Imaging neuroscience (Cambridge, Mass.)最新文献

{"title":"A dual-fMRI investigation of interpersonal emotion regulation: Predicting strategy selection and implementation success from effective brain connectivity.","authors":"Nicola Ngombe, Kristína Czekóová, Martin Gajdoš, Klaus Kessler, Milan Brázdil, Simone Shamay-Tsoory, Daniel Joel Shaw","doi":"10.1162/IMAG.a.1360","DOIUrl":"10.1162/IMAG.a.1360","url":null,"abstract":"<p><p>Inter-personal emotion regulation (ER) is the social process whereby one individual (a \"Regulator\") assists another (the \"Target\") in regulating their emotional state. Despite the importance of inter-personal ER for maintaining well-being, very little is known about the neurocognitive mechanisms that support this process. In the present study, we performed functional magnetic resonance imaging on 23 pairs of Regulators and Targets whilst they engaged in a novel task designed to capture the two stages of inter-personal ER: the Regulator's selection of an ER strategy to recommend and its subsequent implementation by an affiliate Target. This paradigm allowed us to investigate the brain systems supporting both stages of the inter-personal process and identify personality characteristics that might influence the inter-personal dynamic through these neurocognitive mechanisms. Results revealed largely overlapping patterns of brain response during Regulators' selections and Targets' implementation of ER strategies, encompassing medial and lateral prefrontal and temporo-parietal cortices. Moreover, by applying behavioural Dynamic Causal Modelling to the behavioural and brain data acquired during the task, we identified patterns of effective connectivity among these brain regions from which we could accurately estimate Regulators' selections and their effectiveness in down-regulating Targets' emotional responses. Lastly, certain network connections and the effectiveness of Regulators' selections in down-regulating Targets' emotion states were associated with two dissociable styles of self-directed (intra-personal) ER: failure- and decision-related action control.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13576947/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148978389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources of the N15 TMS-evoked potential following motor cortex stimulation localize rostrals to TMS-induced electric fields and depend on dose.","authors":"Sybren Van Hoornweder, Mikkel M Beck, Jesper D Nielsen, Leo Tomasevic, Raf L J Meesen, Hartwig R Siebner, Axel Thielscher","doi":"10.1162/IMAG.a.1356","DOIUrl":"10.1162/IMAG.a.1356","url":null,"abstract":"<p><p>Transcranial magnetic stimulation (TMS) elicits characteristic cortical responses known as TMS-evoked potentials (TEPs) measured via electroencephalography (EEG). An early negative peak can be consistently evoked over the motor cortex at around 15 ms (N15). It remains elusive whether N15 overlaps with the cortical regions receiving the highest TMS-induced electric field (E-field). We characterized the source activity of the N15 component relative to the TMS-induced E-field in 16 healthy adults who underwent TMS-EEG over the left primary motor hand area at six stimulus intensities (-8% to +12% maximum stimulator output relative to resting motor threshold) during rest and tonic contraction. Individualized head models, based on T1 and T2 MRI scans, were used for E-field simulations and source localization with LCMV, dSPM, and eLORETA as inverse solvers. Linear mixed-effects models and spatial clustering were used to assess dose- and state-dependent effects. The N15 source field was consistently located rostral to the TMS-induced electric field, with the spatial disparity decreasing as the stimulation dose increased. N15 source activity primarily clustered in the left premotor and primary motor cortex, while the TMS E-field peaked in the crowns of the pre- and postcentral gyri. All three inverse solvers yielded similar results, demonstrating consistent dose- and state-dependent effects on the N15 and suggesting that solver choice had minimal impact. These findings demonstrate a spatial mismatch between early TMS-evoked potentials following motor cortex stimulation and the cortical regions exposed to peak electric fields. Combined with prior literature, our findings provide evidence that the rostral N15 source activity reflects transsynaptic propagation via direct cortico-cortical or indirect cortico-subcortico-cortical pathways.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13563533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial covariance of mGluR5 density and structural degeneration in behavioral variant frontotemporal degeneration.","authors":"Melanie A Matyi, Maggie K Pecsok, Christopher A Olm, Hamsanandini Radhakrishnan, Laynie Dratch, Vivianna M Van Deerlin, Emma Rhodes, Jeffrey S Phillips, Philip A Cook, James C Gee, David J Irwin, Corey T McMillan, David Roalf, Lauren Massimo","doi":"10.1162/IMAG.a.1358","DOIUrl":"10.1162/IMAG.a.1358","url":null,"abstract":"<p><p>Post-mortem human brain tissue and <i>in vivo</i> imaging studies of behavioral variant frontotemporal degeneration (bvFTD) suggest that metabotropic glutamate receptors (mGluR) may be vulnerable to the disease process. However, these studies lack evidence demonstrating how loss of mGluR relates to clinical features of bvFTD, hindering efforts to identify appropriate therapeutic strategies. Thus, we leveraged existing normative receptor density maps, and a large cohort of individuals with bvFTD to elucidate relationships among structural degeneration, glutamatergic receptor density, and clinical features. We obtained receptor density maps from the neuromaps repository, which contains positron emission tomography-derived receptor maps across many neurotransmitter systems, including mGluR5 and N-methyl-D-aspartate (NMDA). We quantified the spatial covariance of structural degeneration and glutamate receptor density maps in 106 individuals with bvFTD and 165 cognitively unimpaired (CU) individuals. Covariance of each participant's regional cortical volumes and normative receptor density in each region of the Schaefer 100 (7 network) parcellation was computed. Negative covariance indicates a high spatial correspondence such that regions with greater structural degeneration also have high receptor density. Within bvFTD, we tested whether greater spatial covariance of structural degeneration and receptor density maps were associated with disease stage and severity, executive function, and neuropsychiatric symptoms. Comparing bvFTD with CU, we observed significant spatial covariance of structural degeneration and mGluR5, but not NMDA. In bvFTD, greater covariance of structural degeneration and mGluR5 maps was associated with more advanced disease stage (<i>p</i> = .003) and severity (<i>p</i> < .001), and worse category (<i>p</i> < .001) and letter-guided (<i>p</i> < .001) fluency and digit span backward (<i>p</i> = .0257) but not neuropsychiatric symptom severity. Neurodegeneration in bvFTD appears to preferentially affect cortical regions with higher normative mGluR5 density, as reflected by spatial covariance between structural degeneration and mGluR5 maps in a clinically well-characterized cross-sectional cohort. Furthermore, greater covariance of mGluR5 density and structural degeneration with both disease severity and executive dysfunction elucidates potential neural mechanisms of core clinical features of bvFTD. Future work examining <i>in vivo</i> glutamate could provide further insight into the natural history of glutamate dysfunction in bvFTD, facilitating testing of glutamatergic therapies.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13563532/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Social approach-avoidance conflict: Behavioural, emotional, and neural correlates along a depression-social anxiety spectrum.","authors":"Francisco Cervantes Constantino, Alejo Acuña, Catalina Fernandez, Michelle Guillen, Laura Mendaro, Antonella Brandani, Sebastián Morales, Alfonso Pérez, Javier Mattos, Enrique Cuña, Margarita García-Fontes, Álvaro Cabana, Jorge L Armony, Michael Gaebler, Victoria B Gradin","doi":"10.1162/IMAG.a.1363","DOIUrl":"10.1162/IMAG.a.1363","url":null,"abstract":"<p><p>Approach-avoidance conflict, in which the same option entails both rewarding and aversive consequences, has been proposed as a key process in internalizing disorders such as depression and social anxiety. Yet, human paradigms that model approach-avoidance conflict and link it to brain function remain scarce. In particular, it has been emphasized the need for studying this conflict in social contexts. We developed a Social Approach-Avoidance Conflict (SAAC) task that involved a social evaluative demand manipulation, and combined it with functional magnetic resonance imaging (fMRI) in 135 young adults. On each trial, participants decided whether to accept a variable reward at the cost of increasing the presence of more or less demanding judges in a future public speaking evaluation, or to avoid and receive a minimal default reward. Depression and social anxiety (D-SA) symptoms were summarized into a single continuous dimension derived from principal component analysis of psychological questionnaires. Behaviourally, higher payments increased approach, whereas higher judge ranks increased negative affect and avoidance. Higher D-SA scores were associated with reduced positive and heightened negative emotional responses to higher-rank judges, stronger preferences for low-rank judges, and greater avoidance of high-rank judges. Neurally, increasing judge rank recruited the dmPFC/dACC during approach decisions, and higher D-SA symptoms were associated with stronger responses in these regions. Increasing payment during approach engaged dmPFC/vmPFC, PCC, and posterior insula, and these reward-related responses were attenuated at higher D-SA levels. In conclusion, internalizing symptoms of depression and social anxiety are associated with a bias in emotional and behavioural responses when a reward competes with a social evaluative threat. At the neural level, internalizing symptoms were associated with an enhanced aversive/conflict signalling in the dmPFC/dACC, and with reduced reward-related activity. Findings shed light on the mechanisms underlying costly social avoidance in internalizing disorders.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13563531/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biphasic acclimation for simultaneous wide-field fluorescent Ca²⁺ imaging and fMRI of awake mice.","authors":"Francesca Mandino, Taekyung Kang, Xilin Shen, Corey Horien, Xenophon Papademetris, Stephen M Strittmatter, Evelyn M R Lake","doi":"10.1162/IMAG.a.1357","DOIUrl":"10.1162/IMAG.a.1357","url":null,"abstract":"<p><p>Functional magnetic resonance imaging (fMRI) can be applied in mice and humans, making it a key technology in translational neuroimaging research. Yet, most fMRI studies in rodents use anesthesia to limit subject motion and stress. This puts a hard boundary on the range of brain and behavioral states that can be studied in animals, and deviates from the near-universal practice of imaging people while awake. Recent years have seen a push toward the development of acclimation protocols for performing fMRI in mice without anesthesia, but the results have been mixed. In parallel, imaging mice without anesthesia has become routine for complementary neuroimaging methods, including wide-field fluorescence calcium (WF-Ca²⁺) imaging. Our group works with a unique co-implementation of WF-Ca²⁺ and fMRI which enables the collection of complementary measures of brain function, but-until now-has necessitated the use of anesthesia. We present the first longitudinal protocol for simultaneous WF-Ca²⁺ and fMRI in awake mice. Our approach comprised a two-phase (biphasic) acclimation protocol that results in high-quality multimodal data. Comparisons of cortex-wide neuronal activity (WF-Ca²⁺ imaging) and blood-oxygen-level dependent fMRI signals between isoflurane-anesthetized and awake mice reveal both convergent and divergent patterns in brain function between modalities and across time.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13563530/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct roles of brain network flexibility in motor learning across age.","authors":"Kazumasa Uehara, Makoto Hagihara, Keiichi Kitajo","doi":"10.1162/IMAG.a.1359","DOIUrl":"10.1162/IMAG.a.1359","url":null,"abstract":"<p><p>Motor learning is a lifelong process, from infancy through old age. Acquiring new motor actions through repetitive practice requires adjusting motor output in response to sensory input and integrating them to facilitate learning. For this to occur, the central nervous system must flexibly predict and adapt to the dynamic interplay between sensory inputs and motor outputs. Although overall brain function changes with age, it remains unclear how flexible brain networks, reflecting moment-to-moment reconfiguration of large-scale brain networks, influence motor learning ability with aging. To address this, we designed a visuomotor learning task involving both younger and older adults and quantitatively assessed brain network flexibility, leveraging multichannel electroencephalography (EEG) in humans. We found age-group differences in motor learning properties, brain network flexibility, and their neural relationships. In younger adults, the learning aftereffect was associated with brain network flexibility during motor preparation in the learning task. However, this association was not observed in older adults. Together, our findings suggest that brain network flexibility during motor preparation was critical for acquiring and maintaining new motor actions in younger adults, but that this coupling was attenuated with aging.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13559766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148931966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clarifying and extending permutation tests on brain map correspondence through mixed-effects modeling.","authors":"Qiaochu Wang, Lingyi Peng, Thomas E Nichols, Xu Zou, Yaotian Wang, Jie He, Yuexin Zhang, Dana L Tudorascu, Diego Szczupak, Lauren Schaeffer, Emily S Rothwell, Laurel Dieckhaus, Stacey J Sukoff Rizzo, Gregory W Carter, Afonso C Silva, Tingting Zhang","doi":"10.1162/IMAG.a.1350","DOIUrl":"10.1162/IMAG.a.1350","url":null,"abstract":"<p><p>Permutation-based methods such as the spin test, Brain Surrogate Maps with Autocorrelated Spatial Heterogeneity (BrainSMASH), and the simple permutation-based intermodal correspondence (SPICE) test are widely used to assess correspondence between brain maps while accounting for their spatial autocorrelation. However, these methods define and evaluate correspondence in fundamentally different ways, making their results difficult to compare or interpret jointly. We address these limitations by introducing a two-factor mixed-effects model that decomposes brain map variability into components arising from inter-subject variability and spatial variability across brain locations. This formulation provides a principled way to characterize distinct sources of variability in brain maps and to formally link each correspondence test to the specific component it targets. Within this framework, we further provide the analytical expressions of the null distributions of the spin test, BrainSMASH, and SPICE in terms of model parameters. This unified framework clarifies the fundamental distinctions among the permutation tests, reveals their implicit assumptions, and provides a principled way to compare and interpret their results. Beyond clarifying existing methods, the modeling framework naturally motivates a bootstrap-based method that enables simultaneous inference of multiple forms of correspondence arising from different components of brain map variability. Through extensive simulations and empirical analyses of both structural (cortical thickness vs. sulcal depth) and functional (language vs. motor contrast) brain maps, we demonstrate that the bootstrap-based method achieves well-calibrated type I error, substantially higher statistical power, and provides a robust and comprehensive characterization of different forms of brain map correspondence.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148922093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taming dimensionality in big neuroimaging data: Efficient orthonormal projective NMF via stochastic learning and data compression.","authors":"Abdalla Bani, Sung Min Ha, Thomas Earnest, Braden Yang, Pan Xiao, John Lee, Janine Bijsterbosch, Aristeidis Sotiras","doi":"10.1162/IMAG.a.1355","DOIUrl":"10.1162/IMAG.a.1355","url":null,"abstract":"<p><p>Large-scale neuroimaging datasets present remarkable opportunities for advancing our understanding of human brain structure and function. Data-driven pattern analysis methods such as Orthonormal Projective Non-negative Matrix Factorization (opNMF) are particularly well suited to uncover multivariate relationships within these data, offering greater interpretability and reproducibility than more conventional approaches such as principal component analysis (PCA) and independent component analysis (ICA). Despite its utility in clinical computational neuroscience, the application of opNMF in large cohort studies has been impeded by computational challenges and scalability limitations. In this work, we address these issues by introducing a stochastic optimization strategy that processes mini-batches of the data, substantially improving scalability. We further accelerate computation through random data compression and leverage repulsive point processes to diversify mini-batches, reducing redundancy and the variance of updates. We first evaluated our method on gray matter tissue density maps from 1,000 participants in the Open Access Series of Imaging Studies (OASIS). Compared with the original approach, it achieved similar approximation accuracy and factor interpretability while greatly reducing computational cost. To demonstrate practical utility, we then applied the framework to 10,000 participants from the UK Biobank, identifying 20 patterns of structural covariance (PSCs) and examined associations between visceral adipose tissue (VAT) and PSC loadings, finding significant relationships for 13 PSCs in females and 11 PSCs in males, most of which were negative. We further show how these patterns refine in higher-rank decompositions with 40 and 60 components. This enhanced opNMF framework opens new possibilities for large-scale neuroimaging analyses, facilitating deeper insights into brain structure in both health and disease.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556794/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148922118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain network dynamics in the wake-sleep transition reorganize according to task engagement.","authors":"Samika S Kumar, Anat Arzi, Corinne A Bareham, Javier Gonzalez-Castillo, Isabel Fernandez, Enzo Tagliazucchi, Pedro A M Mediano, Peter A Bandettini, Tristan A Bekinschtein","doi":"10.1162/IMAG.a.1336","DOIUrl":"10.1162/IMAG.a.1336","url":null,"abstract":"<p><p>Alertness fluctuations and cognitive processing comprise overlapping brain circuits that include frontoparietal, thalamocortical, and sensory pathways. It is unclear how these brain circuits can simultaneously support such disparate but foundational human processes. To develop an integrated framework of consciousness and cognition, it is important to understand how fluctuations in alertness and cognitive processing interact in their shared circuits. In this electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) study, we assessed individuals who fluctuated between alert and drowsy states while engaged in either an active or passive auditory task. We hypothesized that during periods of low alertness, individuals who actively maintain task engagement would recruit additional frontoparietal and sensory processing networks, while thalamocortical dynamics that typically change during sleep onset would remain unaffected. We found that when alertness decreased, passively listening to auditory tones led to increased synchronization primarily in the parietal lobe, whereas actively performing an auditory task resulted in increased long-range frontoparietal synchronization. During decreasing alertness, passive listening (but not active task engagement) was associated with widespread increased synchronization between the thalamus and cortex. In contrast, active task engagement (but not passive listening) led to increased synchronization between the auditory cortex and the rest of the brain. These results suggest the brain's capacity for flexible functional reorganization when alertness levels decline but cognitive processes persist. The brain patterns that support transitions of consciousness at sleep onset also reflect ongoing cognitive task demands.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556789/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148922112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biophysical simulations of fMRI responses using realistic microvascular models: Insights into distinct hemodynamics in humans and mice.","authors":"Grant Hartung, Avery J L Berman, Sava Sakadžić, Andreas Linninger, David A Boas, Jonathan R Polimeni","doi":"10.1162/IMAG.a.1340","DOIUrl":"10.1162/IMAG.a.1340","url":null,"abstract":"<p><p>Functional magnetic resonance imaging (fMRI) is broadly used to measure human brain activity, however, the hemodynamic changes that comprise the fMRI response to neuronal activity are often interpreted using microscopy data in mice. These microscopy data provide ground-truth observations of how individual blood vessels respond to neuronal activity and thus form the basis of our fundamental understanding of neurovascular coupling. Although these invasive experiments provide invaluable insight, there are striking differences in the vascular architecture of mouse and human brains that may influence the hemodynamic response. Motivated by this, we developed a biophysical modeling framework for realistic hemodynamic simulations in both mouse and human cerebral cortex. For this, we utilized Vascular Anatomical Network (VAN) models that explicitly represent the full microvascular tree as a single connected network, originally based on anatomical reconstructions from a given location of mouse cerebral cortex. We extended the VAN modeling framework using synthetic VAN models representing the microvascular network at a single location of the human cerebral cortex. To account for larger size and complexity of the human VAN models, we developed an efficient computational framework to simulate the full hemodynamic responses in this human model and compared the simulated fMRI responses between mice and humans. Our biophysical simulations are based entirely on first principles (e.g., conservation of mass); model parameter values were fixed across all simulations, not tuned to fit data, as they represent meaningful physical constants taken from previous measurements. Only two simple calibrations were tuned for each simulation, to match baseline perfusion rates (blood flow) and oxygen extraction (OEF). Our results show that differences in microvasculature indeed influenced the hemodynamic response and led to observable differences in timing-for example, the simulated fMRI response peak in humans was delayed by ~2 s compared with that of mice, consistent with prior fMRI observations. While there are many known differences in vascular architecture in rodents and humans, we also discovered that, unexpectedly, an asymmetry in the number of branches of the penetrating intracortical arterioles and venules appears to be conserved across species. We demonstrate through further simulations that this anatomical property may also be needed for suitable hemodynamic responses. Our framework thus provides a valuable tool for bridging <i>in-vivo</i> microscopy of microvascular dynamics to human fMRI.</p>","PeriodicalId":73341,"journal":{"name":"Imaging neuroscience (Cambridge, Mass.)","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556804/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148922137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}