Neuronal splicing regulator RBFOX3 mediates seizures via regulating Vamp1 expression preferentially in NPY-expressing GABAergic neurons.

Epilepsy is a common neurological disorder, which has been linked to mutations or deletions of RNA binding protein, fox-1 homolog (Caenorhabditis elegans) 3 (RBFOX3)/NeuN, a neuronal splicing regulator. However, the mechanism of seizure mediation by RBFOX3 remains unknown. Here, we show that mice with deletion of Rbfox3 in gamma-aminobutyric acid (GABA) ergic neurons exhibit spontaneous seizures and high premature mortality due to increased presynaptic release, postsynaptic potential, neuronal excitability, and synaptic transmission in hippocampal dentate gyrus granule cells (DGGCs). Attenuating early excitatory gamma-aminobutyric acid (GABA) action by administering bumetanide, an inhibitor of early GABA depolarization, rescued premature mortality. Rbfox3 deletion reduced hippocampal expression of vesicle-associated membrane protein 1 (VAMP1), a GABAergic neuron-specific presynaptic protein. Postnatal restoration of VAMP1 rescued premature mortality and neuronal excitability in DGGCs. Furthermore, Rbfox3 deletion in GABAergic neurons showed fewer neuropeptide Y (NPY)-expressing GABAergic neurons. In addition, deletion of Rbfox3 in NPY-expressing GABAergic neurons lowered intrinsic excitability and increased seizure susceptibility. Our results establish RBFOX3 as a critical regulator and possible treatment path for epilepsy.

RTL1/PEG11 imprinted in human and mouse brain mediates anxiety-like and social behaviors and regulates neuronal excitability in the locus coeruleus.

RTL1/PEG11, which has been associated with anxiety disorders, is a retrotransposon-derived imprinted gene in the placenta. However, imprinting patterns and functions of RTL1 in the brain have not been well-investigated. We found Rtl1 was paternally, but not maternally, expressed in brain stem, thalamus, and hypothalamus of mice, and imprinting status of RTL1 was maintained in human brain. Paternal Rtl1 knockout (Rtl1m+/p-) mice had higher neonatal death rates due to impaired suckling, and low body weights beginning on embryonic day 16.5. High paternal expression of Rtl1 was detected in the locus coeruleus (LC) and Rtl1m+/p- mice showed an increased delay in time of onset for action potentials and inward currents with decreased neuronal excitability of LC neurons. Importantly, Rtl1m+/p- mice exhibited behaviors associated with anxiety, depression, fear-related learning and memory, social dominance, and low locomotor activity. Taken together, our findings demonstrate RTL1 is imprinted in brain, mediates emotional and social behaviors, and regulates excitability in LC neurons.

Correlation of altered intrinsic functional connectivity with impaired self-regulation in children and adolescents with ADHD.

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) has a high prevalence of co-occurring impaired self-regulation (dysregulation), exacerbating adverse outcomes. Neural correlates underlying impaired self-regulation in ADHD remain inconclusive. We aimed to investigate the impact of dysregulation on intrinsic functional connectivity (iFC) in children with ADHD and the correlation of iFC with dysregulation among children with ADHD relative to typically developing controls (TDC). METHODS: Resting-state functional MRI data of 71 children with ADHD (11.38 ± 2.44 years) and 117 age-matched TDC were used in the final analysis. We restricted our analyses to resting-state networks (RSNs) of interest derived from independent component analysis. Impaired self-regulation was estimated based on the Child Behavioral Checklist-Dysregulation Profile. RESULTS: Children with ADHD showed stronger iFC than TDC in the left frontoparietal network, somatomotor network (SMN), visual network (VIS), default-mode network (DMN), and dorsal attention network (DAN) (FWE-corrected alpha < 0.05). After adding dysregulation levels as an extra regressor, the ADHD group only showed stronger iFC in the VIS and SMN. ADHD children with high dysregulation had higher precuneus iFC within DMN than ADHD children with low dysregulation. Angular gyrus iFC within DMN was positively correlated with dysregulation in the ADHD group but negatively correlated with dysregulation in the TDC group. Functional network connectivity showed ADHD had a greater DMN-DAN connection than TDC, regardless of the dysregulation level. CONCLUSIONS: Our findings suggest that DMN connectivity may contribute to impaired self-regulation in ADHD. Impaired self-regulation should be considered categorical and dimensional moderators for the neural correlates of altered iFC in ADHD.

Altered synaptic protein expression, aberrant spine morphology, and impaired spatial memory in Dlgap2 mutant mice, a genetic model of autism spectrum disorder.

A microdeletion of approximately 2.4 Mb at the 8p23 terminal region has been identified in a Taiwanese autistic boy. Among the products transcribed/translated from genes mapped in this region, the reduction of DLGAP2, a postsynaptic scaffold protein, might be involved in the pathogenesis of autism spectrum disorder (ASD). DLGAP2 protein was detected in the hippocampus yet abolished in homozygous Dlgap2 knockout (Dlgap2 KO) mice. In this study, we characterized the hippocampal phenotypes in Dlgap2 mutant mice. Dlgap2 KO mice exhibited impaired spatial memory, indicating poor hippocampal function in the absence of DLGAP2. Aberrant expressions of postsynaptic proteins, including PSD95, SHANK3, HOMER1, GluN2A, GluR2, mGluR1, mGluR5, ßCAMKII, ERK1/2, ARC, BDNF, were noticed in Dlgap2 mutant mice. Further, the spine density was increased in Dlgap2 KO mice, while the ratio of mushroom-type spines was decreased. We also observed a thinner postsynaptic density thickness in Dlgap2 KO mice at the ultrastructural level. These structural changes found in the hippocampus of Dlgap2 KO mice might be linked to impaired hippocampus-related cognitive functions such as spatial memory. Mice with Dlgap2 deficiency, showing signs of intellectual disability, a common co-occurring condition in patients with ASD, could be a promising animal model which may advance our understanding of ASD.

Mothering and mother-child interactions in the unaffected siblings of autistic children.

AIM: To investigate parenting and mother-child interactions in unaffected siblings of autistic children. METHOD: This cross-sectional study enrolled 274 probands with a DSM-5 diagnosis of autism spectrum disorder (ASD) (87.4% male; mean [SD] age = 11 years 4 months [3 years 2 months]), their unaffected siblings (n = 274, 46.72% male; mean [SD] age = 11 years 3 months [3 years 4 months]), and 296 age-balanced and sex-balanced typically developing children (82.77% male; mean [SD] age = 11 years 3 months [2 years 8 months]). Maternal parenting styles and mother-child interactions were assessed using maternal reporting. RESULTS: Regardless of the child's age, maternal educational level, or presence of attention-deficit/hyperactivity disorder, autistic children received more overprotective and controlling parental behaviour than unaffected children. Correlates for parenting, mother-child interactions, and behavioural problems in the home setting in children with ASD and typically developing children were autistic traits, maternal anxiety and depressive symptoms, and maternal autistic characteristics; those in unaffected siblings were age, autistic traits, maternal educational level, and maternal autistic characteristics. INTERPRETATION: The diagnosis of ASD in a child can significantly influence maternal parenting behaviours, mother-child interactions, and the child's behavioural problems in the home setting. Furthermore, maternal anxiety or depressive symptoms, along with autistic characteristics in both mother and child, might shape parenting practices and exacerbate behavioural difficulties in autistic children.

Sex-differential patterns of neuropsychological functioning in adults with attention-deficit/hyperactivity disorder.

BACKGROUND: The sex-differential prevalence of attention-deficit/hyperactivity disorder (ADHD) varies across the lifespan, but little is known about sex differences in executive functions in adults with ADHD. METHODS: We assessed 261 adults, aged 18-40 years, diagnosed with ADHD (170 males [assigned at birth], aged 25.81 ± 5.49; 91 females, aged 27.76 ± 5.42) and 308 neurotypical adults (176 males, aged 24.62 ± 5.14; 132 female, aged 25.37 ± 5.42) via psychiatric interviews to confirm ADHD and other psychiatric diagnoses. They were assessed by the Cambridge Neuropsychological Testing Automated Battery (CANTAB) on Reaction Time (arousal/processing speed), Rapid Visual Information Processing (sustained attention), Spatial Span (spatial memory), Spatial Working Memory, Intradimentional/Extradimensional Shift (set-shifting), and Stocking of Cambridge (spatial planning). The primary analyses were adjusted for age, full-scale IQ, and co-occurring psychiatric conditions. RESULTS: Adults with ADHD had various co-occurring psychiatric conditions without sex differences in ADHD-neurotypical differences. Both adult males and females with ADHD performed poorer in all CANTAB tasks than same-sex neurotypical adults. Significant sex-moderating effects were observed in neuropsychological performance, including greater ADHD-neurotypical differences in arousal for females than males and in location memory for spatial tasks in males than females. CONCLUSION: There were no sex-moderating effects in the presence of co-occurring psychiatric conditions in adult ADHD. However, there were sex-moderating effects on how ADHD related to neuropsychological functioning in adulthood. ADHD was associated with more challenges in arousal/processing speed in females and more challenges in strategy use or inhibition in spatial memory in males.

Quality of life and clinical correlates in cognitively-able autistic adults: A special focus on sensory characteristics and perceived parental support.

BACKGROUND: Quality of life (QoL) has been suggested as an indicator of outcomes in autistic adults. Factors associated with QoL in autistic individuals remain unclear. This study aims to examine the subjective QoL for autistic adults in Taiwan and investigate the determinants for different domains of QoL. METHODS: The study comprised 90 autistic adults (aged 26.9, SD 7.3; males, 80.9%). We used Taiwanese version of World Health Organization Quality of Life-BREF to measure QoL. Four domains of QoL were compared with 61 non-autistic controls, including physical, psychological, social, and environment. To identify the correlates of QoL domains, we assessed IQ, personality trait, family support, anxiety/depressive symptoms, autistic severity, and sensory symptoms by various questionnaires, and assessed their association with QoL by correlation analyses and model selection. RESULTS: Our results showed that autistic adults reported lower QoL on the World Health Organization Quality of Life (WHOQOL)-BREF across all domains. QoL was significantly associated with autistic symptom severity, harm avoidance, family support, sensory symptoms, anxiety, and depression, but not intelligence. Model selections revealed male sex, poor paternal support, autism severity, depression, anxiety, and sensory symptoms were associated with specific QoL domains. CONCLUSION: Findings supported lower QoL in autistic adults. Modifying the QoL correlates may improve life quality in autistic adults. Furthermore, our findings revealed the importance of sensory symptoms and paternal support in QoL of autistic adults, which was a novel finding in this population.

Neuregulin 2 Is a Candidate Gene for Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with heterogeneous and complex genetic underpinnings. Our previous microarray gene expression profiling identified significantly different neuregulin-2 gene (NRG2) expression between ASD patients and controls. Thus, we aimed to clarify whether NRG2 is a candidate gene associated with ASD. The study consisted of two stages. First, we used real-time quantitative PCR in 20 ASDs and 20 controls to confirm the microarray gene expression profiling results. The average NRG2 gene expression level in patients with ASD (3.23 ± 2.80) was significantly lower than that in the controls (9.27 ± 4.78, p < 0.001). Next, we conducted resequencing of all the exons of NRG2 in a sample of 349 individuals with ASD, aiming to identify variants of the NRG2 associated with ASD. We identified three variants, including two single nucleotide variants (SNVs), IVS3 + 13A > G (rs889022) and IVS10 + 32T > A (rs182642591), and one small deletion at exon 11 of NRG2 (delGCCCGG, rs933769137). Using data from the Taiwan Biobank as the controls, we found no significant differences in allele frequencies of rs889022 and rs182642591 between two groups. However, there is a significant difference in the genotype and allele frequency distribution of rs933769137 between ASDs and controls (p < 0.0001). The small deletion is located in the EGF-like domain at the C-terminal of the NRG2 precursor protein. Our findings suggest that NRG2 might be a susceptibility gene for ASD.

Effectiveness, durability, and clinical correlates of the PEERS social skills intervention in young adults with autism spectrum disorder: the first evidence outside North America.

BACKGROUND: Despite the fact that social deficits among individuals with autism spectrum disorder (ASD) are lifelong and impact many aspects of personal functioning, evidence-based programs for social skills training were not available until recently. The Program for the Education and Enrichment of Relational Skills (PEERS®) has been shown to effectively improve social skills for adolescents on the spectrum across different social cultures. However, the effectiveness for young adults beyond North America has yet to be examined. This study aimed to investigate the effectiveness of the PEERS intervention in Taiwanese young adults with ASD, and examine its durability and clinical correlates. METHODS: We recruited 82 cognitively-able young adults with ASD, randomized to the PEERS treatment or treatment-as-usual. RESULTS: Following treatment, significant improvement was found in aspects of social deficits, autism severity, social interaction anxiety, empathy, and social skills knowledge either by self-report or coach-report. Additionally, communicative behaviors rated by observers improved throughout the sessions, showing a trend toward more appropriate eye contact, gestures, facial expression during conversation, and appropriate maintenance of conversation and reciprocity. Most effects maintained at 3-month and 6-month follow-ups. The improvement of social deficits was positively correlated with baseline severity, while gains in social skills knowledge were positively correlated with IQ. The improvement of social deficits, autism severity, and empathy were positively correlated with each other. CONCLUSION: Overall, the PEERS intervention appears to effectively improve social functioning in Taiwanese young adults with ASD. Improvement of social response and knowledge may be predicted by baseline severity and intelligence respectively.

Population-attributable risk of psychiatric disorders for suicide among adolescents and young adults in Taiwan.

BACKGROUND: Youth suicide rates have increased markedly in some countries. This study aimed to estimate the population-attributable risk of psychiatric disorders associated with suicide among Taiwanese youth aged 10-24 years. METHODS: Data were obtained from the National Death Registry and National Health Insurance (NHI) claims database between 2007 and 2019. Youth who died by suicide were included, and comparisons, 1:10 matched by age and sex, were randomly selected from the Registry for NHI beneficiaries. We used multivariable logistic regression to estimate suicide odds ratios for psychiatric disorders. The population-attributable fractions (PAF) were calculated for each psychiatric disorder. RESULTS: A total of 2345 youth suicide and 23 450 comparisons were included. Overall, 44.8% of suicides had a psychiatric disorder, while only 7.9% of the comparisons had a psychiatric disorder. The combined PAF for all psychiatric disorders was 55.9%. The top three psychiatric conditions of the largest PAFs were major depressive disorder, dysthymia, and sleep disorder. In the analysis stratified by sex, the combined PAF was 45.5% for males and 69.2% for females. The PAF among young adults aged 20-24 years (57.0%) was higher than among adolescents aged 10-19 years (48.0%). CONCLUSIONS: Our findings of high PAF from major depressive disorder, dysthymia, and sleep disorder to youth suicides suggest that youth suicide prevention that focuses on detecting and treating mental illness may usefully target these disorders.

Mouse hybrid genome mediates diverse brain phenotypes with the specificity of reciprocal crosses.

Hybrid species have more genetic diversity than their parents. However, the impact of the hybrid genome of reciprocal crosses on brain function remains largely unknown. We performed behavioral, molecular, and neuronal analyses on C57BL/6J mice (B6), CAST/EiJ mice (CAST), and hybrid mice resulting from reciprocal crosses of the two strains, B6/CAST F1i and B6/CAST F1r, respectively. Hybrid mice displayed greater motor strength and coordination, food grinding, social dominance, and less sociability compared to their parental strains. Parental origin influenced body weight, locomotor speed, and heat nociception of hybrid mice. Parental origin, cell type, and the interaction of both affected expression patterns of hybrid genomes including imprinted genes. There was a correlation between affected genes and corresponding behavioral phenotypes. Hybrid genomes mediated neuronal activity in the locus coeruleus, a brain region implicated in arousal, adaptive behaviors, and sleep-wake cycle due to its norepinephrine projections throughout the central nervous system. The comprehensive brain phenotypes in these hybrid mice reveal important functional readouts associated with interactions of hybrid genomes and impacts of parental genomes.

Neurodevelopmental model of schizophrenia revisited: similarity in individual deviation and idiosyncrasy from the normative model of whole-brain white matter tracts and shared brain-cognition covariation with ADHD and ASD.

The neurodevelopmental model of schizophrenia is supported by multi-level impairments shared among schizophrenia and neurodevelopmental disorders. Despite schizophrenia and typical neurodevelopmental disorders, i.e., autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), as disorders of brain dysconnectivity, no study has ever elucidated whether whole-brain white matter (WM) tracts integrity alterations overlap or diverge between these three disorders. Moreover, whether the linked dimensions of cognition and brain metrics per the Research Domain Criteria framework cut across diagnostic boundaries remains unknown. We aimed to map deviations from normative ranges of whole-brain major WM tracts for individual patients to investigate the similarity and differences among schizophrenia (281 patients subgrouped into the first-episode, subchronic and chronic phases), ASD (175 patients), and ADHD (279 patients). Sex-specific WM tract normative development was modeled from diffusion spectrum imaging of 626 typically developing controls (5-40 years). There were three significant findings. First, the patterns of deviation and idiosyncrasy of WM tracts were similar between schizophrenia and ADHD alongside ASD, particularly at the earlier stages of schizophrenia relative to chronic stages. Second, using the WM deviation patterns as features, schizophrenia cannot be separated from neurodevelopmental disorders in the unsupervised machine learning algorithm. Lastly, the canonical correlation analysis showed schizophrenia, ADHD, and ASD shared linked cognitive dimensions driven by WM deviations. Together, our results provide new insights into the neurodevelopmental facet of schizophrenia and its brain basis. Individual's WM deviations may contribute to diverse arrays of cognitive function along a continuum with phenotypic expressions from typical neurodevelopmental disorders to schizophrenia.

Differential neural processing of value during decision-making in adults with attention-deficit/hyperactivity disorder and healthy controls.

BACKGROUND: Risk-taking behaviours are observed among adults with attention-deficit/hyperactivity disorder (ADHD). We sought to evaluate altered neural processing of stimuli values associated with risk-taking decision behaviour, distinct from learning requirements, among adults with ADHD. METHODS: Overall, 32 adults with ADHD and 32 healthy controls without ADHD underwent a lottery choice task in a functional magnetic resonance imaging (fMRI) experiment. Participants accepted or rejected stakes with explicit information about variable probabilities of winning or losing points at different magnitudes. Outcomes were independent across trials, circumventing reward learning. Data analysis explored group differences in neurobehavioural responses to stimuli values during choice decision-making processing and outcome feedback. RESULTS: Compared with healthy controls, adults with ADHD had slower response times and tended to accept more stakes with a middle-to-low probability of winning. Adults with ADHD had evidence of lower dorsolateral prefrontal cortex (DLPFC) activity and reduced sensitivity in the ventromedial prefrontal cortex (VMPFC) region of interest in response to linear changes in probability, compared with healthy controls. Lower DLPFC responses were associated with lower VMPFC probability sensitivity and greater risk-taking among healthy controls but not adults with ADHD. Compared with health controls, adults with ADHD showed higher responses to loss outcomes in the putamen and hippocampus. LIMITATIONS: Assessments of real-life decision behaviours are required to further validate the experimental findings. CONCLUSIONS: Our findings explore tonic and phasic neural processing of value-related information that modulates risk-taking behaviours among adults with ADHD. Dysregulated neural computation of the values of behavioural actions and outcomes in the frontostriatal circuits may underlie decision processing distinct from reward learning differences among adults with ADHD. CLINICAL TRIAL REGISTRATION: NCT02642068.

Neural substrates of theory of mind in adults with autism spectrum disorder: An fMRI study of the social animation task.

BACKGROUND: Although the neural mechanisms of the theory of mind (ToM) in children with autism spectrum disorder (ASD) through fMRI using the social animation task have been investigated, little is known in adults with ASD. Therefore, the present study aimed to explore the neural substrates of ToM in adults with ASD. Moreover, we aimed to elucidate the relationship between brain activation and behavior of social interaction in adults with ASD. METHODS: Twenty-four healthy controls and 24 adults with the clinical diagnosis of ASD were recruited. Participants were asked to complete the social animation task in functional magnetic resonance imaging. The imaging analyses of within (whole brain analysis) and between (5 regions of interest) group comparisons were conducted to explore the process of ToM. The correlation analyses were further conducted to explore the relationship between neural activations associated with ToM and social interaction abilities assessed by ADI-R. RESULTS: The ASD group showed greater activation in the left precuneus and right superior temporal gyrus (STG) than the control group. For correlation analyses, greater right STG activation was positively correlated with autistic symptoms assessed by the ADI-R in the ASD group. CONCLUSION: ASD adults might spend a lot of effort on identification processing, thereby influencing social communication skills. Also, the neural deficits of ToM in ASD adults might be associated with their social interaction difficulties.

Prescribing patterns for attention deficit hyperactivity disorder among children and adolescents in Taiwan from 2004 to 2017.

This study documented the prescribing patterns of methylphenidate and atomoxetine among patients aged 3 to 18 in Taiwan diagnosed with attention deficit hyperactivity disorder (ADHD) between 2004 and 2017. Initial treatment for ADHD, the time between the first diagnosis and the first prescription, and medication-switching patterns were investigated. The final cohort consisted of 256,882 patients, and 147,210 (57.3%) of them received medication treatment. Most of the patients (98.2%) received methylphenidate. Atomoxetine use increased from 0.1% in 2007 to 5.5% in 2017. The median time between the ADHD diagnosis and the first prescription was 21 days (IQR: 0-212 days). In patients who initiated methylphenidate, 12,406 (8.4%) patients switched to atomoxetine; 850 (31.3%) of the children began with atomoxetine and switched to methylphenidate. In conclusion, methylphenidate was the predominant treatment for ADHD in 2004-2017. However, the prevalence of pharmacotherapy for ADHD was relatively low. Further investigation on the reasons behind this pattern is recommended.

Psychometric properties of the Mandarin version of the autism diagnostic observation Schedule-Generic.

BACKGROUND/PURPOSE: The diagnosis of autism spectrum disorder (ASD), involving multiple components of clinical assessments, is challenging. The Autism Diagnostic Observation Schedule-Generic (ADOS-G), one of the standardized and validated instruments for ASD diagnostic evaluation, has been widely used in many countries. With the preparation of the Mandarin version of the ADOS-G (Mandarin-ADOS-G), this study aims to examine its psychometric properties, including reliability and validity. METHODS: The sample included 554 individuals clinically diagnosed with ASD (477 males, 86.1%) and 50 typically developing (TD) individuals (29 males, 58.0%) who were assessed with different modules of the Mandarin-ADOS-G between 4.1 and 34.0 years old with a mean age of 13.0 years (Module 1, n = 40; Module 2, n = 46; Module 3, n = 275; Module 4, n = 243). We evaluated the inter-rater reliability, test-retest reliability, internal consistency, and concurrent validity with the Chinese Autism Diagnostic Interview-Revised (ADI-R) and Social Responsiveness Scale (SRS) caregiver-report and self-report forms. The discriminative validity of Mandarin-ADOS-G was also examined. RESULTS: The Mandarin-ADOS-G demonstrated good inter-rater reliability (agreement of ADOS classification 0.91), good test-retest reliability (intraclass correlations 0.55-0.73), and low to high good internal consistency (Cronbach's alpha 0.27-0.86). The concurrent validity showed significant correlations with ADI-R (Pearson correlations 0.22-0.37) and the SRS caregiver-report form (Pearson correlations 0.15-0.23). Moreover, all Mandarin-ADOS-G domains successfully differentiated autistic individuals from TD individuals (all p-values <0.001). CONCLUSION: The Mandarin-ADOS-G is a reliable and valid instrument for assisting the diagnosis of ASD in the Mandarin-speaking population.

Shared intrinsic functional connectivity alterations as a familial risk marker for ADHD: a resting-state functional magnetic resonance imaging study with sibling design.

BACKGROUND: Although aberrant intrinsic functional connectivity has been reported in attention-deficit/hyperactivity disorder (ADHD), we have a limited understanding of whether connectivity alterations are related to the familial risk of ADHD. METHODS: Fifty-three probands with ADHD, their unaffected siblings (n = 53) and typically developing controls (n = 53) underwent resting-state functional magnetic resonance imaging scans. A seed-based approach with the bilateral precuneus/posterior cingulate cortex (PCC) was used to derive a whole-brain functional connectivity map in each subject. The differences in functional connectivity among the three groups were tested with one-way ANOVA using randomized permutation. Comparisons between two groups were also performed to examine the increase or decrease in connectivity. The severity of ADHD symptoms was used to identify brain regions where symptom severity is correlated to the strength of intrinsic functional connectivity. RESULTS: When compared to controls, both probands and unaffected siblings showed increased functional connectivity in the left insula and left inferior frontal gyrus. The connectivity in these regions was linked to better performance in response inhibition in the control group but absent in other groups. Higher ADHD symptom severity was correlated with increased functional connectivity in bilateral fronto-parietal-temporal regions only noted in probands with ADHD. CONCLUSIONS: Alterations in resting-state functional connectivities with the precuneus/PCC, hubs of default-mode network, account for the underlying familial risks of ADHD. Since the left insula and left inferior frontal gyri are key regions of the salience and frontoparietal network, respectively, future studies focusing on alterations of cross-network functional connectivity as the familial risk of ADHD are suggested.

Altered gut microbiota correlates with behavioral problems but not gastrointestinal symptoms in individuals with autism.

BACKGROUND: Despite inconsistent results across studies, emerging evidence suggests that the microbial micro-environment may be associated with autism spectrum disorder (ASD). Geographical and cultural factors highly impact microbial profiles, and there is a shortage of data from East Asian populations. This study aimed to comprehensively characterize microbial profiles in an East Asian sample and explore whether gut microbiota contributes to clinical symptoms, emotional/behavioral problems, and GI symptoms in ASD. METHODS: We assessed 82 boys and young men with ASD and 31 typically developing controls (TDC), aged 6-25 years. We analyzed the stool sample of all participants with 16S V3-V4 rRNA sequencing and correlated its profile with GI symptoms, autistic symptoms, and emotional/behavioral problems. RESULTS: Autistic individuals, compared to TDC, had worse GI symptoms. There were no group differences in alpha diversity of species richness estimates (Shannon-wiener and Simpson diversity indices). Participants with ASD had an increased relative abundance of Fusobacterium, Ruminococcus torques group (at the genus level), and Bacteroides plebeius DSM 17135 (at the species level), while a decreased relative abundance of Ruminococcaceae UCG 013, Ervsipelotrichaceae UCG 003, Parasutterella, Clostridium sensu stricto 1, Turicibacter (at the genus level), and Clostridium spiroforme DSM 1552 and Intestinimonas butyriciproducens (at the species level). Altered taxonomic diversity in ASD significantly correlated with autistic symptoms, thought problems, delinquent behaviors, self dysregulation, and somatic complaints. We did not find an association between gut symptoms and gut microbial dysbiosis. CONCLUSIONS: Our findings suggest that altered microbiota are associated with behavioral phenotypes but not GI symptoms in ASD. The function of the identified microbial profiles mainly involves the immune pathway, supporting the hypothesis of a complex relationship between altered microbiome, immune dysregulation, and ASD that may advance the discovery of molecular biomarkers for ASD.

The norepinephrine transporter gene modulates intrinsic brain activity, visual memory, and visual attention in children with attention-deficit/hyperactivity disorder.

The norepinephrine transporter gene (SLC6A2) and deficits in visual memory and attention were associated with attention-deficit/hyperactivity disorder (ADHD). The present study aimed to examine whether the SLC6A2 rs36011 (T)/rs1566652 (G) haplotype affected the intrinsic brain activity in children with ADHD and whether these gene-brain modulations were associated with visual memory and attention in this population. A total of 96 drug-naive children with ADHD and 114 typically developing children (TDC) were recruited. We analyzed intrinsic brain activity with regional homogeneity (ReHo) and degree centrality (DC). Visual memory and visual attention were assessed by the delayed matching to sample (DMS) and rapid visual information processing (RVIP) tasks, respectively. The SNP genotyping of rs36011 and rs1566652 was performed. Children with ADHD showed lower ReHo and DC in the cuneus and lingual gyri than TDC. The TG haplotype was associated with significantly increased DC in the right precentral and postcentral gyri. Significant interactions of ADHD status and the TG haplotype were found in the right postcentral gyrus and superior parietal lobule for ReHo. For the ADHD-TG group, we found significant correlations of performance on the DMS and RVIP tasks with ReHo in bilateral precentral-postcentral gyri and the right postcentral gyrus-superior parietal lobule and DC in bilateral precentral-postcentral gyri. A novel gene-brain-behavior association was identified in which the intrinsic brain activity of the sensorimotor and dorsal attention networks was related to visual memory and visual attention in ADHD children with the SLC6A2 rs36011 (T)/rs1566652 (G) haplotype.

ADHD symptoms map onto noise-driven structure-function decoupling between hub and peripheral brain regions.

Adults with childhood-onset attention-deficit hyperactivity disorder (ADHD) show altered whole-brain connectivity. However, the relationship between structural and functional brain abnormalities, the implications for the development of life-long debilitating symptoms, and the underlying mechanisms remain uncharted. We recruited a unique sample of 80 medication-naive adults with a clinical diagnosis of childhood-onset ADHD without psychiatric comorbidities, and 123 age-, sex-, and intelligence-matched healthy controls. Structural and functional connectivity matrices were derived from diffusion spectrum imaging and multi-echo resting-state functional MRI data. Hub, feeder, and local connections were defined using diffusion data. Individual-level measures of structural connectivity and structure-function coupling were used to contrast groups and link behavior to brain abnormalities. Computational modeling was used to test possible neural mechanisms underpinning observed group differences in the structure-function coupling. Structural connectivity did not significantly differ between groups but, relative to controls, ADHD showed a reduction in structure-function coupling in feeder connections linking hubs with peripheral regions. This abnormality involved connections linking fronto-parietal control systems with sensory networks. Crucially, lower structure-function coupling was associated with higher ADHD symptoms. Results from our computational model further suggest that the observed structure-function decoupling in ADHD is driven by heterogeneity in neural noise variability across brain regions. By highlighting a neural cause of a clinically meaningful breakdown in the structure-function relationship, our work provides novel information on the nature of chronic ADHD. The current results encourage future work assessing the genetic and neurobiological underpinnings of neural noise in ADHD, particularly in brain regions encompassed by fronto-parietal systems.