Resting-state Functional Imaging Research Articles

Dissociable ventral and dorsal sensorimotor functional circuits linking the hypomanic personality traits to aggression via behavioral inhibition system.

Hypomanic personality traits (HPT) are susceptibility markers for psychiatric disorders, particularly bipolar disorder, and are strongly associated with aggressive behaviors. However, the neuropsychological mechanisms underlying this association remain unclear. This study utilized psychometric network analysis and Inter-Subject Representation Similarity Analysis (IS-RSA) to explore the neuropsychological circuits that link HPT to aggression in a large non-clinical population. Psychometric network analysis (n = 716) identified two key nodes: the Behavioral Inhibition System (BIS) and mood volatility, a core dimension of HPT. We observed a positive correlation between mood volatility and aggression, with BIS serving as a mediating factor. Task-based functional imaging (n = 53) further revealed a double dissociation between the dorsal (dSMC) and ventral (vSMC) sensorimotor cortices to HPT, specifically during the processing of reward magnitude and delay in a delayed reward paradigm. Functional patterns within these regions mediated the relationship between individual differences in mood volatility and aggression, with BIS acting as a mediator through parallel pathways. Resting-state functional imaging (n = 505) replicated this functional segregation and revealed distinct integrative patterns: the dSMC was functionally connected to the frontoparietal network (FPN) and the vSMC to the sensorimotor network (SMN). These circuits collectively mediated the associations among mood volatility, aggression, and BIS. These findings highlight the critical role of sensorimotor circuits and BIS in understanding the neuropsychological pathways linking HPT-related mood volatility to aggression.

Abstract TP373: Impaired resting state functional connectivity in CADASIL mutant mice

Objectives: Cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy (CADASIL) is a leading monogenic cause of cerebral small-vessel disease. This study aimed to evaluate the functional integrity of long white matter tracts in CADASIL transgenic mice and assess the potential of tocotrienol (T3) as a therapeutic agent. Methods: Optical resting-state functional connectivity imaging and behavioral examinations were employed to characterize white matter tracts in CADASIL transgenic mice, both with and without focal white matter lesions in the corpus callosum. Functional connectivity and behavioral outcomes were compared between Notch3 R169C and Notch3 WT mice. The efficacy of T3, a neuroprotective vitamin E derivative, was also evaluated based on findings from previous clinical trials in small vessel disease. Results: After performing stepwise elimination using the Akaike Information Criterion (AIC), the diet variable was removed from the model and we pooled the data in the two diet arms for subsequent analyses of interhemispheric homotopic connectivity. At baseline, resting-state interhemispheric functional connectivity was significantly reduced in Notch3 R169C mice compared to Notch3 WT mice (p=0.004). No significant differences between genotypes were observed on day 1 and day 7 post-lesion. Behavioral analysis using the grid walk test revealed an increased number of foot faults in Notch3 R169C mice at baseline, with similar increases observed in both genotypes one week after lesion induction. Lesion volumes on day 7 did not differ between genotypes. Conclusions: The Notch3 R169C CADASIL model demonstrated impaired resting-state functional connectivity and increased foot faults, indicating significant functional and behavioral deficits. Future research will focus on evaluating therapeutic and preventive interventions in CADASIL models using these parameters.

Impaired Resting State Functional Connectivity in CADASIL Mutant Mice.

Background: Cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy (CADASIL) is the most prevalent monogenic inherited cause of cerebral small-vessel disease. Despite its prevalence, there is currently no proven therapy to prevent or reverse the progression of the disease. Methods: This study aimed to characterize the functional integrity of long white matter tracts in CADASIL transgenic mice, both with and without focal white matter lesions in the corpus callosum added on, utilizing optical resting-state functional connectivity imaging alongside behavioral examinations. Additionally, we examined the efficacy of tocotrienol, a neuroprotective derivative of vitamin E derived from palm oil, which has shown promise in preventing white matter disease progression in clinical trials involving patients with small vessel disease. Results: At baseline, resting-state inter and intrahemispheric functional connectivity was significantly lower in Notch3R169C than in Notch3WT (p=0.004), and the grid walk test revealed a higher number of foot faults in the Notch3R169C group compared to Notch3WT. Sex did not interact with the genotype on the primary outcomes. Introducing a lesion in the corpus callosum compromised functional connectivity and behavior outcomes in both genotypes to a similar extent; lesion volumes did not differ between the genotypes. Tocotrienol treatment did not show any protective effect on any endpoint. Conclusion: These data show impaired resting-state functional connectivity and increased foot faults in the Notch3R169C mutant model of CADASIL. Future work will aim to test therapeutic or preventive interventions in CADASIL mutants using these measures.

Identifying multilayer network hub by graph representation learning.

The recent advances in neuroimaging technology allow us to understand how the human brain is wired in vivo and how functional activity is synchronized across multiple regions. Growing evidence shows that the complexity of the functional connectivity is far beyond the widely used mono-layer network. Indeed, the hierarchical processing information among distinct brain regions and across multiple channels requires using a more advanced multilayer model to understand the synchronization across the brain that underlies functional brain networks. However, the principled approach for characterizing network organization in the context of multilayer topologies is largely unexplored. In this work, we present a novel multi-variate hub identification method that takes both the intra- and inter-layer network topologies into account. Specifically, we put the spotlight on the multilayer graph embeddings that allow us to separate connector hubs (connecting across network modules) with their peripheral nodes. The removal of these hub nodes breaks down the entire multilayer brain network into a set of disconnected communities. We have evaluated our novel multilayer hub identification method in task-based and resting-state functional images. Complimenting ongoing findings using mono-layer brain networks, our multilayer network analysis provides a new understanding of brain network topology that links functional connectivities with brain states and disease progression.

Altered neurovascular coupling and structure-function coupling in Moyamoya disease affect postoperative collateral formation

Chronic ischemia in moyamoya disease (MMD) impaired white matter microstructure and neural functional network. However, the coupling between cerebral blood flow (CBF) and functional connectivity and the association between structural and functional network are largely unknown. 38 MMD patients and 20 sex/age-matched healthy controls (HC) were included for T1-weighted imaging, arterial spin labeling imaging, resting-state functional MRI and diffusion tensor imaging. All patients had preoperative and postoperative digital subtraction angiography. Upon constructing the structural connectivity (SC) and functional connectivity (FC) networks, the SC-FC coupling was calculated. After obtaining the graph theoretical parameters, neurovascular coupling represented the spatial correlation between node degree centrality (DC) of functional networks and CBF. The CBF-DC coupling and SC-FC coupling were compared between MMD and HC groups. We further analyzed the correlation between coupling indexes and cognitive scores, as well as postoperative collateral formation. Compared with HC, CBF-DC coupling was decreased in MMD (p = 0.021), especially in the parietal lobe (p = 0.047). SC-FC coupling in MMD decreased in frontal, occipital, and subcortical regions. Cognitive scores were correlated with the CBF-DC coupling in frontal lobes (r = 0.394, p = 0.029) and SC-FC coupling (r = 0.397, p = 0.027). The CBF-DC coupling of patients with good postoperative collateral formation was higher (p = 0.041). Overall, neurovascular decoupling and structure-functional decoupling at the cortical level may be the underlying neuropathological mechanisms of MMD.

A multimodal neuroimaging meta-analysis of functional and structural brain abnormalities in attention-deficit/hyperactivity disorder

BackgroundNumerous neuroimaging studies utilizing resting-state functional imaging and voxel-based morphometry (VBM) have identified variations in distinct brain regions among individuals with attention-deficit/hyperactivity disorder (ADHD). However, the results have been inconsistent. MethodsA comprehensive voxel-wise meta-analysis was performed on studies employing resting-state functional imaging and gray matter volume (GMV), examining discrepancies between individuals with ADHD and neurotypical controls (NCs). The analysis utilized the Seed-based d Mapping with Permutation of Subject Images software. ResultsA systematic review of the literature identified 21 functional imaging studies (595 ADHD and 564 controls) and 50 GMV studies (1907 ADHD and 1611 controls). In general, individuals with ADHD exhibited increased resting-state functional activity in the right parahippocampal gyrus and bilateral orbitofrontal cortex (OFC), as well as decreased resting-state functional activity in the bilateral cingulate cortex (including the posterior cingulate cortex [PCC], median cingulate cortex [MCC], and anterior cingulate cortex [ACC]). The VBM meta-analysis revealed decreased GMV in the bilateral OFC, right putamen (extending to right superior temporal gyrus [STG]), left inferior frontal gyrus (IFG), right superior frontal gyrus (SFG), ACC, and precentral gyrus among individuals with ADHD. ConclusionsThe multimodal meta-analyses indicated that individuals with ADHD exhibit abnormalities in both function and structure in the bilateral OFC. In addition, a few regions exhibited only functional or only structural abnormalities in ADHD, such as in the limbic, prefrontal, primary sensorimotor regions.

Update on the Neurobiology of Borderline Personality Disorder: A Review of Structural, Resting-State and Task-Based Brain Imaging Studies.

This review summarizes recent advances in research on the neurobiology of borderline personality disorder (BPD) according to structural brain imaging investigations and resting-state and task-based functional brain activation studies. Extending established findings on differences in regional brain volumes and cortical thickness between BPD and healthy controls, recent research illuminates shared and distinct brain structural characteristics compared to other psychiatric diagnoses, and uncovers relations of these brain structures with transdiagnostic symptoms and clinical features. Resting-state functional brain imaging studies reveal disruptions among adolescents and adults with BPD in frontolimbic and default-mode networks, which primarily underlie affect regulation and self-referential processes, respectively. Recent task-based functional brain imaging research builds on existing neurobiological understanding of emotion and cognition in BPD by revealing novel intersections with interpersonal- and stress-related processes. Studies of psychological and pharmacological interventions suggest possible effects on neural regions underlying emotion processing and behavioral control.

Network efficiency of functional brain connectomes altered in type 2 diabetes patients with and without mild cognitive impairment

AimTo explore the topological organization alterations of functional connectomes in type 2 diabetes (T2DM) patients with and without mild cognitive impairment (MCI), and compare these with structural connectomes changes.MethodsTwenty-six T2DM patients with MCI (DM-MCI), 26 without cognitive impairment (DM-NC), and 28 healthy controls were included. Diffusion tensor imaging (DTI) and resting-state functional MRI images were acquired. Networks were constructed and graph-theory based network measurements were calculated. The global network parameters and nodal efficiencies were compared across the three groups using one-way ANOVA and a false-discovery rate correction was applied for multiple comparisons. Partial correlation analyses were performed to investigate relationships between network parameters, cognitive performance and clinical variables.ResultsIn the structural connectome, the DM-MCI group exhibited significantly decreased global efficiency (Eglob) and local efficiency (Eloc) compared to the DM-NC and control groups. In the functional connectome, the DM-MCI group exhibited increased Eloc and clustering coefficient (Cp) compared to the controls. No significant differences were found in Eglob, Eloc, or Cp between the DM-NC and the control group, both in structural and functional connectomes. Nodal efficiencies decreased in some brain regions of structural and functional networks in the DM-MCI and DM-NC groups, but increased in five regions in functional network, some of which were involved in the default-mode network.ConclusionUnlike the consistently decreased global properties and nodal efficiencies in the structural connectome of T2DM patients, increases in Eloc, Cp, and nodal efficiencies in the functional connectome may be viewed as a compensatory mechanism due to functional plasticity and reorganization. Altered nodal efficiency can hint at cognitive decrements at an early stage in T2DM patients.

Enhanced efficiency in the bilingual brain through the inter-hemispheric cortico-cerebellar pathway in early second language acquisition

Bilingualism has a profound impact on the structure and function of the brain, but it is not yet well understood how this experience influences brain functional organization. We examine a large sample (151 participants) of monolinguals and bilinguals with varied age of second language acquisition, who underwent resting-state functional magnetic brain imaging. Whole-brain network analyses reveal higher global efficiency in bilingual individuals than monolinguals, indicating enhanced functional integration in the bilingual brain. Moreover, the age at which the second language was acquired correlated with this increased efficiency, suggesting that earlier exposure to a second language has lasting positive effects on brain functional organization. Further investigation using the network-based statistics approach indicates that this effect is primarily driven by heightened functional connectivity between association networks and the cerebellum. These findings show that the timing of bilingual learning experience alters the brain functional organization at both global and local levels.

The neural plasticity and efficacy of acupuncture for post-stroke dysphagia: protocol for a randomized controlled trial with fMRI and DTI

BackgroundDysphagia, a common complication of acute stroke, is associated with increased mortality and morbidity. Acupuncture, a widely used swallowing therapy in China, has been suggested as an effective therapy for treating Post-Stroke Dysphagia (PSD) by recent meta-analyses and guidelines. The use of resting-state functional Magnetic Resonance Imaging (rs-fMRI) and Diffusion Tensor Imaging (DTI) could explore the change of regional spontaneous neural activity, functional relationships between brain regions, and white matter connectivity patterns after acupuncture intervention for PSD. This trial aims to evaluate the efficacy of acupuncture treatment for PSD and explore its central mechanism by neuroimaging.Methods/designThis randomized controlled trial will recruit 40 PSD patients. All patients will be randomized to either the Real Acupuncture (RA) or Sham Acupuncture (SA) group by a ratio of 1:1. All patients will receive immediate acupuncture treatment in the MRI scanning room, followed by four weeks of long-term acupuncture treatment. The primary outcomes are the rs-fMRI and DTI indicators, which will be evaluated after the immediate and long-term acupuncture treatment. The secondary outcomes are the scales that assess the efficacy, including the Functional Oral Intake Scale (FOIS), Water Swallowing Test (WST), Swallowing Quality Of Life Questionnaire (SWAL-QOL), and National Institute of Health Stroke Scale (NIHSS). The modified version of the Massachusetts General Hospital Acupuncture Sensation Scale (M-MASS) and fMRI sensation record table will also be evaluated.DiscussionThis protocol presents the design of a randomized, single-blind trial that will evaluate the efficacy and explore the neural plasticity of acupuncture treatment for PSD. This trial will deepen our insight into the clinical value of acupuncture for PSD and initially probe into the time-dosage-effect mechanism of acupuncture.Trial registration numbersChinese Clinical Trial Registry (www.chictr.org.cn) ChiCTR2300067480. This study was registered on 9th January 2023.

Changes in functional and structural brain connectivity following bilateral hand transplantation

As a surgical treatment following amputation or loss of an upper limb, nearly 200 hand transplantations have been completed to date. We report here a magnetic resonance imaging (MRI) investigation of functional and structural brain connectivity for a bilateral hand transplant patient (female, 60 years of age), with a preoperative baseline and three postoperative testing sessions each separated by approximately six months. We used graph theoretical analyses to estimate connectivity within and between modules (networks of anatomical nodes), particularly a sensorimotor network (SMN), from resting-state functional MRI and structural diffusion-weighted imaging (DWI). For comparison, corresponding MRI measures of connectivity were obtained from 10 healthy, age-matched controls, at a single testing session. The patient's within-module functional connectivity (both SMN and non-SMN modules), and structural within-SMN connectivity, were higher preoperatively than that of the controls, indicating a response to amputation. Postoperatively, the patient's within-module functional connectivity decreased towards the control participants' values, across the 1.5 years postoperatively, particularly for hand-related nodes within the SMN module, suggesting a return to a more canonical functional organization. Whereas the patient's structural connectivity values remained relatively constant postoperatively, some evidence suggested that structural connectivity supported the postoperative changes in within-module functional connectivity.

Microstructural and functional substrates underlying dispositional greed and its link with trait but not state impulsivity

The interplay between personality traits and impulsivity has long been a central theme in psychology and psychiatry. However, the potential association between Greed Personality Traits (GPT) and impulsivity, encompassing both trait and state impulsivity and future time perspective, remains largely unexplored. To address these issues, we employed questionnaires and an inter-temporal choice task to estimate corresponding trait/state impulsivity and collected multi-modal neuroimaging data (resting-state functional imaging: n = 430; diffusion-weighted imaging: n = 426; task-related functional imaging: n = 53) to investigate the underlying microstructural and functional substrates. Behavioral analyses revealed that GPT mediated the association between time perspective (e.g., present fatalism) and trait impulsivity (e.g., motor impulsivity). Functional imaging analyses further identified that brain activation strengths and patterns related to delay length, particularly in the dorsomedial prefrontal cortex, superior parietal lobule, and cerebellum, were associated with GPT. Moreover, individuals with similar levels of greed exhibited analogous spontaneous brain activity patterns, predominantly in the Default Mode Network (DMN), Fronto-Parietal Network (FPN), and Visual Network (VIS). Diffusion imaging analysis observed specific microstructural characteristics in the spinocerebellar/pontocerebellar fasciculus, internal/external capsule, and corona radiata that support the formation of GPT. Furthermore, the corresponding neural activation pattern, spontaneous neural activity pattern, and analogous functional couplings among the aforementioned brain regions mediated the relationships between time perspective and GPT and between GPT and motor impulsivity. These findings provide novel insights into the possible pathway such as time perspective → dispositional greed → impulsivity and uncover their underlying microstructural and functional substrates.

Similarity and characterization of structural and functional neural connections within species under isoflurane anesthesia in the common marmoset

The common marmoset is an essential model for understanding social cognition and neurodegenerative diseases. This study explored the structural and functional brain connectivity in a marmoset under isoflurane anesthesia, aiming to statistically overcome the effects of high inter-individual variability and noise-related confounds such as physiological noise, ensuring robust and reliable data. Similarities and differences in individual subject data, including assessments of functional and structural brain connectivities derived from resting-state functional MRI and diffusion tensor imaging were meticulously captured. The findings highlighted the high consistency of structural neural connections within the species, indicating a stable neural architecture, while functional connectivity under anesthesia displayed considerable variability. Through independent component and dual regression analyses, several distinct brain connectivities were identified, elucidating their characteristics under anesthesia. Insights into the structural and functional features of the marmoset brain from this study affirm its value as a neuroscience research model, promising advancements in the field through fundamental and translational studies.

Coupled pulsatile vascular and paravascular fluid dynamics in the human brain

BackgroundCardiac pulsation propels blood through the cerebrovascular network to maintain cerebral homeostasis. The cerebrovascular network is uniquely surrounded by paravascular cerebrospinal fluid (pCSF), which plays a crucial role in waste removal, and its flow is suspected to be driven by arterial pulsations. Despite its importance, the relationship between vascular and paravascular fluid dynamics throughout the cardiac cycle remains poorly understood in humans.MethodsIn this study, we developed a non-invasive neuroimaging approach to investigate the coupling between pulsatile vascular and pCSF dynamics within the subarachnoid space of the human brain. Resting-state functional MRI (fMRI) and dynamic diffusion-weighted imaging (dynDWI) were retrospectively cardiac-aligned to represent cerebral hemodynamics and pCSF motion, respectively. We measured the time between peaks (∆TTP) in ddϕfMRI\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{d}{d\\phi }fMRI$$\\end{document} and dynDWI waveforms and measured their coupling by calculating the waveforms correlation after peak alignment (correlation at aligned peaks). We compared the ∆TTP and correlation at aligned peaks between younger [mean age: 27.9 (3.3) years, n = 9] and older adults [mean age: 70.5 (6.6) years, n = 20], and assessed their reproducibility within subjects and across different imaging protocols.ResultsHemodynamic changes consistently precede pCSF motion. ∆TTP was significantly shorter in younger adults compared to older adults (−0.015 vs. −0.069, p < 0.05). The correlation at aligned peaks were high and did not differ between younger and older adults (0.833 vs. 0.776, p = 0.153). The ∆TTP and correlation at aligned peaks were robust across fMRI protocols (∆TTP: −0.15 vs. −0.053, p = 0.239; correlation at aligned peaks: 0.813 vs. 0.812, p = 0.985) and demonstrated good to excellent within-subject reproducibility (∆TTP: intraclass correlation coefficient = 0.36; correlation at aligned peaks: intraclass correlation coefficient = 0.89).ConclusionThis study proposes a non-invasive technique to evaluate vascular and paravascular fluid dynamics. Our findings reveal a consistent and robust cardiac pulsation-driven coupling between cerebral hemodynamics and pCSF dynamics in both younger and older adults.

Brain topology underlying executive functions across the lifespan: focus on the default mode network.

While traditional neuroimaging approaches to the study of executive functions (EFs) have typically employed task-evoked paradigms, resting state studies are gaining popularity as a tool for investigating inter-individual variability in the functional connectome and its relationship to cognitive performance outside of the scanner. Using resting state functional magnetic resonance imaging data from the Human Connectome Project Lifespan database, the present study capitalized on graph theory to chart cross-sectional variations in the intrinsic functional organization of the frontoparietal (FPN) and the default mode (DMN) networks in 500 healthy individuals (from 10 to 100 years of age), to investigate the neural underpinnings of EFs across the lifespan. Topological properties of both the FPN and DMN were associated with EF performance but not with a control task of picture naming, providing specificity in support for a tight link between neuro-functional and cognitive-behavioral efficiency within the EF domain. The topological organization of the DMN, however, appeared more sensitive to age-related changes relative to that of the FPN. The DMN matures earlier in life than the FPN and it ıs more susceptible to neurodegenerative changes. Because its activity is stronger in conditions of resting state, the DMN might be easier to measure in noncompliant populations and in those at the extremes of the life-span curve, namely very young or elder participants. Here, we argue that the study of its functional architecture in relation to higher order cognition across the lifespan might, thus, be of greater interest compared with what has been traditionally thought.

Eight brain structures mediate the age-related alterations of the working memory: forward and backward digit span tasks.

Working memory (WM) as one of the executive functions is an essential neurocognitive ability for daily life. Findings have suggested that aging is often associated with working memory and neural decline, but the brain structures and resting-state brain networks that mediate age-related differences in WM remain unclear. A sample consisting of 252 healthy participants in the age range of 20 to 70years was used. Several cognitive tasks, including the n-back task and the forward and backward digit span tests were used. Also, resting-state functional imaging, as well as structural imaging using a 3T MRI scanner, were performed, resulting in 85 gray matter volumes and five resting-state networks, namely the anterior and posterior default mode, the right and left executive control, and the salience networks. Also, mediation analyses were used to investigate the role of gray matter volumes and resting-state networks in the relationship between age and WM. Behaviorally, aging was associated with decreased performance in the digit span task. Also, aging was associated with a decreased gray matter volume in 80 brain regions, and with a decreased activity in the anterior default mode network, executive control, and salience networks. Importantly, the path analysis showed that the GMV of the medial orbitofrontal, precentral, parieto-occipital, amygdala, middle occipital, posterior cingulate, and thalamus areas mediated the age-related differences in the forward digit span task, and the GMV of superior temporal gyrus mediated the age-related differences in the backward digit span task. This study identified the brain structures mediating the relationship between age and working memory, and we hope that our research provides an opportunity for early detection of individuals at risk of age-related memory decline.

Expression of microRNA induced by postoperative delirium-like behavior is associated with long-term default mode network disruption: Sequencing and a secondary analysis of resting-state fMRI data.

Resting state functional magnetic resonance imaging (rs-fMRI) has been widely used in studying default mode network (DMN) changes in postoperative delirium (POD). Reproducibility and interpretability of the analyzing results remain insufficiently studied. Delirium-like behavior was induced by tibial fixation surgery under isoflurane anesthesia. Firstly, we evaluated delirium-like behavior and inflammatory responses in hippocampus and systemic level. Then the expressions of microRNA (miRNA) and target gene were sequenced and validated. Afterwards the functional connectivity (FC) in DMN was analyzed. Finally, results were correlated with DMN changes. POD-like behavior caused significant changes of miR-34b-5p, miR-328-5p, and miR-3505 in miRNA level and Nos1, Tubb3, and Gys1 in the gene level. The FC in left and right hippocampus (L-Hip and R-Hip) and right auditory cortex (R-AC) was found significantly changed. Significant correlations were found in FCL-Hip/R-AC and FCR-Hip/R-AC for miR-34b-5p and miR-3505, as well as Nos1 and Tubb3. For miR-328-5p, no significant correlations were found. Our study demonstrates that POD-like behavior induced significant miRNA and gene expression changes were associated with hippocampus related long-term FC disruption in DMN. The results increased reproducibility and interpretability for standardized rs-fMRI data analysis, as well as providing potential targets for postoperative delirium treatment.

Gender differences in major depressive disorder at different ages: a REST-meta-MDD project-based study

BackgroundMajor depressive disorder (MDD) is a highly heterogeneous disease, with differences in clinical manifestations among depression patients based on onset ages and genders. The neural mechanisms underlying these differences remain unclear. In this study, we utilized resting state functional imaging data from a large sample database and adopted the ReHo method to investigate gender differences in local brain function in MDD patients across different onset age groups.MethodsThe study included 364 MDD patients and 695 healthy participants who were part of the REST-meta-MDD project. Regional homogeneity (ReHo) assessed gender disparities in MDD and healthy individuals within groups delineated by gender and onset age (young group: 18–29 years; middle-aged group: 30–45 years).ResultsAmong the young MDD groups, there were significant gender differences in the right superior frontal gyrus, right inferior frontal gyrus, left superior temporal gyrus, and right superior parietal lobule, with male MDD patients having higher ReHo values compared to females. When compared to healthy males, male MDD patients exhibited elevated ReHo values in the right superior parietal lobule. In the middle-aged groups, a marked ReHo difference was observed in the bilateral cerebellum posterior lobe, with female MDD patients showing higher ReHo values.ConclusionsThe functional mechanisms of MDD differ between genders and show distinct variations across different onset age groups. These findings underscore the importance of developing personalized interventions that address the unique needs of MDD patients, tailored to their gender and age, and necessitate the development of antidepressant medications targeted at each gender-age subgroup.

Moving beyond processing- and analysis-related variation in resting-state functional brain imaging.

When fields lack consensus standard methods and accessible ground truths, reproducibility can be more of an ideal than a reality. Such has been the case for functional neuroimaging, where there exists a sprawling space of tools and processing pipelines. We provide a critical evaluation of the impact of differences across five independently developed minimal preprocessing pipelines for functional magnetic resonance imaging. We show that, even when handling identical data, interpipeline agreement was only moderate, critically shedding light on a factor that limits cross-study reproducibility. We show that low interpipeline agreement can go unrecognized until the reliability of the underlying data is high, which is increasingly the case as the field progresses. Crucially we show that, when interpipeline agreement is compromised, so too is the consistency of insights from brain-wide association studies. We highlight the importance of comparing analytic configurations, because both widely discussed and commonly overlooked decisions can lead to marked variation.

Feasibility and success of a non-sedated brain MRI training protocol in 7-year-old children from rural and semi-rural Colombia.

Brain magnetic resonance imaging (MRI) is a crucial tool for clinical evaluation of the brain and neuroscience research. Obtaining successful non-sedated MRI in children who live in resource-limited settings may be an additional challenge. To present a feasibility study of a novel, low-cost MRI training protocol used in a clinical research study in a rural/semi-rural region of Colombia and to examine neurodevelopmental factors associated with successful scans. Fifty-seven typically developing Colombian children underwent a training protocol and non-sedated brain MRI at age 7. Group training utilized a customized booklet, an MRI toy set, and a simple mock scanner. Children attended MRI visits in small groups of two to three. Resting-state functional and structural images were acquired on a 1.5-Tesla scanner with a protocol duration of 30-40minutes. MRI success was defined as the completion of all sequences and no more than mild motion artifact. Associations between the Wechsler Preschool and Primary Scale of Intelligence (WPPSI), Movement Assessment Battery for Children (MABC), Behavioral Rating Inventory of Executive Function (BRIEF), Child Behavior Checklist (CBCL), and Adaptive Behavior Assessment System (ABAS) scores and MRI success were analyzed. Mean (SD) age at first MRI attempt was 7.2 (0.2) years (median 7.2 years, interquartile range 7.1-7.3 years). Twenty-six (45.6%) participants were male. Fifty-one (89.5%) children were successful across two attempts; 44 (77.2%) were successful on their first attempt. Six (10.5%) were unsuccessful due to refusal or excessive motion. Age, sex, and scores across all neurodevelopmental assessments (MABC, TVIP, ABAS, BRIEF, CBCL, NIH Toolbox Flanker, NIH Toolbox Pattern Comparison, WPPSI) were not associated with likelihood of MRI success (P=0.18, 0.19, 0.38, 0.92, 0.84, 0.80, 1.00, 0.16, 0.75, 0.86, respectively). This cohort of children from a rural/semi-rural region of Colombia demonstrated comparable MRI success rates to other published cohorts after completing a low-cost MRI familiarization training protocol suitable for low-resource settings. Achieving non-sedated MRI success in children in low-resource and international settings is important for the continuing diversification of pediatric research studies.