Most recent paper

Brain. 2025 Jan 15:awaf008. doi: 10.1093/brain/awaf008. Online ahead of print.

ABSTRACT

Curing Alzheimer's disease remains hampered by an incomplete understanding of its pathophysiology and progression. Exploring dysfunction in medial temporal lobe networks, particularly the anterior-temporal (AT) and posterior-medial (PM) systems, may provide key insights, as these networks exhibit functional connectivity alterations along the entire Alzheimer's continuum, potentially influencing disease propagation. However, the specific changes in each network and their clinical relevance across stages are not yet fully understood. This requires considering commonly used biomarkers, clinical progression, individual variability, and age confounds. Here, we leveraged monocentric longitudinal data from 261 participants spanning the adult lifespan and the Alzheimer's continuum. The sample included cognitively unimpaired adults aged 19 to 85 years (n = 209; eight out of 64 older adults over 60 were Aβ-positive) and Aβ-positive patients fulfilling diagnostic criteria for mild cognitive impairment (MCI, n = 26; 18 progressed to Alzheimer-dementia within seven years) or Alzheimer's type dementia (n = 26). Participants underwent structural and resting-state functional (f) MRI, florbetapir and FDG-PET, and global cognitive assessments, with up to three visits over a maximum period of 47 months. Network connectivity was assessed using seed-based analyses with the perirhinal and parahippocampal cortices as seeds, within data-driven masks reflecting the AT and PM networks. Generalized additive and linear mixed models were run to assess age-specific effects and Alzheimer's-related alterations. In this context, we explored various markers of pathological and clinical severity, including cerebral amyloid uptake, glucose metabolism, hippocampal volume, global cognition, diagnostic staging, and time to dementia onset. Our findings revealed distinct patterns of connectivity linked to normal aging or Alzheimer's disease. Advancing age throughout adulthood was associated with lower PM connectivity and more subtle changes in AT connectivity, while Alzheimer's disease was characterised by AT hyperconnectivity without global changes in PM connectivity. Specifically, AT connectivity was higher in MCI and Alzheimer-dementia patients compared to older controls and was positively associated with amyloid burden, glucose hypometabolism, hippocampal atrophy, and global cognitive deficits in older adults, ranging from unimpaired to demented. Additionally, higher AT connectivity correlated with faster progression to Alzheimer-dementia in MCI patients. This comprehensive approach allowed to reveal that excessive connectivity within the AT network is intrinsically linked to the pathological and clinical progression of Alzheimer's disease. These insights may guide future research to better understand cascading events leading to the disease and hold promise for developing prognostic tools and therapeutic interventions targeting these specific network alterations.

PMID:39813142 | DOI:10.1093/brain/awaf008

Curr Pain Headache Rep. 2025 Jan 15;29(1):27. doi: 10.1007/s11916-024-01351-2.

ABSTRACT

PURPOSE OF REVIEW: To evaluate existing functional magnetic resonance imaging (fMRI) studies on post-traumatic headache (PTH) following traumatic brain injury (TBI).

RECENT FINDINGS: We conducted a systematic search of PubMed and Embase databases from inception to February 1, 2024. Eligible fMRI studies were required to include adult participants diagnosed with acute or persistent PTH post-TBI in accordance with any edition of the International Classification of Headache Disorders. We identified five eligible fMRI studies: two on acute PTH and three on persistent PTH. These studies assessed resting-state functional connectivity involving comparisons with one or more of the following groups: people with migraine, those with mild TBI but no PTH, and healthy controls. In acute PTH, studies focused exclusively on functional connectivity between the periaqueductal gray or hypothalamus and other brain regions. In persistent PTH, evidence of altered functional connectivity was identified primarily within cingulate, sensorimotor, and visual regions, indicating a hypersensitivity to sensory stimuli in PTH. Despite these insights, the fMRI data remains sparse and is limited by inconsistent results and small samples. The paucity of fMRI studies on PTH limits our understanding of its neurobiological basis. The available evidence suggests that alterations in functional connectivity occur within brain areas involved in emotional and sensory discriminative aspects of pain processing. However, inconsistent results and small sample sizes underscore a critical need for larger, more rigorous fMRI studies. Future studies should also consider using task-based fMRI to investigate possible hypersensitivity to different sensory stimuli in PTH after TBI.

PMID:39812946 | DOI:10.1007/s11916-024-01351-2

Chronic Stress (Thousand Oaks). 2025 Jan 12;9:24705470241311285. doi: 10.1177/24705470241311285. eCollection 2025 Jan-Dec.

ABSTRACT

BACKGROUND: Trauma-focused psychotherapy is treatment of choice for post-traumatic stress disorder (PTSD). However, about half of patients do not respond. Recently, there is increased interest in brain criticality, which assesses the phase transition between order and disorder in brain activity. Operating close to this borderline is theorized to facilitate optimal information processing. We studied if brain criticality is related to future response to treatment, hypothesizing that treatment responders' brains function closer to criticality.

METHODS: Functional magnetic resonance imaging resting-state scans were acquired from 46 male veterans with PTSD around the start of treatment. Psychotherapy consisted of trauma-focused cognitive behavioral therapy, eye movement desensitization and reprocessing, or a combination thereof. Treatment response was assessed using the Clinician-Administered PTSD Scale, and criticality was assessed using an Ising temperature approach for seven canonical brain networks (ie, the visual, somatomotor, dorsal attention, ventral attention, limbic, frontoparietal and default mode networks) to measure distance to criticality.

RESULTS: The brains of prospective treatment responders were closer to criticality than nonresponders (P = 0.017), while no significant interaction effect between group and brain network was observed (P = 0.486). In addition, average criticality across networks correlated with future treatment response (P = 0.028).

CONCLUSION: These results show that the brains of prospective PTSD psychotherapy treatment responders operate closer to criticality than nonresponders, and this occurs across the entire brain instead of in separate canonical brain networks. These results suggest that effective psychotherapy is mediated by brains operating closer to criticality.

PMID:39811461 | PMC:PMC11726532 | DOI:10.1177/24705470241311285

Commun Biol. 2025 Jan 15;8(1):54. doi: 10.1038/s42003-025-07470-9.

ABSTRACT

Creativity is hypothesized to arise from a mental state which balances spontaneous thought and cognitive control, corresponding to functional connectivity between the brain's Default Mode (DMN) and Executive Control (ECN) Networks. Here, we conduct a large-scale, multi-center examination of this hypothesis. Employing a meta-analytic network neuroscience approach, we analyze resting-state fMRI and creative task performance across 10 independent samples from Austria, Canada, China, Japan, and the United States (N = 2433)-constituting the largest and most ethnically diverse creativity neuroscience study to date. Using time-resolved network analysis, we investigate the relationship between creativity (i.e., divergent thinking ability) and dynamic switching between DMN and ECN. We find that creativity, but not general intelligence, can be reliably predicted by the number of DMN-ECN switches. Importantly, we identify an inverted-U relationship between creativity and the degree of balance between DMN-ECN switching, suggesting that optimal creative performance requires balanced brain network dynamics. Furthermore, an independent task-fMRI validation study (N = 31) demonstrates higher DMN-ECN switching during creative idea generation (compared to a control condition) and replicates the inverted-U relationship. Therefore, we provide robust evidence across multi-center datasets that creativity is tied to the capacity to dynamically switch between brain networks supporting spontaneous and controlled cognition.

PMID:39809882 | DOI:10.1038/s42003-025-07470-9

Sci Rep. 2025 Jan 14;15(1):1909. doi: 10.1038/s41598-024-84508-8.

ABSTRACT

The conventional statistical approach for analyzing resting state functional MRI (rs-fMRI) data struggles to accurately distinguish between patients with multiple sclerosis (MS) and those with neuromyelitis optic spectrum disorders (NMOSD), highlighting the need for improved diagnostic efficacy. In this study, multilevel functional metrics including resting state functional connectivity, amplitude of low frequency fluctuation (ALFF), and regional homogeneity (ReHo) were calculated and extracted from 116 regions of interest in the anatomical automatic labeling atlas. Subsequently, classifiers were developed using different combinations of these selected features to distinguish between MS and NMOSD. Compared to models based on individual MRI features, support vector machine (SVM) and logistic regression (LR) models that integrated multilevel functional features such as RSFC, ALFF, and ReHo demonstrated the highest levels of performance on the testing cohorts (SVM, AUC = 0.857; LR, AUC = 0.929). Adding structural features of gray matter volume (GMV) data did not notably improve the classification performance of the machine learning models using multilevel rs-fMRI features. Notably, similar trends were observed across different brain templates, with models based on RSFC, ALFF, and ReHo yielding optimal performance. These findings suggest that utilizing multilevel fMRI features can effectively differentiate between MS and NMOSD patients.

PMID:39809878 | DOI:10.1038/s41598-024-84508-8

Prog Neuropsychopharmacol Biol Psychiatry. 2025 Jan 12:111252. doi: 10.1016/j.pnpbp.2025.111252. Online ahead of print.

ABSTRACT

Aging of the human brain involves intricate biological processes, resulting in complex changes in structure and function. While the effects of aging on gray matter (GM) connectivity are extensively studied, white matter (WM) functional changes have received comparatively less attention. This study examines age-related WM functional dynamics using resting-state fMRI across the adult lifespan. We identified GM and WM functional networks (FNs) using k-means clustering. Static and dynamic analyses of WM functional network connectivity (FNC) were performed to explore age effects on WM-FNs and recurrent patterns of dynamic FNC. We identified 9 WM and 12 GM FNs. Age-related effects on WM FNC strength and WM-GM FNC dynamics included linear positive and U-shaped age trajectories in static FNC strength, and linear negative and inverted U-shaped trajectories in FNC temporal variability. Three distinct brain states with significant age-related differences were identified and validated. These findings were largely replicated in the validation analysis. High integration and low temporal variability in WM-GM FNC may indicate reduced adaptability of the network system in older adults, offering insights into brain aging processes.

PMID:39809409 | DOI:10.1016/j.pnpbp.2025.111252

J Affect Disord. 2025 Jan 12:S0165-0327(25)00047-3. doi: 10.1016/j.jad.2025.01.035. Online ahead of print.

ABSTRACT

BACKGROUND: The neurobiological mechanisms behind the antidepressant effect of bright light therapy (BLT) are unclear. We aimed to explore the dynamic functional connectivity (dFC) changes of the cingulate cortex (CC) in subthreshold depression (StD).

METHODS: The StD participants (38 BLT and 39 placebo) underwent resting-state functional magnetic resonance imaging (rs-fMRI) and mood assessment before and after eight-week BLT. Seed-based whole-brain dFC analysis was conducted and multivariate regression model was adopted to predict Hamilton Depression Rating Scale (HDRS) and Centre for Epidemiologic Studies Depression Scale (CESD) scores changes after BLT. JuSpace toolbox was used to calculate the associations between dFC and neurotransmitter activity in the BLT group.

RESULTS: BLT group showed decreased CESD and HDRS scores. Also, BLT group showed increased dFC of the right supracallosal anterior cingulate cortex (supACC)-right temporal pole (TP), left middle cingulate cortex (MCC)-right insula, and left supACC-pons, and decreased dFC of the right supACC- right middle frontal gyrus (MFG). Changes in dFC of the right supACC-right TP showed positive correlation with changes in CESD and HDRS. Moreover, combining the baseline dFC variability of the CC could predict HDRS changes in BLT. Finally, compared to baseline, the supACC and MCC dFC changes showed significant correlations with the neurotransmitter activities.

CONCLUSIONS: BLT alleviates depressive symptoms and changes the CC dFC variability in StD, and pre-treatment dFC variability of the CC could be used as a biomarker for improved BLT treatment in StD. Furthermore, dFC changes with specific neurotransmitter systems after BLT may underline the antidepressant mechanisms of BLT.

PMID:39809355 | DOI:10.1016/j.jad.2025.01.035

Exp Neurobiol. 2024 Dec 31;33(6):282-294. doi: 10.5607/en24022.

ABSTRACT

Research on brain aging using resting-state functional magnetic resonance imaging (rs-fMRI) has typically focused on comparing "older" adults to younger adults. Importantly, these studies have often neglected the middle age group, which is also significantly impacted by brain aging, including by early changes in motor, memory, and cognitive functions. This study aims to address this limitation by examining the resting state networks in middle-aged adults via an exploratory whole-brain ROI-to-ROI analysis. Using rs-fMRI, we compared middle-aged adults (n=30) with younger adults (n=70) via an ROI-to-ROI correlation analysis, showing lower connectivity between the cerebellar (posterior) network and the salience network (left rostral prefrontal cortex), as well as between the salience network and the visual network (occipital regions) in the middle-aged group. This reduced connectivity suggests that aging affects how these brain regions synchronize and process information, potentially impairing the integration of cognitive, sensory, and emotional inputs. Additional within-group analyses showed that middle-aged adults exhibited weakened connections between networks but increased connections within the dorsal attention, fronto-parietal, visual, and default mode networks. In contrast, younger adults demonstrated enhanced connections between networks. These results underscore the role of the cerebellar, salience, and visual networks in brain aging and reveal distinct connectivity patterns associated with signs of early aging.

PMID:39806942 | DOI:10.5607/en24022

Adv Sci (Weinh). 2025 Jan 13:e2406835. doi: 10.1002/advs.202406835. Online ahead of print.

ABSTRACT

Excitation-inhibition (E/I) imbalance is theorized as a key mechanism in the pathophysiology of epilepsy, with ample research focusing on elucidating its cellular manifestations. However, few studies investigate E/I imbalance at the macroscale, whole-brain level, and its microcircuit-level mechanisms and clinical significance remain incompletely understood. Here, the Hurst exponent, an index of the E/I ratio, is computed from resting-state fMRI time series, and microcircuit parameters are simulated using biophysical models. A broad decrease in the Hurst exponent is observed in pharmaco-resistant temporal lobe epilepsy (TLE), suggesting more excitable network dynamics. Connectome decoders point to temporolimbic and frontocentral cortices as plausible network epicenters of E/I imbalance. Furthermore, computational simulations reveal that enhancing cortical excitability in TLE reflects atypical increases in recurrent connection strength of local neuronal ensembles. Mixed cross-sectional and longitudinal analyses show stronger E/I ratio elevation in patients with longer disease duration, more frequent electroclinical seizures as well as interictal epileptic spikes, and worse cognitive functioning. Hurst exponent-informed classifiers discriminate patients from healthy controls with high accuracy (72.4% [57.5%-82.5%]). Replicated in an independent dataset, this work provides in vivo evidence of a macroscale shift in E/I balance in TLE patients and points to progressive functional imbalances that relate to cognitive decline.

PMID:39806576 | DOI:10.1002/advs.202406835

BMC Med Imaging. 2025 Jan 13;25(1):18. doi: 10.1186/s12880-024-01527-7.

ABSTRACT

BACKGROUND: Cognitive networks impairments are common in neuropsychiatric disorders like Attention Deficit Hyperactivity Disorder (ADHD), bipolar disorder (BD), and schizophrenia (SZ). While previous research has focused on specific brain regions, the role of the procedural memory as a type of long-term memory to examine cognitive networks impairments in these disorders remains unclear. This study investigates alterations in resting-state functional connectivity (rs-FC) within the procedural memory network to explore brain function associated with cognitive networks in patients with these disorders.

METHODS: This study analyzed resting-state functional magnetic resonance imaging (rs-fMRI) data from 40 individuals with ADHD, 49 with BD, 50 with SZ, and 50 healthy controls (HCs). A procedural memory network was defined based on the selection of 34 regions of interest (ROIs) associated with the network in the Harvard-Oxford Cortical Structural Atlas (default atlas). Multivariate region of interest to region of interest connectivity (mRRC) was used to analyze the rs-FC between the defined network regions. Significant differences in rs-FC between patients and HCs were identified (P < 0.001).

RESULTS: ADHD patients showed increased Cereb45 l - Cereb3 r rs-FC (p = 0.000067) and decreased Cereb1 l - Cereb6 l rs-FC (p = 0.00092). BD patients exhibited increased rs-FC between multiple regions, including Claustrum r - Caudate r (p = 0.00058), subthalamic nucleus r - Pallidum l (p = 0.00060), substantia nigra l - Cereb2 l (p = 0.00082), Cereb10 r - SMA r (p = 0.00086), and Cereb9 r - SMA l (p = 0.00093) as well as decreased rs-FC in subthalamic nucleus r - Cereb6 l (p = 0.00013) and Cereb9 r - Cereb9 l (p = 0.00033). SZ patients indicated increased Caudate r- putamen l rs-FC (p = 0.00057) and decreased rs-FC in subthalamic nucleus r - Cereb6 l (p = 0.000063), and Cereb1 r - subthalamic nucleus r (p = 0.00063).

CONCLUSIONS: This study found significant alterations in rs-FC within the procedural memory network in patients with ADHD, BD, and SZ compared to HCs. These findings suggest that disrupted rs-FC within this network may related to cognitive networks impairments observed in these disorders.

CLINICAL TRIAL NUMBER: Not applicable.

PMID:39806317 | DOI:10.1186/s12880-024-01527-7

Neuroimage. 2025 Jan 11:121024. doi: 10.1016/j.neuroimage.2025.121024. Online ahead of print.

ABSTRACT

Functional MRI (fMRI) is an important tool for investigating functional networks. However, the widely used fMRI with T2*-weighted imaging in rodents has the problem of signal lack in the lateral ventral area of forebrain including the amygdala, which is essential for not only emotion but also noxious pain. Here, we scouted the zero-echo time (ZTE) sequence, which is robust to magnetic susceptibility and motion-derived artifacts, to image activation in the whole brain including the amygdala following the noxious stimulation to the hind paw. ZTE exhibited higher spatial and temporal signal-to-noise ratios than conventional fMRI sequences. Electrical sensory stimulation of the hind paw evoked ZTE signal increase in the primary somatosensory cortex. Formalin injection into the hind paw evoked early and latent change of ZTE signals throughout the whole brain including the subregions of amygdala. Furthermore, resting-state fMRI using ZTE demonstrated the functional connectivity, including that of the amygdala. These results indicate the feasibility of ZTE for whole brain fMRI including the amygdala and we first show acute and latent activity in different subnuclei of the amygdala complex after nociceptive stimulation.

PMID:39805408 | DOI:10.1016/j.neuroimage.2025.121024

bioRxiv [Preprint]. 2025 Jan 4:2025.01.04.631289. doi: 10.1101/2025.01.04.631289.

ABSTRACT

The origins of resting-state functional MRI (rsfMRI) signal fluctuations remain debated. Recent evidence shows coupling between global cortical rsfMRI signals and cerebrospinal fluid inflow in the fourth ventricle, increasing during sleep and decreasing with Alzheimer's disease (AD) progression, potentially reflecting brain clearance mechanisms. However, the existence of more complex brain-ventricle coupling modes and their relationship to cognitive decline remains unexplored. Analyzing 599 minimally-preprocessed rsfMRI scans from 163 elderly participants across the AD spectrum, we identified distinct brain-ventricle coupling modes that differentiate across groups and correlate with cognitive scores. Beyond the known anti-phase coupling between global brain signals and ventricles -more frequent in cognitively normal controls- we discovered additional modes where specific brain areas temporarily align with ventricle signals. At the cortical level, these modes form canonical resting-state networks, such as the Default Mode Network, which occurs less in AD or the Frontoparietal Network, which correlates positively with memory scores. The direct link between ventricle and brain signals challenges the common practice of removing CSF components from rsfMRI analyses and questions the origin of cortical signal fluctuations forming functional networks, which may reflect region-specific fluid inflow patterns. These findings provide new insights into the relationship between brain clearance mechanisms and network dysfunction in neurodegenerative diseases.

PMID:39803532 | PMC:PMC11722378 | DOI:10.1101/2025.01.04.631289

medRxiv [Preprint]. 2025 Jan 5:2025.01.03.25319980. doi: 10.1101/2025.01.03.25319980.

ABSTRACT

BACKGROUND: Reading impairments, a common consequence of stroke-induced aphasia, significantly hinder life participation, affecting both functional and leisure activities. Traditional post-stroke rehabilitation strategies often show limited generalization beyond trained materials, underscoring the need for novel interventions targeting the underlying neural mechanisms.

METHOD: This study investigates the feasibility and potential effectiveness of real-time functional magnetic resonance imaging (fMRI) neurofeedback (NFB) intervention for reading deficits associated with stroke and aphasia. We enrolled left-hemisphere stroke survivors in the subacute recovery period and healthy controls in an fMRI NFB intervention study focusing on increasing activation within the left supramarginal gyrus (SMG), a critical region for reading supporting orthography-phonology conversion.

RESULTS: Preliminary findings demonstrate that stroke participants showed significant improvements in reading comprehension and phonological awareness, as evidenced by marked gains on the Reading Comprehension Battery for Aphasia (RCBA) and a phonology two-alternative forced choice test. Functional MRI results indicated that stroke participants exhibited increased activation from day 1 to day 3 of NFB training within the left SMG and the broader left hemisphere reading network, particularly during challenging nonword reading tasks. Healthy controls also showed increased activation during NFB regulation and reading tasks, but these changes were outside the traditional reading network, involving regions associated with cognitive control, reward anticipation, and learning. In both stroke participants and healthy controls, we also found changes in dynamic functional connectivity of multiple resting state networks from before to after NFB training.

CONCLUSIONS: Although preliminary, this research contributes to the development of biologically informed interventions for reading deficits in aphasia, representing an early step towards improving post-stroke rehabilitation outcomes. Future randomized controlled trials are necessary to validate these findings by including a sham NFB control group within a larger participant sample.

REGISTRATION: The study was preregistered on ClinicalTrials.gov, NCT# NCT04875936.

PMID:39802782 | PMC:PMC11722485 | DOI:10.1101/2025.01.03.25319980

Sci Rep. 2025 Jan 13;15(1):1769. doi: 10.1038/s41598-025-85514-0.

ABSTRACT

Inflammatory processes have been implicated in the pathophysiology of depression. In human studies, inflammation has been shown to act as a critical disease modifier, promoting susceptibility to depression and modulating specific endophenotypes of depression. However, there is scant documentation of how inflammatory processes are associated with neural activity in patients with depression. We therefore tested the hypothesis that the peripheral inflammation markers IL-6 and TNF-α correlate with neural resting state network functional connectivity in depression using functional magnetic resonance imaging (fMRI) and compared it with healthy controls. We used fMRI to investigate the functional connectivity (FC) of the resting state Default Mode Network (DMN) and Salience/Ventral Attention Network (SAL) and their association with the peripheral inflammation markers IL-6 and TNF-α in 25 patients with depression and compared it to 24 healthy subjects. Results of this imaging study revealed that both DMN and SAL resting state networks are differentially associated with distinct immunological pathways depending on whether a person has a depressive phenotype or is healthy. While the DMN FC correlated with the concentration of the cytokine IL-6 in healthy subjects, SAL FC's connectivity correlated with the cytokine TNF-α's concentration. This study highlights the importance of peripheral inflammatory processes in depression and suggests a modulatory effect on neural resting state networks depending on the state of depression.

PMID:39800770 | DOI:10.1038/s41598-025-85514-0

Schizophrenia (Heidelb). 2025 Jan 11;11(1):3. doi: 10.1038/s41537-024-00552-3.

ABSTRACT

The neural mechanisms underlying the association between childhood trauma (CT) and psychosis spectrum disorders remains unclear. The objective of this study is to examine the relationship between childhood trauma and functional connectivity of fronto-limbic regions in a large sample of antipsychotic-naïve patients with first episode psychosis (FEP). Resting state fMRI data from 105 FEP patients and 123 healthy controls (HC) were used. Our regions of interest included bilateral hippocampus/amygdala and ventromedial prefrontal cortex (vmPFC). Childhood Trauma Questionnaire (CTQ) total and subscale scores were correlated with the resting state functional connectivity (rsFC) data. Partial correlation analyses indicated that higher CTQ sexual abuse subscale scores in FEP patients were associated with increased left amygdala-vmPFC rsFC (r(59) = 0.27, p < 0.05) and higher CTQ emotional neglect subscale scores in FEP patients were associated with increased left hippocampus-vmPFC rsFC (r(59) = 0.26, p < 0.05). Follow-up analysis showed a significant interaction effect of group (FEP and HC) and CTQ score (sexual abuse subscale) on left amygdala-vmPFC rsFC (β = 0.014, p < 0.05). Higher CTQ sexual abuse subscale scores were associated with increased rsFC in FEP patients (β = 0.56, p < 0.001). but reduced rsFC in healthy controls (β = -0.56, p < 0.001). The results also provide support for the long-term differential impact of trauma subtypes on the human brain. Overall, the results contribute to the understanding of the neural mechanisms underlying the association between childhood trauma and psychosis spectrum disorders.

PMID:39799137 | DOI:10.1038/s41537-024-00552-3

Neuroscience. 2025 Jan 9:S0306-4522(25)00017-X. doi: 10.1016/j.neuroscience.2025.01.015. Online ahead of print.

ABSTRACT

Psychogenic erectile dysfunction (pED) is often accompanied by abnormal brain activities. This study aimed to develop an automaticclassifier to distinguish pED from healthy controls (HCs) by identified brain-basedcharacteristics. Resting-state functional magnetic resonance imaging data were acquired from 45 pED patients and 43 HCs. Regional homogeneity (ReHo) and functional connectivity (FC) values were calculated and compared between groups. Moreover, based on altered ReHo and FC values, support vector machine (SVM) classifier, incorporating recursive feature elimination (RFE), an SVM-RFE diagnostic model was established using leave-one-out cross-validation. Patients demonstrated reduced ReHo values in the left middle temporal gyrus (had decreased FC values with the left medial superior frontal gyrus and cuneus), orbital part of inferior frontal gyrus (had decreased FC values within the same region), triangular part of inferior frontal gyrus, anterior cingulate gyrus (had decreased FC values with the left inferior temporal gyrus, anterior cingulate gyrus, cuneus and right supplementary motor area) and middle frontal gyrus. The right calcarine fissure displayed increased ReHo values. The diagnostic model demonstrated excellent performance, achieving an accuracy rate of 90.80%. This study identified altered regional activity and FC in specific brain regions of pED patients, which might be related to the development of pED. The application of machine learning confirmed the distinctive characteristics of these functional changes in the brain. The high accuracy of our diagnostic model suggested a promising direction for developing objective diagnostic tools for psychological disorders.

PMID:39798834 | DOI:10.1016/j.neuroscience.2025.01.015

Biol Psychiatry Cogn Neurosci Neuroimaging. 2025 Jan 9:S2451-9022(25)00015-1. doi: 10.1016/j.bpsc.2024.12.016. Online ahead of print.

ABSTRACT

The default mode network (DMN) is intricately linked with processes such as self-referential thinking, episodic memory recall, goal-directed cognition, self-projection, and theory of mind. Over recent years, there has been a surge in examining its functional connectivity, particularly its relationship with frontoparietal networks (FPN) involved in top-down attention, executive function, and cognitive control. The fluidity in switching between these internal and external modes of processing-highlighted by anti-correlated functional connectivity-has been proposed as an indicator of cognitive health. Due to the ease of estimation of functional connectivity-based measures through resting state fMRI paradigms, there is now a wealth of large-scale datasets, paving the way for standardized connectivity benchmarks. This review delves into the promising role of DMN connectivity metrics as potential biomarkers of cognitive state across attention, internal mentation, mind wandering and meditation states, and investigating deviations in trait-level measures across aging and in clinical conditions such as Alzheimer's disease, Parkinson's, depression, ADHD, and others. Additionally, we tackle the issue of reliability of network estimation and functional connectivity and share recommendations for using functional connectivity measures as a biomarker of cognitive health.

PMID:39798799 | DOI:10.1016/j.bpsc.2024.12.016

Brain Res. 2025 Jan 8:149450. doi: 10.1016/j.brainres.2025.149450. Online ahead of print.

ABSTRACT

Disruption of the glymphatic system plays a vital role in pathogenesis of neurodegeneration in normal tension glaucoma (NTG). We evaluated the impairment of glymphatic system of NTG patients by diffusion tensor image analysis along the perivascular space (DTI-ALPS), and explored the correlation between the ALPS index and dysfunction of visual cortices in resting state. DTI-ALPS was applied to 37 normal controls (NCs) and 37 NTG patients. Multidirectional diffusivity maps and fractional anisotropy (FA) maps were reconstructed to calculate ALPS index. The Amplitude of low-frequency fluctuation (ALFF) in visual cortices (V1-V5) were calculated using resting-state fMRI. Clinical data and ALPS indexes were compared between the groups. Lateralization of ALPS indexes and differences in visual field of two eyes were analyzed. Subsequently, regression analyses between ALPS indexes and mean deviation (MD) values of bilateral eyes and ALFF of visual cortices were performed. The bilateral ALPS indexes of NTG patients decreased significantly. In NCs and NTG patients, ALPS indexes in right hemisphere were lower than that in left hemisphere. The right ALPS indexes of NTG patients were positively correlated with the MD values of the left eyes. In NTG patients, decreased ALFF was detected in right V1 and bilateral V2-5, and the left ALPS indexes were positively correlated with ALFF in bilateral V1, V2, V5, and right V3V area. The ALPS index decreased in NTG patients, correlated with visual defects and ALFF, indicating impairment of the glymphatic system and the potential to be a biomarker in the future.

PMID:39793917 | DOI:10.1016/j.brainres.2025.149450

Biol Psychol. 2025 Jan 8:108983. doi: 10.1016/j.biopsycho.2025.108983. Online ahead of print.

ABSTRACT

Research on how functional connectivity (FC) during resting-state relates to humor styles and sex is limited. This study aimed to address this knowledge gap by analyzing resting-state fMRI data from 56 healthy participants and measuring FC. In addition, participants completed the Humor Styles Questionnaire. We found distinct FC patterns linked to humor styles that differed by sex. Men demonstrated stronger FC between the anterior cingulate cortex (ACC) and the right anterior insula (rAI), right inferior frontal gyrus (rIFG) and right frontal pole (rFP), and between the right rostral prefrontal cortex (rRPFC) and rIFG. These patterns were associated with aggressive and self-enhancing humor. Conversely, women exhibited stronger FC between rRPFC and the posterior cingulate gyrus (PCC), left rostral prefrontal cortex (lRPFC) and right thalamus, correlating with self-defeating and less aggressive humor. These findings suggest a neurobiological basis for sex differences in humor, indicating that men's FC between the salience network (SN), particularly in cognitive monitoring regions, may be linked to aggressive humor. Their FC between the executive control network (ECN) and between the SN and ECN are related to self-enhancing humor and reflect an emphasis on executive function. Conversely, women's FC between the SN and default mode network is correlated with self-defeating humor, suggesting a stronger focus on self-reflection and social relationships.

PMID:39793726 | DOI:10.1016/j.biopsycho.2025.108983

J Neuroimaging. 2025 Jan-Feb;35(1):e70007. doi: 10.1111/jon.70007.

ABSTRACT

BACKGROUND AND PURPOSE: Working memory, a primary cognitive domain, is often impaired in pediatric brain tumor survivors, affecting their attention and processing speed. This study investigated the long-term effects of treatments, including surgery, radiotherapy (RT), and chemotherapy (CT), on working memory tracts in children with posterior fossa tumors (PFTs) using resting-state functional MRI (rs-fMRI) and diffusion MRI tractography.

METHODS: This study included 16 medulloblastoma (MB) survivors treated with postoperative RT and CT, 14 pilocytic astrocytoma (PA) survivors treated with surgery alone, and 16 healthy controls from the Imaging Memory after Pediatric Cancer in children, adolescents, and young adults study (NCT04324450). Working memory tracts were identified by combining seed masks from rs-fMRI maps and whole-brain tractography from diffusion MRI. Connectivity alterations were assessed qualitatively and quantitatively, alongside neuropsychological evaluations and correlations with behavioral outcomes and mean supratentorial dose.

RESULTS: Compared to controls, MB survivors exhibited significant impairments in the working memory network, including reductions in tract volume (TV), fiber density, fiber cross-section (FC), mean streamline length (MLS), and fractional anisotropy (FA) (all p = 0.04). Lower working memory scores were correlated with reduced TV and FA in MB survivors. Higher mean supratentorial doses were associated with lower TV, FC, and FA values across multiple tracts, particularly in the arcuate and superior longitudinal fasciculi.

CONCLUSIONS: Tractography-derived features highlighted white matter damage as a biomarker of treatment-related neurotoxicity in PFTs survivors. These findings underscore the detrimental impact of RT and CT on working memory networks and emphasize the importance of preserving cognitive function during treatment planning.

PMID:39789950 | DOI:10.1111/jon.70007