe walking disease in ASD patients.

Transcranial Photobiomodulation for the Treatment of Children with Autism Spectrum Disorder (ASD): A Retrospective Study

Children with Autism Spectrum Disorder (ASD) face several challenges due to deficits in social function and communication along with restricted patterns of behaviors. Often, they also have difficult-to-manage and disruptive behaviors. At the moment, there are no pharmacological treatments for ASD core features. Recently, there has been a growing interest in non-pharmacological interventions for ASD, such as neuromodulation. In this retrospective study, data are reported and analyzed from 21 patients (13 males, 8 females) with ASD, with an average age of 9.1 (range 5−15), who received six months of transcranial photobiomodulation (tPBM) at home using two protocols (alpha and gamma), which, respectively, modulates the alpha and gamma bands. They were evaluated at baseline, after three and six months of treatment using the Childhood Autism Rating Scale (CARS), the Home Situation Questionnaire-ASD (HSQ-ASD), the Autism Parenting Stress Index (APSI), the Montefiore Einstein Rigidity Scale−Revised (MERS−R), the Pittsburgh Sleep Quality Index (PSQI) and the SDAG, to evaluate attention. Findings show that tPBM was associated with a reduction in ASD severity, as shown by a decrease in CARS scores during the intervention (p < 0.001). A relevant reduction in noncompliant behavior and in parental stress have been found. Moreover, a reduction in behavioral and cognitive rigidity was reported as well as an improvement in attentional functions and in sleep quality. Limitations were discussed as well as future directions for research.

The relationship between irritability and autism symptoms in children with ASD in COVID-19 home confinement period

OBJECTIVE

This study investigated the impact of COVID-19 home confinement on autism spectrum disorder (ASD) symptoms and irritability in children and adolescents with ASD.

METHOD

The study participants included 46 drug-naive children aged 4-17 years diagnosed with ASD. Parents of the participants completed the Autism Behaviour Checklist (AuBC) and Affective Reactivity Index (ARI) scales for both normal conditions and COVID-19 home confinement.

RESULTS

All subscale scores for AuBC (sensory, relating, body and object use, language, and social and self-help) and ARI scores significantly increased during the COVID-19 home confinement period (P < .05). The participants' irritability and ASD symptoms were significantly worse during the COVID-19 outbreak and home confinement period compared to normal conditions. The variables that predicted irritability were the social and self-help subscales of AuBC.

DISCUSSION

These results have alerted us of the importance of focusing on the symptoms such as irritability exhibited by extremely vulnerable populations during disease outbreaks and of the necessity of developing new strategies to avoid such adverse outcomes in similar situations.

Relationship between Sensory Alterations and Repetitive Behaviours in Children with Autism Spectrum Disorders: A Parents' Questionnaire Based Study

The relationship between sensory profile and repetitive behaviours in autism spectrum disorder (ASD) has long been known. However, there is no consensus on the type of relationship that exists between them. This monocentric retrospective-prospective observational study aimed (a) to detect a clinical correlation between the severity of repetitive behaviours and the alterations of sensory profile in a sample of 50 children diagnosed with ASD; (b) to evaluate how different patterns of stereotypies and sensory alterations correlate with each other and with the main clinical-instrumental variables in the same sample. We enrolled 29 children in the retrospective phase of the study and 21 in the prospective phase. The Repetitive Behaviour Scale-Revised (RBS-R) and the Short Sensory Profile (SSP) were administered to the caregivers, and clinical-instrumental data were collected. SSP and RBS-R total scores directly correlated with a high significance rate. Among the subscales, the strongest correlations involved "Visual/Auditory Sensitivity", related to "Stereotyped Behaviour" and "Sameness Behaviour". "Under-Responsive/Seeks Sensation" related to "Stereotyped Behaviour". Sex and intellectual disability significantly influenced both the stereotypies and the sensory alterations of the examined population. In conclusion, this study provides new insights into the relationship between sensory alterations and repetitive behaviours in ASD children by using direct medical observation and parent observation.

Reliability and validity of a novel caregiver-assessed skills system based on the ALSO conception in children with autism spectrum disorders

BACKGROUND

In responding to the potential challenges in the transition from childhood to adulthood for individuals with autism spectrum disorders (ASD) in China, a novel conception of "ALSO" was proposed to bridge the transitional needs and early intervention. To facilitate the application of ALSO in early intervention, ALSOLIFE skills assessment system (ALSOLIFE Assessment) was developed to enable caregivers to evaluate their children's skills guided by the ALSO conception. Given that the critical shortage of qualified professionals in China, many caregivers of children with ASD must function as home therapists. To address the practical needs of Chinese families of children with ASD, ALSOLIFE Assessment is designed as a free, online, technology-assisted, self-operated and behavioral intervention approaches supported system. The assessment report then further served as the basis for caregivers to deliver the tailored educational intervention to their children. Although ALSOLIFE Assessment provides caregivers a home-based intervention program, it is still unclear whether its evaluation is reliable and accurate. Therefore, we conduct this study to investigate the reliability and validity of the ALSOLIFE Assessment.

METHODS

A total of 1,050 children with ASD (1 to 10 years old) were recruited from 31 provinces of mainland China. Their caregivers participated simultaneously as ALSOLIFE Assessment evaluators. The testing results of Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP) and Psychoeducational Profile-3 (PEP-3) were also collected for a portion of the child participants (VB-MAPP, N=34; PEP-3, N=31) to check criterion-related validity.

RESULTS

The reliability and validity of the ALSOLIFE Assessment satisfied psychometric requirements after the reduction from 511 to 464 items. Exploratory factor analysis (EFA) of ALSOLIFE Assessment scoring data yielded six factors, and confirmatory factor analysis (CFA) verified the best fitting construct model is a bifactorial model with one general factor and six group factors. Compared to the VB-MAPP and PEP-3, the ALSOLIFE Assessment exhibited good criterion-related validity across three levels: total scores, 6 skill domains, and 22 skill subdomains. The reliability tests indicated its strong internal consistency, test-retest reliability, and inter-rater reliability.

CONCLUSIONS

The reliability and validity of the revised ALSOLIFE Assessment (464-items) satisfied psychometric requirements. It is essential to develop validated and comprehensive evaluation tools, embedded on the needs of Chinese families of children with ASD.

Neural Mechanisms Underlying Repetitive Behaviors in Rodent Models of Autism Spectrum Disorders

Autism spectrum disorder (ASD) is comprised of several conditions characterized by alterations in social interaction, communication, and repetitive behaviors. Genetic and environmental factors contribute to the heterogeneous development of ASD behaviors. Several rodent models display ASD-like phenotypes, including repetitive behaviors. In this review article, we discuss the potential neural mechanisms involved in repetitive behaviors in rodent models of ASD and related neuropsychiatric disorders. We review signaling pathways, neural circuits, and anatomical alterations in rodent models that display robust stereotypic behaviors. Understanding the mechanisms and circuit alterations underlying repetitive behaviors in rodent models of ASD will inform translational research and provide useful insight into therapeutic strategies for the treatment of repetitive behaviors in ASD and other neuropsychiatric disorders.

Detection of disease-associated microRNAs - application for autism spectrum disorders

Autism spectrum disorders (ASD) diagnostic procedure still lacks a uniform biological marker. This review gathers the information on microRNAs (miRNAs) specifically as a possible source of biomarkers of ASD. Extracellular vesicles, and their subset of exosomes, are believed to be a tool of cell-to-cell communication, and they are increasingly considered to be carriers of such a marker. The interest in studying miRNAs in extracellular vesicles grows in all fields of study and therefore should not be omitted in the field of neurodevelopmental disorders. The summary of miRNAs associated with brain cells and ASD either studied directly in the tissue or biofluids are gathered in this review. The heterogeneity in findings from different studies points out the fact that unified methods should be established, beginning with the determination of the accurate patient and control groups, through to sample collection, processing, and storage conditions. This review, based on the available literature, proposes the standardized approach to obtain the results that would not be affected by technical factors. Nowadays, the method of high-throughput sequencing seems to be the most optimal to analyze miRNAs. This should be followed by the uniformed bioinformatics procedure to avoid misvalidation. At the end, the proper validation of the obtained results is needed. With such an approach as is described in this review, it would be possible to obtain a reliable biomarker that would characterize the presence of ASD.