Neuropsychopathology of Autism Spectrum Disorder: Complex Interplay of Genetic, Epigenetic, and Environmental Factors

Propionic acid affects the synaptic architecture of rat hippocampus and prefrontal cortex

It is well documented that propionic acid (PPA) produces behavioral, morphological, molecular and immune responses in rats that are characteristic of autism spectrum disorder in humans. However, whether PPA affects the ultrastructure and synaptic architecture of regions of autistic brain has not been adequately addressed. Earlier we show that single intraperitoneal (IP) injection of PPA (175 mg/kg) produces superficial changes in the spatial memory and learning of adolescent male Wistar rats. However, in neurons, synapses and glial cells of hippocampal CA1 area and medial prefrontal cortex transient (mainly) or enduring alterations were detected. In this study, we used electron microscopic morphometric analysis to test the effect of PPA on different structural parameters of axodendritic synapses of the hippocampus and prefrontal cortex. The animals were treated with a single IP injection of PPA (175 mg/kg). The length and width of synaptic active zone, the area of presynaptic and postsynaptic mitochondria, the distance between presynaptic mitochondria and the synapse active zone, the distance between postsynaptic mitochondria and postsynaptic density and the depth and opening diameter of neuronal porosome complex were evaluated. Our results show that synaptic mitochondria of the hippocampus and prefrontal cortex are the most vulnerable to PPA treatment: in both regions, the area of postsynaptic mitochondria were increased. In general, our results show that even small dose of PPA, which produces only superficial effects on spatial memory and learning is able to alter the synapse architecture in brain regions involved in cognition and autism pathogenesis. Therefore, the microbiome may be involved in the control of neurotransmission in these regions.

Effect of Ketamine Treatment on Social Withdrawal in Autism and Autism-Like Conditions

OBJECTIVE

Ketamine and esketamine have been used in the field of psychiatry to alleviate conditions such as major depressive disorder. Our objective was to evaluate the current literature on the use of ketamine for symptoms of social withdrawal in autism spectrum disorder (ASD) and autism-like conditions.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to identify literature involving the use of ketamine to treat symptoms of autism and social withdrawal. Patients with comorbid disorders were also included.

RESULTS

Two original studies were found, showing mixed results on the use of ketamine for ASD. The use of esketamine found no statistically significant results, whereas the use of intravenous ketamine was shown to alleviate symptoms of social withdrawal especially in the short term. Neither study reported a significant amount of serious adverse events. Five case reports were also included, showing decreased depressive symptoms and evidence of increased social condition.

CONCLUSIONS

Research on the use of ketamine for ASD and ASD-related conditions is limited. Evidence of improved social condition exists, but further studies should be conducted to increase sample power and test various doses and methods of administration.

Socio-economic status and autism spectrum disorder: A case-control study in Bangladesh

There are unexpectedly a few statistics about the socio-economic status (SES) and related socio-demographic factors (SDFs) of parents having child with ASD in Bangladesh. The prevalence of ASD might correlate with SES and related SDFs. A case-control study was conducted in 24 locations across 21 districts, encompassing all divisions, to assess the association between SES and the risk of developing ASD in Bangladesh. The structured questionnaire was administered through face-to-face interviews with 620 parents of the subject (310 ASD and 310 healthy controls) from January 2020 to June 2021. For univariate, bivariate and multivariate analyses, IBM SPSS version 23 was employed. The significance level was set at P ≤ 0.05, and the Odds Ratio (OR) within a 95 % CI was used to determine whether the variable poses a higher odd or not. After adjusting all significant covariates of binary logistic regression (including some dummy variables) in forward logistic regression model analysis, the higher level of SES, advanced level of father's education (≥master), 22-35 years old age group of the father, and nuclear family were strongly associated with decreased odds of ASD compared to healthy controls. Only the male gender was strongly associated with an increased odds of ASD compared to the control. The results will aid policymakers in developing plans considering the SES and related SDFs that influence the risk of developing ASD in Bangladesh. Further research using population-based cohorts or nested case-control designs with matched control is necessary to observe and generalize the association.

Epigenetic changes in sperm are associated with paternal and child quantitative autistic traits in an autism-enriched cohort

There is a need to consider paternal contributions to autism spectrum disorder (ASD) more strongly. Autism etiology is complex, and heritability is not explained by genetics alone. Understanding paternal gametic epigenetic contributions to autism could help fill this knowledge gap. In the present study, we explored whether paternal autistic traits, and the sperm epigenome, were associated with autistic traits in children at 36 months enrolled in the Early Autism Risk Longitudinal Investigation (EARLI) cohort. EARLI is a pregnancy cohort that recruited and enrolled pregnant women in the first half of pregnancy who already had a child with ASD. After maternal enrollment, EARLI fathers were approached and asked to provide a semen specimen. Participants were included in the present study if they had genotyping, sperm methylation data, and Social Responsiveness Scale (SRS) score data available. Using the CHARM array, we performed genome-scale methylation analyses on DNA from semen samples contributed by EARLI fathers. The SRS-a 65-item questionnaire measuring social communication deficits on a quantitative scale-was used to evaluate autistic traits in EARLI fathers (n = 45) and children (n = 31). We identified 94 significant child SRS-associated differentially methylated regions (DMRs), and 14 significant paternal SRS-associated DMRs (fwer p < 0.05). Many child SRS-associated DMRs were annotated to genes implicated in ASD and neurodevelopment. Six DMRs overlapped across the two outcomes (fwer p < 0.1), and, 16 DMRs overlapped with previous child autistic trait findings at 12 months of age (fwer p < 0.05). Child SRS-associated DMRs contained CpG sites independently found to be differentially methylated in postmortem brains of individuals with and without autism. These findings suggest paternal germline methylation is associated with autistic traits in 3-year-old offspring. These prospective results for autism-associated traits, in a cohort with a family history of ASD, highlight the potential importance of sperm epigenetic mechanisms in autism.

The Use of Umbilical Cord Blood Nucleated Cells in the Treatment of Regressive Autism: A Case Report

BACKGROUND

Interest in the issue of childhood autism has surged in the recent decades. At the same time, despite the significant progress achieved in understanding the etiological and pathogenetic aspects of the condition, effective ways to treat it have continued to elude us. Stem cell therapy appears to hold great promise in the treatment and rehabilitation of patients with both neurological diseases (cerebral palsy, hydrocephalus) and mental disorders (autism, schizophrenia).

METHODS

This article presents a case report describing the use of nucleated cord blood cells in a patient with regressive autism and resistance to standard therapies. The child's condition was assessed before treatment and 6 and 12 months after.

RESULTS

Clinical observation, psychometric, and instrumental diagnostic methods led to a significant improvement in the child's condition in the form of perception development, reduction of somatosensory disorders, normalization of emotional status, and a development of social and communication skills.

CONCLUSION

We assume that the result obtained may be associated with the normalization of the immunological status of our patient thanks to the cord blood cells therapy and consider it necessary to conduct further studies into the effectiveness of the method, taking the pathogenic mechanisms of autism into account.

Abnormal Porphyrin Metabolism in Autism Spectrum Disorder and Therapeutic Implications

Autism spectrum disorder (ASD) is a mosaic of neurodevelopmental conditions composed of early-onset social interaction and communication deficits, along with repetitive and/or restricted patterns of activities, behavior, and interests. ASD affects around 1% of children worldwide, with a male predominance. Energy, porphyrin, and neurotransmitter homeostasis are the key metabolic pathways affected by heavy metal exposure, potentially implicated in the pathogenesis of ASD. Exposure to heavy metals can lead to an altered porphyrin metabolism due to enzyme inhibition by heavy metals. Heavy metal exposure, inborn genetic susceptibility, and abnormal thiol and selenol metabolism may play a significant role in the urinary porphyrin profile anomalies observed in ASD. Altered porphyrin metabolism in ASD may also be associated with, vitamin B6 deficiency, hyperoxalemia, hyperhomocysteinemia, and hypomagnesemia. The present review considers the abnormal porphyrin metabolism in ASD in relation to the potential pathogenic mechanism and discusses the possible metabolic therapies such as vitamins, minerals, cofactors, and antioxidants that need to be explored in future research. Such targeted therapeutic therapies would bring about favorable outcomes such as improvements in core and co-occurring symptoms.

NGS Custom Panel Implementation in Patients with Non-Syndromic Autism Spectrum Disorders in the Clinical Routine of a Tertiary Hospital

Autism spectrum disorder (ASD) is a set of neurodevelopmental disorders characterized by deficiencies in communication, social interaction, and repetitive and restrictive behaviors. The discovery of genetic involvement in the etiology of ASD has made this condition a strong candidate for genome-based diagnostic tests. Next-generation sequencing (NGS) is useful for the detection of variants in the sequence of different genes in ASD patients. Herein, we present the implementation of a personalized NGS panel for autism (AutismSeq) for patients with essential ASD over a prospective period of four years in the clinical routine of a tertiary hospital. The cohort is composed of 48 individuals, older than 3 years, who met the DSM-5 (The Diagnostic and Statistical Manual of Mental Disorders) diagnostic criteria for ASD. The NGS customized panel (AutismSeq) turned out to be a tool with good diagnostic efficacy in routine clinical care, where we detected 12 "pathogenic" (including pathogenic, likely pathogenic, and VUS (variant of uncertain significance) possibly pathogenic variations) in 11 individuals, and 11 VUS in 10 individuals, which had previously been negative for chromosomal microarray analysis and other previous genetic studies, such as karyotype, fragile-X, or MLPA/FISH (Multiplex Ligation dependent Probe Amplification/Fluorescence in situ hybridization) analysis. Our results demonstrate the high genetic and clinical heterogeneity of individuals with ASD and the current difficulty of molecular diagnosis. Our study also shows that an NGS-customized panel might be useful for diagnosing patients with essential/primary autism and that it is cost-effective for most genetic laboratories.

The Neurogenetics of Functional Connectivity Alterations in Autism: Insights From Subtyping in 657 Individuals

BACKGROUND

There is little consensus and controversial evidence on anatomical alterations in the brains of people with autism spectrum disorder (ASD), due in part to the large heterogeneity present in ASD, which in turn is a major drawback for developing therapies. One strategy to characterize this heterogeneity in ASD is to cluster large-scale functional brain connectivity profiles.

METHODS

A subtyping approach based on consensus clustering of functional brain connectivity patterns was applied to a population of 657 autistic individuals with quality-assured neuroimaging data. We then used high-resolution gene transcriptomic data to characterize the molecular mechanism behind each subtype by performing enrichment analysis of the set of genes showing a high spatial similarity with the profiles of functional connectivity alterations between each subtype and a group of typically developing control participants.

RESULTS

Two major stable subtypes were found: subtype 1 exhibited hypoconnectivity (less average connectivity than typically developing control participants) and subtype 2, hyperconnectivity. The 2 subtypes did not differ in structural imaging metrics in any of the analyzed regions (68 cortical and 14 subcortical) or in any of the behavioral scores (including IQ, Autism Diagnostic Interview, and Autism Diagnostic Observation Schedule). Finally, only subtype 2, comprising about 43% of ASD participants, led to significant enrichments after multiple testing corrections. Notably, the dominant enrichment corresponded to excitation/inhibition imbalance, a leading well-known primary mechanism in the pathophysiology of ASD.

CONCLUSIONS

Our results support a link between excitation/inhibition imbalance and functional connectivity alterations, but only in one ASD subtype, overall characterized by brain hyperconnectivity and major alterations in somatomotor and default mode networks.

Integrated gene expression profiling and functional enrichment analyses to discover biomarkers and pathways associated with Guillain-Barré syndrome and autism spectrum disorder to identify new therapeutic targets

Guillain-Barré syndrome (GBS) is one of the most prominent and acute immune-mediated peripheral neuropathy, while autism spectrum disorders (ASD) are a group of heterogeneous neurodevelopmental disorders. The complete mechanism regarding the neuropathophysiology of these disorders is still ambiguous. Even after recent breakthroughs in molecular biology, the link between GBS and ASD remains a mystery. Therefore, we have implemented well-established bioinformatic techniques to identify potential biomarkers and drug candidates for GBS and ASD. 17 common differentially expressed genes (DEGs) were identified for these two disorders, which later guided the rest of the research. Common genes identified the protein-protein interaction (PPI) network and pathways associated with both disorders. Based on the PPI network, the constructed hub gene and module analysis network determined two common DEGs, namely CXCL9 and CXCL10, which are vital in predicting the top drug candidates. Furthermore, coregulatory networks of TF-gene and TF-miRNA were built to detect the regulatory biomolecules. Among drug candidates, imatinib had the highest docking and MM-GBSA score with the well-known chemokine receptor CXCR3 and remained stable during the 100 ns molecular dynamics simulation validated by the principal component analysis and the dynamic cross-correlation map. This study predicted the gene-based disease network for GBS and ASD and suggested prospective drug candidates. However, more in-depth research is required for clinical validation.Communicated by Ramaswamy H. Sarma.

Maternal Chronic Ultrasound Stress Provokes Immune Activation and Behavioral Deficits in the Offspring: A Mouse Model of Neurodevelopmental Pathology

Neurodevelopmental disorders stemming from maternal immune activation can significantly affect a child's life. A major limitation in pre-clinical studies is the scarcity of valid animal models that accurately mimic these challenges. Among the available models, administration of lipopolysaccharide (LPS) to pregnant females is a widely used paradigm. Previous studies have reported that a model of 'emotional stress', involving chronic exposure of rodents to ultrasonic frequencies, induces neuroinflammation, aberrant neuroplasticity, and behavioral deficits. In this study, we explored whether this model is a suitable paradigm for maternal stress and promotes neurodevelopmental abnormalities in the offspring of stressed females. Pregnant dams were exposed to ultrasound stress for 21 days. A separate group was injected with LPS on embryonic days E11.5 and E12.5 to mimic prenatal infection. The behavior of the dams and their female offspring was assessed using the sucrose test, open field test, and elevated plus maze. Additionally, the three-chamber sociability test and Barnes maze were used in the offspring groups. ELISA and qPCR were used to examine pro-inflammatory changes in the blood and hippocampus of adult females. Ultrasound-exposed adult females developed a depressive-like syndrome, hippocampal overexpression of GSK-3β, IL-1β, and IL-6 and increased serum concentrations of IL-1β, IL-6, IL-17, RANTES, and TNFα. The female offspring also displayed depressive-like behavior, as well as cognitive deficits. These abnormalities were comparable to the behavioral changes induced by LPS. The ultrasound stress model can be a promising animal paradigm of neurodevelopmental pathology associated with prenatal 'emotional stress'.

Artificial intelligence and bioinformatics analyze markers of children's transcriptional genome to predict autism spectrum disorder

Introduction

Autism spectrum disorder (ASD), characterized by difficulties in social interaction and communication as well as restricted interests and repetitive behaviors, is extremely challenging to diagnose in toddlers. Early diagnosis and intervention are crucial however.

Methods

In this study, we developed a machine learning classification model based on mRNA expression data from the peripheral blood of 128 toddlers with ASD and 126 controls. Differentially expressed genes (DEGs) between ASD and controls were identified.

Results

We identified genes such as UBE4B, SPATA2 and RBM3 as DEGs, mainly involved in immune-related pathways. 21 genes were screened as key biomarkers using LASSO regression, yielding an accuracy of 86%. A neural network model based on these 21 genes achieved an AUC of 0.88.

Discussion

Our findings suggest that the identified neurotransmitters and 21 immune-related biomarkers may facilitate the early diagnosis of ASD. The mRNA expression profile sheds light on the biological underpinnings of ASD in toddlers and potential biomarkers for early identification. Nevertheless, larger samples are needed to validate these biomarkers.

Biochemical, Genetic and Clinical Diagnostic Approaches to Autism-Associated Inherited Metabolic Disorders

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders characterized by impaired social interaction, limited communication skills, and restrictive and repetitive behaviours. The pathophysiology of ASD is multifactorial and includes genetic, epigenetic, and environmental factors, whereas a causal relationship has been described between ASD and inherited metabolic disorders (IMDs). This review describes biochemical, genetic, and clinical approaches to investigating IMDs associated with ASD. The biochemical work-up includes body fluid analysis to confirm general metabolic and/or lysosomal storage diseases, while the advances and applications of genomic testing technology would assist with identifying molecular defects. An IMD is considered likely underlying pathophysiology in ASD patients with suggestive clinical symptoms and multiorgan involvement, of which early recognition and treatment increase their likelihood of achieving optimal care and a better quality of life.

Poly(I:C)-induced maternal immune activation causes elevated self-grooming in male rat offspring: Involvement of abnormal postpartum static nursing in dam

Introduction: Maternal immune activation (MIA) is closely related to the onset of autism-like behaviors in offspring, but the mechanism remains unclear. Maternal behaviors can influence offspring’s development and behaviors, as indicated in both human and animal studies. We hypothesized that abnormal maternal behaviors in MIA dams might be other factors leading to delayed development and abnormal behaviors in offspring.

Methods: To verify our hypothesis, we analyzed poly(I:C)-induced MIA dam’s postpartum maternal behavior and serum levels of several hormones related to maternal behavior. Pup’s developmental milestones and early social communication were recorded and evaluated in infancy. Other behavioral tests, including three-chamber test, self-grooming test, open field test, novel object recognition test, rotarod test and maximum grip test, were performed in adolescence of pups.

Results: Our results showed that MIA dams exhibit abnormal static nursing behavior but normal basic care and dynamic nursing behavior. The serum levels of testosterone and arginine vasopressin in MIA dams were significantly reduced compared with control dams. The developmental milestones, including pinna detachment, incisor eruption and eye opening, were significantly delayed in MIA offspring compared with control offspring, while the weight and early social communication showed no significant differences between the two groups. Behavioral tests performed in adolescence showed that only male MIA offspring display elevated self-grooming behaviors and reduced maximum grip.

Discussion: In conclusion, MIA dams display abnormal postpartum static nursing behavior concomitantly with reduced serum levels of testosterone and arginine vasopressin, possibly involving in the pathogenesis of delayed development and elevated self-grooming in male offspring. These findings hint that improving dam’s postpartum maternal behavior might be a potential regime to counteract delayed development and elevated self-grooming in male MIA offspring.

Artemisia annua Extract Improves the Cognitive Deficits and Reverses the Pathological Changes of Alzheimer’s Disease via Regulating YAP Signaling

Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by the occurrence of cognitive deficits. With no effective treatments available, the search for new effective therapies has become a major focus of interest. In the present study, we describe the potential therapeutic effect of Artemisia annua (A. annua) extract on AD. Nine-month-old female 3xTg AD mice were treated with A. annua extract for three months via oral administration. Animals assigned to WT and model groups were administrated with an equal volume of water for the same period. Treated AD mice significantly improved the cognitive deficits and exhibited reduced Aβ accumulation, hyper-phosphorylation of tau, inflammatory factor release and apoptosis when compared with untreated AD mice. Moreover, A. annua extract promoted the survival and proliferation of neural progenitor cells (NPS) and increased the expression of synaptic proteins. Further assessment of the implicated mechanisms revealed that A. annua extract regulates the YAP signaling pathway in 3xTg AD mice. Further studies comprised the incubation of PC12 cells with Aβ1–42 at a concentration of 8 μM with or without different concentrations of A. annua extract for 24 h. Obtained ROS levels, mitochondrial membrane potential, caspase-3 activity, neuronal cell apoptosis and assessment of the signaling pathways involved was performed using western blot and immunofluorescence staining. The obtained results showed that A. annua extract significantly reversed the Aβ1–42-induced increase in ROS levels, caspase-3 activity and neuronal cell apoptosis in vitro. Moreover, either inhibition of the YAP signaling pathway, using a specific inhibitor or CRISPR cas9 knockout of YAP gene, reduced the neuroprotective effect of the A. annua extract. These findings suggest that A. annua extract may be a new multi-target anti-AD drug with potential use in the prevention and treatment of AD.

The Rationale for Vitamin, Mineral, and Cofactor Treatment in the Precision Medical Care of Autism Spectrum Disorder

Children with autism spectrum disorder may exhibit nutritional deficiencies due to reduced intake, genetic variants, autoantibodies interfering with vitamin transport, and the accumulation of toxic compounds that consume vitamins. Importantly, vitamins and metal ions are essential for several metabolic pathways and for neurotransmitter functioning. The therapeutic benefits of supplementing vitamins, minerals (Zinc, Magnesium, Molybdenum, and Selenium), and other cofactors (coenzyme Q10, alpha-lipoic acid, and tetrahydrobiopterin) are mediated through their cofactor as well as non-cofactor functions. Interestingly, some vitamins can be safely administered at levels far above the dose typically used to correct the deficiency and exert effects beyond their functional role as enzyme cofactors. Moreover, the interrelationships between these nutrients can be leveraged to obtain synergistic effects using combinations. The present review discusses the current evidence for using vitamins, minerals, and cofactors in autism spectrum disorder, the rationale behind their use, and the prospects for future use.

Lack of voluntary interest and difficulty making eye contact are the most discriminative behaviors of the ASQ:SE and might suggest delays: Results from a large-scale assessment

BACKGROUND

Every child is unique, but development tends to occur in predictable steps and stages. The early identification of infants who face developmental delays is critical, boosting the use of screening tools to determine risks for delays. The city of Rio de Janeiro conducted a large-scale assessment of children who were enrolled in educational facilities using the Ages & Stages Questionnaires: Social-Emotional (ASQ:SE).

OBJECTIVES

We examined the internal structure of the ASQ:SE and its most discriminative items of risks of delays in development among 12- to 60-month-old children. The trajectory of the discrimination parameter of eight anchor items was used to check how well they inform the risk of social-emotional competence delays throughout development.

METHODS

Data from 79,332 children (1-5 years) were analyzed via Samejima Graded Response model of Item Response Theory (IRT). The discrimination (a) and threshold (b) parameters were computed, and errors were achieved via maximum likelihood. Data/codes are available at https://osf.io/by6sf/.

RESULTS

(a) Item Response Theory analyses supported the unidimensionality of data via the root mean square error of approximation and standardized root mean square residual results (RMSEA). (b) The lack of voluntary interest was the most discriminative risk behavior in the first 5 years. (c) Lack of interest was the most persistent risk behavior. (d) Difficulty making eye contact was nearly as informative as lack of interest.

CONCLUSION

Lack of voluntary interest in things should be considered a critical risk-related behavior, and making eye contact is a vital aspect of typical development. Both behaviors may be predictors of children's delays.MAIN OUTCOMESThe ASQ:SE is a valid and reliable tool to measure child development.The internal structure of the ASQ:SE is well-fitted with a unidimensional solution.A child's age is a vital aspect of the discrimination parameter of the IRT model.Lack of interest in things and difficulty making eye contact are critical risk-related behaviors.

Associations of essential element serum concentrations with autism spectrum disorder

This case-control study explored the associations between autism spectrum disorder (ASD) and the serum concentration of nine chemical elements in children. The study recruited 92 Chinese children with ASD and 103 typically developing individuals. Serum concentrations of nine chemical elements (calcium, iodine, iron, lithium, magnesium, potassium, selenium, strontium, and zinc) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). An unconditional logistic regression model was used to analyze the associations between the serum concentrations of the elements and the risk of ASD. After adjusting for confounders, the multivariate analysis results showed that zinc ≤ 837.70 ng/mL, potassium > 170.06 μg/mL, and strontium ≤ 52.46 ng/mL were associated with an increased risk of ASD, while selenium > 159.80 ng/mL was associated with a decreased risk of ASD. Furthermore, the degree of lithium and zinc deficiency was associated with ASD severity. The results indicated that metallomic profiles of some specific elements might play important roles in the development of ASD, a finding of scientific significance for understanding the etiology, and providing dietary guidance for certain ASD types.

Exploration of potential targets and mechanisms of Naringenin in treating autism spectrum disorder via network pharmacology and molecular docking

Naringenin (NR) is a kind of flavonoid which plays a great role in the treatment of autism spectrum disorder (ASD). However, the underlying mechanism of NR in treating ASD still remains unclear. This study used network pharmacology and molecular docking to examine the potential targets and pharmacological mechanism of NR on ASD. Targets related to NR were screened from Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP), Encyclopedia of Traditional Chinese Medicine Database (ETCM), Traditional Chinese Medicine Integrated Database (TCMID), PharmaMapper database, and targets related to ASD were screened from Online Mendelian Inheritance In Man (OMIM), Disgenet, GeneCards, Therapeutic Target Database (TTD), Drugbank, and ETCM. Screened of the intersected gene targets. Then, we used the protein-protein interaction (PPI) networks to construct a PPI network and used Network Analyzer plug-in to perform topological analysis to screen out the core target. We used Metascape platform to perform gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and used Chem draw, Pymol, AutoDock 1.5.6 software for molecular docking verification with core targets. A total of 149 targets of NR and 1594 potential targets of ASD were screened, and 43 intersected targets and 8 key targets were obtained and screened. A total of 176 GO items were obtained by GO enrichment analysis (P < .05), 153 entries on biological process (BP), 12 entries on BP and 11entries on cell composition (CC) were included. A total of 100 signaling pathways were obtained by KEGG pathway enrichment screening (P < .05).The pathways that are closely related to the pathogenesis of ASD are estrogen signaling, thyroid hormone signaling pathway, prolactin signaling pathway, and endocrine resistance pathway. Molecular docking results showed that NR had the best docking activity with the core target CASP3, and had good binding ability with AKT1, ESR1, ACTB and MAPK3. Taken together, our findings support that NR exerts therapeutic effects on ASD with multi-target, and multi-pathway characteristics, which provides a preliminary theoretical basis for clinical trials. The mechanism of anti-oxidative stress response, anti-apoptosis, regulation of cell growth and metabolism, anti-inflammatory, balance hormone levels may be important for the therapeutic effect.

A more than four-fold sex-specific difference of autism spectrum disorders and the possible contribution of pesticide usage in China 1990-2030

Autism spectrum disorders (ASDs) are prevalent in children and adolescents and disproportionately affect males, and the main contributing factors underlying male vulnerability remain widely unknown. Pesticide use is widely reported to be associated with ASD risk, and the cases of pesticide poisoning incidence in rural areas are remarkably higher than those in the urban areas while the prevalence of ASDs in rural areas was higher than that in urban areas and the rate of male pesticide poisoning was significantly higher than female. Thus, pesticide usage may be an important contributing factor for causing sex-specific differences of ASD incidence. ASD burden was analyzed by using the data of ASD number, ASD rate (ASD cases per 100,000 persons) and disability-adjusted life years (DALYs) from 1990 to 2019. The changes from 1990 to 2030 were predicted using autoregressive integrated moving average (ARIMA) in time series forecasting based on the small values of Akaike information criterion and Bayesian information criterion. Finally, the relationship between ASD rate and pesticide usage risk index (PURI) was analyzed via Pearson's correlation coefficient. ASD number, ASD rate and DALYs will be reduced by 45.5% ± 8.2% (t = 9.100 and p = 0.0119), 56.6% ± 10.2% (t = 9.111 and p = 0.0118), and 44.9% ± 7.0% (t = 20.90 and p = 0.0023) from 1990 to 2030 in China. PURI has a strong relationship with ASD rate (rho = 0.953 to 0.988 and p < 0.0001). Pesticide poisoning incidence in males is up to 2-fold higher than that in females. ASD number and DALYs in males are 4-fold higher than those in females. Furthermore, there is growing evidence supporting that males are more susceptible than females to pesticides with sex differences in neurotoxicogenetics. Therefore, pesticide poisoning may be a contributing factor for causing the sex differences of ASD. Much work still needs to be done to confirm that.

Urinary Untargeted Metabolic Profile Differentiates Children with Autism from Their Unaffected Siblings

Autism Spectrum Disorder (ASD) encompasses a clinical spectrum of neurodevelopmental conditions that display significant heterogeneity in etiology, symptomatology, and severity. We previously compared 30 young children with idiopathic ASD and 30 unrelated typically-developing controls, detecting an imbalance in several compounds belonging mainly to the metabolism of purines, tryptophan and other amino acids, as well as compounds derived from the intestinal flora, and reduced levels of vitamins B6, B12 and folic acid. The present study describes significant urinary metabolomic differences within 14 pairs, including one child with idiopathic ASD and his/her typically-developing sibling, tightly matched by sex and age to minimize confounding factors, allowing a more reliable identification of the metabolic fingerprint related to ASD. By using a highly sensitive, accurate and unbiased approach, suitable for ensuring broad metabolite detection coverage on human urine, and by applying multivariate statistical analysis, we largely replicate our previous results, demonstrating a significant perturbation of the purine and tryptophan pathways, and further highlight abnormalities in the “phenylalanine, tyrosine and tryptophan” pathway, essentially involving increased phenylalanine and decreased tyrosine levels, as well as enhanced concentrations of bacterial degradation products, including phenylpyruvic acid, phenylacetic acid and 4-ethylphenyl-sulfate. The outcome of these within-family contrasts consolidates and extends our previous results obtained from unrelated individuals, adding further evidence that these metabolic imbalances may be linked to ASD rather than to environmental differences between cases and controls. It further underscores the excess of some gut microbiota-derived compounds in ASD, which could have diagnostic value in a network model differentiating the metabolome of autistic and unaffected siblings. Finally, it points toward the existence of a “metabolic autism spectrum” distributed as an endophenotype, with unaffected siblings possibly displaying a metabolic profile intermediate between their autistic siblings and unrelated typically-developing controls.

The association between ST8SIA2 gene and behavioral phenotypes in children with autism spectrum disorder

Objective

ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 2 (ST8SIA2) encodes a type II membrane protein that is thought to catalyze the transfer of sialic acid (SA) from CMP-SA to N-linked oligosaccharides and glycoproteins. Some population and animal studies have indicated an association between the ST8SIA2 gene and autism spectrum disorder (ASD). However, there is limited information on the correlation between ST8SIA2 and autistic behavioral symptoms.

Methods

In this study, 69 ASD and 76 normal control children who were age- and sex-matched were recruited. ST8SIA2 expression and methylation levels were measured by reverse transcription quantitative real-time PCR and pyrosequencing, respectively, and the behavioral phenotypes of ASD children were assessed.

Results

The ASD group had lower ST8SIA2 gene expression levels than the control group [t(0.05/2,143) = 2.582, p = 0.011]. Moreover, ST8SIA2 expression levels were positively correlated with daily life skills (rs = 0.381, p = 0.008) and negatively associated with stereotyped behaviors in the ASD group (rs = -0.510, p = 0.004). The methylation levels of the Chr. 15: 92984625 and Chr. 15: 92998561 sites of the ST8SIA2 gene in ASD children were higher than those of controls. The Chr. 15: 92984625 site was positively correlated with the stereotyped behaviors of ASD children (rs = 0.41, p = 0.039).

Conclusion

This study provides a scientific basis to elucidate the relationship between the ST8SIA2 gene and behavioral phenotypes of ASD.

Foundations and implications of astrocyte heterogeneity during brain development and disease

Astrocytes play crucial roles in regulating brain circuit formation and physiology. Recent technological advances have revealed unprecedented levels of astrocyte diversity encompassing molecular, morphological, and functional differences. This diversification is initiated during embryonic specification events and (in rodents) continues into the early postnatal period where it overlaps with peak synapse development and circuit refinement. In fact, several lines of evidence suggest astrocyte diversity both influences and is a consequence of molecular crosstalk among developing astrocytes and other cell types, notably neurons and their synapses. Neurological disease states exhibit additional layers of astrocyte heterogeneity, which could help shed light on these cells' key pathological roles. This review highlights recent advances in clarifying astrocyte heterogeneity and molecular/cellular crosstalk and identifies key outstanding questions.

mTOR Signaling Pathway Regulates the Release of Proinflammatory Molecule CCL5 Implicated in the Pathogenesis of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex pervasive neurodevelopmental disorder and neuroinflammation may contribute to the pathogenesis of ASD. However, the exact mechanisms of abnormal release of proinflammatory mediators in ASD remain poorly understood. This study reports elevated plasma levels of the proinflammatory chemokine (C-C motif) ligand 5 (CCL5) in children with ASD, suggesting an aberrant inflammatory response appearing in the development of ASD. Mining of the expression data of brain or blood tissue from individuals with ASD reveals that mTOR signaling is aberrantly activated in ASD patients. Our in vitro study shows that suppression of mTOR reduces the gene expression and release of CCL5 from human microglia, supporting that CCL5 expression is regulated by mTOR activity. Furthermore, bacterial lipopolysaccharide (LPS)-induced CCL5 expression can be counteracted by siRNA against NF-κB, suggests a determining role of NF-κB in upregulating CCL5 expression. However, a direct regulatory relationship between the NF-κB element and the mTOR signaling pathway was not observed in rapamycin-treated cells. Our results show that the phosphorylated CREB can be induced to suppress CCL5 expression by outcompeting NF-κB in binding to CREB-binding protein (CREBBP) once the mTOR signaling pathway is inhibited. We propose that the activation of mTOR signaling in ASD may induce the suppression of phosphorylation of CREB, which in turn results in the increased binding of CREBBP to NF-κB, a competitor of phosphorylated CREB to drive expression of CCL5. Our study sheds new light on the inflammatory mechanisms of ASD and paves the way for the development of therapeutic strategy for ASD.

Social touch-like tactile stimulation activates a tachykinin 1-oxytocin pathway to promote social interactions

It is well known that affective and pleasant touch promotes individual well-being and facilitates affiliative social communication, although the neural circuit that mediates this process is largely unknown. Here, we show that social-touch-like tactile stimulation (ST) enhances firing of oxytocin neurons in the mouse paraventricular hypothalamus (PVH) and promotes social interactions and positively reinforcing place preference. These results link pleasant somatosensory stimulation to increased social interactions and positive affective valence. We further show that tachykinin 1 (Tac1⁺) neurons in the lateral and ventrolateral periaqueductal gray (l/vlPAG) send monosynaptic excitatory projections to PVH oxytocin neurons. Functionally, activation of PVH-projecting Tac1⁺ neurons increases firing of oxytocin neurons, promotes social interactions, and increases preference for the social touch context, whereas reducing activity of Tac1⁺ neurons abolishes ST-induced oxytocin neuronal firing. Together, these results identify a dipeptidergic pathway from l/vlPAG Tac1⁺ neurons to PVH oxytocin neurons, through which pleasant sensory experience promotes social behavior.

The epilepsy-autism spectrum disorder phenotype in the era of molecular genetics and precision therapy

Autism spectrum disorder (ASD) is frequently associated with infants with epileptic encephalopathy, and early interventions targeting social and cognitive deficits can have positive effects on developmental outcome. However, early diagnosis of ASD among infants with epilepsy is complicated by variability in clinical phenotypes. Commonality in both biological and molecular mechanisms have been suggested between ASD and epilepsy, such as occurs with tuberous sclerosis complex. This review summarizes the current understanding of causal mechanisms between epilepsy and ASD, with a particularly genetic focus. Hypothetical explanations to support the conjugation of the two conditions include abnormalities in synaptic growth, imbalance in neuronal excitation/inhibition, and abnormal synaptic plasticity. Investigation of the probable genetic basis has implemented many genes, although the main risk supports existing hypotheses in that these cluster to abnormalities in ion channels, synaptic function and structure, and transcription regulators, with the mammalian target of rapamycin (mTOR) pathway and "mTORpathies" having been a notable research focus. Experimental models not only have a crucial role in determining gene functions but are also useful instruments for tracing disease trajectory. Precision medicine from gene therapy remains a theoretical possibility, but more contemporary developments continue in molecular tests to aid earlier diagnoses and better therapeutic targeting.

Fecal Microbiota Transplantation Relieves Gastrointestinal and Autism Symptoms by Improving the Gut Microbiota in an Open-Label Study

Autism spectrum disorder (ASD) is a severe brain development disorder that is characterized by deficits in social communication and restricted, repetitive and stereotyped behaviors. Accumulating evidence has suggested that gut microbiota disorders play important roles in gastrointestinal symptoms and neurodevelopmental dysfunction in ASD patients. Manipulation of the gut microbiota by fecal microbiota transplantation (FMT) was recently shown to be a promising therapy for the treatment of various diseases. Here, we performed a clinical trial to evaluate the effect of FMT on gastrointestinal (GI) and ASD symptoms and gut microbiota alterations in children with ASD. We found that there was a large difference in baseline characteristics of behavior, GI symptoms, and gut microbiota between children with ASD and typically developing (TD) control children. FMT could improve GI symptoms and ASD symptoms without inducing any severe complications. Similarly, FMT significantly changed the serum levels of neurotransmitters. We further observed that FMT could promote the colonization of donor microbes and shift the bacterial community of children with ASD toward that of TD controls. The abundance of Eubacterium coprostanoligenes pre-FMT was positively correlated with high GSRS scores, whereas a decrease in Eubacterium coprostanoligenes abundance induced by FMT was associated with the FMT response. Our data suggest that FMT might be a promising therapeutic strategy to improve the GI and behavioral symptoms of patients with ASD, possibly due to its ability to alter gut microbiota and highlight a specific microbiota intervention that targets Eubacterium coprostanoligenes that can enhance the FMT response. This trial was registered at the Chinese Clinical Trial Registry (www.chictr.org.cn) (trial registration number ChiCTR1800014745).

DNA methylation in stress and depression: from biomarker to therapeutics

Epigenetic mechanisms such as DNA methylation (DNAm) have been associated with stress responses and increased vulnerability to depression. Abnormal DNAm is observed in stressed animals and depressed individuals. Antidepressant treatment modulates DNAm levels and regulates gene expression in diverse tissues, including the brain and the blood. Therefore, DNAm could be a potential therapeutic target in depression. Here, we reviewed the current knowledge about the involvement of DNAm in the behavioural and molecular changes associated with stress exposure and depression. We also evaluated the possible use of DNAm changes as biomarkers of depression. Finally, we discussed current knowledge limitations and future perspectives.

Automatic classification of autism spectrum disorder in children using cortical thickness and support vector machine

OBJECTIVE

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a heterogeneous phenotype. The role of biomarkers in ASD diagnosis has been highlighted; cortical thickness has proved to be involved in the etiopathogenesis of ASD core symptoms. We apply support vector machine, a supervised machine learning method, in order to identify specific cortical thickness alterations in ASD subjects.

METHODS

A sample of 76 subjects (9.5 ± 3.4 years old) has been selected, 40 diagnosed with ASD and 36 typically developed subjects. All children underwent a magnetic resonance imaging (MRI) examination; T1-MPRAGE sequences were analyzed to extract features for the characterization and parcellation of regions of interests (ROI); average cortical thickness (CT) has been measured for each ROI. For the classification process, the extracted features were used as input for a classifier to identify ASD subjects through a "learning by example" procedure; the features with best performance was then selected by "greedy forward-feature selection." Finally, this model underwent a leave-one-out cross-validation approach.

RESULTS

From the training set of 68 ROIs, five ROIs reached accuracies of over 70%. After this phase, we used a recursive feature selection process in order to identify the eight features with the best accuracy (84.2%). CT resulted higher in ASD compared to controls in all the ROIs identified at the end of the process.

CONCLUSION

We found increased CT in various brain regions in ASD subjects, confirming their role in the pathogenesis of this condition. Considering the brain development curve during ages, these changes in CT may normalize during development. Further validation on a larger sample is required.

Zinc and Copper Brain Levels and Expression of Neurotransmitter Receptors in Two Rat ASD Models

Zinc and copper are important trace elements necessary for the proper functioning of neurons. Impaired zinc and/or copper metabolism and signaling are implicated in many brain diseases, including autism (ASD). In our studies, autistic-like behavior in rat offsprings was induced by application to pregnant mothers valproic acid or thalidomide. Zinc and copper contents were measured in serum and brain structures: hippocampus, cerebral cortex, and cerebellum. Our research shows no interconnections in the particular metal concentrations measured in autistic animal brains and their sera. Based on patient researches, we studied 26 genes belonging to disturbed neurotransmitter pathways. In the same brain regions, we examined the expression of genes encoding proteins of cholinergic, adrenergic, serotonin, and dopamine receptors. In both rats’ ASD models, 17 out of the tested gene expression were decreased. In the cerebellum and cerebral cortex, expression of genes encoding cholinergic, adrenergic, and dopaminergic receptors decreased, whereas in the hippocampus only expression of serotoninergic receptors genes was downregulated. The changes in metals content observed in the rat brain can be secondary phenomena, perhaps elements of mechanisms that compensate for neurotransmission dysfunctions.

The Dopamine Hypothesis of Autism Spectrum Disorder Revisited: Current Status and Future Prospects

Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders characterized by social deficits and stereotyped behaviors. Despite intensive research, its etiopathogenesis remains largely unclear. Although studies consistently reported dopaminergic anomalies, a coherent dopaminergic model of ASD was lacking until recently. In 2017, we provided a theoretical framework for a "dopamine hypothesis of ASD" which proposed that autistic behavior arises from a dysfunctional midbrain dopaminergic system. Namely, we hypothesized that malfunction of 2 critical circuits originating in the midbrain, that is, the mesocorticolimbic and nigrostriatal pathways, generates the core behavioral features of ASD. Moreover, we provided key predictions of our model along with testing means. Since then, a notable number of studies referenced our work and numerous others provided support for our model. To account for these developments, we review all these recent data and discuss their implications. Furthermore, in the light of these new insights, we further refine and reconceptualize our model, debating on the possibility that various etiologies of ASD converge upon a dysfunctional midbrain dopaminergic system. In addition, we discuss future prospects, providing new means of testing our hypothesis, as well as its limitations. Along these lines, we aimed to provide a model which, if confirmed, could provide a better understanding of the etiopathogenesis of ASD along with new therapeutic strategies.

Family-based association study identifies SNAP25 as a susceptibility gene for autism in the Han Chinese population

Autism is a neurodevelopmental disorder with high heritability. Synaptosome associated protein 25 (SNAP25) encodes a presynaptic membrane-binding protein. It plays a crucial role in neurotransmission and may be involved in the pathogenesis of autism. However, the association between SNAP25 and autism in the Han Chinese population remains unclear. To investigate whether single nucleotide polymorphisms (SNPs) in SNAP25 contribute to the risk of autism, we performed a family-based association study of 14 tagSNPs in SNAP25 in 640 Han Chinese autism trios. Our results demonstrated that rs363018 in SNAP25 was significantly associated with autism under both additive (A > G, Z = 3.144, P = .0017) and recessive models (A > G, Z = 3.055, P = .0023) after Bonferroni correction (P < .0036). An additional SNP, rs8636, was nominally associated with autism under the recessive model (C > T, Z = 1.972, P = .0487). Haplotype-based association test revealed that haplotypes A-T (Z = 2.038, P = .0415) and G-T (Z = -3.114, P = .0018) of rs363018-rs362582 were significantly associated with autism after the permutation test (P = .0158). These findings suggest that SNAP25 may represent a susceptibility gene for autism in the Han Chinese population.

Oxytocin and cortisol concentrations in adults with and without autism spectrum disorder in response to physical exercise

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, whose core symptoms consist of deficits in social interaction and communication as well as restricted and repetitive behavior. Brain oxytocin (OXT) has been associated with various prosocial behaviors, and might, therefore, be involved in the pathogenesis of disorders associated with socio-emotional dysfunctions such as ASD. However, significant associations between central and peripheral OXT levels may only be present in response to physiological or stressful stimuli but were not shown under baseline conditions. In this study, we, therefore, investigated salivary and plasma OXT in response to physical exercise in adults with ASD (n ​= ​33, mean age: 36.8 ​± ​10.7 years) without intellectual impairment (IQ ​> ​70) and neurotypical controls (n ​= ​31, mean age: 31.0 ​± ​11.7 years). To stimulate the OXT system, we used rapid cycling and measured cortisol (CORT) concentrations to monitor the physiological stress response. When controlling for age, neither salivary OXT (p ​= ​.469), plasma OXT (p ​= ​.297) nor CORT (p ​= ​.667) concentrations significantly differed between groups at baseline. In addition, neither OXT nor CORT concentrations significantly differed between groups after physical exercise. Social anxiety traits were negatively correlated with plasma, but not saliva OXT concentrations in neurotypicals at baseline, while empathetic traits were positively correlated with saliva, but not plasma concentrations in autistic patients at baseline. No significant correlations between salivary and plasma OXT concentrations were found at any time point. Future studies including adult participants should investigate the effect of age on CORT and OXT concentrations in response to stress.

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Basal levels of cortisol and oxytocin did not differ in adults with ASD from controls.

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After physical exercise plasma oxytocin increased in ASD with low cortisol-response.

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Cortisol and oxytocin levels post-task did not significantly differ between groups.

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Social phobic traits predicted lower plasma oxytocin concentrations in controls.

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Empathetic traits predicted higher salivary oxytocin levels in ASD.

High Depression Symptoms and Burnout Levels Among Parents of Children with Autism Spectrum Disorders: A Multi-Center, Cross-Sectional, Case-Control Study

The diagnosis of autism spectrum disorder (ASD) in a child affects family processes, increases parenting stress and marital conflicts, and may lead to parental psychopathology. It may also affect the prognosis for their children. The aim of this study is to determine depression and burnout levels as well as their predictors among parents of children with ASD compared with those of healthy children. We also sought to evaluate rate of complementary and alternative medicine (CAM) interventions among parents and explore the associations of this phenomenon in an exploratory fashion. 145 children with ASD and 127 control children were enrolled along with their mothers and fathers. Beck Depression Inventory and Maslach Burnout Inventory were used to evaluate parents' depression symptoms and burnout levels. Symptoms of children with ASDs were evaluated according to the Childhood Autism Rating Scale by the clinicians. Family, child and CAM variables were screened by means of a sociodemographic data form. Descriptive, bivariate and correlation analyses were used in statistical evaluations. Predictors of burnout were evaluated with multiple regression analysis. Burnout and depression levels among parents of children with ASD were significantly elevated compared to controls. Burnout levels of mothers were significantly elevated compared to fathers while depression scores of fathers were significantly elevated compared to mothers. Maternal burnout was significantly predicted by presence of functional speech in child while paternal burnout was significantly predicted by paternal vocation. Maternal depression was associated with paternal depression, lack of speech in child and attendance of child to special education services. Paternal depression was associated with autistic symptom severity and maternal depression. More than half the parents sought CAM interventions. Education level did not affect search for CAM interventions while both maternal and paternal psychopathology and presence of epilepsy among children increased use of CAM methods. Psychological support should be provided to both mothers and fathers of a child receiving a diagnosis of ASD. Addressing parents' burnout and stress levels and facilitating their negotiation of knowledge on etiology and treatments for ASD may be beneficial for the family unit as a whole.

Fecal Microbiota Transplantation: A New Therapeutic Attempt from the Gut to the Brain

Gut dysbacteriosis is closely related to various intestinal and extraintestinal diseases. Fecal microbiota transplantation (FMT) is a biological therapy that entails transferring the gut microbiota from healthy individuals to patients in order to reconstruct the intestinal microflora in the latter. It has been proved to be an effective treatment for recurrent Clostridium difficile infection. Studies show that the gut microbiota plays an important role in the pathophysiology of neurological and psychiatric disorders through the microbiota-gut-brain axis. Therefore, reconstruction of the healthy gut microbiota is a promising new strategy for treating cerebral diseases. We have reviewed the latest research on the role of gut microbiota in different nervous system diseases as well as FMT in the context of its application in neurological, psychiatric, and other nervous system-related diseases (Parkinson's disease, Alzheimer's disease, multiple sclerosis, epilepsy, autism spectrum disorder, bipolar disorder, hepatic encephalopathy, neuropathic pain, etc.).

Brain Disorders and Chemical Pollutants: A Gap Junction Link?

The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Endocrine Insights into the Pathophysiology of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a class of neurodevelopmental disorders that affects males more frequently than females. Numerous genetic and environmental risk factors have been suggested to contribute to the development of ASD. However, no one factor can adequately explain either the frequency of the disorder or the male bias in its prevalence. Gonadal, thyroid, and glucocorticoid hormones all contribute to normal development of the brain, hence perturbations in either their patterns of secretion or their actions may constitute risk factors for ASD. Environmental factors may contribute to ASD etiology by influencing the development of neuroendocrine and neuroimmune systems during early life. Emerging evidence suggests that the placenta may be particularly important as a mediator of the actions of environmental and endocrine risk factors on the developing brain, with the male being particularly sensitive to these effects. Understanding how various risk factors integrate to influence neural development may facilitate a clearer understanding of the etiology of ASD.

Cerebral organoids as tools to identify the developmental roots of autism

Some autism spectrum disorders (ASD) likely arise as a result of abnormalities during early embryonic development of the brain. Studying human embryonic brain development directly is challenging, mainly due to ethical and practical constraints. However, the recent development of cerebral organoids provides a powerful tool for studying both normal human embryonic brain development and, potentially, the origins of neurodevelopmental disorders including ASD. Substantial evidence now indicates that cerebral organoids can mimic normal embryonic brain development and neural cells found in organoids closely resemble their in vivo counterparts. However, with prolonged culture, significant differences begin to arise. We suggest that cerebral organoids, in their current form, are most suitable to model earlier neurodevelopmental events and processes such as neurogenesis and cortical lamination. Processes implicated in ASDs which occur at later stages of development, such as synaptogenesis and neural circuit formation, may also be modeled using organoids. The accuracy of such models will benefit from continuous improvements to protocols for organoid differentiation.