NeuroImage最新文献

{"title":"Differences in brain structure and cognitive performance between patients with long-COVID and those with normal recovery","authors":"Breanna K. Nelson ,&nbsp;Lea N. Farah ,&nbsp;Ava Grier ,&nbsp;Wayne Su ,&nbsp;Johnson Chen ,&nbsp;Vesna Sossi ,&nbsp;Mypinder S. Sekhon ,&nbsp;A. Jon Stoessl ,&nbsp;Cheryl Wellington ,&nbsp;William G. Honer ,&nbsp;Donna Lang ,&nbsp;Noah D. Silverberg ,&nbsp;William J. Panenka","doi":"10.1016/j.neuroimage.2024.120859","DOIUrl":"10.1016/j.neuroimage.2024.120859","url":null,"abstract":"<div><h3>Background</h3><div>The pathophysiology of protracted symptoms after COVID-19 is unclear. This study aimed to determine if long-COVID is associated with differences in baseline characteristics, markers of white matter diffusivity in the brain, and lower scores on objective cognitive testing.</div></div><div><h3>Methods</h3><div>Individuals who experienced COVID-19 symptoms for more than 60 days post-infection (long-COVID) (<em>n</em> = 56) were compared to individuals who recovered from COVID-19 within 60 days of infection (normal recovery) (<em>n</em> = 35). Information regarding physical and mental health, and COVID-19 illness was collected. The National Institute of Health Toolbox Cognition Battery was administered. Participants underwent magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI). Tract-based spatial statistics were used to perform a whole-brain voxel-wise analysis on standard DTI metrics (fractional anisotropy, axial diffusivity, mean diffusivity, radial diffusivity), controlling for age and sex. NIH Toolbox Age-Adjusted Fluid Cognition Scores were used to compare long-COVID and normal recovery groups, covarying for Age-Adjusted Crystallized Cognition Scores and years of education. False discovery rate correction was applied for multiple comparisons.</div></div><div><h3>Results</h3><div>There were no significant differences in age, sex, or history of neurovascular risk factors between the groups. The long-COVID group had significantly (<em>p</em> &lt; 0.05) lower mean diffusivity than the normal recovery group across multiple white matter regions, including the internal capsule, anterior and superior corona radiata, corpus callosum, superior fronto-occiptal fasciculus, and posterior thalamic radiation. However, the effect sizes of these differences were small (all <span><math><mi>β</mi></math></span>&lt;|0.3|) and no significant differences were found for the other DTI metrics. Fluid cognition composite scores did not differ significantly between the long-COVID and normal recovery groups (<em>p</em> &gt; 0.05).</div></div><div><h3>Conclusions</h3><div>Differences in diffusivity between long-COVID and normal recovery groups were found on only one DTI metric. This could represent subtle areas of pathology such as gliosis or edema, but the small effect sizes and non-specific nature of the diffusion indices make pathological inference difficult. Although long-COVID patients reported many neuropsychiatric symptoms, significant differences in objective cognitive performance were not found.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120859"},"PeriodicalIF":4.7,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning enables accurate brain tissue microstructure analysis based on clinically feasible diffusion magnetic resonance imaging","authors":"Yuxing Li ,&nbsp;Zhizheng Zhuo ,&nbsp;Chenghao Liu ,&nbsp;Yunyun Duan ,&nbsp;Yulu Shi ,&nbsp;Tingting Wang ,&nbsp;Runzhi Li ,&nbsp;Yanli Wang ,&nbsp;Jiwei Jiang ,&nbsp;Jun Xu ,&nbsp;Decai Tian ,&nbsp;Xinghu Zhang ,&nbsp;Fudong Shi ,&nbsp;Xiaofeng Zhang ,&nbsp;Aaron Carass ,&nbsp;Frederik Barkhof ,&nbsp;Jerry L Prince ,&nbsp;Chuyang Ye ,&nbsp;Yaou Liu","doi":"10.1016/j.neuroimage.2024.120858","DOIUrl":"10.1016/j.neuroimage.2024.120858","url":null,"abstract":"<div><div><em>Diffusion magnetic resonance imaging</em> (dMRI) allows non-invasive assessment of brain tissue microstructure. Current model-based tissue microstructure reconstruction techniques require a large number of diffusion gradients, which is not clinically feasible due to imaging time constraints, and this has limited the use of tissue microstructure information in clinical settings. Recently, approaches based on <em>deep learning</em> (DL) have achieved promising tissue microstructure reconstruction results using clinically feasible dMRI. However, it remains unclear whether the subtle tissue changes associated with disease or age are properly preserved with DL approaches and whether DL reconstruction results can benefit clinical applications. Here, we provide the first evidence that DL approaches to tissue microstructure reconstruction yield reliable brain tissue microstructure analysis based on clinically feasible dMRI scans. Specifically, we reconstructed tissue microstructure from four different brain dMRI datasets with only 12 diffusion gradients, a clinically feasible protocol, and the <em>neurite orientation dispersion and density imaging</em> (NODDI) and <em>spherical mean technique</em> (SMT) models were considered. With these results we show that disease-related and age-dependent alterations of brain tissue were accurately identified. These findings demonstrate that DL tissue microstructure reconstruction can accurately quantify microstructural alterations in the brain based on clinically feasible dMRI.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120858"},"PeriodicalIF":4.7,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliable measurement of auditory-driven gamma synchrony with a single EEG electrode: A simultaneous EEG-MEG study","authors":"Giovanni Pellegrino ,&nbsp;Silvia L. Isabella ,&nbsp;Giulio Ferrazzi ,&nbsp;Laura Gschwandtner ,&nbsp;Martin Tik ,&nbsp;Giorgio Arcara ,&nbsp;Daniele Marinazzo ,&nbsp;Anna-Lisa Schuler","doi":"10.1016/j.neuroimage.2024.120862","DOIUrl":"10.1016/j.neuroimage.2024.120862","url":null,"abstract":"<div><h3>Objective</h3><div>Auditory-driven gamma synchrony (GS) is linked to the function of a specific cortical circuit based on a parvalbumin+ and pyramidal neuron loop. This circuit is impaired in neuropsychiatric conditions (i.e. schizophrenia, Alzheimer's disease, stroke etc.) and its relevance in clinical practice is increasingly being recognized. Auditory stimulation at a typical gamma frequency of 40 Hz can be applied as a ‘stress test’ of excitation/inhibition (E/I) of the entire cerebral cortex, to drive GS and record it with magnetoencephalography (MEG) or high-density electroencephalography (EEG). However, these two techniques are costly and not widely available. Therefore, we assessed whether a single EEG electrode is sufficient to provide an accurate estimate of the auditory-driven GS level of the entire cortical surface while expecting the highest correspondence in the auditory and somatosensory cortices.</div></div><div><h3>Methods</h3><div>We measured simultaneous EEG-MEG in 29 healthy subjects, utilizing 3 EEG electrodes (C4, F4, O2) and a full MEG setup. Recordings were performed during binaural exposure to auditory gamma stimulation and during silence. We compared GS measurement of each of the three EEG electrodes separately against full MEG mapping. Time-resolved phase locking value (PLVt) was computed between EEG signals and cortex reconstructed MEG signals.</div></div><div><h3>Results</h3><div>During auditory stimulation, but not at rest, EEG captures a significant amount of GS, especially from both auditory cortices and motor-premotor regions. This was especially true for frontal (C4) and central electrodes (F4).</div></div><div><h3>Discussion and Conclusions</h3><div>While hd-EEG and MEG are necessary for accurate spatial mapping of GS at rest and during auditory stimulation, a single EEG channel is sufficient to detect the global level of GS. These results have great translational potential for mapping GS in standard clinical settings.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120862"},"PeriodicalIF":4.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142292259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vivo visualization of white matter fiber tracts in the brainstem using low flip angle double echo 3D gradient echo imaging at 3T","authors":"Qiuyun Xu ,&nbsp;Yongsheng Chen ,&nbsp;Stephan Miller ,&nbsp;Kunal Bajaj ,&nbsp;Jairo Santana ,&nbsp;Mohamed Badawy ,&nbsp;Haiying Lyu ,&nbsp;Yu Liu ,&nbsp;Naying He ,&nbsp;Fuhua Yan ,&nbsp;E. Mark Haacke","doi":"10.1016/j.neuroimage.2024.120857","DOIUrl":"10.1016/j.neuroimage.2024.120857","url":null,"abstract":"<div><h3>Background</h3><div>White matter (WM) fiber tracts in the brainstem communicate with various regions in the cerebrum, cerebellum, and spinal cord. Clinically, small lesions, malformations, or histopathological changes in the brainstem can cause severe neurological disorders. A direct and non-invasive assessment approach could bring valuable information about the intricate anatomical variations of the white matter fiber tracts and nuclei. Although tractography from diffusion tensor imaging has been commonly used to map the WM fiber tracts connectivity, it is difficult to differentiate the complex WM tracts anatomically. Both high field MRI methods and ultrahigh-field MRI methods at 7T and 11.7 T have been used to enhance the contrast of WM fiber tracts. Despite their promising results, it is still challenging to achieve wide clinical adoption at 3T. In this study, we explored a clinically feasible method using a proton density weighted (PDW) 3D gradient echo (GRE) sequence to directly image the WM fiber tracts in the brainstem at 3T <em>in vivo</em>.</div></div><div><h3>Methods</h3><div>We optimized a 3D high resolution, double echo, short TR, PDW GRE sequence on 5 healthy volunteers using a clinical 3T scanner to visualize the complicated anatomy of WM fiber tracts in the brain stem. Tissue properties including T1, proton density and T2* from <em>in vivo</em> quantitative MRI data were used for simulations to determine the optimal flip angle for the sequence. The visualization of multiple WM fiber tracts in the brainstem was assessed qualitatively and quantitatively using relative contrast and contrast-to-noise ratio (CNR). To improve the CNR, the final images were created by averaging over all echoes from two consecutive scans at the optimal flip angle. The results were compared to anatomical atlases and histology sections to identify the major fiber tracts. All the identified major fiber tracts were labeled on axial, sagittal and coronal slices.</div></div><div><h3>Results</h3><div>The WM fiber tracts were found to have distinct hypointense signal throughout the brainstem and most of the major WM fiber tracts, such as the corticospinal tract, medial lemniscus, medial longitudinal fasciculus, and central tegmental tract, in the brainstem up to and including the thalamus were identified in all subjects. Both qualitative and quantitative evaluations showed that the 3° scan offered the best contrast for WM fiber tracts for a TR of 20 ms. The average over the first two echo times and two consecutive 3° scans gave a CNR of 47.8 ± 6.2 for the pyramidal tracts in particular and CNRs values greater than 6.5 ± 2.4 for the rest of the fiber tracts.</div></div><div><h3>Conclusions</h3><div>All the major fiber tracts in the brainstem could be visualized. Given the reasonably short scan time of 10 min at 3T, double echo PDW GRE sequence is a very practical approach for clinical adoption.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120857"},"PeriodicalIF":4.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003549/pdfft?md5=bdbb3734d5d26e1c2262279b85f57e03&pid=1-s2.0-S1053811924003549-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142292257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural and functional substrates underlying dispositional greed and its link with trait but not state impulsivity","authors":"Keying Jiang ,&nbsp;Jinlian Wang ,&nbsp;Yuanyuan Gao ,&nbsp;Xiang Li ,&nbsp;Hohjin Im ,&nbsp;Yingying Zhu ,&nbsp;Hanxiao Du ,&nbsp;Lei Feng ,&nbsp;Wenwei Zhu ,&nbsp;Guang Zhao ,&nbsp;Ying Hu ,&nbsp;Peng Zhu ,&nbsp;Wenfeng Zhu ,&nbsp;He Wang ,&nbsp;Qiang Wang","doi":"10.1016/j.neuroimage.2024.120856","DOIUrl":"10.1016/j.neuroimage.2024.120856","url":null,"abstract":"<div><p>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: <em>n</em> = 430; diffusion-weighted imaging: <em>n</em> = 426; task-related functional imaging: <em>n</em> = 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.</p></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120856"},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003537/pdfft?md5=709db1bb77b0071c538b6a24ae915429&pid=1-s2.0-S1053811924003537-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lightweight and wearable magnetoencephalography system based on spatially-grid constrained coils and compact magnetically shielded room","authors":"Shuai Dou ,&nbsp;Xikai Liu ,&nbsp;Ya Deng ,&nbsp;Yimin Chen ,&nbsp;Pengfei Song ,&nbsp;Tong Wen ,&nbsp;Bangcheng Han","doi":"10.1016/j.neuroimage.2024.120842","DOIUrl":"10.1016/j.neuroimage.2024.120842","url":null,"abstract":"<div><div>Magnetoencephalography based on optically pumped magnetometers can passively detect the ultra-weak brain magnetic field signals, which has significant clinical application prospects for the diagnosis and treatment of cerebral disorders. This paper proposes a brain magnetic signal measurement method on the basis of the active–passive coupling magnetic shielding strategy and helmet-mounted detection array, which has lower cost and comparable performance over the existing ones. We first utilized the spatially-grid constrained coils and biplanar coils with proportion–integration–differentiation controller with tracking differentiator to ensure a near-zero and stable magnetic field environment with large uniform region. Subsequently, we implemented the brain magnetic signal measurement with the subject randomly moving fingers through tapping a keyboard and with the condition of opening and closing the eyes. Effectively induced brain magnetic signals were detected at the motor functional area and occipital lobe area in the two experiments, respectively. The proposed method will contribute to the development of functional brain imaging.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120842"},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003392/pdfft?md5=4208d7189b7a2abe691e02c6d4d27b6d&pid=1-s2.0-S1053811924003392-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142292258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Individual contralesional recruitment in the context of structural reserve in early motor reorganization after stroke","authors":"Maike Mustin ,&nbsp;Lukas Hensel ,&nbsp;Gereon R. Fink ,&nbsp;Christian Grefkes ,&nbsp;Caroline Tscherpel","doi":"10.1016/j.neuroimage.2024.120828","DOIUrl":"10.1016/j.neuroimage.2024.120828","url":null,"abstract":"<div><p>The concept of structural reserve in stroke reorganization assumes that the relevance of the contralesional hemisphere strongly depends on the brain tissue spared by the lesion in the affected hemisphere. Recent studies, however, have indicated that the contralesional hemisphere's impact exhibits region-specific variability with concurrently existing maladaptive and supportive influences. This challenges traditional views, necessitating a nuanced investigation of contralesional motor areas and their interaction with ipsilesional networks.</p><p>Our study focused on the functional role of contralesional key motor areas and lesion-induced connectome disruption early after stroke.</p><p>Online TMS data of twenty-five stroke patients was analyzed to disentangle interindividual differences in the functional roles of contralesional primary motor cortex (M1), dorsal premotor cortex (dPMC), and anterior interparietal sulcus (aIPS) for motor function. Connectome-based lesion symptom mapping and corticospinal tract lesion quantification were used to investigate how TMS effects depend on ipsilesional structural network properties.</p><p>At group and individual levels, TMS interference with contralesional M1 and aIPS but not dPMC led to improved performance early after stroke. At the connectome level, a more disturbing role of contralesional M1 was related to a more severe disruption of the structural integrity of ipsilesional M1 in the affected motor network. In contrast, a detrimental influence of contralesional aIPS was linked to less disruption of the ipsilesional M1 connectivity.</p><p>Our findings indicate that contralesional areas distinctively interfere with motor performance early after stroke depending on ipsilesional structural integrity, extending the concept of structural reserve to regional specificity in recovery of function.</p></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120828"},"PeriodicalIF":4.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003252/pdfft?md5=215a1f0e29e486e12dda4c7c9be349b7&pid=1-s2.0-S1053811924003252-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High autistic traits linked with reduced performance on affective task switching: An ERP study","authors":"Siyuan Zhou ,&nbsp;Zongping Chen ,&nbsp;Gang Liu ,&nbsp;Lingfei Ma ,&nbsp;Ya Liu","doi":"10.1016/j.neuroimage.2024.120855","DOIUrl":"10.1016/j.neuroimage.2024.120855","url":null,"abstract":"<div><div>Few studies have investigated affective flexibility in individuals with high autistic traits. In the present study, we employed affective task-switching paradigm combined with event related potential (ERP) technology to explore affective flexibility in individuals with high autistic traits. Participants were instructed to switch between identifying the gender (gender task) and emotion (emotion task) of presented faces. Two groups of participants were recruited based on the Autism Spectrum Quotient (AQ) scores: a High Autistic Group (HAG) and a Low Autistic Group (LAG). The results confirmed that the HAG exhibited greater behavioral emotion switch costs and increased N2 and decreased P3 components when switching to the emotion task. Additionally, we identified an affective asymmetric switch cost in the HAG, where the switch cost for the emotion task was larger than for the gender task at both behavioral and electrophysiological levels. In contrast, a symmetrical switch cost was observed in the LAG. These findings indicate that the HAG experiences difficulties with affective flexibility, particularly in tasks involving emotional processing. The patterns of affective asymmetric switch costs observed in both groups differed from previous results in autistic children and the general population, suggesting that the relative dominance of gender and emotion tasks may vary between the two groups. We propose that the dominance of emotion tasks declines as autistic traits increase.</div></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120855"},"PeriodicalIF":4.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003525/pdfft?md5=16dd9f8a5d2e79924159aa94e3f6a75d&pid=1-s2.0-S1053811924003525-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142292260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-analytic three-shell forward calculation for magnetoencephalography","authors":"Dionysia Kaziki,&nbsp;Guido Nolte","doi":"10.1016/j.neuroimage.2024.120836","DOIUrl":"10.1016/j.neuroimage.2024.120836","url":null,"abstract":"<div><p>In previous studies, the magnetic lead field theorem in the quasi-static approximation was derived and used for the development of a method for the forward problem of MEG. It was applied and tested on a single-shell model of the human head and the question whether one shell is adequate enough for the calculation of the magnetic field is the main reason for this study. This forward method is based on the fundamental concept that one can calculate the lead field for MEG by decomposing it into two parts: the lead field of an arbitrary volume conductor that is already known and the gradient of basis functions that have to be harmonic, here derived from spherical harmonics. The problem then is reduced to evaluating the coefficients found in the basis functions. In this research we aim to improve the accuracy of the forward model, hence improving the localization accuracy in inverse methods by introducing a more detailed realistic head model. We here generalize the algorithm developed for a single-shell volume conductor to a three-shell volume conductor representing the brain, the skull and the skin with homogenous and isotropic conductivities in realistic ratios. The expansion to three shells could be tested as the three-shell algorithm is approaching the single-shell with high accuracy in special cases where three-shell solutions can also be calculated using a single-shell solution, especially for higher levels of expansion. The deviation in the calculation of the lead field is also evaluated when using three shells with realistic conductivities. The magnetic field turned out to differ to an important measurable extend in particular for deeper sources, making the three-shell algorithm substantially more accurate for these dipole locations.</p></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"299 ","pages":"Article 120836"},"PeriodicalIF":4.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003331/pdfft?md5=0a9251a7ae10c3d26551cba22d884b35&pid=1-s2.0-S1053811924003331-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Similarity and characterization of structural and functional neural connections within species under isoflurane anesthesia in the common marmoset","authors":"Daisuke Yoshimaru ,&nbsp;Tomokazu Tsurugizawa ,&nbsp;Junichi Hata ,&nbsp;Kanako Muta ,&nbsp;Takuto Marusaki ,&nbsp;Naoya Hayashi ,&nbsp;Shuhei Shibukawa ,&nbsp;Kei Hagiya ,&nbsp;Hideyuki Okano ,&nbsp;Hirotaka James Okano","doi":"10.1016/j.neuroimage.2024.120854","DOIUrl":"10.1016/j.neuroimage.2024.120854","url":null,"abstract":"<div><p>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.</p></div>","PeriodicalId":19299,"journal":{"name":"NeuroImage","volume":"300 ","pages":"Article 120854"},"PeriodicalIF":4.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1053811924003513/pdfft?md5=8a3d5ad92266435c09e3c05c2241d0d9&pid=1-s2.0-S1053811924003513-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}