Most recent paper

Front Neurol. 2026 Jan 12;16:1684824. doi: 10.3389/fneur.2025.1684824. eCollection 2025.

ABSTRACT

BACKGROUND: Bell's palsy (BP) is an acute facial palsy caused by the inflammation of the facial nerve. Previous research indicates that the striatum may be involved following acute peripheral nerve injury, and acupuncture is a recognized treatment for BP. However, it remains unclear whether the striatum is functionally engaged during the recovery process with acupuncture.

METHOD: Using resting-state functional MRI (fMRI), we investigated striatum-related neural activity in BP patients by measuring two key metrics of local brain function: regional homogeneity (ReHo, reflecting local neural synchrony) and fractional amplitude of low-frequency fluctuations (fALFFs, reflecting the intensity of spontaneous neural activity). We further examined corticostriatal and internal striatal functional connectivity. Patients underwent fMRI scans before and immediately after (15 min following needle withdrawal) an acupuncture treatment session to capture dynamic changes.

RESULTS: The post-treatment scan was associated with significant alterations in both ReHo and fALFFs, including increased fALFFs in the left postcentral gyrus and the precentral gyrus and increased ReHo in the right cerebellum (Crus2). Several striatal subregions also exhibited significantly enhanced internal connectivity.

CONCLUSION: Our results indicate that the striatum undergoes functional alterations during the recovery period, which may provide preliminary insight into neural processes associated with treatment for BP.

PMID:41602988 | PMC:PMC12832370 | DOI:10.3389/fneur.2025.1684824

Front Neurol. 2026 Jan 12;16:1618388. doi: 10.3389/fneur.2025.1618388. eCollection 2025.

ABSTRACT

Right temporal lobe epilepsy (rTLE) is associated with disruptions in functional brain networks and structural connectivity, yet underlying mechanisms remain unclear. This study investigated the alterations in modular interactions, connector hub (CH) topology, and related structural changes in rTLE patients. It included 30 rTLE patients and 30 matched healthy controls (HCs), all of whom underwent resting-state functional MRI (rs-fMRI), diffusion-weighted imaging (DWI), and volumetric MRI (vMRI). Functional networks were analyzed by assessing modular interactions, functional connectivity (FC), and CH topological properties. White matter microstructural differences were examined using tract-based spatial statistics (TBSS), while cortical morphometry was evaluated in key CH regions. Compared with HCs, rTLE patients showed reduced modularity (Q), small-world index (σ), and clustering coefficient (γ), along with enhanced modular interactions, particularly between the supplementary motor area (SMA) and inferior temporal gyrus (ITG). CHs exhibited increased participation coefficient (PC), within-module degree z-score (WMD), and local efficiency. Structural analyses revealed reduced fractional anisotropy (FA) and increased radial diffusivity (RD) in the corpus callosum, as well as cortical thinning in the ITG and SMA. We confirmed that rTLE is characterized by disrupted modular architecture and CH topology, leading to network reorganization and associated structural abnormalities. These findings offer new insights into rTLE pathophysiology.

PMID:41602986 | PMC:PMC12832528 | DOI:10.3389/fneur.2025.1618388

Front Neurol. 2026 Jan 12;16:1738198. doi: 10.3389/fneur.2025.1738198. eCollection 2025.

ABSTRACT

INTRODUCTION: Cognitive impairment is a common complication of chronic kidney disease (CKD), but its underlying mechanisms are not fully understood. This study aims to investigate the glymphatic system function in CKD patients with and without cognitive impairment (CI) by analyzing the coupling between the global blood oxygen level-dependent (gBOLD) signal and the cerebrospinal fluid (CSF) signal using resting-state functional magnetic resonance imaging (rs-fMRI).

METHODS: Twenty-nine patients with CKD were enrolled (19 with CI and 10 without), along with 22 healthy controls (HCs). All patients underwent high-resolution structural MRI and rs-fMRI scans. The gBOLD-CSF coupling was quantified by calculating the maximum negative correlation within a predefined time-lag range between the gBOLD signal and the fourth ventricular CSF signal. The gBOLD-CSF coupling was compared between the CKD and HC groups using analysis of covariance (ANCOVA), adjusting for age, sex, education, and mean framewise displacement (FD). The difference between patients with CKD with and without CI was assessed using ANCOVA, after adjusting for age, sex, education, hypertension, diabetes, and mean FD. Partial correlation analysis was performed to explore the associations between gBOLD-CSF coupling and clinical indicators, such as estimated glomerular filtration rate (eGFR), Montreal Cognitive Assessment (MoCA) scores, and other laboratory data.

RESULTS: After adjusting for covariates, gBOLD-CSF coupling was significantly lower in the CKD group than in the HC group (β = -0.178, p = 0.003). This finding remained robust in sensitivity analyses adjusting for hypertension and diabetes. Within the CKD group, patients with CI had significantly lower gBOLD-CSF coupling than those without CI (β = -0.135, p = 0.040). Correlation analyses revealed that gBOLD-CSF coupling tended to be positively associated with hemoglobin, MoCA score, and eGFR, and negatively associated with blood urea and creatinine; however, none of these correlations reached statistical significance after false discovery rate correction (all q > 0.05).

CONCLUSION: Patients with CKD exhibit impaired glymphatic system function, manifested as reduced gBOLD-CSF coupling, which is associated with the severity of CI. These findings support the hypothesis that impaired glymphatic clearance may contribute to cognitive decline in CKD via the kidney-brain axis. Larger longitudinal studies are needed to validate its clinical significance.

PMID:41602980 | PMC:PMC12832948 | DOI:10.3389/fneur.2025.1738198

IBRO Neurosci Rep. 2024 Dec 4;19:1128-1140. doi: 10.1016/j.ibneur.2024.11.014. eCollection 2025 Dec.

ABSTRACT

Mapping consistent longitudinal intrinsic connectivity networks (ICNs) is crucial for understanding brain functional development over various life stages. However, achieving consistent longitudinal ICNs has been challenging due to the lack of methodologies that maintain temporal consistency. To address this gap, we introduce an innovative approach named Longitudinal Sparse Dictionary Learning (LSDL). This method utilizes an additional Frobenius norm to bridge gaps between consecutive ICNs, facilitating the continuous transfer of the learned feature matrix to subsequent stages. Moreover, Matrix Backpropagation (MBP) is employed to effectively mitigate potential accumulative errors. Our validation results demonstrate that LSDL can successfully extract 21 consistent longitudinal ICNs in macaque brains. In comparative empirical evaluations with established methodologies, Fast Independent Component Analysis (FICA) and Sparse Dictionary Learning (SDL), LSDL showcases superior efficacy in modeling longitudinal functional Magnetic Resonance Imaging (fMRI) data. This approach opens new avenues for research into developmental brain dynamics and neurodegenerative disorders, providing a robust framework for tracking the evolution of brain connectivity over time.

PMID:41601563 | PMC:PMC12834029 | DOI:10.1016/j.ibneur.2024.11.014

Front Neurosci. 2026 Jan 12;19:1686273. doi: 10.3389/fnins.2025.1686273. eCollection 2025.

ABSTRACT

BACKGROUND: Patients with active ulcerative colitis (UC) frequently exhibit emotional disturbances and cognitive deficits. However, the neurobiological basis of these manifestations remains poorly understood. This study investigates neurostructural and functional alterations in UC patients using multimodal MRI to identify potential neural correlates.

METHODS: We enrolled 45 active-stage UC patients and 48 healthy controls, all of whom underwent structural MRI, resting-state functional MRI (rs-fMRI), neurocognitive testing, and clinical assessments. Regional neural activity was evaluated using fractional amplitude of low-frequency fluctuations (fALFF), while gray matter volume (GMV) was analyzed to assess structural differences. Brain regions showing significant abnormalities were further examined for correlations with cognitive performance and clinical scale results.

RESULTS: Compared to the healthy control group, the UC patient group exhibited higher scores in PSQI, PSS, SAS, and SDS. Furthermore, the UC patient group displayed varying degrees of impairment in attention, working memory, and executive function. The GMV of the bilateral thalamus in UC patients decreased, while the fALFF values in bilateral posterior cingulate gyrus (PCG) and left lingual gyrus increased. Conversely, the fALFF values in multiple brain regions, including bilateral frontal lobes, the right temporal lobe, and the right inferior parietal lobule, were decreased. Multiple brain regions with reduced activity in the bilateral frontal lobes are closely related to emotions and executive control, while the increased activity in the bilateral PCG is strongly correlated with stress and anxiety. The reduction GMV in bilateral thalamic is associated with working memory and attention.

CONCLUSION: Cognitive impairment and emotional abnormalities in UC are associated with the functional activity and structure of multiple brain regions, particularly in the bilateral frontal lobes, PCG and thalamus. These findings provide potential neuroimaging evidence for the activation of the gut-brain axis due to chronic inflammation, and that certain brain regions may be considered as key targets for predicting cognitive impairment for UC patients.

PMID:41601538 | PMC:PMC12832693 | DOI:10.3389/fnins.2025.1686273

Front Neurosci. 2026 Jan 12;19:1714446. doi: 10.3389/fnins.2025.1714446. eCollection 2025.

ABSTRACT

PURPOSE: Herpes simplex encephalitis (HSE) is a severe neurological condition associated with significant cognitive impairment and structural brain changes. This study aimed to investigate microstructural and functional connectivity (FC) alterations in HSE patients and their association with cognitive function, cerebrospinal fluid (CSF) parameters, and inflammatory markers.

METHODS: A single-center cohort study was conducted with 73 HSE patients and 76 cognitively unimpaired controls. Voxel-based morphometry (VBM) and resting-state functional MRI (rs-fMRI) were used to assess VBM grey matter volume (GMV) and FC. Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA). CSF pressure, protein levels, and proinflammatory cytokines (IL-6, IL-1β, IL-2, IL-4, IL-5, IL-10) were measured. Statistical analyses included group comparisons and multivariable regression adjusted for age, gender, and hypertension.

RESULTS: HSE patients exhibited significant GMV reductions in the right hippocampal gyrus, left precuneus, and left posterior cingulate gyrus (all p < 0.001). Enhanced FC was observed between the left hippocampus and medial prefrontal cortex (mPFC), while weakened connectivity was noted between the left precuneus, posterior cingulate gyrus, and mPFC in controls. Cognitive scores (MoCA) were lower in HSE patients (p < 0.001) and positively correlated with GMV and FC metrics (p < 0.05). Elevated CSF pressure, protein, and proinflammatory cytokines (particularly IL-6) were negatively associated with cerebral metrics (p < 0.001). A significant interaction between IL-6 and cerebral metrics further influenced cognitive outcomes (p < 0.05).

CONCLUSION: HSE is associated with distinct microstructural and functional connectivity changes that are correlated with cognitive impairment and neuroinflammation. Our findings suggest a potential interaction between IL-6 levels, cerebral alterations, and cognitive dysfunction, which may inform the exploration of neuroimaging and inflammatory biomarkers in personalized therapeutic strategies. However, these represent observational associations, and further prospective studies are needed to validate these findings and establish causal relationships.

PMID:41601536 | PMC:PMC12833072 | DOI:10.3389/fnins.2025.1714446

Front Neurosci. 2026 Jan 12;19:1629305. doi: 10.3389/fnins.2025.1629305. eCollection 2025.

ABSTRACT

OBJECTIVE: This review aimed to summarize neuroimaging evidence on the effects of acupuncture in post-ischemic stroke cognitive impairment (PISCI) and to explore its potential neural mechanisms.

METHODS: A systematic search was conducted across multiple databases, including China National Knowledge Infrastructure (CNKI), SinoMed (China Biology Medicine Disc), the Chinese Scientific Journal Database (VIP), Wanfang Data, PubMed, the Cochrane Library, Embase, and Web of Science. Studies were selected according to inclusion and exclusion criteria. Risk of bias was assessed for all eligible studies.

RESULTS: Eight studies met the inclusion criteria. These studies utilized resting-state functional magnetic resonance imaging (rs-fMRI) and magnetic resonance spectroscopy (MRS) to investigate the effects of acupuncture on brain activity and metabolic changes. The neuroimaging findings showed that all studies focused on the sustained effects of acupuncture on brain functional activity.

CONCLUSIONS: This review provides preliminary neuroimaging evidence supporting the potential benefits of acupuncture for PISCI. The findings suggest that the possible mechanisms of acupuncture for PISCI involve changes in the activity and enhanced functional connectivity of cognition-related brain regions. Additionally, acupuncture may influence brain networks and regulate neurochemical metabolites within cognition-related regions. However, as this field remains in its early stages, further validation is needed. Future studies should focus on well-designed, multicenter randomized controlled trials (RCTs) with large sample sizes and incorporate multiple neuroimaging techniques to better clarify and verify the neural mechanisms of acupuncture in PISCI.

SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier: CRD420250652194.

PMID:41601528 | PMC:PMC12832758 | DOI:10.3389/fnins.2025.1629305

Sensors (Basel). 2026 Jan 21;26(2):716. doi: 10.3390/s26020716.

ABSTRACT

Independent vector analysis (IVA) has emerged as a powerful tool for fusing and analyzing functional magnetic resonance imaging (fMRI) data. Applying IVA to multi-task fMRI data enhances analytical power by capturing the relationships across different tasks in order to discover their underlying multivariate relationship to one another. Incorporation of prior information into IVA enhances the separability and interpretability of estimated components. In this paper, we demonstrate successful fusion of multi-task fMRI feature data under two settings: constrained IVA and constrained transposed IVA (tIVA). We show that using these methods for fusing multi-task fMRI feature data offers novel ways to improve the quality and interpretability of the analysis. While constrained IVA extracts components linked to distinct brain networks, tIVA reverses the roles of spatial components and subject profiles, enabling flexible analysis of behavioral effects. We apply both methods to a multi-task fMRI dataset of 247 subjects. We demonstrate that for task-based fMRI, structural MRI (sMRI) references provide a better match for task data than resting-state fMRI (rs-fMRI) references, and using sMRI priors improves identification of group differences in task-related networks, such as the sensory-motor network during the Auditory Oddball (AOD) task. Additionally, constrained tIVA allows for targeted investigation of the effects of behavioral variables by applying them individually during the analysis. For instance, by using the letter number sequence subtest, a measure of working memory, as a behavioral constraint in tIVA, we observed significant group differences in the auditory and sensory-motor networks during the AOD task. Results show that the use of two constrained approaches, guided by well-aligned structural and behavioral references, enables a more comprehensive analysis of underlying brain function as modulated by task.

PMID:41600509 | DOI:10.3390/s26020716

J Clin Med. 2026 Jan 22;15(2):909. doi: 10.3390/jcm15020909.

ABSTRACT

Introduction: Massage therapy delivers structured mechanosensory input that can influence brain function, yet the central mechanisms and potential for neuroplastic change have not been synthesized across neuroimaging modalities. This mechanistic review integrates evidence from electroencephalography (EEG), functional MRI (fMRI), and functional near-infrared spectroscopy (fNIRS) to map how massage alters human brain activity acutely and over time and to identify signals of longitudinal adaptation. Materials and Methods: We conducted a scoping, mechanistic review informed by PRISMA/PRISMA-ScR principles. PubMed/MEDLINE, Cochrane Library, Google Scholar, and ResearchGate were queried for English-language human trials (January 1990-July 2025) that (1) delivered a practitioner-applied manual massage (e.g., Swedish, Thai, shiatsu, tuina, reflexology, myofascial techniques) and (2) measured brain activity with EEG, fMRI, or fNIRS pre/post or between groups. Non-manual stimulation, structural-only imaging, protocols, and non-English reports were excluded. Two reviewers independently screened and extracted study, intervention, and neuroimaging details; heterogeneity precluded meta-analysis, so results were narratively synthesized by modality and linked to putative mechanisms and longitudinal effects. Results: Forty-seven studies met the criteria: 30 EEG, 12 fMRI, and 5 fNIRS. Results: Regarding EEG, massage commonly increased alpha across single sessions with reductions in beta/gamma, alongside pressure-dependent autonomic shifts; moderate pressure favored a parasympathetic/relaxation profile. Connectivity effects were state- and modality-specific (e.g., reduced inter-occipital alpha coherence after facial massage, preserved or reorganized coupling with hands-on vs. mechanical delivery). Frontal alpha asymmetry frequently shifted leftward (approach/positive affect). Pain cohorts showed decreased cortical entropy and a shift toward slower rhythms, which tracked analgesia. Somatotopy emerged during unilateral treatments (contralateral central beta suppression). Adjuncts (e.g., binaural beats) enhanced anti-fatigue indices. Longitudinally, repeated programs showed attenuation of acute EEG/cortisol responses yet improvements in stress and performance; in one program, BDNF increased across weeks. In preterm infants, twice-daily massage accelerated EEG maturation (higher alpha/beta, lower delta) in a dose-responsive fashion; the EEG background was more continuous. In fMRI studies, in-scanner touch and reflexology engaged the insula, anterior cingulate, striatum, and periaqueductal gray; somatotopic specificity was observed for mapped foot areas. Resting-state studies in chronic pain reported normalization of regional homogeneity and/or connectivity within default-mode and salience/interoceptive networks after multi-session tuina or osteopathic interventions, paralleling symptom improvement; some task-based effects persisted at delayed follow-up. fNIRS studies generally showed increased prefrontal oxygenation during/after massage; in motor-impaired cohorts, acupressure/massage enhanced lateralized sensorimotor activation, consistent with use-dependent plasticity. Some reports paired hemodynamic changes with oxytocin and autonomic markers. Conclusions: Across modalities, massage reliably modulates central activity acutely and shows convergent signals of neuroplastic adaptation with repeated dosing and in developmental windows. Evidence supports (i) rapid induction of relaxed/analgesic states (alpha increases, network rebalancing) and (ii) longer-horizon changes-network normalization in chronic pain, EEG maturation in preterm infants, and neurotrophic up-shifts-consistent with trait-level recalibration of stress, interoception, and pain circuits. These findings justify integrating massage into rehabilitation, pain management, mental health, and neonatal care and motivate larger, standardized, multimodal longitudinal trials to define dose-response relationships, durability, and mechanistic mediators (e.g., connectivity targets, neuropeptides).

PMID:41598846 | DOI:10.3390/jcm15020909

J Clin Med. 2026 Jan 9;15(2):534. doi: 10.3390/jcm15020534.

ABSTRACT

Background/Objectives: This study aimed to characterize objective sleep measures in subacute acquired brain injury (ABI) and examine if disturbed sleep is associated with poor recovery outcomes. Another objective was to compare the functional connectivity of the brain between ABI poor sleepers and ABI normal sleepers as measured by resting state functional magnetic resonance imaging (rs-fMRI). Methods: This was a pilot, prospective, observational study of ABI subjects compared with age and gender-matched healthy controls. A total of 27 ABI subjects (consisting of ischemic or haemorrhagic stroke, or traumatic injury) were recruited from the outpatient clinics of a tertiary hospital with a neurological centre, and 49 healthy controls were recruited by word-of-mouth referrals. Study procedure involved subjective and objective sleep measures, self-report psychological measures, cognitive tests, and structural and functional MRI of the brain. Results: The frequency of poor-quality sleep was 66.67% in the ABI group and not significantly different from 67.35% in the control group when compared by chi-squared test (p = 0.68). ABI subjects with poor sleep had worse performance on a test of sustained attention (Colour Trails Test 1) than healthy controls with poor sleep when compared by Student's t-test (mean 55.95 s, SD ± 18.48 vs. mean 40.04 s, SD ± 14.31, p = 0.01). Anxious ABI subjects have poorer sleep efficiency and greater time spent awake after sleep onset (WASO). ABI-poor sleepers show significantly greater functional connectivity within a frontoparietal network and bilateral cerebellum. Conclusions: Sleep problems after ABI are associated with poorer cognitive and psychological outcomes. ABI-poor sleepers exhibit altered functional connectivity within regions that contribute to motor planning, attention, and self-referential processes, suggesting that disrupted sleep after ABI may impair the integration of sensorimotor and cognitive control systems, and therefore, impair recovery.

PMID:41598471 | DOI:10.3390/jcm15020534

Brain Sci. 2026 Jan 13;16(1):88. doi: 10.3390/brainsci16010088.

ABSTRACT

Background/Objectives: Anxiety disorders (ADs) affect up to 20% of mothers in the postpartum period, characterized by psychological symptoms (e.g., emotion dysregulation; ER) and physical symptoms (e.g., disrupted bodily awareness). Although Cognitive Behavioural Therapy effectively reduces anxiety and mood symptoms, it shows limited efficacy in addressing ER difficulties and rarely targets interoceptive dysfunction-both common in postpartum ADs. This study evaluates the effectiveness of a brief mindfulness-based intervention in improving anxiety, ER, and interoception in mothers with postpartum ADs. A secondary aim is to examine changes in brain connectivity associated with these domains. Methods: This protocol describes a proof-of-concept randomized controlled trial involving 50 postpartum mothers with ADs. Participants will be randomized to receive either a 4-week mindfulness intervention plus treatment-as-usual (TAU) or TAU alone. Participants in the mindfulness + TAU group will complete a virtual 4-week group intervention adapted from Mindfulness-Based Cognitive Therapy. The TAU group will receive usual care for 4 weeks and then be offered the mindfulness intervention. Self-report measures of anxiety, ER, and interoception will be collected at baseline, post-intervention, and at a 3-month follow-up. Resting-state functional MRI will be conducted at baseline and post-intervention to assess functional connectivity changes. This trial has been registered on ClinicalTrials.gov (NCT07262801). Results: Improvements in anxiety, ER, and interoception are anticipated, along with decreased default mode network, and increased salience network connectivity post-intervention is hypothesized. Conclusions: This study will be the first to examine the combined psychological and neural effects of mindfulness in postpartum ADs, offering a potentially scalable mind-body treatment.

PMID:41594809 | DOI:10.3390/brainsci16010088

Brain Sci. 2025 Dec 30;16(1):55. doi: 10.3390/brainsci16010055.

ABSTRACT

Objectives: Innovative, evidence-based interventions for developmental dyslexia (DD) are necessary. While traditional methods remain valuable, newer approaches, such as cognitive-motor training, show the potential to improve literacy skills for those with DD. Verbal Working Memory-Balance (VWM-B) is a novel cognitive-motor training program that has demonstrated positive effects on reading, cognitive functions, and motor skills in children with DD. This extension study explored the neural mechanisms of VWM-B through voxel-to-voxel intrinsic functional connectivity (FC) analysis in children with DD. Methods: Resting-state fMRI data from 16 participants were collected in a quasi-double-blind randomized clinical trial with control and experimental groups, pre- and post-intervention measurements, and 15 training sessions over 5 weeks. Results: The mixed ANOVA interaction was significant for the right and left postcentral gyrus, bilateral precuneus, left superior frontal gyrus, and left posterior division of the supramarginal and angular gyri. Decreased FC in the postcentral gyri indicates reduced motor task engagement due to automation following VWM-B training. Conversely, increased FC in the bilateral precuneus, left superior frontal gyrus, and left posterior divisions of the supramarginal and angular gyri suggests a shift of cognitive resources from motor tasks to the cognitive functions associated with VWM-B. Conclusions: In conclusion, the study highlights that cognitive-motor dual-task training is more effective than single-task cognitive training for improving cognitive and motor functions in children with DD, emphasizing the importance of postural control and automaticity in dyslexia. The trial for this study was registered on 8 February 2018 with the Iranian Registry of Clinical Trials (IRCT20171219037953N1).

PMID:41594776 | DOI:10.3390/brainsci16010055

Brain Sci. 2025 Dec 23;16(1):16. doi: 10.3390/brainsci16010016.

ABSTRACT

Objectives: With the development of advanced neuroimaging techniques, including resting-state functional magnetic resonance imaging and diffusion tensor imaging, Parkinson's disease (PD) has increasingly been recognized as a complex brain network disorder. In this review, we summarized research on brain networks in PD to elucidate the network abnormalities underlying its four major motor symptoms and to identify the networks modulated by deep brain stimulation (DBS). Materials and Methods: We searched PubMed and Web of Science for the most recent literature on brain network alterations in PD. Eligible studies included those investigating the general PD network (n = 10), symptom-specific networks-tremor-dominant (n = 13), postural instability and gait disorder (n = 9), freezing of gait (n = 9), akinetic-rigidity (n = 3)-as well as DBS-modulated networks (n = 14). Based on these studies, we integrated the findings and used BrainNet Viewer to generate schematic network visualizations. Results: The symptom-specific networks exhibited common abnormalities within the sensorimotor network. Evidence from DBS studies suggested that therapeutic effects were associated with modulation of the motor cortex through both functional and structural connectivity. Moreover, the four motor symptoms each demonstrated distinct network features. Specifically, the tremor network was characterized by widespread alterations in the cortico-thalamic-cerebellar circuitry; the postural instability and gait disorder network showed more severe disruptions within the striatum and visual cortex; the freezing of gait network exhibited disruptions in midbrain regions, notably the pedunculopontine nucleus; and the akinetic-rigidity network involved changes in cognition-related networks, particularly the default mode network. Conclusions: PD motor symptoms exhibit both distinct network features and shared alterations within the sensorimotor network. DBS modulates large-scale brain networks, especially motor-related networks, contributing to the alleviation of motor symptoms. Characterizing symptom-specific networks may support precision DBS target selection and parameter optimization.

PMID:41594737 | DOI:10.3390/brainsci16010016

Entropy (Basel). 2026 Jan 10;28(1):83. doi: 10.3390/e28010083.

ABSTRACT

This work investigates the mechanisms of information transfer underlying causal relationships between brain regions during resting-state conditions in patients with schizophrenia (SCZ). A large fMRI dataset including healthy controls and SCZ patients was analyzed to estimate directed information flow using local Transfer Entropy (TE). Four functional interaction patterns-referred to as rules-were identified between brain regions: activation in the same state (ActS), activation in the opposite state (ActO), turn-off in the same state (TfS), and turn-off in the opposite state (TfO), indicating a dynamics toward converging (Acts/Tfs = S) and diverging (ActO/TfO = O) states of brain regions. These interactions were integrated within a multiplex network framework, in which each rule was represented as a directed network layer. Our results reveal widespread alterations in the functional architecture of SCZ brain networks, particularly affecting schizophrenia-related systems such as bottom-up sensory pathways and associative cortical dynamics. An imbalance between S and O rules was observed, leading to reduced network stability. This shift results in a more randomized functional network organization. These findings provide a mechanistic link between excitation/inhibition (E/I) imbalance and mesoscopic network dysconnectivity, in agreement with previous dynamic functional connectivity and Dynamic Causal Modeling (DCM) studies. Overall, our approach offers an integrated framework for characterizing directed brain communication patterns and psychiatric phenotypes. Future work will focus on systematic comparisons with DCM and other functional connectivity methods.

PMID:41593990 | DOI:10.3390/e28010083

Tomography. 2025 Dec 23;12(1):2. doi: 10.3390/tomography12010002.

ABSTRACT

Objective: This study aimed to investigate the functional connectivity (FC) of three amygdala subregions-the laterobasal amygdala (LBA), centromedial amygdala (CMA), and superficial amygdala (SFA)-with large-scale brain networks in individuals with schizophrenia (SCZ) compared to healthy controls (HC). Methodology: Resting-state functional magnetic resonance imaging (rs-fMRI) data were obtained from 100 participants (50 SCZ, 50 HC) with balanced age and gender distributions. FC between amygdala subregions and target functional networks was assessed using a region-of-interest (ROI)-to-ROI approach implemented in the CONN toolbox. Result: Connectivity patterns of the LBA, CMA, and SFA differed between SCZ and HC groups. After false discovery rate (FDR) correction (p < 0.05), SCZ patients exhibited significantly increased FC between the left CMA and both the default mode network (DMN) and the visual network (VN). In contrast, decreased FC was observed between the right LBA and the sensorimotor network (SMN) in SCZ compared with HC. Conclusions: These findings reveal novel FC alterations linking amygdala subregions with large-scale networks in schizophrenia. The results underscore the importance of examining the amygdala as distinct functional subregions rather than as a single structure, offering new insights into the neural mechanisms underlying SCZ.

PMID:41591135 | DOI:10.3390/tomography12010002

J Alzheimers Dis. 2026 Jan 27:13872877251411478. doi: 10.1177/13872877251411478. Online ahead of print.

ABSTRACT

BackgroundIndividuals with mild cognitive impairment (MCI) are at an increased risk of developing Alzheimer's disease. Anatomical and functional brain alterations associated with this condition are still elusive.ObjectiveThis study explored the cognitive correlates of cortical thickness, white matter (WM) volume, and resting-state connectivity among people with MCI.MethodsA total of 56 older participants (aged 51 to 92 years) with amnestic MCI were recruited. Cognitive abilities were measured using the Trail Making Task, the Stroop Color-Word Test, the Forward and Backward Digit Span test, and computerized n-back tasks. Morphometry was used to measure cortical thickness and WM volume from 3 T MR images, while functional connectivity was measured using resting-state fMRI and calculated using Independent Component Analysis. Voxel-wise regressions were used to test associations between cognitive scores and brain measures.ResultsWorse working memory updating (n-back) performance was associated with lower cortical thickness of the left middle temporal gyrus. Additionally, at a lower demand, working memory performance was linked to frontoparietal network (FPN) intrinsic connectivity, while WM volume within the anterior segment of the left arcuate fasciculus and default mode network (DMN) resting-state connectivity were relevant when the demand was higher. Lower DMN connectivity was also associated with worse conflict monitoring (Stroop) performance (all cluster-corrected ps < 0.05).ConclusionsThe findings highlight the relevance of the perisylvian region to working memory updating and conflict monitoring in people with MCI.

PMID:41589476 | DOI:10.1177/13872877251411478

J Affect Disord. 2026 Jan 24:121229. doi: 10.1016/j.jad.2026.121229. Online ahead of print.

ABSTRACT

BACKGROUND: Visual cortical dysfunction has been implicated in the early stages of psychosis and associated with psychotic symptoms. However, the functional connectivity (FC) of visual regions in early-onset bipolar disorder (EOBD) remains poorly understood. This study aimed to examine visual-related FC alterations in EOBD and explore their associations with psychiatric symptoms and clinical characteristics.

METHODS: Eighty-eight EOBD individuals and 56 healthy controls (HCs) underwent resting-state functional MRI. Visual cortical regions were selected by seeds from a probabilistic visual atlas. Twenty-five seed-based FC were compared between groups. Partial correlations with multiple comparison corrections were conducted to examine associations between altered FC and psychiatric symptoms in EOBD.

RESULTS: Compared to HCs, 14 visual cortical seeds showed higher FC with frontal and posterior temporal areas, while 5 visual cortical seeds showed lower FC with temporal and sensorimotor related regions. Higher psychotic positive, negative, and general scores were significantly associated with higher FC in visual and frontal regions, particularly involving the right lateral occipital complex area 1 (LO1), LO2, human middle temporal visual area (hMT/V5), intraparietal sulcus (IPS5), precentral gyri, and superior frontal gyri.

CONCLUSION: Individuals with EOBD exhibited altered visual system connectivity, characterized by higher FC with frontal regions and lower FC with sensorimotor and emotion regulation related regions. These findings suggest that visual-related FC abnormalities may emerge in the early course of BD and are associated with psychotic symptoms, potentially serving as early markers of vulnerability to psychosis.

PMID:41587694 | DOI:10.1016/j.jad.2026.121229

Front Syst Neurosci. 2026 Jan 8;19:1713434. doi: 10.3389/fnsys.2025.1713434. eCollection 2025.

ABSTRACT

OBJECTIVES: Although neuroticism is a major risk factor for adverse health outcomes, its neural basis is obscured by inconsistent findings from studies of regional gray matter volume (GMV) correlates. This study sought to identify convergent functional brain networks underlying these heterogeneous GMV correlates using functional connectivity network mapping (FCNM), and to explore their neurochemical basis.

METHODS: We systematically identified 10 voxel-based morphometry (VBM) studies (N = 1,595) reporting neuroticism-associated GMV coordinates. Using resting-state fMRI data from 1,093 healthy Human Connectome Project participants, FCNM was applied to map functional connectivity patterns associated with these coordinates. Overlap with canonical networks was assessed. The Juspace toolbox explored spatial relationships between identified networks and major neurotransmitter receptor distributions.

RESULTS: Despite spatial heterogeneity, neuroticism-related GMV changes consistently mapped onto three principal functional networks: the default mode network (DMN), frontoparietal network (FPN), and ventral attention network (VAN). These mappings were robust across varied analytical parameters. Moreover, the implicated networks demonstrated significant spatial correlation with the distributions of 5-hydroxytryptamine receptor 2A (5-HT2A), cannabinoid receptor type 1 (CB1), and metabotropic glutamate receptor 5 (mGluR5).

CONCLUSION: Despite regional variability, GMV correlates of neuroticism converge on common large-scale brain networks involved in self-referential processing, cognitive control, and salience processing. Their significant spatial coupling with 5-HT2A, CB1, and mGluR5 receptor distributions suggests serotonergic, endocannabinoid, and glutamatergic modulatory mechanisms contributing to network-level alterations. This cross-modal and network-based approach provides a unified framework for understanding the biological substrates of neuroticism, reconciling prior inconsistencies, and identifying key targets for prevention or biomarker development.

PMID:41586162 | PMC:PMC12823854 | DOI:10.3389/fnsys.2025.1713434

Imaging Neurosci (Camb). 2026 Jan 22;4:IMAG.a.1108. doi: 10.1162/IMAG.a.1108. eCollection 2026.

ABSTRACT

We have previously shown that autocorrelation analyses of BOLD signal applied to single voxels in healthy controls can identify behaviorally-relevant gradients of temporal dynamics throughout the hippocampal long-axis. A question that remains is how changes in the brain's functional and structural integrity affect single-voxel autocorrelation. In this study, we investigate how hippocampal autocorrelation is affected by hippocampal dysfunction by investigating a population of patients with unilateral temporal lobe epilepsy (TLE). Many patients with TLE have mesial temporal sclerosis (MTS), characterized by scarring and neuronal loss, particularly in the anterior hippocampus. Here, we compared patients with left and right TLE, some with and without MTS, to healthy controls. We applied our single-voxel autocorrelation method and data-driven clustering approach to segment the hippocampus based on the autocorrelation of resting-state fMRI. We found that patients with left TLE had longer intrinsic timescales (i.e., higher autocorrelation) compared to controls, particularly in the anterior-medial portion of the hippocampus. This was true for both the epileptogenic and non-epileptogenic hemispheres. We also evaluated the extent of cluster preservation (i.e., spatial overlap with controls) of patient autocorrelation clusters and the relationship to verbal and visuospatial memory. We found that patients with greater cluster preservation in the anterior-medial hippocampus had better memory performance. Surprisingly, we did not find any effect of MTS on single-voxel autocorrelation, despite the structural changes associated with the condition. These results suggest that spatiotemporal dynamics of activity can be informative regarding the functional integrity of the hippocampus in TLE.

PMID:41585470 | PMC:PMC12828354 | DOI:10.1162/IMAG.a.1108

Front Psychiatry. 2026 Jan 8;16:1725066. doi: 10.3389/fpsyt.2025.1725066. eCollection 2025.

ABSTRACT

BACKGROUND: Generalized Anxiety Disorder (GAD), characterized by excessive worry and somatic symptoms. Although neuroimaging studies have identified alterations in functional connectivity (FC), structural integrity, and neural activation in GAD, most include medicated or psychotherapy-treated patients, limiting insights into the neurobiology of the untreated state. This study investigated resting-state FC (rsFC) abnormalities in medication-naïve GAD patients using a whole-brain, data-driven approach.

METHODS: In this cross-sectional study, medication-naïve GAD patients (n = 85) and HCs (n = 82) underwent rs-fMRI at Guang'anmen Hospital on a Siemens 3.0T scanner. Data were analyzed using CONN toolbox (v22.v2407). After preprocessing, cluster-based rsFC was examined across 9, 453 connections in 138 ROIs (FSL Harvard-Oxford atlas, excl. cerebellum). Clusters correlated with HAMA scores; rsFC for 10 ROI pairs extracted via MATLAB; key ROIs seeded voxel-wise maps in SBC, controlling gender.

RESULTS: Significant group differences emerged in rsFC clusters, centered on connections between the posterior cingulate cortex (PCC) and right supramarginal gyrus (SMG). Compared to HCs, GAD patients exhibited hyper-connectivity in 5 connections and hypo-connectivity in 5 others within these clusters. Four connections showed positive correlations with HAMA scores.

LIMITATIONS: The analysis of 9, 354 connections may have reduced statistical power, possibly obscuring additional relevant findings.

CONCLUSION: This study demonstrates aberrant resting-state functional connectivity in medication-naïve GAD patients, particularly enhanced PCC-SMG rsFC correlated with anxiety severity, suggesting a potential role for interoceptive hypersensitivity in GAD pathophysiology. These findings support the hypothesis of SMG-driven vigilance engaging PCC and mPFC to perpetuate anxiety cycles, warranting future validation with direct interoceptive measures and highlighting neural targets for interventions.

PMID:41584758 | PMC:PMC12823798 | DOI:10.3389/fpsyt.2025.1725066