Most recent paper

Comput Biol Med. 2026 Sep 21;215:111941. doi: 10.1016/j.compbiomed.2026.111941. Online ahead of print.

ABSTRACT

Self-supervised pretraining is promising for large-scale neuroimaging representation learning, yet the impact of region-aware masking and hybrid sequence modeling remains underexplored. In this work, we introduce Rhamba, a region-aware pretraining framework that integrates anatomically guided masking with hybrid Attention-Mamba architectures for resting state functional magnetic resonance imaging (fMRI) analysis. Models were pretrained on the ABIDE dataset using region-aligned patch embeddings and three masking strategies with increasing spatial specificity. We evaluated four architectural variants: a Mamba-dominant model, an Alternate architecture with interleaved Mamba and Attention blocks, and two hybrid encoder-decoder configurations (Attention-Mamba (AM) and Mamba-Attention (MA)). The pretrained models were fine-tuned on downstream classification tasks using the COBRE and ADHD-200 datasets for schizophrenia and attention-deficit/hyperactivity disorder discrimination. We employed Integrated Gradients, an explainable AI method, to identify the brain regions contributing to model predictions. Our masking strategy strongly influenced reconstruction behavior, with reconstruction loss following a consistent ordering (Any>Majority>Pure). However, this trend did not directly translate into downstream performance, where differences were modest and dataset-dependent. The hybrid architecture with the MA configuration achieved the highest average AUROC across both datasets. Rhamba demonstrated competitive performance against state-of-the-art methods. Region-wise analysis showed that peak performance depends on the interaction between masking strategy and architecture rather than a single dominant configuration. The hybrid architectures underscore the importance of combining global context modeling with efficient sequence dynamics. Overall, Rhamba offers a flexible framework for balancing interpretability, scalability, and performance in large-scale fMRI representation learning.

PMID:42767064 | DOI:10.1016/j.compbiomed.2026.111941

Proc Natl Acad Sci U S A. 2026 Sep 29;123(39):e2602353123. doi: 10.1073/pnas.2602353123. Epub 2026 Sep 21.

ABSTRACT

In congenital handlessness, where individuals rely on their feet for compensatory manual functions, reorganization in the primary somatosensory cortex (SI) appears to be limited to local shifts by adjacent body parts. It remains unclear how congenital handlessness and lifelong compensatory foot use shape the sensorimotor system beyond SI, and whether compensatory abilities can drive broader functional reorganization. Here, we used task-based and resting-state functional MRI (fMRI) to investigate how compensatory foot use changes body representations in the secondary somatosensory cortex (SII) in people born without hands (individuals with upper-limb dysplasia, IDs). We found that IDs showed a shift toward foot selectivity in the left hand-selective SII, with stronger foot activity than typically developed (TD) control participants during action execution. Notably, this reorganization in the left SII hand area cannot simply be explained by this area's intrinsic organization-the typical secondary preference of this area in the TDs when hand responses are excluded: TDs showed both shoulder and foot selectivity when the hand activity was excluded from the analysis in this area, whereas the reorganization in IDs was limited to the foot. This indicates a functional reweighting that stems from the IDs' sensorimotor experience. Resting-state results further revealed altered functional connectivity between SII and primary sensorimotor regions in IDs. Our findings suggest that SII exhibits flexible, experience-dependent plasticity, revealing a hierarchical principle of cortical plasticity, whereby reorganization in the SI is constrained by somatotopic principles while SII reflects functional or experience-dependent reweighting plasticity.

PMID:42766749 | DOI:10.1073/pnas.2602353123

Psychiatry Res Neuroimaging. 2026 Sep 11;364:112331. doi: 10.1016/j.pscychresns.2026.112331. Online ahead of print.

ABSTRACT

BACKGROUND: Body dysmorphic disorder (BDD) is prevalent in cosmetic surgery populations, but its neurobiological mechanisms remain unclear.

OBJECTIVE: To identify brain functional and structural alterations in BDD using multimodal MRI.

METHODS: Twenty BDD patients and 20 healthy controls were recruited. After quality control, 16 per group were included in final analyses. ALFF, ReHo, functional connectivity (FC), VBM, and SBM analyses were performed, with correlations to clinical severity.

RESULTS: BDD patients showed increased ALFF in right cerebellar lobule VIII and increased ReHo in left cerebellar lobule VIII. FC revealed enhanced mPFC-rectus gyrus connectivity and reduced PCC connectivity with left inferior parietal lobule and right midcingulate cortex. Exploratory structural analyses suggested increased gray matter in left middle occipital gyrus, decreased cerebellar/parietal volumes, altered white matter, cortical thickening in left pars triangularis, thinning in left inferior parietal lobule, and gyrification changes, but these did not survive multiple-comparison correction and require independent replication. Left inferior parietal cortical thickness positively correlated with BDD severity.

CONCLUSIONS: BDD involves abnormalities in default mode, cerebellar-cortical, and visual processing networks, providing preliminary neurobiological insights into BDD. These group-level findings are exploratory and do not yet support individual-level applications. Given the modest sample size, replication in larger cohorts is required.

PMID:42763974 | DOI:10.1016/j.pscychresns.2026.112331

Int J Endocrinol Metab. 2026 Aug 11;24(4):e168867. doi: 10.5812/ijem-168867. eCollection 2026 Oct 31.

ABSTRACT

BACKGROUND: Subclinical metabolic disturbances have been associated with functional brain changes; however, the neural pathways mediating their cognitive effects remain unclear.

OBJECTIVES: This study investigated whether large-scale brain network connectivity mediates associations between metabolic risk factors and cognition in healthy young adults.

METHODS: Data were obtained from 676 participants (22 - 37 years) in the Human Connectome Project. Metabolic indices (body mass index (BMI), glycated hemoglobin, thyroid-stimulating hormone (TSH), systolic/diastolic blood pressure, and hematocrit) were assessed alongside the National Institutes of Health (NIH) Toolbox Cognition Battery scores, the Mini-Mental State Examination, and fluid intelligence measures. Resting-state fMRI data underwent group independent component analysis to identify 14 intrinsic connectivity networks. Partial correlations were computed between network time series, and multiple regression models were adjusted for age, sex, race, and education. Mediation analyses with bootstrapped confidence intervals were conducted to test whether network connectivity explained the metabolic-cognition relationships.

RESULTS: We found that large-scale resting-state networks significantly mediated the associations between specific metabolic risk factors and cognitive performance. Specifically, BMI, hematocrit, and TSH showed significant associations with both cognition and network connectivity (all P < 0.05). BMI-related reductions in vocabulary performance were fully mediated by altered connectivity in the frontoparietal-language, sensorimotor-frontoparietal, primary visual-auditory, and default mode-executive attention networks and partially mediated (compensatory effect) by salience-sensorimotor connectivity (indirect effects: -0.0238, -0.0115, -0.0110, -0.0096, and 0.0068, respectively; 95% CIs: [-0.0421, -0.0085], [-0.0239, -0.0030], [-0.0237, -0.00016], [-0.0206, -0.0014], and [0.0001, 0.0165], respectively). Hematocrit's positive association with vocabulary performance was partially mediated by the primary visual-auditory, salience-auditory, and language-dorsal attention networks, with primary visual-ventral attention connectivity exerting a suppressive effect (indirect effects: 0.0094, 0.0149, 0.0074, and -0.0113, respectively; 95% CIs: [0.0007, 0.0215], [0.0032, 0.0319], [0.0001, 0.0197], and [-0.0249, -0.0012], respectively). TSH was positively associated with fluid intelligence via a direct pathway (P = 0.010), without mediation by resting-state connectivity.

CONCLUSIONS: These findings highlight large-scale brain networks as potential intermediate phenotypes that link metabolic health to cognition, suggesting that targeted neuromodulation of vulnerable circuits, combined with metabolic interventions, may offer novel strategies for preserving cognition in at-risk populations.

PMID:42763643 | PMC:PMC13589462 | DOI:10.5812/ijem-168867

Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2026 Jul 28;51(7):1449-1461. doi: 10.11817/j.issn.1672-7347.2026.260177.

ABSTRACT

OBJECTIVES: Patients with bipolar disorder (BD) have a high prevalence of smoking. Smoking status may interact with disease-related brain functional abnormalities and jointly influence resting-state brain activity. This study aims to investigate the independent and interactive effects of BD diagnosis and smoking status on the dynamic instability of regional brain activity. Based on resting-state functional magnetic resonance imaging (fMRI) data, dynamic amplitude of low-frequency fluctuation (dALFF), dynamic fractional amplitude of low-frequency fluctuation (dfALFF), and dynamic regional homogeneity (dReHo) were integrated to evaluate fluctuations in regional brain activity. Furthermore, associations between abnormal brain regions, clinical symptoms, and daily cigarette consumption were analyzed.

METHODS: From July 2022 to November 2025, a total of 113 participants were recruited at the Second Xiangya Hospital of Central South University, including 25 smoking patients with BD (BDsm group), 33 non-smoking patients with BD (BDnsm group), 23 smoking healthy controls (HCsm group), and 32 non-smoking healthy controls (HCnsm group). The BDsm and BDnsm groups were combined as the BD group, while the HCsm and HCnsm groups were combined as the healthy control (HC) group. Resting-state fMRI data were collected and preprocessed, followed by calculation of dALFF, dfALFF, and dReHo using a sliding-window approach. The 3 dynamic indices were standardized and subjected to principal component analysis, with the first principal component extracted as a composite measure of dynamic regional brain activity. Whole-brain two-way analysis of covariance (ANCOVA) was performed to examine the interaction effects and main effects of BD diagnosis and smoking status, with age, sex, years of education, and dataset source included as covariates. Brain regions showing significant effects were further analyzed using post hoc comparisons and Pearson correlation analyses.

RESULTS: Whole-brain analysis revealed a significant interaction effect between BD diagnosis and smoking status in the right thalamus. Post hoc analyses showed that dynamic activity instability in the right thalamus was significantly higher in the BDsm group than in the HCsm group (t=3.955, P<0.001) and the BDnsm group (t=5.987, P<0.001). The BDnsm group exhibited lower right thalamic dynamic activity instability than the HCnsm group (t=-6.681, P<0.001), and the HCsm group showed lower instability than the HCnsm group (t=-4.530, P<0.001). After controlling for dataset source, the interaction effect remained significant, and the results were replicated only in the male subgroup. A main effect of BD diagnosis was identified in the ventromedial prefrontal cortex and left dorsolateral prefrontal cortex. Post hoc analyses showed that dynamic activity instability in the ventromedial prefrontal cortex and left dorsolateral prefrontal cortex was significantly higher in the BDsm group than in the HCsm group (ventromedial prefrontal cortex: t=5.046, P<0.001; left dorsolateral prefrontal cortex: t=3.152, P=0.003). Similarly, the BDnsm group exhibited significantly higher dynamic activity instability in these regions than the HCnsm group (ventromedial prefrontal cortex: t=3.440, P=0.001; left dorsolateral prefrontal cortex: t=4.684, P<0.001). No significant main effect of smoking status was observed. Among all smokers, daily cigarette consumption was positively correlated with dynamic activity instability in the right thalamus (r=0.335, P=0.026). Among smoking patients with BD, dynamic activity instability in the left dorsolateral prefrontal cortex was positively correlated with anxiety symptoms (r=0.451, P=0.031).

CONCLUSIONS: BD diagnosis and smoking status exert interactive effects on dynamic activity in the right thalamus. Under non-smoking conditions, patients with BD exhibited reduced thalamic dynamic activity instability; however, this BD-associated reduction was attenuated among smokers and showed an association with smoking exposure intensity. Patients with BD demonstrated increased dynamic activity instability in prefrontal regions, suggesting abnormalities in brain regions involved in emotional regulation and cognitive control.

PMID:42763300 | DOI:10.11817/j.issn.1672-7347.2026.260177

Neuroimage. 2026 Sep 19:122248. doi: 10.1016/j.neuroimage.2026.122248. Online ahead of print.

ABSTRACT

Radiologists acquire expert-level performance in detecting abnormalities in chest X-rays over years of training. Holistic processing has been proposed to support this acquired visual expertise, but its neural implementation remains unclear. Because face perception is a canonical form of holistic/configural processing and reliably engages occipitotemporal regions such as the fusiform face area (FFA) and occipital face area (OFA), a key question is whether these regions also contribute to expertise-related holistic processing in a non-face professional domain. Here, we focused on face-selective regions as theoretically motivated regions of interest, while also using whole-brain searchlight decoding and resting-state functional connectivity analyses to characterize broader expertise-related changes across the brain. We combined behavioral and fMRI experiments in which radiologists and laypeople viewed faces, buildings, and chest X-rays under two manipulations of holistic processing: upright versus inverted presentation and amodally completed versus uncompleted images. Behavioral results indicated that radiologists adopted experience-dependent holistic strategies when interpreting chest X-rays. Multivariate pattern analysis (MVPA) revealed that disrupting holistic processing significantly reduced decoding accuracy for X-rays versus buildings in the left FFA and left OFA, indicating their involvement in expertise-related holistic processing. In addition, radiologists showed stronger face representations across stimulus forms in bilateral FFA. Resting-state analyses further revealed reorganization of intrinsic functional connectivity across the face-processing network. These findings suggest that radiological expertise engages left-lateralized holistic mechanisms in occipitotemporal cortex and is accompanied by stronger face representations and altered intrinsic connectivity within the face-processing network, supporting a model in which new expertise emerges through the adaptive reuse and amplification of pre-existing neural representations.

PMID:42763004 | DOI:10.1016/j.neuroimage.2026.122248

Psychiatry Res Neuroimaging. 2026 Sep 14;364:112332. doi: 10.1016/j.pscychresns.2026.112332. Online ahead of print.

ABSTRACT

BACKGROUND: Rumination is a central cognitive mechanism in major depressive disorder (MDD) that contributes to symptom persistence, recurrence, and relapse. Although resting-state abnormalities of the default mode network (DMN) are widely reported in depression, it remains unclear which alterations are specifically associated with depressive rumination rather than broader MDD-related dysfunction.

OBJECTIVE: To synthesise resting-state fMRI evidence on DMN functional connectivity associated with rumination in clinically diagnosed depression.

METHODS: A systematic search of PubMed, Embase, and Cochrane databases was conducted in January 2025 in accordance with PRISMA guidelines (PROSPERO: CRD420251104487). Eligible studies included clinically diagnosed MDD, rumination using validated measures, and a healthy control group. Task-based fMRI studies were excluded. Owing to methodological heterogeneity, findings were synthesised narratively.

RESULTS: Twelve studies comprising 314 depressed individuals and 308 controls met inclusion criteria. Rumination was associated with a distinct DMN-centred resting-state profile involving increased anterior DMN connectivity, altered connectivity between DMN subsystems, interactions between DMN regions and frontal-control or salience networks, and increased engagement of DMN-related functional states. Dynamic findings linked rumination to greater DMN-state entries, increased synchrony, and reduced metastability. Several abnormalities observed in MDD, including reduced posterior DMN connectivity, mPFC-parahippocampal and mPFC-PCC variability, were not consistently associated with rumination.

CONCLUSION: Rumination in clinically diagnosed depression is associated with a distinct DMN-centred resting-state connectivity profile rather than the broader pattern of DMN abnormalities observed in MDD. These findings may help refine neurobiological models of rumination in depression and identify connectivity markers relevant to symptom persistence, relapse risk, and treatment response.

PMID:42762770 | DOI:10.1016/j.pscychresns.2026.112332

Eur Arch Psychiatry Clin Neurosci. 2026 Sep 19. doi: 10.1007/s00406-026-02355-2. Online ahead of print.

ABSTRACT

BACKGROUND: Accelerated transcranial magnetic stimulation (aTMS) is an effective treatment for depression, but its neurobiological mechanisms of action remain to be elucidated. This study used high-resolution 7-Tesla MRI to investigate changes in resting-state functional connectivity (rs-FC) of the subgenual anterior cingulate cortex (sgACC) following a treatment series of aTMS. We hypothesized a decrease in sgACC rs-FC with key cortical regions of the default mode network (DMN), reflecting a downregulation of a network that is overactive in depression.

METHODS: Twenty-two patients with current depression underwent 7-Tesla MRI scans before and after a two-week aTMS treatment series (24,000 pulses) targeting the left dorsolateral prefrontal cortex. Fourteen healthy participants were also scanned twice as a control group. Longitudinal changes in sgACC seed-based rs-FC were compared between groups. Furthermore, group differences were assessed at baseline and at follow-up. Exploratory correlations between longitudinal changes in sgACC rs-FC, depression severity, mindfulness, and affect were also evaluated.

RESULTS: There was a reduction in rs-FC between the sgACC and bilateral precunei, and between sgACC and left frontal pole in patients receiving aTMS. At baseline, patients had increased rs‑FC between the sgACC and a cluster including the left precuneus and a cluster in the right superior frontal gyrus. Exploratory correlations suggest an association between sgACC-precunei rs-FC changes and mindfulness (p = 0.008, uncorrected for multiple comparisons), while no associations were found with depression severity or affect.

CONCLUSIONS: Treatment with aTMS is associated with a reduction in rs‑FC between the sgACC and the DMN. Exploratory correlations with mindfulness warrant replication in larger, independent samples.

PMID:42762242 | DOI:10.1007/s00406-026-02355-2

Eur Arch Psychiatry Clin Neurosci. 2026 Sep 19. doi: 10.1007/s00406-026-02377-w. Online ahead of print.

ABSTRACT

BACKGROUND: Borderline Personality Disorder (BPD) involves affective instability, impaired emotion regulation, and self-injurious behavior, often linked to childhood adversity. Although prefrontal and insular abnormalities have been reported, the relationship between structural and functional changes in BPD is not well characterized.

METHODS: We combined voxel-based morphometry (VBM) and resting-state functional magnetic resonance imaging in female patients with BPD (VBM n = 48; rs-fMRI n = 41) and female healthy controls (VBM n = 54; rs-fMRI n = 51). Regions with gray matter differences in the whole-brain VBM served as seeds for resting-state functional connectivity (rs-FC) analyses. Associations with childhood maltreatment (CTQ), borderline symptom severity (BSL-23) including self-harm (DSHI) were assessed.

RESULTS: Patients showed gray matter reductions in bilateral insula and middle and superior frontal gyri (MFG; SFG). Rs-FC analyses revealed increased connectivity from right MFG and SFG to the left orbitofrontal cortex, temporal pole, inferior temporal gyrus, frontal pole regions, and superior frontal gyrus. Borderline symptom severity correlated with rMFG/ rSFG-left orbitofrontal/ precentral/ postcentral regions connectivity, while self-harm correlated with increased rSFG-left frontal pole/ orbitofrontal cortex/ SFG/ posterior middle temporal gyrus connectivity and rMFG-left hippocampus/ right precentral gyrus connectivity. Within patients, emotional abuse during childhood was associated with enhanced rSFG-lateral occipital cortex/ thalamus connectivity. Physical neglect and abuse were linked to reduced rSFG-left precentral gyrus and rMFG-postcentral connectivity, alongside increased rMFG-temporal pole connectivity.

CONCLUSIONS: Structural alterations in insular and prefrontal regions and altered prefrontal connectivity were linked to childhood maltreatment, symptom severity, and self-harm, suggesting disrupted network organization as a neural correlate of BPD features.

PMID:42762241 | DOI:10.1007/s00406-026-02377-w

Imaging Neurosci (Camb). 2026 Sep 17;4:IMAG.a.1362. doi: 10.1162/IMAG.a.1362. eCollection 2026.

ABSTRACT

Ultra-high-field magnetic resonance imaging (MRI) promises major gains in blood oxygen level dependent (BOLD) sensitivity but introduces severe challenges such as RF field inhomogeneity, B 0 field inhomogeneity, motion and vibration-induced field variations. We report the first whole-brain resting-state and task-based fMRI experiments at 11.7T. A 3D-EPI sequence was optimized using tailored parallel-transmit RF pulses, gradient reshaping to suppress vibration-induced B 0 fluctuations, and prospective motion correction using servo navigation combined with retrospective phase equalization (PEERS). Four participants were scanned at 11.7T with whole-brain 1.2 mm isotropic resolution with servo navigation and PEERS that considerably reduced residual motion and increased temporal signal-to-noise ratio (SNR). The Default Mode Network in resting state could be detected and a physiological-noise-dominated regime was identified. Four additional but different participants were scanned at 7T for tSNR comparison and validation of the protocol, data quality, and processing pipeline. Task-based fMRI likewise was conducted at 11.7T and yielded robust, spatially specific activations across motor, visual, mathematical, and language networks, again with improved sensitivity and cleaner BOLD responses when using servo navigation and PEERS. These results demonstrate the feasibility and reliability of whole-brain human fMRI at 11.7T and constitute a first-quality control milestone to further increase resolution at that field strength.

PMID:42761695 | PMC:PMC13588317 | DOI:10.1162/IMAG.a.1362

Am J Alzheimers Dis Other Demen. 2026 Jan-Dec;41:15333175261491804. doi: 10.1177/15333175261491804. Epub 2026 Sep 18.

ABSTRACT

We present a resting-state fMRI-based protocol for quantifying anatomical distance-dependent functional connectivity strength (FCS) and demonstrate its application in vascular cognitive impairment, no dementia (VCIND). Resting-state fMRI data from VCIND patients and demographically matched normal controls were analyzed using voxel-wise FCS across six anatomical distance intervals to characterize short-, medium-, and long-range functional connectivity. Network-level analyses were also performed to identify large-scale network involvement. The results reveal a hierarchical distance-dependent organization of functional connectivity, with short-range connectivity concentrated in primary sensory systems and long-range connectivity increasingly involving higher-order association networks. In VCIND, significant alterations were observed particularly within the frontoparietal network, suggesting compensatory network reorganization associated with cognitive performance. These distance-dependent FCS alterations may serve as potential neuroimaging markers for early identification and risk stratification of VCIND and may also support longitudinal monitoring of functional network changes.

PMID:42760808 | DOI:10.1177/15333175261491804

BMC Psychiatry. 2026 Sep 18;26(1):733. doi: 10.1186/s12888-026-08360-y.

ABSTRACT

BACKGROUND: Parental education is associated with body mass index (BMI), mental health, and neurodevelopment in young adults, yet the neurobiological mechanisms remain unclear. This study investigated whether parental education is related to BMI and depressive scores through brain structural-functional connectivity (SC-FC) coupling.

METHODS: This study included 490 healthy young adults who underwent resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) scans. Parental education was measured as years of schooling, BMI by weight/height2, and depressive scores by the Beck Depression Inventory-II (BDI). SC and FC were derived from DTI and rs-fMRI, respectively. SC-FC coupling was quantified using Spearman's correlation between SC and FC matrices. Associations among variables were examined using Pearson correlation and mediation analyses.

RESULTS: Paternal education was significantly correlated with BMI (r = 0.10, P < 0.05) and depressive scores (r = -0.09, P < 0.05). Additionally, paternal education, BMI, and depressive scores were positively associated with SC-FC coupling in the right inferior parietal lobule (IPL, r = 0.19, corrected P < 0.001; r = 0.12, corrected P < 0.05; r = 0.10, corrected P < 0.05, respectively). Mediation analysis showed that the right IPL statistically mediated the associations of paternal education with both BMI (indirect effect = 0.01, 95% confidence interval (CI): 0.001-0.04) and depressive scores (indirect effect = 0.01, 95% CI: 0.001-0.03).

CONCLUSION: In this cross-sectional study, paternal education was associated with BMI and depressive scores, with SC-FC coupling in the right IPL statistically mediating these associations. No corresponding effects were observed for maternal education. These findings suggest a potential neural pathway linking socioeconomic factors to physical and mental health outcomes.

CLINICAL TRIAL NUMBER: Not applicable.

PMID:42760514 | DOI:10.1186/s12888-026-08360-y

Transl Psychiatry. 2026 Sep 2;16(1):473. doi: 10.1038/s41398-026-04401-y.

ABSTRACT

Individuals with methamphetamine use disorder (MUD) exhibited functional and structural brain recovery during abstinence. However, longitudinal neural changes of large-scale brain networks after prolonged abstinence remain unclear. Here, energy landscape analysis was applied to resting-state fMRI to characterize dominant activity patterns in 41 healthy controls and 40 individuals with MUD at baseline and after prolonged abstinence. We compared the dynamic characteristics of these patterns across groups and stages. Support vector regression model was constructed using baseline dynamic indices to predict craving changes after prolonged abstinence. We found that individuals with MUD exhibited rigid brain dynamics, which were correlated with abnormal brain network coordination and behaviors. Following prolonged abstinence, neural flexibility showed partial improvement, and dynamic indices could predict longitudinal craving changes. We revealed atypical brain network dynamics and their partial recovery during prolonged abstinence in MUD and suggested that dynamic indices could serve as biomarkers for predicting craving changes.

PMID:42760282 | DOI:10.1038/s41398-026-04401-y

Neuroimage. 2026 Sep 18:122246. doi: 10.1016/j.neuroimage.2026.122246. Online ahead of print.

ABSTRACT

Functional connectomics has advanced our understanding of child development, neurodiversity, and brain organization. Most studies assume that collected fMRI data approximate the stable, trait-like connectome of interest. Here, we asked how stable a young child's functional connectome is, how stability is affected by scan paradigm (rest vs. passive viewing) and age, and how much data are needed to estimate a "stable connectome." We addressed these questions using a densely sampled single-subject dataset and a multi-subject pediatric cohort. We first collected 25 hours of resting-state and passive-viewing data from a single child, ages 5 to 9. Split-half connectome stability was near perfect (r = 0.98), even when data were split chronologically (r = 0.97). Connectome similarity differed across scan paradigms and collection years. Consistent patterns were observed in the multi-subject cohort, where individual-specific effects substantially outweighed movie-specific effects. A linear mixed-effects model showed that greater head motion and longer scan intervals were associated with lower session-to-session stability, whereas older age was associated with greater stability. A whole-connectome similarity threshold of r ≥ 0.8 was reached with 13.5 minutes of raw passive-viewing data, although many high-motion recordings failed to reach this threshold within the available recording duration. Similarly, ∼15.4 minutes of post-censor data were required for 70% of participants in the multi-subject cohort to reach r ≥ 0.7, while most high-motion scans failed to reach this threshold. Allowing for typical motion-related data loss (∼22% of volumes censored), these findings support approximately 20-minute acquisitions to obtain about 15 minutes of usable data, with longer recordings or multiple sessions for children with elevated head motion.

PMID:42759782 | DOI:10.1016/j.neuroimage.2026.122246

J Psychoactive Drugs. 2026 Sep 18:1-11. doi: 10.1080/02791072.2026.2729619. Online ahead of print.

ABSTRACT

Due to the psychotropic properties of kratom (Mitragyna speciosa), further studies are needed to measure its neurobiological impacts. This exploratory study employed resting-state functional magnetic resonance imaging (rs-fMRI) to examine alterations in brain activity and functional connectivity (FC) among kratom users. A total of 43 respondents were recruited (22 regular kratom users and 21 healthy controls). RS-fMRI data were acquired using a 1.5T GE Signa HDxt scanner. Preprocessing and analysis were performed with Statistical Parametric Mapping 12 (SPM 12) and CONN toolbox. Group differences in the low-frequency fluctuations (LFFs) and FC were examined. Kratom users exhibited reduced LFF in brain regions critical to the default mode network (DMN), cognitive control, and self-referential processing, including the precuneus, superior frontal gyrus, and cerebellar and cingulate cortices. They also showed increased FC between salience and cerebellar networks, specifically in the posterior cerebellum, and left rostral prefrontal cortex (RPFC). Chronic kratom consumption may alter brain activity, especially in areas linked to the DMN, cognition, and reward processing. Enhanced FC between salience and cerebellar networks may reflect compensatory mechanisms or adaptations to kratom's effects. Further research is crucial to elucidate the underlying mechanisms and potential implications for cognitive function and addictive behaviors.

PMID:42757738 | DOI:10.1080/02791072.2026.2729619

Rhinology. 2026 Sep 18. doi: 10.4193/Rhin25.519. Online ahead of print.

ABSTRACT

BACKGROUND: Olfactory training (OT) has emerged as a first-line non-pharmacological treatment for olfactory dysfunction. This study aimed to determine whether multisensory stimulation during OT improves olfactory recovery and to explore the underlying neurobiological mechanisms.

METHODOLOGY: Individuals aged 18-80 years with post-viral or idiopathic olfactory dysfunction lasting for at least one month were recruited. Participants were allocated to either multisensory OT (MOT, odor-congruent video clips during OT) or conventional OT (COT) for three months. A subset of participants underwent resting-state fMRI at baseline and post-training to evaluate changes in olfactory network connectivity, using the piriform cortex and orbitofrontal cortex as the predefined seed regions. Statistical analyses were performed using repeated-measures ANOVA to evaluate changes over time and between groups.

RESULTS: Ninety-five patients (MOT=51, COT=44) were included. Significant improvements in odor discrimination and composite TDI scores were observed across participants without significant session x group interaction. In the MOT group, pre-post gains were observed in odor discrimination, identification, and TDI. In the MRI subgroup (MOT=21, COT=18), MOT was associated with reduced functional connectivity between the right orbitofrontal cortex and the superior occipital, superior temporal, and postcentral gyri.

CONCLUSIONS: MOT was associated with olfactory improvement over the training period. Although between-group differences were not statistically significant, exploratory neuroimaging findings suggest post-MOT functional reorganization between olfactory and visual, auditory, and somatosensory regions. Incorporating multisensory stimulation into OT warrants further investigation as a potential strategy for olfactory rehabilitation.

PMID:42757552 | DOI:10.4193/Rhin25.519

Brain Behav Immun Health. 2026 Sep 10;57:101351. doi: 10.1016/j.bbih.2026.101351. eCollection 2026 Nov.

ABSTRACT

Prenatal inflammation is a recognized risk factor for autism spectrum disorder (ASD), but the neural pathways linking in utero immune exposure to later outcomes remain unclear. We examined whether chronic placental inflammation (CPI), a sustained immune response within the placenta, is associated with fetal brain functional connectivity differences and later ASD traits. A cohort of 105 pregnant individuals (85.7% African American/Black, 1.0% Asian American, 4.8% Bi-racial, 4.8% White, 1.0% Other, 2.9% Missing) underwent fetal resting-state fMRI between 24 and 38 weeks' gestation. After delivery, placental tissues were evaluated by expert pathologists for CPI lesions. Fetuses exposed to CPI (n = 44) showed significant differences in resting-state functional connectivity (RSFC) compared to non-exposed fetuses (n = 61) across ten network pairs, with the greatest effects in prefrontal, cerebellar, visual, and motor regions. These connectivity differences were associated with behavioral outcomes: cerebellar-medial visual RSFC was the strongest prenatal predictor of ASD traits at age 3. An exploratory structural equation modeling indicated that CPI was associated with reduced cerebellum-medial visual RSFC, which was associated with higher ASD trait scores, though the indirect pathway did not reach statistical significance. This study provides the first human evidence that chronic placental inflammation is associated with large-scale fetal brain network differences that are also associated with autism traits, suggesting that prenatal immune activity may be relevant to neurodevelopmental trajectories.

PMID:42756825 | PMC:PMC13583612 | DOI:10.1016/j.bbih.2026.101351

Front Neurol. 2026 Sep 3;17:1796739. doi: 10.3389/fneur.2026.1796739. eCollection 2026.

ABSTRACT

BACKGROUND: Migraine is a prevalent and disabling neurological disorder. Resting-state functional magnetic resonance imaging (rs-fMRI) studies have investigated regional intrinsic neural activity alterations in migraine but have often yielded inconsistent findings. Emerging network perspectives suggest that brain disorders may be better understood through disruptions in large-scale networks.

METHODS: This systematic review included 31 rs-fMRI studies (1,238 migraine patients; 1,005 controls; 302 altered ALFF/ReHo coordinates) to clarify these discrepancies. Using functional connectivity network mapping (FCNM) with Human Connectome Project data (n = 1,093), we identified that heterogeneous regional intrinsic neural activity alterations in migraine converge onto common brain functional networks. Spatial relationships between the identified brain networks and the distribution of major neurotransmitter receptors/transporters were subsequently characterized using the Juspace toolbox.

RESULTS: FCNM analysis revealed that heterogeneous regional intrinsic neural activity alterations reported in migraine studies mapped to common brain functional networks, particularly within visual, somatomotor, and attention systems. The FCNM-identified migraine network exhibited significant spatial correlations with normative distributions of metabotropic glutamate receptor 5 (mGluR5), 5-hydroxytryptamine receptor 2A (5-HT2A), and noradrenaline transporter (NAT).

CONCLUSION: These findings suggest that intrinsic neural dysfunctions in migraine map to large-scale networks with multi-neurochemical susceptibility. This framework suggests that heterogeneous regional intrinsic activity alterations in migraine are preferentially connected to visual, somatomotor, and attentional systems and are spatially aligned with normative neurochemical maps. These findings are hypothesis-generating and should not be interpreted as evidence of causality or patient-specific receptor alterations.

PMID:42755892 | PMC:PMC13581937 | DOI:10.3389/fneur.2026.1796739

Front Nutr. 2026 Sep 3;13:1917977. doi: 10.3389/fnut.2026.1917977. eCollection 2026.

ABSTRACT

BACKGROUND: Obesity affects the brain, but most neuroimaging studies examine a single modality, leaving it unclear whether obesity-related functional, microstructural, and perfusion abnormalities co-localize. We combined three modalities across the normal-weight-overweight-obese spectrum.

METHODS: Of 80 adults enrolled, 10 were excluded (sleep, incomplete acquisition, artifacts), leaving 70 (normal-weight, n = 27; overweight, n = 21; obese, n = 22), who did not differ in age, sex, or education. All underwent resting-state functional MRI, diffusion tensor imaging, and 3D arterial spin labeling at 3.0 T, yielding amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), functional connectivity (FC), fractional anisotropy (FA), mean (MD), axial, and radial diffusivity (RD), and cerebral blood flow (CBF). Group differences were assessed with covariate-adjusted models; diffusion metrics were tested across all 48 atlas regions with false-discovery-rate (FDR) correction, and body mass index (BMI) relationships by whole-sample regression without prior region selection. Spatial convergence was tested by minimum-statistic conjunction and random-displacement permutation.

RESULTS: Obese participants showed lower ALFF than controls in the cerebellar posterior lobe (vermis, left lobule VIII, right Crus II) and left superior frontal gyrus, higher ALFF in the bilateral parahippocampal gyri, lower ReHo in the left superior frontal gyrus, and lower ReHo than overweight participants in the left middle cingulate gyrus. No regional diffusion difference survived FDR correction, but BMI predicted FA, MD, and RD in the right inferior cerebellar peduncle in whole-sample regression (all q < 0.015), the only associations to survive. CBF was reduced in the cerebellar posterior lobe and increased in the left inferior frontal and right postcentral gyri. ALFF-CBF overlap there exceeded chance at every threshold, reaching 43.1-fold at P < 0.001, confirmed by conjunction and permutation (P = 0.0002-0.0008); peak-level in the left lobule VIII and right Crus II, but atlas-level only at the vermis. FC showed no group differences.

CONCLUSION: Overweight and obesity are associated with spatially convergent functional, microstructural, and perfusion abnormalities preferentially involving cerebellar and cortico-limbic regions, scaling continuously with BMI in the right inferior cerebellar peduncle. Because cognition was assessed only by the MMSE, these roles suggest hypotheses rather than conclusions about cognition.

PMID:42755846 | PMC:PMC13581818 | DOI:10.3389/fnut.2026.1917977

Front Neurol. 2026 Sep 3;17:1865496. doi: 10.3389/fneur.2026.1865496. eCollection 2026.

ABSTRACT

INTRODUCTION: This study investigated the immediate effects of LiuZiJue breathing practice on executive control and its associated neural correlates using a multimodal approach combining behavioral testing, functional near-infrared spectroscopy (fNIRS), resting-state functional MRI (rs-fMRI), and transcranial magnetic stimulation (TMS).

METHODS: A randomized crossover design was conducted in 20 healthy young adults. Participants completed Stroop task performance and TMS assessments under LiuZiJue and control conditions (eyes-closed rest). Resting-state fMRI and task-based fNIRS recordings were additionally acquired to examine brain activity and functional connectivity changes.

RESULTS: LiuZiJue significantly reduced Stroop reaction time compared with both baseline and control conditions (p < 0.05), without affecting accuracy. fNIRS results showed decreased oxygenated hemoglobin (HBO) signals in the prefrontal cortex, premotor area, supplementary motor area, and primary motor cortex during the LiuZiJue task (p < 0.05). Resting-state fMRI revealed altered regional brain activity and functional connectivity (FDR-corrected, p < 0.05), including decreased zALFF in precentral gyrus, middle temporal gyrus, postcentral gyrus, and insula and increased zALFF in cerebellar vermis lobule IX. Functional connectivity analysis indicated significant alterations in interregional connectivity (FDR-corrected, p < 0.05). TMS results indicated a significant prolongation of cortical silent period (CSP, p < 0.01), while short-interval intracortical inhibition (SICI) remained unchanged.

CONCLUSION: LiuZiJue was associated with changes in behavioral performance, cortical excitability, and large-scale brain activity in healthy young adults. These findings suggest potential modulation of executive-related neural processes; however, causal interpretations and underlying mechanisms should be considered cautiously given the exploratory nature of the study and limited sample size.

CLINICAL TRIAL REGISTRATION: https://www.chictr.org.cn/searchprojEN.html, identifier: ChiCTR2400087145.

PMID:42755788 | PMC:PMC13581813 | DOI:10.3389/fneur.2026.1865496