Autism Spectrum Disorder Factors Research Articles

Exploring the Mechanisms of Neuronal Protection by Glial Cell Line-Derived Neurotrophic Factor in Autism Spectrum Disorder.

A complicated neurological disease known as autism spectrum disorder (ASD) is typified by issues with social interaction, communication, and repetitive behavior. The neural protective mechanisms in ASD are thought to be influenced by genetic variables, including the expression of neurotrophic genes such as glial cell line-derived neurotrophic factor (GDNF). The aim was to examine the relationship between neuronal protection and cognitive functioning by crosslinking GDNF gene expression and serum levels in individuals with relation to Mini-Mental State Examination (MMSE) scores in ASD patients. After getting study approval and informed consent of patients, this case-control study experimental study was conducted for six months between July 2023 and December 2023. The blood samples (5 ml each) were drawn from the study population (n = 140), including 100 ASD patients with a disease course of30 months based on patients' reports data and 40 healthy controls from four major clinical and hospital settings in Lahore, Karachi, and Bahawalpur from Pakistan. The analytical procedures included nucleic acid extraction, primer design and optimization, and GDNF-targeted real-time quantitative polymerase chain reaction expression analysis. To measure cognitive and behavioral deficits, enzyme-linked immunosorbent assay-based serum GDNF levels (pg/ml) and MMSE scores were compared, concluding the neuronal protection potential of GDNF. In patients with ASD, lower serum levels of GDNF (9.371 ± 2.388 pg/ml) were linked to more severe behavioral and cognitive deficits confirmed by MMSE scores (13.6 ± 3.5) of ASD patients in comparison with the control group (27.1 ± 2.1). Healthy individuals showed higher relative gene fold expression (11.71) compared to the ASD patients (5.51). There is a notable decrease in GDNF gene expression in people with ASD, which raises the possibility that GDNF is important for both cognitive performance and neuronal protection in these people. GDNF may be a useful biomarker for identifying ASD and comprehending its molecular causes, opening the door for focused treatment approaches.

Early-Life Exposure to 4-Hydroxy-4'-Isopropoxydiphenylsulfone Induces Behavioral Deficits Associated with Autism Spectrum Disorders in Mice.

Exposure to bisphenol A (BPA) during gestation and lactation is considered to be a potential risk factor for autism spectrum disorder (ASD) in both humans and animals. As a novel alternative to BPA, 4-hydroxy-4'-isopropoxydiphenylsulfone (BPSIP) is frequently detected in breast milk and placental barrier systems, suggesting potential transmission from the mother to offspring and increased risk of exposure. Gestation and lactation are critical periods for central nervous system development, which are vulnerable to certain environmental pollutants. Herein, we investigated the behavioral impacts and neurobiological effects of early-life exposure to BPSIP (0.02, 0.1, and 0.5 mg/kg body weight/day) in mice offspring. Behavioral studies indicated that BPSIP exposure induced ASD-like behaviors, including elevated anxiety-related behavior and decreased spatial memory, in both male and female pups. A distinct pattern of reduced social novelty was observed only in female offspring, accompanied by significant alterations in antioxidant levels. Transcriptome analysis demonstrated that differentially expressed genes (DEGs) were mainly enriched in pathways related to behaviors and neurodevelopment, which were consistent with the observed phenotype. Besides, a decrease in the protein levels of complex IV (COX IV) across all tested populations suggests a profound impact on mitochondrial function, potentially leading to abnormal energy metabolism in individuals with autism. Additionally, changes in synaptic proteins, evidenced by alterations in synapsin 1 (SYN1) and postsynaptic density protein-95 (PSD95) levels in the cerebellum and hippocampus, support the notion of synaptic involvement. These findings suggest that BPSIP may induce sex-specific neurotoxic effects that involve oxidative stress, energy generation, and synaptic plasticity.

Altered prefrontal and cerebellar parvalbumin neuron counts are associated with cognitive changes in male rats.

Exposure to valproic acid (VPA), a common anti-seizure medication, in utero is a risk factor for autism spectrum disorder (ASD). People with ASD often display changes in the cerebellum, including volume changes, altered circuitry, and changes in Purkinje cell populations. ASD is also characterized by changes in the medial prefrontal cortex (mPFC), where excitatory/inhibitory balance is often altered. This study exposed rats to a high dose of VPA during gestation and assessed cognition and anxiety-like behaviors during young adulthood using a set-shifting task and the elevated plus maze. Inhibitory parvalbumin-expressing (PV +) neuron counts were assessed in the mPFC and cerebellar lobules VI and VII (Purkinje cell layers), which are known to modulate cognition. VPA males had increased PV + counts in crus I and II of lobule VII. VPA males also had decreased parvalbumin-expressing neuron counts in the mPFC. It was also found that VPA-exposed rats, regardless of sex, had increased parvalbumin-expressing Purkinje cell counts in lobule VI. In males, this was associated with impaired intra-dimensional shifting on a set-shifting task. Purkinje cell over proliferation may be contributing to the previously observed increase in volume of Lobule VI. These findings suggest that altered inhibitory signaling in cerebellar-frontal circuits may contribute to the cognitive deficits that occur within ASD.

Effects of Cohabitation on Neurodevelopmental Outcomes in Rats Discordant for Neonatal Exposure to Sevoflurane

BackgroundHaving a sibling with autism spectrum disorder is a risk factor for autism spectrum disorder. We used a rat model in which the general anesthetic sevoflurane (SEVO) induces autism spectrum disorder–like neurodevelopmental abnormalities to test whether they can be transmitted via cohabitation. MethodsMale rat pups from several litters were mixed and randomized to 3 new litter types: SEVO-exposed (SEVO), SEVO-unexposed (control), and equal numbers of SEVO-exposed and SEVO-unexposed (MIXED). After weaning, rats in experiment 1 were housed with littermates in SEVO, control, and MIXED (MIXED-exposed and MIXED-unexposed) pairs. In experiment 2, MIXED-exposed and MIXED-unexposed rats were paired with an unfamiliar naïve cagemate. Corticosterone levels, gene expression, central inflammatory markers (experiment 1), and behavior and corticosterone levels (experiment 2) were assessed in adulthood. ResultsIn experiment 1, compared with control rats, SEVO rats exhibited abnormalities in the hypothalamic-pituitary-adrenal axis, inflammatory markers, oxytocin, arginine vasopressin, and DNA methylation systems. Almost all these measures in MIXED-exposed and MIXED-unexposed rats were statistically indistinguishable from and similar to those in SEVO or control rats, with most measures in MIXED rats being similar to those in SEVO rats. Experiment 2 showed that pairing with unfamiliar, naïve rats after weaning caused MIXED-unexposed and MIXED-exposed rats’ behavior to be no different from that of control and SEVO rats, respectively; however, the 2 groups of MIXED rats also did not differ from each other. ConclusionsThese findings suggest that neurodevelopmental abnormalities can be transmitted to otherwise healthy individuals through interactions during cohabitation; however, subsequent pairing with unfamiliar, naïve cohabitants may weaken this interaction effect.

Aerobic exercise improves cognitive flexibility and modulates regional volume changes in a rat model of autism

Gestational exposure to valproic acid (VPA) is a risk factor for autism spectrum disorder (ASD). Rodents exposed to VPA in utero display common features of ASD, including volumetric dysregulation in higher-order cognitive regions like the medial prefrontal cortex (mPFC), the anterior cingulate cortex (ACC), and the hippocampus. Exercise has been shown in elderly populations to boost cognition and to buffer against brain volume losses with age. This study employed an adolescent treadmill exercise intervention to facilitate cognitive flexibility and regional brain volume regulation in rats exposed to VPA during gestation. It was found that exercise improved performance on extra-dimensional shifts of attention on a set-shifting task, which is indicative of improved cognitive flexibility. Exercise decreased frontal cortex volume in females, whereas in males exercise increased the ventral hippocampus. These findings suggest that aerobic exercise may be an effective intervention to counteract the altered development of prefrontal and hippocampal regions often observed in ASD.

Anti-Inflammatory Interventions for Autism Spectrum Disorder

One of the defining factors of Autism Spectrum Disorder (ASD) is neuroinflammation, which may be targeted to find effective therapies in managing ASD symptoms. Some promising treatments include mesenchymal STEM cell (MSCs) therapy, cxytocin (OT), sulforaphane (SFN), and resveratrol (RSV). MSCs are located in many parts of the body that can reduce secondary neurodegeneration and neuroinflammation while promoting neurogenesis and angiogenesis. OT is a hormone that moderates social and emotional communication, bonding, and social learning, while also having profound antiinflammatory effects. SFN is a naturally occurring compound in cruciferous vegetables, such as broccoli and sprouts, and activates a transcription factor which regulates anti-inflammatory and antioxidant genes. RSV is found in plants, such as grapes and berries, and helps stabilize the central and peripheral immune response and oxidative stress markers, subsequently reducing neuroinflammation. All of these treatments have shown promising potential, but it is abundantly clear that further research is needed in addition to combined therapies. Since ASD is a spectrum, not every case can be treated the exact same way. By targeting neuroinflammation, we can address the root cause of ASD rather than the symptoms.

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review.

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Parental psychiatric diagnoses as predictive factors for autism spectrum disorder in the child: confluence of genetics and environment

Parental psychiatric diagnoses as predictive factors for autism spectrum disorder in the child: confluence of genetics and environment

Chd8 haploinsufficiency impacts rearing experience in C57BL/6 mice.

Mutations in CHD8 are one of the highest genetic risk factors for autism spectrum disorder. Studies in mice that investigate underlying mechanisms have shown Chd8 haploinsufficient mice display some trait disruptions that mimic clinical phenotypes, although inconsistencies have been reported in some traits across different models on the same strain background. One source of variation across studies may be the impact of Chd8 haploinsufficiency on maternal-offspring interactions. While differences in maternal care as a function of Chd8 genotype have not been studied directly, a previous study showed that pup survival was reduced when reared by Chd8 heterozygous dams compared with wild-type (WT) dams, suggesting altered maternal care as a function of Chd8 genotype. Through systematic observation of the C57BL/6 strain, we first determined the impact of Chd8 haploinsufficiency in the offspring on WT maternal care frequencies across preweaning development. We next determined the impact of maternal Chd8 haploinsufficiency on pup care. Compared with litters with all WT offspring, WT dams exhibited less frequent maternal behaviors toward litters consisting of offspring with mixed Chd8 genotypes, particularly during postnatal week 1. Dam Chd8 haploinsufficiency decreased litter survival and increased active maternal care also during postnatal week 1. Determining the impact of Chd8 haploinsufficiency on early life experiences provides an important foundation for interpreting offspring outcomes and determining mechanisms that underlie heterogeneous phenotypes.

Prenatal, perinatal and parental risk factors for autism spectrum disorder in China: a case- control study.

Autism spectrum disorder (ASD) is heritable neurodevelopmental disorders (NDDs), but environmental risk factors have also been suggested to a play a role in its development. Prenatal, perinatal and parental factors have been associated with an increased risk of ASD in children. The aim of the present study was to explore the prenatal, perinatal, and parenting risk factors in children with autism spectrum disorder (ASD) from Beijing, China by comparing them with typically developing (TD) children. A sample of 151 ASD children's parents who from rehabilitation institutions in Beijing were enrolled in this study, and an additional 151 children from kindergartens in Beijing were recruited as a control group (child age: mean = 4.4 years). TD children were matched according to age, sex and maternal education. We explored the maternal AQ (Autism Spectrum Quotient) scores (mean:19.40-19.71, no significant difference between two groups) to referring the genetic baseline. This study evaluated 17 factors with unadjusted and adjusted analyses. Birth asphyxia was associated with a more than a thirteen-fold higher risk of ASD (adjusted odds ratio (AOR) = 13.42). Breastfeeding difficulties were associated with a higher risk of ASD(AOR = 3.46). Parenting influenced the risk of ASD, with low responding (LR) and harsh or neglectful parenting associated with a higher risk of ASD in offspring (AOR = 2.37 for LR, AOR = 3.42 for harsh parenting and AOR = 3.01 for neglectful parenting). Maternal fever during pregnancy was associated with a higher risk of ASD in offspring (AOR = 3.81). Many factors were associated with ASD in offspring. Further assessment is needed to elucidate the role of modifiable environmental factors to inform prevention strategies.

Influence of parental education on the intelligence quotient profiles and socially adaptive behavior of school-age children with autism spectrum disorder in eastern China.

Intelligence quotient (IQ) and adaptive behavior are the influencing factors of autism spectrum disorder (ASD) in children entering mainstream schools. This study explored the association between parental education level, IQ, and adaptive behavior in ASD groups. A total of 257 school-age ASD children were enrolled in our study from January 2017 to June 2021. Their parents completed a standard demographic form, including age at autism diagnosis, gender, school placement, and parents' educational background. The Chinese version of the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) was completed by a certified assessor for each enrolled child. Parents were interviewed on adaptive behavior using the Chinese version of the Adaptive Behavior Assessment System, Second Edition (ABAS-II). The average IQ of school-age ASD children was 76.88 (standard deviation (SD)=22.62) and boys had higher IQ levels than girls. The IQ was positively correlated with age. The General Adaptive Composite (GAC) score was 82.47 (SD=15.86) and adaptive behavior did not increase with age. ASD children who attended mainstream schools had better adaptive behavior profiles than other children. The mother's education level showed a significant correlation with the IQ and adaptive behavior of autistic children, while the father's education level did not. Consequently, better training and support for parents may help autistic children enter mainstream schools, with adaptive training being the most urgently required skill for parents.

Maternal Thyroid Dysfunction During Pregnancy as an Etiologic Factor in Autism Spectrum Disorder: Challenges and Opportunities for Research.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition with unknown etiology. Both genetic and environmental factors have been associated with ASD. Environmental exposures during the prenatal period may play an important role in ASD development. This narrative review critically examines the evidence for a relationship between maternal thyroid dysfunction during pregnancy and ASD in the child. Summary: Studies that assessed the associations of hypothyroidism, hyperthyroidism, hypothyroxinemia, thyroid hormone concentrations, or autoimmune thyroid disease with ASD outcomes were included. Most research focused on the relationship between hypothyroidism and ASD. Multiple population-based studies found that maternal hypothyroidism was associated with higher likelihood of an ASD diagnosis in offspring. Associations with other forms of maternal thyroid dysfunction were less consistent. Findings may have been affected by misclassification bias, survival bias, or publication bias. Studies using medical records may have misclassified subclinical thyroid dysfunction as euthyroidism. Two studies that assessed children at early ages may have misclassified those with ASD as typically developing. Most studies adjusted for maternal body mass index (BMI) and/or mental illness, but not interpregnancy interval or pesticide exposure, all factors associated with fetal survival and ASD. Most studies reported a combination of null and statistically significant findings, although publication bias is still possible. Conclusions: Overall, evidence supported a positive association between maternal thyroid dysfunction during pregnancy and ASD outcomes in the child, especially for hypothyroidism. Future studies could reduce misclassification bias by using laboratory measures instead of medical records to ascertain thyroid dysfunction and evaluating children for ASD at an age when it can be reliably detected. Survival bias could be further mitigated by adjusting models for more factors associated with fetal survival and ASD. Additional research is needed to comprehensively understand the roles of maternal levothyroxine treatment, iodine deficiency, or exposure to thyroid-disrupting compounds in the relationship between maternal thyroid dysfunction and child ASD outcomes.

Peripheral oxytocin levels are linked to hypothalamic gray matter volume in autistic adults: a cross-sectional secondary data analysis

Oxytocin (OXT) is known to modulate social behavior and cognition and has been discussed as pathophysiological and therapeutic factor for autism spectrum disorder (ASD). An accumulating body of evidence indicates the hypothalamus to be of particular importance with regard to the underlying neurobiology. Here we used a region of interest voxel-based morphometry (VBM) approach to investigate hypothalamic gray matter volume (GMV) in autistic (n = 29, age 36.03 ± 11.0) and non-autistic adults (n = 27, age 30.96 ± 11.2). Peripheral plasma OXT levels and the autism spectrum quotient (AQ) were used for correlation analyses. Results showed no differences in hypothalamic GMV in autistic compared to non-autistic adults but suggested a differential association between hypothalamic GMV and OXT levels, such that a positive association was found for the ASD group. In addition, hypothalamic GMV showed a positive association with autistic traits in the ASD group. Bearing in mind the limitations such as a relatively small sample size, a wide age range and a high rate of psychopharmacological treatment in the ASD sample, these results provide new preliminary evidence for a potentially important role of the HTH in ASD and its relationship to the OXT system, but also point towards the importance of interindividual differences.

Induction of autism-related behavior in male mice by early-life vitamin D deficiency: association with disruption of the gut microbial composition and homeostasis.

Vitamin D deficiency (VDD) during early life emerges as a potential risk factor for autism spectrum disorder (ASD). Individuals with autism commonly exhibit lower vitamin D (VD) levels compared to the general population, and VD deficiency is prevalent during pregnancy and lactation. Moreover, gastrointestinal comorbidity, prevalent in ASD patients, correlates closely with disruptions in the gut microbiota and altered intestinal permeability. Therefore, it is fascinating and significant to explore the effects of maternal VD deficiency during pregnancy and lactation on the maturation of the gut microbiota of the offspring and its relevance to autism spectrum disorders. In this study, we established maternal pregnancy and lactation VD-deficient mouse models, employed shotgun macrogenomic sequencing to unveil alterations in the gut microbiome of offspring mice, and observed autism-related behaviours. Furthermore, fecal microbial transplantation (FMT) reversed repetitive and anxious behaviours and alleviated social deficits in offspring mice by modulating the gut microbiota and increasing short-chain fatty acid levels in the cecum, along with influencing the concentrations of claudin-1 and occludin in the colon. Our findings confirm that VDD during pregnancy and lactation is a risk factor for autism in the offspring, with disturbances in the structure and function of the offspring's gut microbiota contributing at least part of the effect. The study emphasises the importance of nutrition and gut health early in life. Simultaneously, this study further demonstrates the effect of VDD on ASD and provides potential ideas for early prevention and intervention of ASD.

A Narrative Review of Autism Spectrum Disorder in the Indian Context

Autism is called “spectrum” disorder because there is a wide variation in the type and the severity of symptoms that people experience. India has a vast population, diverse cultures, and multiple languages, making it crucial to under- stand the unique challenges faced by individuals with autism spectrum disorder in the Indian context. This narrative review explores the current state of knowledge about autism spectrum disorder in the Indian context. Databases such as PubMed, Google Scholar, Sage journals, and other sources were searched with relevant terms for preparing this review. All published literature till January 2023 was studied and those which met the inclusion criteria were included. The resources included were original research articles, review articles, web pages, and book chapters addressing the purpose of the paper. Forty-eight such studies which met the inclusion criteria were included in the study. Results showed that the prevalence of autism varied across different studies in India. The study found advanced paternal age, fetal distress, gestational respiratory infections, labor complications, preterm birth, neonatal jaundice, delayed birth cry, birth asphyxia, late initiation of breastfeeding, neonatal seizures, use of maternal hormonal intervention, and consanguinity as some of the identified risk factors of autism spectrum disorder. Parents and families of children with autism have to go through a complex negative experience, both in the family and the community. This negative experience is further compounded by the lack of awareness and access to appropriate professional help and resources. It can be concluded that there is an urgent need for services that help parents cope with the stress of parenting a child with autism.

Exposure to nonylphenol in early life causes behavioural deficits related with autism spectrum disorders in rats

Early-life exposure to environmental endocrine disruptors (EDCs) is a potential risk factor for autism spectrum disorder (ASD). Exposure to nonylphenol (NP), a typical EDC, is known to cause some long-term behavioural abnormalities. Moreover, these abnormal behaviours are the most frequent psychiatric co-morbidities in ASD. However, the direct evidence for the link between NP exposure in early life and ASD-like behavioural phenotypes is still missing. In the present study, typical ASD-like behaviours induced by valproic acid treatment were considered as a positive behavioural control. We investigated impacts on social behaviours following early-life exposure to NP, and explored effects of this exposure on neuronal dendritic spines, mitochondria function, oxidative stress, and endoplasmic reticulum (ER) stress. Furthermore, primary cultured rat neurons were employed as in vitro model to evaluate changes in dendritic spine caused by exposure to NP, and oxidative stress and ER stress were specifically modulated to further explore their roles in these changes. Our results indicated rats exposed to NP in early life showed mild ASD-like behaviours. Moreover, we also found the activation of ER stress triggered by oxidative stress may contribute to dendritic spine decrease and synaptic dysfunction, which may underlie neurobehavioural abnormalities induced by early-life exposure to NP.

Zebrafish embryonically exposed to valproic acid present impaired retinal development and sleep behavior.

Prenatal exposure to valproic acid (VPA), a drug widely used to treat epilepsy and bipolar disorder, is an environmental risk factor for autism spectrum disorder (ASD). VPA has been used to reproduce the core symptoms of ASD in animal model organisms, including zebrafish. Visual system functioning is essential in the interpretation of social conditions and plays an important role of several behavioral responses. We hypothesized that behavioral deficits displayed by ASD patients may involve impaired visual processing. We used zebrafish as model organism to investigate the visual system after embryonic exposure to VPA using histological, behavioral and gene expression analysis. We analyzed the pineal gland of zebrafish and sleep-like behavior to study how VPA exposure alters photo-sensibility of zebrafish. VPA-exposed zebrafish showed a delay in the development of the retina and optic nerve, which normalized at five days post fertilization. At larval stage, VPA-exposed zebrafish showed sleep disturbances associated with a reduced number of serotonin-producing cells of the pineal gland. In addition, the number of hypocretin/orexin (hcrt) expressing neurons in the rostral hypothalamus at 6 and 14 days post fertilization was reduced. In conclusion, we demonstrated that although VPA exposure leads to a delay in visual system development, it does not affect larval visual function. The novel finding that VPA alters significantly cells involved in sleep regulation and the sleep-like state itself may be relevant for understanding sleep disturbances in ASD patients.

The association between prenatal psychosocial factors and autism spectrum disorder in offspring at 3years: a prospective cohort study.

Few studies of risk factors for autism spectrum disorder (ASD) have been prospective in design or investigated the role of psychosocial factors measured during pregnancy. We aimed to investigate associations between prenatal psychosocial factors and risk of ASD in offspring, as part of a multicenter prospective cohort study of more than 2000 mother-child pairs. Nulliparous women aged 18-35years, living in Pennsylvania, USA, were interviewed during pregnancy and multiple times postpartum over the course of a 3-year period. There were 2388 mothers who completed the Screen for Social Interaction Toddler Version (SSI-T), a measure of risk of ASD, when their child was 3-years old. Multivariable logistic regression models were used to investigate the associations between prenatal psychosocial factors-including total scores on three scales (social-support, stress and depression), trouble paying for basic needs, mental illness diagnosis and use of antidepressants-and risk of ASD in offspring at the age of 3-years, controlling for relevant confounding variables. There were 102 children (4.3%) who were scored as at-risk of ASD at 3-years. Prenatal psychosocial factors that were significantly associated with risk of ASD in the adjusted models were lower social-support (p < 0.001); stress (p = 0.003): depression (< 0.001), trouble paying for basic needs (p = 0.012), mental illness diagnosis (p = 0.016), and use of antidepressants (p < 0.001). These findings suggest that maternal experience of adverse psychosocial factors during pregnancy may be important intrauterine exposures related to the pathogenesis of ASD.

Socioeconomic and demographic risk factors of autism spectrum disorder among children and adolescents in Bangladesh: Evidence from a cross-sectional study in 2022.

Autism spectrum disorder (ASD) is the assorted uneven conditions of the human brain that lead to developmental disabilities. This cross-sectional study aimed to identify the substantial risk factors of ASD among children in Bangladesh. The data were collected using convenience sampling through a questionnaire filled up by the trained interviewers. Mann-Whitney U and Kruskal-Wallis H tests were applied as bivariate analysis, and generalized beta regression was performed to determine the significant risk factors of autism spectrum disorder. The odds ratio (OR) along with 95% confidence interval (CI) were the measuring parameters of the risk factors of ASD. The result revealed that later birth order children have more risk of ASD (OR = 1.13, CI: 1.014-1.264, p = 0.027) compared to the children whose birth order is first. Premature birth of the child (OR: 0.87, CI: 0.76-1.00, p = 0.05) and father's age (OR: 0.86, CI: 0.76-0.97, p = 0.020) substantially affects ASD. The maternal history of specific illness (diabetes, thyroiditis, and hypertension) during pregnancy also significantly affect ASD (OR: 1.34, CI: 1.14-1.61, p = 0.002). The results of this study would assist policymakers in taking necessary steps to reduce the incidence of this disorder by targeting the potential risk factors.

Chronic exposure of female mice to selective serotonin reuptake inhibitors during lactation induces vocal behavior deficits in pre-weaned offspring

Developmental factors for autism spectrum disorders (ASDs) have been an ongoing debate despite an increasing number of reports on genetic factors. Recent studies have suggested maternal intake of selective serotonin reuptake inhibitors (SSRIs) as a possible developmental factor elevating the risk for ASD in offspring. Here, we show that maternal exposure of mice to an SSRI, Fluoxetine (FLX), induces abnormal ultrasonic vocalizations (USVs), an indicator of ASD-related behavior. We tested the effect of FLX intake during pregnancy, lactation, or both. We found that the lactation and both conditions decreased the number of USVs emitted by offspring pups. An index for assessing the syllables' frequency modulation revealed that highly modulated syllables appeared to be inhibited only in both conditions. Furthermore, we found that the number of serotonergic neurons at adulthood was reduced in the progeny of mice treated with FLX in all conditions. In addition, maternal exposure to FLX through pregnancy and lactation induced a high death rate of early post-natal pups. These suggest that the maternal exposure to SSRIs affects early development of offsprings as well as the serotonergic system. Focusing on vocal communication, our results indicate that intake of an SSRI during lactation increases the risk of abnormal USVs in pups, and provides potential insights into the development of ASD.