The pattern of disease in the family was consistent with X-linked recessive inheritance. Researchers classified the newly identified variant as a variant of uncertain significance, meaning that the available evidence does not establish that it is pathogenic. The investigators combined clinical phenotyping, standardized olfactory testing, chromosome and copy-number analysis, targeted sequencing, a cell-based splicing assay, whole-blood RNA sequencing and quantitative reverse-transcription PCR.

Constitutional karyotypes were normal in both affected brothers, as were array comparative genomic hybridization results, and no clinically relevant copy-number changes were detected. The team also sequenced the coding regions and flanking sequences of all 14 ANOS1 exons and all four PROK2 exons. The ANOS1 variant had not previously been reported in ClinVar, dbSNP or gnomAD.

Computational tools including SIFT and PolyPhen-2 predicted that the substitution could be deleterious, but integrated interpretation under American College of Medical Genetics and Genomics and Association for Molecular Pathology criteria left the variant in the uncertain-significance category. Both affected brothers had micropenis, cryptorchidism and delayed puberty. Endocrine testing showed reduced testosterone, luteinizing hormone and follicle-stimulating hormone, together with blunted luteinizing hormone and follicle-stimulating hormone responses to gonadotropin-releasing hormone stimulation.

They also shared a narrow bitemporal diameter, epicanthal folds, facial asymmetry and antimongoloid palpebral fissures. The younger brother additionally had right renal agenesis, a supernumerary nipple and agenesis of the left maxillary second tooth. The mother had normal odor-identification performance.

Because this was a small family cohort, the clinical findings describe the phenotype observed in the two affected brothers but do not establish how much of the syndrome is attributable to the ANOS1 variant. Smell function was evaluated with the 12-item Odorized Markers Test, a standardized forced-choice procedure in which participants identify odors presented through pen-like devices. The older brother correctly identified four odors with each nostril and four when both nostrils were tested.

The younger brother identified four odors with the left nostril, six with the right and four during bilateral testing. These results were interpreted against age- and sex-adjusted Polish reference data derived from 9,139 subjects. Because the assessment measured odor identification rather than directly demonstrating complete absence of smell, the investigators described the brothers as having markedly impaired odor identification in the context of their reported anosmia, rather than definitively categorizing the results as normosmia, hyposmia or anosmia.

Magnetic resonance imaging of the olfactory bulbs was unavailable, leaving the study without direct anatomical evidence of olfactory-bulb abnormalities. The p.Cys151Ser substitution lies in exon 4 of ANOS1, within the whey acidic protein-like, or WAP, domain of anosmin-1. This extracellular glycoprotein contains a WAP domain with eight conserved cysteine residues forming a four-disulfide core, a structural feature considered important for proper folding and extracellular interactions.

The altered cysteine is one of those residues, and previous ANOS1 substitutions affecting other cysteines in the domain have been associated with impaired disulfide bonding and reduced protein stability. Those findings make the location of p.Cys151Ser biologically relevant, but the researchers did not directly measure disulfide formation, protein folding, secretion or interactions of the mutant protein with potential molecular partners. In silico predictions and the conserved position of the residue therefore supported further investigation rather than proving a functional mechanism.

Because ANOS1 expression was negligible in peripheral blood, the team could not directly assess splicing in patient-derived RNA. Instead, the investigators built minigene constructs containing intron 3, exon 4 and intron 4 of ANOS1 from either the patient or a control. These constructs were introduced into HEK293T and SH-SY5Y cells.

Reverse-transcription PCR produced a single product of the expected 1,130-base-pair size for both wild-type and mutant constructs, indicating that c.452G>C did not cause a detectable alteration in ANOS1 pre-mRNA splicing under the experimental conditions tested. The assay does not exclude effects on other expression mechanisms, including protein stability or secretion, and the two cell lines do not reproduce every feature of the developing olfactory and hypothalamic systems. Whole-blood RNA sequencing generated approximately 100 million paired-end reads per sample and compared the two affected brothers, one heterozygous female carrier and two unaffected controls.

No widespread gene-level differences met the adjusted significance threshold across the analyzed comparisons. ANOS1 abundance remained below 0.02 transcripts per million in every sample and was undetectable by quantitative reverse-transcription PCR, precluding reliable gene- and exon-level assessment of that gene in blood. Most of the selected candidate genes, including ANOS1, CCDC141, DUSP6, SMCHD1 and TCF25, did not show significant gene-level differences between affected individuals and controls.

By contrast, the combined affected-group comparison showed significantly higher PROK2 expression than the male control: 66.4 versus 34.28 fragments per kilobase per million, corresponding to approximately 1.94-fold upregulation and an FDR-adjusted P value of 0.00853. No significant differences in PROK2 exon usage were detected. Sanger sequencing of the PROK2 coding region and splice sites also found no sequence variants in either affected brother, indicating that the increased expression was not accompanied by a detectable coding or splice-site defect.

Reference-gene normalization used HPRT1 and TBP, and each reaction was performed in technical duplicates. Because the number of independent biological samples was small, the researchers did not perform inferential statistical testing on the reverse-transcription PCR data; they used the measurements to assess concordance with RNA sequencing. Semi-quantitative reverse-transcription PCR also found no major change in transcript size or pattern for PROK2.

Exon-level analysis identified reduced use of exon 3 in DUSP6 by approximately 2.3-fold, with an adjusted P value of 8.82 × 10−10, and moderate changes in several exonic regions of TCF25. These differences were not accompanied by consistent changes in overall expression and were not supported by quantitative reverse-transcription PCR for DUSP6 or by semi-quantitative reverse-transcription PCR for either gene. They may therefore represent subtle regulatory differences or technical artifacts rather than reproducible transcriptional changes.

The clearer transcriptomic observation was increased PROK2 abundance, which was detected by both RNA sequencing and quantitative reverse-transcription PCR but was not explained by detectable changes in PROK2 coding sequence, splice sites or exon usage. The interpretation remains constrained by the two patients being siblings, the small number of controls and the use of peripheral blood rather than disease-relevant neural tissue. Sampling time was not standardized, and inflammatory markers and leukocyte profiles were not systematically assessed.

Circadian phase, inflammation, blood-cell composition, pubertal state and treatment could therefore have influenced expression measurements. The related-network analysis found no direct ANOS1–PROK2 interaction. Instead, the two genes appeared within a broader network containing regulators of olfactory development and gonadotropin-releasing hormone neuron migration, including CHD7, FGFR1, FGF8 and PROKR2.

This network arrangement is consistent with possible pathway convergence, but it does not establish that ANOS1 dysfunction causes PROK2 upregulation or that the blood signal reflects events in the olfactory bulb and hypothalamus. Overall, the study provides a framework for testing how a primary ANOS1 variant might be accompanied by secondary changes in a functionally related pathway. The affected brothers carried a family-segregated variant affecting a structurally important part of anosmin-1, yet its clinical interpretation and biochemical effects remain uncertain.

Their shared increase in PROK2 was reproduced by two expression methods and was not explained by detectable PROK2 coding variants or altered exon usage. Whether the signal reflects a compensatory response, an indirect consequence of disrupted anosmin-1 signaling, or a feature of blood composition in this family cannot be settled by the present data. Replication in unrelated patients, together with neuronal, induced pluripotent stem-cell-derived or olfactory-cell models, will be needed to determine whether the proposed ANOS1–PROK2 relationship is reproducible and biologically relevant.

Subject of Research: Genetic and transcriptomic analysis of ANOS1-associated familial Kallmann syndrome

Article Title: ANOS1 variant and PROK2 upregulation in familial Kallmann syndrome: integrative genetic, transcriptomic, and phenotypic study

Article References: Bilińska, K., Gajewska, A., Hołub, K., Wojciechowski, P., de Castro, F., & Pasińska, M. (2026). ANOS1 variant and PROK2 upregulation in familial Kallmann syndrome: integrative genetic, transcriptomic, and phenotypic study. Frontiers in Molecular Neuroscience, 19, 1960672. https://doi.org/10.3389/fnmol.2026.1960672

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DOI: 10.3389/fnmol.2026.1960672

Keywords: Kallmann syndrome, ANOS1, PROK2, anosmia, hypogonadotropic hypogonadism, variant interpretation, RNA sequencing, gene regulation, neurodevelopment, variant, upregulation, familial

The study included neonates hospitalized with intraventricular hemorrhage, cerebral parenchymal hemorrhage, or both between 2015 and 2018. Of the 109 participants, 44, or 40.4%, had isolated intraventricular hemorrhage, 41, or 37.6%, had isolated cerebral parenchymal hemorrhage, and 24, or 22.0%, had combined intraventricular and parenchymal involvement. Moderate-to-severe imaging-defined post-hemorrhagic ventricular dilatation occurred in 61.4% of the isolated intraventricular hemorrhage group, 24.4% of the isolated parenchymal hemorrhage group, and 70.8% of the combined group. The severity differences among these groups were statistically significant, with a reported P value below 0.001, indicating an association between ventricular involvement and more severe ventricular enlargement in this cohort.

Clinical outcomes did not differ significantly among the three hemorrhage groups. Across the cohort, 41 neonates died, representing 37.6% of those studied; 21, or 19.3%, had a recorded neurodevelopmental abnormality; and 47, or 43.1%, had favorable outcomes. The overall distribution of outcomes among the hemorrhage groups was not significant, with a reported P value of 0.693. Multivariable logistic regression identified lower gestational age and higher clinical severity scores as factors independently associated with mortality. Thus, while hemorrhage distribution corresponded with the degree of ventricular dilatation, the analysis did not identify it as an independent correlate of death or neurodevelopmental abnormality.

The investigators also evaluated cerebrospinal fluid drainage and neurosurgical intervention. Either form of treatment was associated with lower odds of neurodevelopmental abnormality, with an odds ratio of 0.115, a 95% confidence interval of 0.022–0.595, and a P value of 0.010. This association cannot be interpreted as evidence that drainage or surgery prevented neurological impairment. The retrospective, single-center, nonrandomized design allowed selection and survivorship bias to influence which infants received particular interventions and which outcomes were observed, preventing causal or preventive-effect inferences. The confidence interval was also wide, reflecting uncertainty in the estimated association.

Brain imaging supplied complementary anatomical information for the assessment. Magnetic resonance imaging, performed in a subset of infants, additionally identified deep, posterior-fossa, subarachnoid, and small focal hemorrhagic lesions. The authors characterize ultrasound and MRI as complementary for evaluating neonatal brain injury and ventricular enlargement. Overall, the findings indicate that hemorrhage involving the ventricles identifies infants with a greater observed burden of significant ventricular dilatation, while gestational maturity and systemic disease burden remain important determinants of outcome. The evidence does not establish whether hemorrhage distribution independently affects survival or neurological development, nor whether cerebrospinal fluid-directed treatment improves those outcomes.

Subject of Research: Associations among hemorrhage distribution, post-hemorrhagic ventricular dilatation, and outcomes in neonates with intraventricular or cerebral parenchymal hemorrhage.

Article Title: Hemorrhage distribution, imaging-defined post-hemorrhagic ventricular dilatation, and clinical outcomes in neonates with intraventricular and cerebral parenchymal hemorrhage: a single-center retrospective cohort study

Article References: Zhang, X., Cai, Y., Huang, S., Shi, H., Chen, L., Wu, S., & Xiang, Y. (2026). Hemorrhage distribution, imaging-defined post-hemorrhagic ventricular dilatation, and clinical outcomes in neonates with intraventricular and cerebral parenchymal hemorrhage: a single-center retrospective cohort study. Frontiers in Pediatrics, 14, Article 1965213. https://doi.org/10.3389/fped.2026.1965213

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DOI: 10.3389/fped.2026.1965213

Keywords: neonatal brain hemorrhage, intraventricular hemorrhage, cerebral parenchymal hemorrhage, post-hemorrhagic ventricular dilatation, neonatal mortality, neurodevelopment, cranial ultrasound, brain MRI, Hemorrhage, distribution, imaging-defined, post-hemorrhagic

Researchers used data from the EPIPAGE-2 population-based cohort, which included liveborn infants delivered at 22 to 34 weeks’ gestation in 2011. The children were followed to five years of age, and neurodevelopmental outcomes were assessed at two years’ corrected age and at five years. In unadjusted analyses, exposure to maternal autoimmune disease was initially associated with more impaired personal-social skills on the Ages & Stages Questionnaire at two years and a lower prevalence of high scores on the Social Communication Questionnaire at five years. Neither association remained statistically significant after adjustment.

Adjusted analyses also showed no significant association between maternal autoimmune diseases and global developmental delay, autism spectrum disorder risk or behavioral difficulties at two or five years. Subgroup analyses divided by gestational age and by exposure to immunosuppressive therapy did not identify an increased risk. These subgroup results should be interpreted in light of the small number of exposed children, which limited the statistical precision of the assessments.

The study examined a question arising because maternal immune activation and preterm birth have each been associated with increased autism spectrum disorder risk, while their combined influence in preterm children was unclear. The EPIPAGE-2 findings do not support evidence that maternal autoimmune disease during pregnancy increased the early behavioral or social communication difficulties measured in this cohort. The authors cautioned that the conclusion is not definitive: only 155 children were exposed, the exposed group predominantly included children whose mothers had endocrine autoimmune diseases, and the study lacked immune activation biomarkers. Larger studies with more diverse exposure groups and direct immunological measurements are therefore needed to clarify whether the observed null associations reflect a genuine absence of relationship or limited statistical power.

Subject of Research: Maternal autoimmune disease and neurodevelopmental outcomes in a French cohort of preterm children

Article Title: Exploring the effect of maternal autoimmune diseases on behavioral and social difficulties risk in children born preterm: evidence from EPIPAGE-2 study

Article References: Ellul, P., Marchand-Martin, L., Salmon, F., Ancel, P.-Y., Pierrat, V., & Letouzey, M. (2026). Exploring the effect of maternal autoimmune diseases on behavioral and social difficulties risk in children born preterm: evidence from EPIPAGE-2 study. Translational Psychiatry. https://doi.org/10.1038/s41398-026-04534-0

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DOI: 10.1038/s41398-026-04534-0

Keywords: maternal autoimmune disease, preterm birth, EPIPAGE-2, neurodevelopment, behavioral difficulties, social communication, autism spectrum disorder, developmental delay, maternal immune activation, French cohort, Exploring, effect

Tic disorders, including Tourette syndrome, persistent motor or vocal tic disorder and provisional tic disorder, are neurodevelopmental conditions marked by sudden, rapid, recurrent and non-rhythmic movements or vocalizations that begin during childhood or adolescence. Their expression can change in frequency, intensity, distribution and complexity across the day and across settings. This variability makes a single clinical observation an incomplete representation of a child’s condition. Although characterizing tic type, frequency, intensity, complexity and interference remains essential for diagnosis, differential diagnosis, monitoring and treatment decisions, the most conspicuous symptom may not be the most clinically important one.

The first domain of the proposed framework is observable tic phenomenology and severity. Clinicians can characterize motor and phonic tics using the Yale Global Tic Severity Scale, which separately rates motor and vocal phenomena and includes an impairment component. Parent-reported questionnaires such as the Parent Tic Questionnaire may provide complementary information about tic frequency and intensity. However, the scale’s total tic score primarily quantifies tic characteristics rather than comprehensively measuring overall functioning, participation, adaptive functioning or quality of life. Tic expression may increase or decrease with fatigue, emotional arousal, attentional demands, social settings and opportunities for suppression. A consultation therefore provides only a sample of a child’s tic repertoire and may underestimate or occasionally overestimate its usual expression. Information from children, parents and schools, together with longitudinal history and, when appropriate, brief videos obtained in everyday contexts, may provide a more representative picture.

The second domain turns to the child’s internal experience of tics. Premonitory sensations may feel like tension, pressure, itching, a build-up of energy, incompleteness or a “not just right” state. Such sensations are conceptually distinct from more persistent sensory hypersensitivity. Rating instruments can help characterize urges, but younger children may have limited language, body awareness or metacognitive abilities that affect their capacity to identify and describe internal sensations. Limited reporting of premonitory sensations should therefore not automatically be interpreted as their absence. Tic suppression is similarly more complex than a simple measure of voluntary control. Experimental studies indicate that children and adolescents can reduce observable tics through reinforced suppression without a parallel reduction in premonitory sensations. Suppressibility varies across individuals, tics, contexts, attentional resources and environmental conditions, and observable suppression may conceal rather than eliminate the effort involved. Group studies do not consistently demonstrate clinically meaningful attentional fatigue, impaired concentration, executive overload or delayed functional consequences.

Physical and emotional consequences also belong in this domain. Forceful or repetitive movements may cause musculoskeletal discomfort, injury, headache or local pain, while self-injurious tics or repeated vocalizations may produce additional physical distress. Pain is recognized as clinically relevant in Tourette syndrome but remains incompletely represented in commonly used tic outcome measures. Subjective experience may also include embarrassment, stigma-related distress, fear of others’ reactions and the perceived effort involved in managing or concealing tics. These experiences may not be inferred from visible tic expression and should be explored directly with the child. Pain, distress and suppression effort should be distinguished from tic frequency because the number of movements does not itself describe their functional importance.

The third domain covers the broader neurological, neurodevelopmental and psychiatric profile. Attention-deficit/hyperactivity disorder, obsessive-compulsive symptoms, anxiety, depression, emotional dysregulation and sleep difficulties are established contributors to daily functioning and quality of life in tic disorders. Assessment should not stop at categorical diagnoses, because subthreshold difficulties may still affect learning, relationships and self-regulation. Initial inquiries may combine standardized parent and teacher questionnaires with self-report from children or adolescents when developmentally appropriate. If first-level assessment identifies persistent or functionally relevant concerns, more detailed evaluation can use neuropsychological tests, structured psychopathological assessment, standardized motor assessment or formal sensory assessment according to the area of concern.

Motor coordination, neurological soft signs, sensory processing and executive functioning may also contribute independently of tic severity, but the supporting evidence is uneven. Soft signs—including overflow movements, subtle abnormalities of balance or gait, mild tone changes and dysmetria—are generally regarded as markers of neurodevelopmental variability rather than disorder-specific abnormalities. Studies have reported motor and neurological soft-sign differences in children with tic disorders, yet the available evidence does not establish a robust, disorder-specific phenotype. Coordination, balance, motor planning, visuomotor integration, rhythm and fine-motor difficulties warrant further attention when they arise in the history or examination and are associated with functional consequences. Sensory processing deserves focused consideration when persistent hypersensitivity or difficulty filtering or adapting to environmental stimuli extends beyond tic-specific premonitory urges. Studies have associated sensory dysregulation with executive difficulties and comorbidity, but relationships among sensory profiles, tic severity and premonitory urges remain heterogeneous, and a disorder-specific sensory phenotype has not been established.

Executive difficulties may also contribute to everyday impairment, particularly in the presence of ADHD. Meta-analytic evidence suggests that inhibitory-control differences in Tourette syndrome are generally small to moderate and strongly influenced by comorbid ADHD. More detailed assessment may be appropriate when difficulties involving attention, working memory, flexibility, planning, automatization or self-regulation emerge from the history, observation or school functioning and affect daily performance or treatment planning. Whether adequate performance on structured tasks relies on increased attentional or compensatory resources in some children remains insufficiently established, and routine neuropsychological testing is not indicated for every child with tics. Importantly, abnormal neurological findings or reduced performance on standardized motor or neuropsychological measures do not by themselves establish clinically meaningful impairment. Their relevance must instead be judged in relation to everyday functioning and participation.

The framework uses functional outcomes as transversal measures through which findings in all three domains are judged. The authors distinguish several related constructs. Symptom severity describes the characteristics of a symptom itself; neurological or neuropsychological performance refers to findings obtained through examination or standardized tasks; functional impairment concerns interference with age-appropriate activities; adaptive functioning refers to age-appropriate conceptual, social and practical independence; participation concerns involvement in life situations; and health-related quality of life reflects perceived physical, emotional, social and functional wellbeing. These constructs may overlap but are not interchangeable. Functional impact should be assessed across informants and contexts because children, parents and schools may provide complementary perspectives according to environmental demands, opportunities for suppression and social responses. Child and parent reports should be considered jointly, and disagreements may be clinically informative. Self-rated and parent-proxy assessments of health-related quality of life are not fully interchangeable in adolescents with Tourette syndrome.

Functional consequences may arise from any of the three domains. Tics may interfere directly with school or social activities; premonitory sensations, pain, embarrassment or suppression effort may contribute to distress, avoidance or concealment; and psychiatric, motor, sensory or executive characteristics may independently affect learning, relationships, autonomy or participation. The central functional question is what currently limits the child’s everyday functioning, participation, wellbeing or developmental opportunities. The intended result is selective prioritization rather than exhaustive testing. Assessment should focus on findings with meaningful functional consequences, and clinical priorities should be determined by modifiable factors associated with those consequences rather than by tic visibility alone. Mild, non-painful and minimally interfering tics may require only psychoeducation, monitoring and environmental adjustments, whereas other manifestations may warrant more focused evaluation or intervention. Children, caregivers, teachers and clinicians may assign different importance to the same manifestations, making shared and revisable decision-making important. Treatment goals may extend beyond tic reduction to reduced pain, distress, avoidance, stigma or effort and improved participation.

Because the clinical relevance of the three domains can change with development and context, reassessment should focus on whether the child is functioning better, not simply whether tics are less frequent. The accompanying clinical interview guide is a qualitative orientation tool for child- and caregiver-centered exploration; it is not a validated screening, diagnostic, severity or scoring instrument and does not validate the framework. Empirical evaluation is still required. Future studies could examine whether the framework helps clinicians organize information, identify priorities missed by tic-severity measures and support individualized assessment and treatment planning. Qualitative studies could assess its acceptability and usefulness across clinical settings and developmental stages, while longitudinal research could test whether identified priorities relate to functioning, participation, quality of life, treatment response and developmental trajectories. The broader evidence also requires caution: psychiatric comorbidities have well-established links to daily outcomes, whereas evidence concerning neurological soft signs, motor coordination, sensory processing and possible compensatory executive costs remains limited or inconsistent.

Subject of Research: A clinical framework for assessing functional burden in children with tic disorders

Article Title: When tics are not the whole story: rethinking clinical assessment in children with tic disorders

Article References: Magostini, F., & Capuano, A. (2026). When tics are not the whole story: rethinking clinical assessment in children with tic disorders. Frontiers in Neurology, 17, Article 1971225. https://doi.org/10.3389/fneur.2026.1971225

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DOI: 10.3389/fneur.2026.1971225

Keywords: tic disorders, Tourette syndrome, children, clinical assessment, tic severity, premonitory urges, functional impairment, neurodevelopment, psychiatric comorbidity, quality of life, tics, whole

The research team, led by investigators affiliated with West China Hospital of Sichuan University, recruited 49 patients with first-episode, drug-naïve major depressive disorder and 35 healthy controls. Restricting the comparison to people who had never received antidepressant medication was a deliberate methodological choice, because drugs such as selective serotonin reuptake inhibitors are known to alter both gut microbial composition and epigenetic marks. By studying participants before any pharmacological intervention, the researchers aimed to capture biological signals more closely tied to the illness itself rather than to its treatment.

To quantify circadian disruption, the team used the Munich Chronotype Questionnaire, a validated self-report instrument that characterizes individual differences in sleep timing. Two derived metrics anchored the analysis: corrected mid-sleep time on free days, which estimates a person’s internal sleep phase once the constraints of workdays are removed, and social jetlag, which measures the mismatch between that internal timing and the schedule imposed by social obligations. Social jetlag has attracted increasing attention in chronobiology because it captures a form of chronic circadian misalignment that is common in modern life and has been linked to metabolic and mood disturbances in prior research.

The microbial arm of the study relied on shotgun metagenomic sequencing of fecal samples, a technique that reads the collective genomes of gut bacteria directly rather than profiling only a marker gene. This approach allows researchers to characterize microbial communities at higher resolution than targeted amplicon sequencing. Meanwhile, the epigenetic arm used reduced-representation bisulfite sequencing on peripheral blood DNA, a method that enriches for regions dense in CpG sites, the cytosine-guanine sequences where methylation changes most often influence gene regulation. Bisulfite treatment converts unmethylated cytosines into uracil, allowing methylation status at individual sites to be read out across the genome.

The first major finding concerned community structure rather than richness. Alpha diversity, which measures the number and evenness of microbial species within a single individual, was comparable between patients and controls. Beta diversity, by contrast, which quantifies differences in community composition between individuals, revealed significantly distinct gut microbial communities in the depressed group. In practical terms, patients did not necessarily carry fewer microbial species, but the identity and relative abundance of those species differed in ways that separated them from healthy participants.

To make sense of the high-dimensional microbial data, the researchers applied weighted gene co-expression network analysis, a computational framework originally developed for genomics that groups correlated features into modules and tests whether module-level behavior tracks clinical variables. When applied to the metagenomic profiles, this approach detected microbial modules whose abundance patterns were significantly correlated with the circadian parameters, suggesting that the relationship between sleep timing and gut ecology is not scattered across individual taxa but organized into coherent community-level signatures.

The methylation analysis yielded an even larger signal. Reduced-representation bisulfite sequencing identified 9,749 differentially methylated genes in the depression group, and gene ontology and KEGG pathway analyses showed that these genes were enriched in neural-related pathways, including processes tied to neurodevelopment and synaptic function. The authors are careful to frame this appropriately: peripheral blood methylation does not directly mirror methylation in brain tissue, and the enrichment patterns provide hypothesis-generating evidence for systemic associations rather than proof that the observed epigenetic changes reflect what is happening in the central nervous system.

The most striking result emerged when the three data layers were integrated. Correlation analyses linking the microbial modules, the circadian metrics, and the methylation data identified nine key metagenomic operational taxonomic units that were simultaneously associated with circadian rhythm measures and with the methylation rates of 898 differentially methylated genes related to neurodevelopment and synaptic function. This tripartite overlap is what elevates the study beyond parallel descriptions of three altered systems. It proposes a specific, testable network in which sleep timing, particular gut microbes, and the epigenetic regulation of neural genes are interconnected in depression.

Several biological mechanisms could plausibly underlie such a network. Gut microbes produce and modulate short-chain fatty acids, metabolites that influence both host metabolism and epigenetic machinery, since butyrate in particular is known to inhibit histone deacetylases and thereby affect chromatin state. Circadian disruption can alter gut microbial rhythms through feeding time and stress hormone fluctuations, and the hypothalamic-pituitary-adrenal axis provides a well-documented channel through which circadian and microbial signals can influence systemic physiology, including immune and epigenetic processes. The study was not designed to test these mechanisms directly, but the observed correlations are consistent with such frameworks.

The authors and the data itself are explicit about the study’s limits. It is a cross-sectional pilot with a modest sample size, meaning it captures associations at a single point in time and cannot establish whether circadian disruption drives microbial change, whether microbial metabolites shape methylation, whether methylation influences mood symptoms, or whether all three reflect a shared upstream cause. The findings are best read as a preliminary multi-omic network hypothesis, a map of candidate relationships that now invites longitudinal follow-up, mechanistic experiments in model systems, and replication in larger and more diverse cohorts. If the network holds up, it could point toward interventions that target sleep timing and gut ecology as complementary levers in depression care.

Subject of Research: Multi-omics associations among circadian rhythm disruption, gut microbiota, and DNA methylation in major depressive disorder

Article Title: Associations between circadian rhythm disruption, specific gut microbiota, and DNA methylation in major depressive disorder: a pilot study

Article References: Fan, H., Wang, Y., Guan, X., Yuan, Y., Xie, Q., & Dong, Z. (2026). Associations between circadian rhythm disruption, specific gut microbiota, and DNA methylation in major depressive disorder: a pilot study. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08619-4

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DOI: 10.1186/s12888-026-08619-4

Keywords: major depressive disorder, circadian rhythm, gut microbiota, DNA methylation, social jetlag, shotgun metagenomics, reduced-representation bisulfite sequencing, WGCNA, multi-omics, epigenetics, psychiatry, neurodevelopment

Insight in psychiatry refers to a patient’s recognition that they are ill, that their unusual experiences are symptoms of a disorder, and that treatment is needed. It is measured in the study using the Birchwood Insight Scale, a brief instrument that scores three dimensions: awareness of illness, attribution of symptoms to that illness, and the perceived need for treatment. Poor insight is one of the strongest predictors of medication non-adherence, relapse, and poor prognosis in schizophrenia, yet its biological roots have remained murky. Twin and family studies hinted that insight is partly heritable, and earlier work had flagged variants in two genes—SOX2-OT and DISC1—as candidates. What was missing was direct evidence that a specific variant actually influences clinical outcomes through insight, rather than merely correlating with it.

To close that gap, the researchers enrolled 233 patients experiencing their first episode of schizophrenia, all of whom were free of antipsychotic medication at baseline. Studying first-episode, drug-naive patients is a methodological advantage: it removes the confounding effects of prior treatment histories, chronicity, and medication-induced changes that plague studies of long-standing illness. Each patient was genotyped for five single-nucleotide polymorphisms previously implicated in insight: rs1479165 in the SOX2-OT locus, and four variants in the DISC1 gene (rs821616, rs821597, rs821633, and rs6675281). Insight was assessed before treatment began, and response was quantified as the percentage reduction in total score on the Positive and Negative Syndrome Scale (PANSS) after eight weeks of standard antipsychotic therapy.

The genetic signal was striking and unambiguous. Carrying the C allele of SOX2-OT rs1479165 was significantly associated with better insight at baseline, with an effect size of β = 2.03 and a p-value below 0.001. In other words, patients who inherited this variant scored measurably higher on the Birchwood Insight Scale before ever taking a single dose of medication. By contrast, the four DISC1 variants told a messier story: their individual associations with insight pointed in inconsistent directions, and when the researchers aggregated them, no significant combined genetic effect emerged. This asymmetry matters, because DISC1 has long been a celebrated candidate gene in schizophrenia research, and the new results suggest that, at least for insight, its contribution may be weaker or more heterogeneous than the SOX2-OT signal.

The second link in the chain was equally firm. Baseline insight scores significantly predicted how much patients improved on antipsychotics, with each unit of the Birchwood Insight Scale associated with a β = 3.175 increase in PANSS reduction rate (p < 0.001). Patients who understood their illness better at the outset tended to experience greater symptom relief over the eight-week treatment period. That observation alone would be clinically useful, but the study went further, asking whether the genetic variant’s apparent effect on treatment response actually flows through insight—a question answered with formal mediation analysis.

Mediation analysis is a statistical technique for decomposing an effect into direct and indirect pathways. Here, the indirect pathway—the average causal mediation effect, or ACME—was 6.11, with a 95 percent confidence interval of 3.93 to 8.43 and a p-value below 0.001. The mediation proportion, meaning the fraction of the genetic variant’s total effect on treatment response that is explained by insight, was a remarkable 78.1 percent. In plain terms, roughly three-quarters of the way in which this DNA variant relates to how well a patient responds to antipsychotics appears to operate by shaping the patient’s insight into their own illness. This is, according to the authors, the first time such a complete mechanistic pathway—from genotype, through a clinical cognitive phenotype, to treatment outcome—has been demonstrated in schizophrenia.

But a statistical chain is only as credible as its biology, and the team pursued two independent lines of molecular evidence to give the association a plausible mechanism. The first came from expression quantitative trait locus, or eQTL, analysis using the GTEx v8 database, a large public resource that catalogs how genetic variants influence gene expression across human tissues. The analysis revealed that the effect allele of rs1479165 increases the expression of RP11-275H4.1, a transcript belonging to the SOX2-OT long non-coding RNA, across twelve brain regions. The strongest effects appeared in the hippocampus, the caudate nucleus, and the prefrontal cortex—three structures with well-established roles in memory, reward processing, self-referential thinking, and the higher-order cognition that underlies something as introspective as illness awareness.

The second line of evidence came from the STRING protein–protein interaction network, a computational map of known and predicted functional relationships among genes and their protein products. When the researchers placed SOX2-OT within this network, it turned out to be embedded in a transcriptional regulatory hub centered on some of the most famous genes in developmental biology: SOX2, POU5F1 (also known as OCT4), NANOG, KLF4, CTNNB1, and PAX6. These factors govern neural stem cell maintenance and cell fate commitment—the molecular decisions that determine what a developing neural cell will become. The enrichment was highly significant for pathways of neurodevelopment and neural plasticity, suggesting that the genetic variant may act through a region-specific transcriptional cascade that subtly shapes brain circuits during development, with downstream consequences for how insight emerges—and how treatment unfolds—years later.

The study also carries a demographic significance that the authors emphasize. Most genetic findings in psychiatry are first established in European-ancestry populations, and their replication elsewhere is never guaranteed. This is the first independent validation of the association between SOX2-OT rs1479165 and insight in non-European individuals with schizophrenia, and the fact that the signal survived in a Chinese cohort strengthens the case that the finding reflects a general biological mechanism rather than a population-specific artifact. The work was approved by the Ethics Committee of Huai’an No. 3 People’s Hospital, conducted under the Declaration of Helsinki, and supported by the Huai’an Natural Science Research Program and the Huai’an Basic Research Program.

The clinical implications are tantalizing, though the authors are careful about what the data can and cannot support. If insight is a genetically influenced, measurable phenotype that mediates treatment response, then insight itself becomes a legitimate therapeutic target—something clinicians might assess early, monitor over time, and address with psychoeducational or cognitive interventions designed to improve illness awareness. Poor insight, in this framing, is not a character flaw or an untouchable symptom but a partially biological, partially modifiable state sitting squarely on the causal path between a patient’s genome and their recovery. At the same time, the study is observational, the mediation analysis captures statistical pathways rather than proven causation, and a single variant explains only a slice of the enormous variability in antipsychotic response. The DISC1 results are a reminder that candidate-gene findings can be fragile. Still, by knitting together genetics, brain expression data, network biology, and a longitudinal clinical outcome in one coherent narrative, the study offers something psychiatry has long sought: a concrete, testable model of how a risk variant becomes a treatment-relevant phenotype. For the 233 patients whose data made it possible, and for the millions with schizophrenia worldwide, it suggests that the road to better treatment response may begin with something as deceptively simple as knowing that one is ill.

Subject of Research: The mediating role of insight impairment in the effect of the SOX2-OT rs1479165 polymorphism on antipsychotic response in first-episode schizophrenia.

Article Title: Insight impairment mediates the effect of SOX2-OT polymorphism on antipsychotic response in first-episode schizophrenia

Article References: Zhuang, L., Sun, T., Shi, W., Feng, H., Wang, C., Cheng, J., Huang, C., & Zhang, X. (2026). Insight impairment mediates the effect of SOX2-OT polymorphism on antipsychotic response in first-episode schizophrenia. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08590-0

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08590-0

Keywords: schizophrenia, insight impairment, SOX2-OT, antipsychotic response, mediation analysis, eQTL, DISC1, neurodevelopment, Birchwood Insight Scale, PANSS, first-episode psychosis, pharmacogenetics

Gestational diabetes is defined as diabetes first diagnosed or recognized during pregnancy, and it is among the most common metabolic complications of gestation. According to the Developmental Origins of Health and Disease (DOHaD) concept, adverse conditions during sensitive windows of fetal development can trigger long-lasting structural and functional adaptations that shape health across the lifespan. In pregnancies complicated by GDM, the fetus is bathed in an altered metabolic milieu: maternal glucose crosses the placenta freely, potentially driving fetal hyperglycemia and compensatory fetal hyperinsulinemia, while lipid disturbances, altered adipokine and cytokine concentrations, oxidative stress, and changes in placental nutrient transfer add further layers of complexity. These effects need not be visible at birth; they may only surface later in childhood, when neurodevelopmental demands become more intricate.

There is now a growing body of neuroimaging evidence pointing to structural differences in the brains of children exposed to maternal diabetes in utero. Studies have reported reduced cortical thickness in the occipital lobes, the right postcentral gyrus, and the left superior parietal cortex among preadolescent children, along with selective morphological and volumetric changes in the hippocampus, microstructural white matter abnormalities in infants, and reduced cortical excitability and neuroplasticity in children aged 11 to 13. Because successful motor performance requires the coordinated interaction of motor planning and execution, sensory feedback, visuomotor processing, and postural control, gross motor abilities serve as a sensitive neurodevelopmental indicator. Motor and cognitive development are closely intertwined, especially for complex tasks that cannot be completed without typical cognitive functioning, making motor assessment a practical window onto whether an altered fetal metabolic environment is associated with long-term developmental outcomes.

The new study is a 10-year follow-up of a prospectively established cohort in which fetal neurobehavior had previously been assessed. The original sample comprised pregnant women with singleton pregnancies between 32 and 38 weeks of gestation: 82 women diagnosed with GDM and 82 women with uncomplicated pregnancies and normal oral glucose tolerance test results. GDM was diagnosed using a 75-g OGTT according to the HAPO criteria, with fasting plasma glucose of at least 5.1 mmol/L, 1-hour plasma glucose of at least 10.0 mmol/L, and 2-hour plasma glucose of at least 8.5 mmol/L. Critically, all women with GDM were managed with dietary treatment only, and none received insulin therapy, meaning the cohort represents the milder end of the disease spectrum. Fetal neurobehavior was evaluated during the third trimester using the modified Kurjak Antenatal Neurodevelopmental Test (KANET) with four-dimensional ultrasound, which enables standardized evaluation of both the quantity and quality of fetal movements, from isolated head anteflexion and eye blinking to hand-to-face movements and the overall impression of general movements. The fetal assessor was blinded to GDM exposure status.

At the 10-year follow-up, 55 of the original 82 GDM-exposed families and 54 of the 82 unexposed families could be contacted, corresponding to contact rates of 67.1 and 65.9 percent. After exclusions for genetic developmental difficulties, perinatal or postnatal complications, or acquired impairments, the final sample comprised 50 children in each group. The GDM-exposed group included 36 girls and 14 boys, while the unexposed group included 20 girls and 30 boys, an imbalance that reflects the composition of the original cohort rather than sex-based selection. The children’s mean age was 10 years, with a range from 9 years and 3 months to 11 years and 1 month, deliberately before pubertal maturation typically introduces substantial biological and psychomotor changes that would complicate interpretation. Importantly, the two groups did not differ in anthropometric characteristics, including body weight, height, and body fat percentage.

Gross motor functioning was assessed across six domains: coordination, agility, flexibility, explosive strength, muscular endurance, and balance. Coordination was measured with the Backwards Obstacle Course and Ball Rolling with the Non-Dominant Hand tests, agility with the Side Steps and Shuttle Run Transfer tests, flexibility with the Straddle Forward Bend and Bench Forward Bend tests, explosive strength with the Standing Long Jump and 20-meter Sprint, and muscular endurance with the Sit-Up and Squat tests, all drawn from the CROFIT norm battery. Balance was assessed separately using quiet standing with eyes closed on a specially designed unstable platform, with the Gyko inertial sensor system recording platform displacement path length, velocity, mean distance, mean frequency, and root mean square distance. The kinesiologist conducting the childhood assessments was blinded to prenatal GDM exposure status.

Because several motor outcomes deviated from normality and subgroup sizes were relatively small, the researchers employed an Aligned Rank Transform (ART) factorial ANOVA to examine the effects of group, sex, and the group-by-sex interaction, with effect sizes expressed as partial eta squared. Benjamini-Hochberg false discovery rate (FDR) correction was applied to the p-values for the main effect of group to account for multiple comparisons, performed separately for the motor performance outcomes and the five balance parameters derived from the same quiet-standing assessment. A post hoc power analysis showed that the final sample of 100 participants provided a statistical power of 0.74 for detecting a medium effect size, below the conventional threshold of 0.80, so non-significant findings were interpreted cautiously.

The headline result is one of reassurance with nuance. Gross motor functioning was largely comparable between the groups, with no significant main effect of group for sprint, standing long jump, lateral steps, shuttle run, sit-ups, backward obstacle course, bench forward bend, or any of the balance parameters. However, three specific motor tasks remained statistically significant after FDR correction: children in the GDM-exposed group performed poorer in squats (FDR-adjusted p = 0.027, partial eta squared = 0.079) and ball rolling with the non-dominant hand (FDR-adjusted p = 0.001, partial eta squared = 0.152), while they performed better in the straddle forward bend (FDR-adjusted p = 0.027, partial eta squared = 0.072). The magnitude of the group effects was moderate for squats and the straddle forward bend and large for ball rolling with the non-dominant hand. Sex showed significant main effects for several motor outcomes, and significant group-by-sex interactions were observed for sprint, shuttle run, and ball rolling, highlighting the importance of considering sex when interpreting motor performance in this age group.

The task-specific pattern is what makes these findings scientifically intriguing. No difference was found in coordination during the backward obstacle course, yet the GDM group achieved a poorer result when rolling a ball with the non-dominant hand. Rolling a ball with the non-dominant hand requires coordination of the upper limbs, continuous adjustment of movement direction and intensity, spatial orientation, visual tracking, and control of the non-dominant side of the body, placing greater demands on visuomotor integration and bimanual organization of movement. This interpretation is partly consistent with earlier work by Bolaños and colleagues, who reported poorer graphic, spatial, and bimanual abilities and a higher frequency of minor neurological signs among school-aged children born from GDM pregnancies. Similarly, in muscular endurance, no difference emerged in sit-ups, but the GDM group completed significantly fewer squats within one minute, a task involving repeated dynamic activation of the lower-limb and trunk muscles, postural control, and effective temporal and spatial organization of a repeated movement pattern. The better straddle forward bend performance was unexpected, particularly because no significant difference was found in the bench forward bend; the two protocols are performed from different starting positions and may not reflect the same components of flexibility equally. One potential, though still insufficiently studied, biological factor is the hormone relaxin, which remodels connective tissue and collagen. Numerically higher plasma relaxin concentrations have been observed in women with GDM, and higher relaxin-2 levels correlated with C-peptide concentrations in early GDM, but whether altered maternal relaxin during pregnancy can affect fetal connective and musculoskeletal development is unknown, so this remains a biological hypothesis rather than an explanation of the results.

The authors emphasize that these findings do not indicate generalized gross motor impairment but suggest that prenatal exposure to the metabolic environment associated with GDM may be related to subtle, task-specific differences in motor functioning that remain detectable during school age. The encouraging absence of differences in most abilities does not support the assumption of a general motor deficit later in childhood. Still, the study has limitations: the sex distribution differed between groups, the GDM-exposed group included only diet-treated pregnancies so findings may not generalize to more severe or insulin-treated GDM, and the long interval between fetal assessment and follow-up without intermediate developmental assessments means individual trajectories could not be reconstructed. Confounders such as socioeconomic status, maternal pre-pregnancy BMI, gestational weight gain, and maternal education were not included in the analyses. The researchers suggest that more detailed monitoring of motor functioning may be useful for children born from GDM pregnancies who also show coordination difficulties, reduced motor competence, or lower participation in physical activities, and that regular, developmentally appropriate, structured activities focusing on coordination, balance, movement control, and muscular endurance should be provided to those with difficulties. Further longitudinal research with larger samples and detailed information on maternal metabolic factors, physical activity, and neurodevelopmental functioning is needed to determine the developmental stability and clinical relevance of these outcomes.

Subject of Research: A 10-year follow-up study finds mostly comparable gross motor function at age ten in children prenatally exposed to diet-treated gestational diabetes, with subtle task-specific differences in squats, non-dominant hand ball rolling, and straddle forward bend flexibility.

Article Title: Fetal behavior as a window to later gross motor function: a 10-year follow-up of children prenatally exposed to gestational diabetes mellitus

Article References: Vasilj, O., Marinić, D., Trošt, T., & Žeželj, Z. (2026). Fetal behavior as a window to later gross motor function: a 10-year follow-up of children prenatally exposed to gestational diabetes mellitus. Frontiers in Clinical Diabetes and Healthcare, 7, Article 1938676. https://doi.org/10.3389/fcdhc.2026.1938676

Image Credits: AI Generated

DOI: 10.3389/fcdhc.2026.1938676

Keywords: gestational diabetes, fetal behavior, gross motor development, neurodevelopment, DOHaD, pediatric health, longitudinal study, kinesiology, Fetal, behavior, window, later

The developmental sequence at the heart of SPP is explicitly directional. It begins with somatic organization: the alignment, mobility, and coordination of axial and appendicular musculoskeletal structures, together with the mechanical, metabolic, and humoral environment surrounding peripheral autonomic pathways. From there, the trajectory proceeds through proprioceptive and interoceptive accuracy—the fidelity with which the nervous system maps the body in space and reads its internal physiological state—and culminates in autonomic regulation, emotional stability, and cognitive–social maturation. In typical development, the infant engages with the world long before cortical networks mature through fluctuations of muscle tone, gravitational orientation, visceral rhythms, autonomic states, and a proprioceptive field that anchors every movement and early interaction. What later becomes thought initially exists as patterning within physiological experience: changes in breathing, shifts in arousal, transitions between comfort and distress, and variations in postural readiness continuously shaped by bodily signals.

Živný is careful about the epistemological status of the proposal. SPP is presented not as a finalized mechanistic theory or an empirically confirmed causal account, but as a structured and testable developmental hypothesis derived from longitudinal clinical observation and theoretical synthesis across developmental neuroscience, autonomic physiology, embodied cognition, and systems-based models of neurodevelopment. The framework advances the concept of developmental priority rather than deterministic causation: somatic and autonomic processes constitute developmentally upstream regulatory layers that constrain and shape the emergence, stability, and flexibility of emotional and cognitive functions, without denying the reciprocal interactions that contemporary neuroscience clearly demonstrates between bodily states, autonomic regulation, emotional experience, and cognitive appraisal. The term universal, within this framework, denotes a developmentally constrained organizing principle rather than an invariant pathway—it does not imply that all psychopathology originates in somatic disturbance, and genetic, central, inflammatory, cultural, and neurodiverse factors may interact with, modify, or override the pathway in complex ways.

The framework delineates three central afferent modalities through which somatic integrity is communicated to the nervous system. Proprioception, generated by muscle spindles, Golgi tendon organs, joint receptors, ligamentous and fascial mechanoreceptors, and micro-movements across intervertebral segments, provides a continuous, layered, moment-to-moment representation of posture and movement. When axial structures lose physiological mobility or symmetry, this mapping becomes distorted—a state the framework terms Distorted Proprioceptive Information, or DPI, reflecting a mismatch between peripheral somatic input and the central nervous system’s predictive models of posture and movement. Inconsistent proprioceptive input disrupts vestibular calibration, ocular-motor control, anticipatory postural strategies, and the stability of sensorimotor loops, thereby tending to bias autonomic regulation toward rigidity and threat monitoring. Interoceptive afference, in parallel, conveys visceral tension, respiratory and cardiovascular rhythms, and metabolic load, providing a continuous internal context that interacts with proprioceptive and nociceptive inputs in shaping autonomic regulation.

Fascial tissue occupies a special place in this architecture. Beyond skeletal muscles, the ubiquitous fascia forms a continuous, body-wide sensory network that predominantly provides modulatory somatosensory afferent input encompassing nociceptive, interoceptive, and more modestly proprioceptive components. While this system exhibits a degree of regional topographic organization, its afferent signalling is largely diffuse and low-resolution, serving primarily to modulate central autonomic nervous system state rather than to convey discrete sensory content. Consequently, fascial afference influences psychological responses only indirectly, through its impact on central autonomic regulation. A third major mechanism involves persistent nociceptive input, often low-grade and easily overlooked: irritated zygapophyseal joints, strained paraspinal musculature, ligamentous micro-irritation, dural tension, and altered load distribution can all contribute to a persistent nociceptive drive even in the absence of consciously perceived pain. Neuroimaging and systems-level studies demonstrate that nociceptive input engages distributed networks implicated in autonomic output, affect regulation, and salience detection, and within spinal and brainstem circuits nociceptive and proprioceptive channels converge—when nociceptive input becomes persistent, these circuits are sensitized and autonomic regulation is biased toward defensive readiness even without overt injury.

An additional, often overlooked component involves direct mechanical influences on peripheral autonomic structures themselves. The sympathetic chain, vagal branches, and autonomic plexuses course through regions mechanically coupled to the axial skeleton, rib cage, diaphragm, and cervical connective tissues, so altered mobility, sustained muscular tension, or fascial densification can directly modulate autonomic signalling through autonomic afferent fibres and ganglia rather than through somatosensory pathways. Experimental and clinical evidence indicate that mechanical stimulation or restriction of spinal and paraspinal tissues alters sympathetic outflow, heart rate variability, and visceral function. The framework specifies two directionally convergent pathways activated by the same peripheral mechanical inputs: one involving direct mechanical modulation of peripheral autonomic structures, typically with relatively predictable effects, and a second, indirect pathway in which the same mechanical influences are transduced into proprioceptive, interoceptive, and nociceptive afferent signals that are centrally integrated and subsequently modulate autonomic centres in the brain. These proposed peripheral mechanical influences are framed as probabilistic modulatory factors rather than deterministic causal mechanisms requiring targeted empirical verification.

When distorted proprioception, altered interoceptive signalling, persistent low-grade nociceptive drive, and direct peripheral autonomic modulation together exceed adaptive capacity, the Somato-Psychic Pathway shifts from physiological integration into pathological operation. The result is a state the framework terms Somato-Psychic Autonomic Dysregulation, or SPAD, characterized by chronically reduced autonomic flexibility, impaired physiological recovery, and a sustained bias toward threat-oriented physiological states. Under physiological conditions, autonomic regulation is flexible: the sympathetic and parasympathetic branches dynamically adjust to context, enabling rapid mobilization when required and an efficient return to a regulated baseline once demands subside, with myelinated vagal pathways supporting social engagement and flexible regulation. When somatic input is persistently dysregulating, this flexibility diminishes, variability falls, and recovery slows. Prolonged operation of the pathway in this pathological mode gives rise to the clinical phenotype the article designates Somato-Psychic Syndrome, or SPS, marked by axial instability or rigidity, sensory hypersensitivity, autonomic lability, emotional dysregulation, attentional fluctuation, and variable developmental delay. This phenotype spans traditional diagnostic categories and provides an explanatory framework for comorbidity and symptom variability, offering an explanatory layer beneath existing diagnoses rather than replacing them.

The downstream consequences follow from well-established interoceptive and affective neuroscience. Contemporary models emphasize that emotion emerges from the brain’s interpretation of interoceptive signals rather than from isolated cortical appraisal, and within SPAD interoceptive signalling is chronically biased toward threat. Emotional responses may become exaggerated or blunted, stress tolerance decreases, and attentional resources are increasingly diverted toward internal regulation rather than exploration or learning. Cognitively, chronic autonomic dysregulation progressively constrains executive function, working memory, and attentional stability, with sustained physiological stress tending to bias behavior toward rigidity, avoidance, or repetitive patterns. Within SPP, these cognitive and behavioral phenotypes are understood as downstream expressions of autonomic state rather than as primary deficits. Perhaps most strikingly, the framework holds that when somatic integrity and autonomic regulation are restored, developmental functions often re-emerge in a predictable reverse sequence: autonomic calming precedes emotional stabilization, which in turn precedes improvements in attention, communication, and learning—a restitutive unfolding interpreted as consistent with the proposed developmental directionality, though the author stresses such observations remain hypothesis-generating rather than confirmatory.

What elevates the article beyond conceptual synthesis is its explicit empirical roadmap. SPP predicts that in typical ontogeny, maturation of somatic organization and postural stability will precede the stabilization of autonomic flexibility, which in turn will precede the consolidation of sustained emotional regulation and higher cognitive control—longitudinal designs assessing axial alignment, proprioceptive accuracy, and autonomic indices such as heart rate variability and pupillary dynamics alongside affective and executive measures could examine whether these domains show temporally ordered coupling. A second prediction concerns mediation: if the framework is valid, autonomic regulation should statistically mediate the relationship between somatic structural–functional integrity and downstream emotional or cognitive outcomes, so that improvements in postural organization or reductions in persistent nociceptive input correlate with changes in autonomic flexibility indices, which in turn predict improvements in emotional regulation or attentional stability. A third predicts reverse-sequence clinical change in interventional contexts, with somatically targeted interventions producing measurable autonomic changes prior to observable emotional and cognitive gains; preliminary pilot-level observations reported in conference abstract form illustrate this hypothesized pattern, but controlled interventional trials with repeated multimodal measurement are necessary. The article also specifies falsification criteria: a failure to observe systematic temporal ordering between somatic maturation, autonomic stabilization, and emotional–cognitive development would challenge the directional claim, and if autonomic markers do not mediate the somatic–psychological relationship, the central integrative role proposed for SPAD would require reconsideration. The framework acknowledges that bidirectional and common-cause models remain plausible alternatives, and empirical differentiation between somatic-primary, autonomic-primary, and central-primary models will require multimodal designs incorporating structural, physiological, and behavioral measures across development.

Conceptually, SPP situates itself in conversation with predictive processing frameworks, polyvagal theory, embodied cognition, and developmental systems theory, and its organization may be viewed as conceptually analogous to hierarchical descriptions of autonomic regulation, although the present framework is derived from developmental and clinical observations rather than phylogenetic taxonomy. Its primary contribution lies in articulating a directionally explicit, clinically grounded pathway linking somatic organization, autonomic regulation, and psychological development across both physiology and pathology. By integrating the somatic, autonomic, emotional, and cognitive domains into a single regulatory continuum, the Somato-Psychic Pathway offers a biologically grounded model with implications for understanding childhood neurodevelopmental disorders and guiding future therapeutic strategies. Whether the proposed directionality survives controlled longitudinal and interventional testing remains an open question—but the framework has been built to be tested, and its value, as the author argues, lies precisely in its capacity to articulate explicit developmental hypotheses, specify mediating mechanisms, define boundary conditions, and stimulate the research designed to examine the proposed ordering and its clinical implications.

Subject of Research: A theoretical framework linking somatic integrity, autonomic regulation, and mind development

Article Title: Somato-Psychic Pathway: a universal developmental trajectory linking somatic structural–functional integrity, autonomic regulation, and the emergence of mind

Article References: Živný, B. (2026). Somato-Psychic Pathway: a universal developmental trajectory linking somatic structural–functional integrity, autonomic regulation, and the emergence of mind. Frontiers in Integrative Neuroscience, 20, Article 1771123. https://doi.org/10.3389/fnint.2026.1771123

Image Credits: AI Generated

DOI: 10.3389/fnint.2026.1771123

Keywords: Somato-Psychic Pathway, autonomic dysregulation, interoception, proprioception, neurodevelopment, embodied cognition, developmental psychopathology, autonomic regulation, nociception, fascia, polyvagal theory, childhood disorders

The consequences of leaving this pain untreated are not trivial. In extremely preterm infants, those born at twenty-eight weeks of gestation or earlier, exposure to high numbers of noxious stimuli has been associated with disruption of thalamocortical development, the intricate wiring process that connects the brain’s sensory relay station to its outer cortex. Follow-up studies of these children have linked early pain exposure to unfavorable cognitive, sensory, and behavioral outcomes years later. Care teams do what they can with gentler tools: topical anesthetics, oral sucrose, skin-to-skin contact, swaddling, and non-nutritive sucking all help for minor procedures. But for unsettled, endotracheally intubated, hemodynamically unstable infants, or those undergoing surgery, stronger medicine is required, typically morphine, a natural opioid, or fentanyl, a synthetic, lipophilic phenylpiperidine opioid agonist.

Among neonates, fentanyl has largely displaced morphine as the analgesic of choice, and for understandable pharmacological reasons. It causes less cardiovascular instability and fewer episodes of hypotension, binds with higher specificity to mu-opioid receptors, and is fifty to four hundred times more potent than morphine, which acts as a non-specific opioid receptor agonist. Its efficacy in blunting the surgical stress response was demonstrated decades ago in a randomized trial of preterm babies undergoing ligation of a patent ductus arteriosus, a landmark study that helped establish opioid anesthesia for the tiniest surgical patients. But effectiveness comes with a shadow. Opioid exposure in the NICU has been associated with smaller cerebellar volumes, cerebellar hemorrhages, and altered long-term neurodevelopment. Earlier work suggested that infants exposed to greater numbers of painful experiences who received morphine for more than seven days showed lower cognition, while shorter exposures had less negative impact. A longitudinal study of 936 extremely preterm infants born at twenty-four to twenty-seven weeks of gestation found that prolonged exposure, longer than seven days, to morphine, fentanyl, midazolam, or lorazepam was associated with adverse effects on two-year neurodevelopmental outcomes, reflected in lower scores on the Bayley Scales of Infant Development, Third Edition. A retrospective study of infants born between twenty-three and thirty-two weeks similarly found that cumulative opioid exposure in the NICU was negatively associated with cognitive and motor development at three years of adjusted age. These findings raise an uncomfortable clinical dilemma: how to manage pain effectively while minimizing the adverse outcomes that the analgesics themselves may carry.

Into this dilemma steps an unexpected player, one that until recently had little place in conversations about neonatal analgesia: the gut microbiome. The community of trillions of microbes colonizing the infant intestine is increasingly recognized as a critical regulator of developmental processes far beyond digestion, shaping immune responses, metabolism, and hormonal signaling in both the gut and remote organs, including the brain. This microbiome-gut-brain axis has become one of the most active frontiers in developmental biology, and the early weeks of life represent a uniquely sensitive window during which microbial colonization patterns can have lasting consequences.

Preterm infants, it turns out, start life with a microbial handicap. Compared with their term-born counterparts, they carry gut microbiomes characterized by lower diversity and a conspicuous lack of Bifidobacterium species, beneficial members of the phylum Actinobacteriota that normally dominate the healthy infant gut. Their microbial communities are also particularly vulnerable to the hospital environment, being seeded less by maternal microbes and more by whatever organisms circulate in the intensive care unit. Given all of this, a pressing question arises: what happens to this fragile ecosystem when the infant is repeatedly dosed with one of the most potent opioids in clinical use? Until now, the effect of opioid exposure on the early-life microbiome had not been well studied.

A new investigation by David and colleagues, published in Pediatric Research and accompanied by a commentary from researchers at the University of Calgary, set out to answer exactly that question. The study leveraged the prospective Microbiome analysis in Neonatal Development, or MIND, cohort, which enrolled 250 infants born at less than thirty-seven weeks of gestation. For the fentanyl analysis, the researchers compared twenty-two infants with no fentanyl exposure, whose mean gestational age was thirty-one weeks, against forty-six infants who received the drug, whose mean gestational age was twenty-seven weeks. The team collected a wide range of clinical covariates, including sociodemographic information, mode of delivery, sex, postmenstrual age, length of NICU stay, intrauterine and extrauterine growth differences, enteral feeding patterns, antibiotic use, and major clinical morbidities, all of which are known to independently shape the infant microbiome.

What distinguishes this study technically is the depth of its microbiological and statistical toolkit. Rather than relying on a single sequencing approach, the researchers deployed 16S rRNA gene sequencing to profile microbial composition, deep shotgun metagenomic sequencing to resolve the functional potential of the microbial communities at the level of individual genes, and fecal metabolomics to measure the actual chemical products of gut microbial metabolism. This three-pronged strategy allowed them to dissect not just which microbes were present, but what those microbes might be doing, and how their metabolic output differed between fentanyl-exposed and unexposed infants. On the neurodevelopmental side, outcomes were assessed at two years of age using the Bayley Scales of Infant Development, Third Edition, and again between three and eight years of age using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition, providing both early and later cognitive measures. Statistical analysis employed linear regression models and mixed binomial regression models to test the relationship between fentanyl exposure and microbiome features while adjusting for the extensive panel of clinical covariates.

The headline finding is striking: fentanyl exposure was associated with measurable alterations in the gut microbiome, and these microbial changes appeared to be linked to adverse cognitive outcomes in the preterm children when they were assessed at two to eight years of age. In other words, the study suggests that the drug given to protect the developing brain from pain may, through the intermediary of the gut’s microbial ecosystem, contribute to the very neurodevelopmental harms clinicians have been trying to understand. The commentary’s authors, Chunlong Mu, Kamran Yusuf, and Shabih U. Hasan of the Cumming School of Medicine at the University of Calgary, were careful to commend the study’s rigor, particularly the painstaking effort to account for a large number of maternal and infant variables in the statistical analyses, a step many microbiome studies skip at their peril.

Yet the same commentators, and the study’s own design, demand caution before drawing firm conclusions. The sample size was small, with only sixty-eight infants in the final analysis, and the complexity of confounding variables in this population is formidable. Fentanyl-exposed infants were, on average, born four weeks earlier than unexposed infants, and greater prematurity independently predicts both altered microbiome development and worse neurodevelopmental outcomes. Even the most sophisticated regression models cannot fully disentangle such entangled factors. As a result, a direct causal link between fentanyl exposure and neurodevelopmental outcomes cannot be established from this study. The association between the drug, the microbiome, and later cognition is real and intriguing, but the direction of causality and the magnitude of any true drug effect remain open questions.

What the study does establish is a compelling new framework for thinking about neonatal analgesia. If opioids reshape the preterm gut microbiome, and if those microbial shifts contribute to cognitive outcomes years later, then the microbiome becomes a modifiable target, a potential mediator whose effects might be buffered by probiotics, tailored nutrition, or more judicious dosing strategies. It also adds urgency to efforts to reduce opioid exposure where possible, expanding non-pharmacological comfort care and reserving sedation for infants who truly need it. The research was supported by a grant from the Canadian Institutes of Health Research, and its authors declare no competing interests. For the thousands of infants who pass through neonatal intensive care each year, and for the clinicians who must balance the immediate imperative of pain relief against the long-term imperative of healthy brain development, this work opens a promising and unexpected avenue: protecting the developing mind by tending the garden of microbes in the gut.

Subject of Research: The association between early-life fentanyl exposure, gut microbiome alterations, and neurodevelopmental outcomes in preterm infants

Article Title: Early-life fentanyl exposure, microbiome-brain axis and neurodevelopment

Article References: Mu, C., Yusuf, K., & Hasan, S. U. (2026). Early-life fentanyl exposure, microbiome-brain axis and neurodevelopment. Pediatric Research. https://doi.org/10.1038/s41390-026-05424-3

Image Credits: AI Generated

DOI: 10.1038/s41390-026-05424-3

Keywords: fentanyl, preterm infants, gut microbiome, microbiome-gut-brain axis, neonatal intensive care, neurodevelopment, neonatal pain, opioids, shotgun metagenomics, Bayley Scales, Pediatric Research, Bifidobacterium

The research team, led by Rebekah E. Townsley, Jonathan C. Andrews, and colleagues in the laboratories of Shinya Yamamoto and Michael F. Wangler, focused on three human NLGN3 variants that had been identified in people with autism. The first, p.R451C, is historically significant: it was the very first variant that connected NLGN3 to autism spectrum disorder, discovered in two brothers, and it has been studied intensively ever since. The second, p.R175W, is a de novo variant, meaning it arose fresh in the affected individual rather than being inherited; it was found in a heterozygous female with autism. The third, p.R597W, was inherited from an unaffected mother by a male patient who had both autism and a diagnosed sleep disorder. Despite decades of work on p.R451C, the functional consequences of the other variants had remained largely unexplored in a living animal.

To fill that gap, the researchers turned to Drosophila, the fruit fly, whose nervous system offers a powerful combination of genetic tractability and well-mapped synaptic anatomy. Flies carry a homolog of the human gene called Nlg3, and when the team removed it, the flies showed measurable disruptions in three domains: their sleep patterns changed, the structure of their synapses was altered, and the dynamics of synaptic vesicles, the tiny membrane sacs that store and release neurotransmitters, were disturbed. Crucially, when the researchers introduced the normal human reference version of NLGN3 into these mutant flies, all of these defects were rescued. That result confirmed two important things at once: the fly gene and the human gene are functionally equivalent enough to stand in for each other, and the observed phenotypes genuinely trace back to loss of neuroligin-3 function rather than to experimental side effects.

Neuroligin-3 itself is a synaptic adhesion molecule, a protein embedded in the postsynaptic membrane that reaches across the synaptic cleft and physically locks onto partners on the presynaptic side. This molecular handshake helps organize the synapse, aligning the machinery for neurotransmitter release on one side with receptor arrays on the other. Because neuroligins sit at this structural and functional crossroads, mutations in their coding sequence can plausibly disturb either the building of synapses or the moment-to-moment signaling they carry out, and the new study shows that different mutations do indeed split along those lines.

When the researchers expressed each human variant in flies lacking endogenous Nlg3, a clear division of labor emerged. The p.R175W variant and the maternally inherited p.R451C variant both altered synapse morphology, reshaping the physical structure of neural junctions, while leaving vesicle dynamics largely intact. In sharp contrast, the p.R597W variant, the one associated with a sleep disorder in its human carrier, produced the opposite profile: it disturbed sleep and vesicle dynamics but had minimal impact on synapse shape. This dissociation is the conceptual heart of the paper. It demonstrates that a single gene can be broken in different ways by different mutations, with each break producing a different downstream signature in the nervous system.

The team then pushed further by asking what happens when NLGN3 is present in excess rather than absent. In overexpression models, even the normal human reference allele changed sleep patterns and synaptic morphology, indicating that neuroligin-3 dosage itself matters for nervous system function. Against this background, the variants revealed additional layers of difference. The p.R175W variant worsened the sleep phenotypes beyond what simple overexpression produced, and both p.R175W and p.R451C exacerbated the synapse morphology defects. Taken together with the rescue experiments, these results led the authors to a specific mechanistic conclusion: the de novo p.R175W variant, found in a heterozygous female, behaves as a gain-of-function mutation, actively adding disruptive activity rather than merely removing normal function.

The picture for the maternally inherited variants is more nuanced. Because most reported NLGN3 variants have been found in affected males who inherited them from unaffected mothers, the researchers note that these variants appear to have context-dependent functional impact. A mother carrying the variant on one of her two X chromosomes can remain unaffected, while a son who receives it and has no second X chromosome copy to buffer the effect may develop autism. This pattern fits the well-known sex bias in X-linked neurodevelopmental conditions and helps explain why NLGN3 variants cluster in male patients, even as de novo variants also surface in affected females.

For the broader autism field, the study carries a message that goes beyond NLGN3 itself. Autism spectrum disorder is defined by its heterogeneity: hundreds of genes have been implicated, and no two patients present identically. Much of the research effort has focused on establishing whether a given gene is associated with autism at all, treating each gene as a single entity. This work shows that within one gene, the variants are not interchangeable. Some NLGN3 variants disrupt synaptic development, the slow process of building proper connections, while others alter synaptic function, the fast process of transmitting signals, including the vesicle cycling that underlies neurotransmitter release. If this principle generalizes, then variant-level functional characterization, not just gene-level association, will be essential for understanding why one patient sleeps badly and another does not, or why synaptic architecture is disrupted in one brain and signaling dynamics in another.

The choice of Drosophila as the experimental platform also deserves attention. Sleep in flies is a well-established model system, governed by conserved neural circuitry, and synaptic vesicle dynamics can be imaged and quantified with precision in the fly nervous system. By establishing that the human reference NLGN3 can rescue the fly Nlg3 loss-of-function phenotype, the researchers created a platform in which any NLGN3 variant, including ones not yet discovered, can be tested for its functional signature in a living animal within a manageable timeframe. That kind of scalable variant-to-function pipeline is increasingly seen as necessary as human genetics keeps identifying variants faster than traditional animal models can evaluate them.

The study leaves open questions that future work will need to address, including how the distinct synaptic and behavioral phenotypes produced by different variants map onto the specific clinical profiles of the patients who carried them, and whether the gain-of-function behavior of p.R175W points to therapeutic strategies different from those suited to loss-of-function variants. But the central finding stands on its own: three variants in the same autism risk gene, in the same animal model, produce three distinguishable patterns of synaptic and behavioral disruption. The heterogeneity of autism, the authors suggest, may begin at the level of the individual variant, and understanding that variant-level diversity may be a prerequisite for understanding the disorder itself.

Subject of Research: Functional differences among NLGN3 autism variants in synapse morphology, vesicle dynamics, and sleep behavior in Drosophila

Article Title: NLGN3 autism variants have distinct functional impact on synapses and sleep behavior in Drosophila

Article References: Townsley, R. E., Andrews, J. C., Srivastav, S., Jangam, S. V., Hannan, S. B., Kanca, O., Marcogliese, P. C., Yamamoto, S., & Wangler, M. F. (2026). NLGN3 autism variants have distinct functional impact on synapses and sleep behavior in Drosophila. PLOS Genetics, 22(10), e1012341. https://doi.org/10.1371/journal.pgen.1012341

Image Credits: AI Generated

DOI: 10.1371/journal.pgen.1012341

Keywords: autism spectrum disorder, NLGN3, neuroligin-3, Drosophila, synapse morphology, synaptic vesicle dynamics, sleep behavior, gain-of-function, X-linked gene, de novo variant, PLOS Genetics, neurodevelopment