Brain Structure & Function最新文献

{"title":"The proto-cortical amygdala: a perspective on the functional and evolutionary relationship between the basolateral amygdala complex and neocortex in mammals.","authors":"Fionnghuala L J James, Sayed K Ahamed, Cheng Yang, Richard Wilson, Juan J Canales, Vanni Caruso, Luke R Johnson","doi":"10.1007/s00429-026-03194-6","DOIUrl":"https://doi.org/10.1007/s00429-026-03194-6","url":null,"abstract":"<p><p>The basolateral amygdala complex (BNC) plays an important role in learning, memory, motivation, and social behaviour, with its dysfunction implicated in a wide variety of psychiatric disorders. Despite being one of the most intensely researched areas of the brain, much is still unknown about its microanatomical structure and function, relationships and evolutionary origins. In this review, we offer a multidisciplinary approach through the lens of comparative anatomy and evolutionary developmental studies to provide a better understanding of the anatomical and functional relationship between the amygdala and cortex in memory, learning, and social behaviour. Particular attention is paid to the evolutionary origin of pallial areas across amniotes, as well as homology between principal neurons, cortical layers, BNC nuclei, and connectivity between these areas. We argue that the basolateral amygdala complex functions as an early form of the mammalian neocortex. This theory will help to further the understanding of amygdala and cortex function in both health and psychiatric disease.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13630959/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149103985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unifying orientation-dependent relaxation and diffusion around axonal fibers in DTI: characterizing fiber-tract-specific anisotropic R₂ profiles of the corpus callosum.","authors":"Yuxi Pang, Rajikha Raja, Wilburn E Reddick","doi":"10.1007/s00429-026-03200-x","DOIUrl":"https://doi.org/10.1007/s00429-026-03200-x","url":null,"abstract":"<p><p>This work aims to characterize fiber-tract-specific, orientation-dependent [Formula: see text] values across seven callosal segments (CC1[Formula: see text]CC7) using high-resolution diffusion tensor imaging (DTI) datasets from the Human Connectome Project. White matter (WM) voxels within each segment were identified using jointly applied thresholds of fractional anisotropy (FA) and mode of anisotropy (MO) to ensure robust selection of coherently oriented fibers. Orientation-dependent [Formula: see text] profiles were then derived from T2W images (b = 0), incorporating voxel-wise principal fiber orientations. These profiles were modeled using a cone-based framework that captures directional variations in transverse relaxation, enabling a clean separation of the magnitude of anisotropic [Formula: see text] component ([Formula: see text]) from its isotropic counterpart. Across segments, fits obtained at different b-values showed no major discrepancies aside from changes in [Formula: see text]. On average, [Formula: see text] increased from 2.4 ± 0.2 s^- 1 to 3.2 ± 0.3 s^- 1 with higher b-values. Additionally, [Formula: see text] showed an increasing trend from CC1 to CC7, while the cone's opening angle [Formula: see text] remained around 65°. As expected, FA also increased from CC1 to CC7 and with decreasing b-values. In conclusion, this study demonstrates that fiber-tract-specific anisotropic [Formula: see text] profiles in callosal segments can be quantified using a cone model, providing a valuable framework for reinterpreting existing clinical DTI data and guiding future studies targeting WM microstructure in both healthy and diseased populations.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149103972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occupational stress and white matter integrity: a methodological perspective : Short title: White matter integrity and burnout: considerations.","authors":"Matlyuba Sanoeva, Nikki Ghadiminia, Zafar Mamajonov, Nargiza Quchqorova, Nodira Rasulova, Xolidaxon Rakhmatova, Gulnoza Turaeva, Azamjon Makhmudov","doi":"10.1007/s00429-026-03204-7","DOIUrl":"https://doi.org/10.1007/s00429-026-03204-7","url":null,"abstract":"<p><p>Work-related stress and burnout are increasingly prevalent, yet their neural correlates remain poorly understood. Kokubun and colleagues recently reported that fractional anisotropy in the superior longitudinal fasciculus, internal capsule, and external capsule statistically links workload to cynicism in healthy adults. While the original authors acknowledged several limitations, tract-averaging, FA non-specificity, and the heuristic use of Conservation of Resources theory, we argue that their implications deserve further emphasis. Atlas-based tract averaging may obscure regional variability within functionally distinct SLF subcomponents. FA cannot specify underlying biological mechanisms. And despite explicit qualifications, the metaphorical language of depletion and recharge sits in tension with the cross-sectional data. We suggest that future studies incorporate along-tract profiling, complementary diffusion metrics, and greater conceptual precision to strengthen this promising line of research.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149103537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ancestral organisation and asymmetric circuit architecture of the habenula revealed in a basal ray-finned fish.","authors":"P Ahumada-Galleguillos, M L Concha","doi":"10.1007/s00429-026-03196-4","DOIUrl":"https://doi.org/10.1007/s00429-026-03196-4","url":null,"abstract":"<p><p>The habenula is a conserved dorsal diencephalic hub that integrates information related to motivational state, behavioural flexibility, and cognitive control. In many vertebrates, it displays pronounced left-right asymmetry, yet how structural lateralisation is reflected in circuit architecture remains poorly understood, partly because phylogenetically informative lineages remain undersampled. Here, we characterise habenular connectivity in the Senegal bichir (Polypterus senegalus), a member of an early-diverging ray-finned fish lineage with marked habenular asymmetry. Using neuronal tracing, histology, and immunohistochemistry, we show that Polypterus retains a conserved vertebrate connectivity scaffold, with afferents arising from subpallial, hypothalamic, and posterior tubercular territories and efferents projecting primarily to the interpeduncular and raphe nuclei. Layered onto this scaffold are distinctive organisational features, including traits shared with teleosts that may represent an ancient actinopterygian condition, as well as apparent lineage-specific specialisations of bichirs. Notably, the enlarged right habenula receives both ipsilateral and contralateral inputs, whereas the left habenula is largely restricted to ipsilateral afferents, revealing a right-dominant mode of hemispheric integration. At the output level, left and right habenular efferents terminate in segregated dorsal and ventral territories of the interpeduncular nucleus, respectively. This organisation indicates that asymmetric integration within the habenula is associated with segregated engagement of downstream pathways. Together, these findings establish bichirs as a key comparative model for reconstructing early osteichthyan habenular circuitry and provide insight into the evolutionary origins of mechanisms linking habenular asymmetry to lateralised circuit organisation across vertebrates.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149058532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autoencoders for unsupervised analysis of rat myeloarchitecture.","authors":"Melina Estela, Raimo A Salo, Isabel San Martín Molina, Omar Narvaez, Ville Kolehmainen, Jussi Tohka, Alejandra Sierra","doi":"10.1007/s00429-026-03166-w","DOIUrl":"10.1007/s00429-026-03166-w","url":null,"abstract":"<p><p>Quantitative assessment of brain histology is often constrained by predefined feature sets and labor-intensive manual annotations. To overcome these limitations, we employed unsupervised deep learning to automatically extract and quantify tissue organizational patterns from myelin-stained rat brain sections without the need for prior labeling. We evaluated nonlinear convolutional autoencoders (AEs) against linear principal component analysis (PCA) and DINOv3, a self-supervised foundation model applied without task-specific fine-tuning, for feature representation, followed by clustering with Gaussian mixture models. Compared to both PCA and DINOv3, AEs better preserved fine axonal architecture and produced more consistent and interpretable tissue clusters across hierarchical levels. The resulting clusters revealed anatomically meaningful tissue organization, including different white matter densities and grey matter subregions. When applied to tissue from sham and mild traumatic brain injury animals, AE-derived features also captured pathology-related alterations, such as white matter loss and injury-specific microstructural changes. These findings suggest that task-specific unsupervised training on domain-specific histological data can automatically characterize tissue organization at multiple scales and detect pathological changes, offering a scalable, annotation-free approach to computational neuropathology.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13616018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149058486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does the stria of Gennari integrity reflect acquired visual field defects?","authors":"Carlien Roelofzen, Giorgio L Porro, Maria M van Genderen, Douwe P Bergsma, Natalia Petridou, Serge O Dumoulin, Alessio Fracasso","doi":"10.1007/s00429-026-03191-9","DOIUrl":"https://doi.org/10.1007/s00429-026-03191-9","url":null,"abstract":"<p><p>Visual input reaches the primary visual cortex (V1) at the stria of Gennari, a band of highly myelinated fibers at the level of layer IV. Damage to the visual pathways can cause visual field defects (scotomas) that prevent visual input from reaching V1. Here, we evaluate whether the stria of Gennari degrades in the absence of visual input. Using 7 Tesla MRI, we investigate the integrity of the stria of Gennari in case of acquired homonymous visual field defects, in particular hemianopia: the loss of vision in half of the visual field. These visual field defects allow us to compare stria of Gennari integrity between the two hemispheres within the same participant, i.e., the hemisphere that is deprived of visual input (affected hemisphere) versus the hemisphere receiving visual information (unaffected hemisphere). Therefore, we focus on cases of acquired blindness following damage between the optic chiasm and V1. We quantify the stria of Gennari integrity both by measuring the T1-weighted intensity at the middle of cortical depth and using a modeling approach that captures T1-weighted intensity variations across cortical depth. Our results show that the stria of Gennari remains intact in both the affected and unaffected hemisphere, suggesting that the stria of Gennari integrity is not altered in the absence of visual input.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149057985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thalamocortical white matter microstructure and cognition following mild traumatic brain injury: A fixel-based analysis.","authors":"Maggie Baird, Marc L Seal, Richard Beare, Joseph Yuan-Mou Yang, Jacqueline F I Anderson","doi":"10.1007/s00429-026-03193-7","DOIUrl":"10.1007/s00429-026-03193-7","url":null,"abstract":"<p><p>The thalamus, an essential hub for cognitive integration across distributed brain networks, has emerged as a key structure implicated in mild traumatic brain injury (mTBI). However, while white matter microstructural injury is considered a core pathophysiological substrate of mTBI, few studies have examined thalamocortical microstructure following injury. The present study applied an advanced diffusion MRI-based white matter microstructural model, fixel-based analysis (FBA), to examine thalamocortical white matter microstructure and its associations with cognitive performance at approximately two-months following mTBI. The final analysed dataset included 39 mTBI patients and 28 trauma control (TC) patients aged 18-60 years, who were recruited following hospital admission for physical injury. Participants completed a range of cognitive tests and an MRI protocol including diffusion weighted sequences at 6-12 weeks following injury. Thalamocortical tracts were delineated bilaterally using the TractSeg algorithm, an automated white matter bundle segmentation tool. While whole-brain FBA showed no statistically significant differences in fixel metrics between groups, tract-based analyses showed that mTBI was associated with reduced fibre density (FD) of the right thalamo-precentral (BF₁₀ = 6.849), right thalamo-parietal (BF₁₀ = 3.708) and left thalamo-precentral (BF₁₀ = 1.276) tracts. Despite these structural differences, the groups were comparable with respect to performance on cognitive tests. However, models with interaction effects indicated that associations between thalamocortical FD and cognitive performance differed between groups, most frequently on measures of processing speed and attention. Together, these findings indicate at this stage of recovery, changes in white matter microstructure are detectable in thalamocortical tracts, and that structure-cognition relationships may differ between mTBI and TC groups even in the absence of objective cognitive impairment.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13615928/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149058015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Probiotic effects on cognitive performance, hippocampal oxidative stress, and structural damage induced by icv STZ in Alzheimer-like rat model.","authors":"Ardeshir Nabizadeh, Ali Rafati, Narges Karbalaei, Mohammad Reza Namavar, Saeid Hosseinzadeh, Hadi Moatamed Jahromi, Atefeh Rahimi, Maryam Naseh","doi":"10.1007/s00429-026-03195-5","DOIUrl":"https://doi.org/10.1007/s00429-026-03195-5","url":null,"abstract":"","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149015382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex-related variability of white-matter tracts is robust to tractography methodology.","authors":"Matthew Amandola, Bastien Herlin, Michael E Kim, Simon Vandekar, Ivy Uszynski, Bennett Landman, Cyril Poupon, Kurt G Schilling","doi":"10.1007/s00429-026-03198-2","DOIUrl":"10.1007/s00429-026-03198-2","url":null,"abstract":"<p><p>Diffusion tractography is the prominent in-vivo technique to study and investigate white-matter pathways in the human brain. While tractography is a powerful method, recent work suggests that different tractography methods can produce strikingly different representations of the same white-matter pathway. This multitude of differing options and diverging pipelines makes tractography related group-effects difficult to generalize, as it is currently unclear whether group-level inferences made using one tractography pipeline can be expected to hold when a different, equally defensible pipeline is applied to the same data. Here, we test the generalizability of sex-related changes on tractography-derived features by analyzing the exact same datasets with two equally reasonable pipelines which differ in model fitting, tractography reconstruction, and microstructure and volumetric analysis. We found that despite differences in analysis, the resulting patterns and biological interpretations of sex effects rarely disagreed across methods. Microstructural sex-related effects between methods were remarkably consistent between protocols, only displaying one statistically significant disagreement out of 343 comparisons (0.29%). However, discrepancies were more common among normalized pathway-volume effects, producing 8 out of the 9 total statistically significant disagreements between methods. Moreover, we found that the two tractography methods are differentially sensitive to tractography-derived features, as bundles derived from targeted tractography were much more sensitive to volumetric effects than tractogram-based tractography, potentially explaining the volumetric discrepancy between methods. This study indicates that reasonable methodological choices are unlikely to lead two investigators to fundamentally opposing conclusions about sex differences in white-matter, and that the robustness of tractography findings is similar to established fields of science. More broadly, this study presents an optimistic outlook on the future of tractography, and provides an initial empirical comparison of cross-pipeline robustness.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13589754/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149008111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Daily rhythms in fear extinction memory reflect structural and functional changes in a prefrontal-amygdala circuit.","authors":"Noah R R Andrys, Elise A Johnson, Ethan B Rowe, Luke A Millisor, Breyton K McDole, Michael V Baratta, Jason J Radley, Robert L Spencer","doi":"10.1007/s00429-026-03176-8","DOIUrl":"10.1007/s00429-026-03176-8","url":null,"abstract":"<p><p>Circadian rhythms exert widespread influences on learning and memory processes across diverse brain regions. The extinction of emotional memories is enhanced when training and testing occur during the circadian active phase in both rodents and humans, yet the underlying neural mechanisms remain poorly understood. Here, we examined time-of-day differences in conditioned fear extinction memory and associated neural activity within the ventromedial prefrontal cortex (vmPFC), including within a vmPFC-to-basolateral/basomedial amygdala (BLA/BMA) pathway in rats. Using an intersectional viral strategy to label vmPFC to BLA/BMA projection neurons, we found that female rats trained and tested during their active phase exhibited superior extinction recall compared to rats trained and tested during their inactive phase. The superior extinction recall was associated with greater FOS expression throughout the vmPFC, including within vmPFC to BLA/BMA projection neurons. In a follow-up experiment, we examined dendritic spine morphology in untrained female and male rats. We observed greater dendritic spine density in vmPFC to BLA/BMA neurons during the active phase compared to inactive phase, with this difference driven primarily by increased thin and stubby spine subtypes. These findings demonstrate that superior active phase extinction memory is associated with enhanced vmPFC circuit activity and corresponds to time-of-day differences in dendritic spine density within extinction-relevant neural pathways. Our results reveal a potential structural plasticity mechanism by which circadian rhythms modulate fear extinction learning and memory.</p>","PeriodicalId":9145,"journal":{"name":"Brain Structure & Function","volume":"231 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13589713/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149008165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}