Most recent paper

J Neurosci. 2025 Mar 27:e0975242025. doi: 10.1523/JNEUROSCI.0975-24.2025. Online ahead of print.

ABSTRACT

Encoding new memories relies on functional connections between the medial temporal lobe and the frontoparietal cortices. Multi-scan fMRI showed changes in these functional connections before and after memory encoding, potentially influenced by the thalamus. As different thalamic nuclei are interconnected with distinct cortical networks, we hypothesized that variations in cortico-thalamic recruitment may impact individual memory performance.We used a multi-scan fMRI protocol including a resting-state scan followed by an associative memory task encompassing encoding and retrieval phases, in two independent samples of healthy adults (N1=29, mean age=26, males=35%; N2=108; mean age=28, males=52%). Individual activity and functional connectivity were analyzed in the native space to minimize registration bias. By modeling the direct and indirect effects of cortico-thalamic recruitment on memory using Structural Equation Modeling, we showed a positive association between resting-state functional connectivity of the medial thalamic subdivision within the frontoparietal network and memory performance across samples (effect size R2 ranging between 0.27 and 0.36; p-values between 0.01 and 4e-05). This direct relationship was mediated by decreased activation of the anterior subdivision during encoding (R2 ranging between 0.04 and 0.2; p-values between 0.05 and 0.006) and by increased activation of the medial subdivision during retrieval (R2 ranging between 0.04 and 0.2; p-values between 0.05 and 0.004). Moreover, three distinct clusters of individuals displayed different cortico-thalamic patterns across memory phases.We suggest that associative memory encoding relies on the distinct cortico-thalamic pathways involving medial thalamic recruitment and suppression of anterior subdivision to support the successful encoding of new memories.Significance statement Every person is unique in their learning process and related brain functional organization. Prior research has mainly aimed to find shared patterns in how the brain responds to external stimuli, often overlooking individual behavioral differences. We hypothesized that individuals may recruit different neural resources supporting their learning abilities. We investigated whether specific brain configurations are beneficial to individual memory performance. We found that the baseline configuration of select cortico-thalamic networks involving the medial thalamic subdivision supports memory performance via the indirect effects of the anterior thalamic subdivision deactivation and medial activation during the memory task. We propose that cortico-thalamic functioning involving the anterior and medial thalamus underlies interindividual variability in associative memory encoding.

PMID:40147936 | DOI:10.1523/JNEUROSCI.0975-24.2025

Psychiatry Res Neuroimaging. 2025 Mar 9;349:111973. doi: 10.1016/j.pscychresns.2025.111973. Online ahead of print.

ABSTRACT

OBJECTIVE: Premenstrual syndrome (PMS) is a risk factor for female depression, linked to neural circuit dysfunction. This study investigates PMS-related brain network patterns, focusing on the triple network's integration and segregation.

MATERIALS & METHODS: The study enrolled 56 PMS patients and 67 healthy controls (HCs), assessed via the Daily Record of Severity of Problems (DRSP). Functional MRI (fMRI) was analyzed using independent component analysis (ICA) to calculate functional connectivity (FC) and functional network connectivity (FNC) within and between brain networks. Correlation analysis examined links between imaging metrics and DRSP scores.

RESULTS: Compared with HCs, PMS patients showed increased FC in the left inferior frontal gyrus of the salience network (SN). Additionally, there was increased FNC between the dorsal default mode network (dDMN), while a decrease was observed between the right execution network (RECN) and SN. Conversely, the FNC between RECN and dDMN was enhanced. Significant correlations were found between the FC values within the SN and DRSP scores. Similarly, the abnormal FNC pattern also correlated significantly with DRSP scores.

CONCLUSION: Triple-network dysconnectivity may serve as a biomarker for PMS, offering insights into its pathophysiology and potential targets for network-based neuromodulation therapies.

CLINICAL RELEVANCE STATEMENT: Identifying network dysconnectivities in PMS offers potential biomarkers for diagnosis and targets for neuromodulation therapy, ultimately improving symptom management and patient outcomes.

PMID:40147104 | DOI:10.1016/j.pscychresns.2025.111973

Appl Neuropsychol Adult. 2025 Mar 27:1-18. doi: 10.1080/23279095.2025.2470415. Online ahead of print.

ABSTRACT

Elucidating the mechanisms of successful word retrieval by anomia therapy could improve our knowledge about language processing and also help design effective treatments. The two main subcomponents of resting-state networks related to language processing are the default mode network (DMN) and the language network (LN). To study how changes in brain activation occur due to anomia therapy, we investigated pre-and-post changes in the DMN and LN activation nodes in a deficit-based treatment of 15 persons with aphasia (PWAs). In this method, seven participants (mean age 46.71 ± 8.99) with predominant semantic type errors received the semantic feature analysis (SFA) treatment approach, and 8 participants (mean age 46.5 ± 10.47) with mostly phonological type errors were treated with phonological components analysis (PCA) intervention. Both treatments improved word retrieval and had generalization effects on the language function. Increased activation in frontoparietal areas was observed after PCA therapy, while naming improvement after SFA was associated with increased activation in frontotemporal areas. These findings show that focusing on the impaired level of word retrieval processing may also be associated with changes in activation in brain areas related to that impaired level. Future studies could investigate the DMN and LN networks of the resting state-functional magnetic resonance imaging (rs-fMRI) to understand the mechanisms involved in aphasia therapy.

PMID:40145234 | DOI:10.1080/23279095.2025.2470415

Front Neurosci. 2025 Mar 12;19:1543206. doi: 10.3389/fnins.2025.1543206. eCollection 2025.

ABSTRACT

PURPOSE: In this study we develop undersampled echo-volumar imaging (EVI) using multi-band/simultaneous multi-slab encoding in conjunction with multi-shot slab-segmentation to accelerate 3D encoding and to reduce the duration of EVI encoding within slabs. This approach combines the sampling efficiency of single-shot 3D encoding with the sensitivity advantage of multi-echo acquisition. We describe the pulse sequence development and characterize the spatial-temporal resolution limits and BOLD sensitivity of this approach for high-speed task-based and resting-state fMRI at 3 T. We study the feasibility of further acceleration using compressed sensing (CS) and assess compatibility with NORDIC denoising.

METHODS: Multi-band echo volumar imaging (MB-EVI) combines multi-band encoding of up to 6 slabs with CAIPI shifting, accelerated EVI encoding within slabs using up to 4-fold GRAPPA accelerations, 2-shot kz-segmentation and partial Fourier acquisitions along the two phase-encoding dimensions. Task-based and resting-state fMRI at 3 Tesla was performed across a range of voxel sizes (between 1 and 3 mm isotropic), repetition times (118-650 ms), and number of slabs (up to 12). MB-EVI was compared with multi-slab EVI (MS-EVI) and multi-band-EPI (MB-EPI).

RESULTS: Image quality and temporal SNR of MB-EVI was comparable to MS-EVI when using 2-3 mm spatial resolution. High sensitivity for mapping task-based activation and resting-state connectivity at short TR was measured. Online deconvolution of T2* signal decay markedly reduced spatial blurring and improved image contrast. The high temporal resolution of MB-EVI enabled sensitive mapping of high-frequency resting-state connectivity above 0.3 Hz with 3 mm isotropic voxel size (TR: 163 ms). Detection of task-based activation with 1 mm isotropic voxel size was feasible in scan times as short as 1 min 13 s. Compressed sensing with up to 2.4-fold retrospective undersampling showed negligible loss in image quality and moderate region-specific losses in BOLD sensitivity. NORDIC denoising significantly enhanced fMRI sensitivity without introducing image blurring.

CONCLUSION: Combining MS-EVI with multi-band encoding enables high overall acceleration factors and provides flexibility for maximizing spatial-temporal resolution and volume coverage. The high BOLD sensitivity of this hybrid MB-EVI approach and its compatibility with online image reconstruction enables high spatial-temporal resolution real-time task-based and resting state fMRI.

PMID:40143844 | PMC:PMC11936983 | DOI:10.3389/fnins.2025.1543206

Transl Psychiatry. 2025 Mar 26;15(1):96. doi: 10.1038/s41398-025-03327-1.

ABSTRACT

The relationship between brain asymmetry and inattention, and their heritability is not well understood. Utilizing advanced neuroimaging, we examined brain asymmetry with data from the Adolescent Brain Cognitive Development (ABCD; n = 8943; 9-10 y) and the Human Connectome Project (HCP) cohorts (n = 1033; 5-100 y). Data-driven metrics from resting-state fMRI and morphometrics revealed reproducible and stable brain asymmetry patterns across the lifespan. In children, high levels of inattention were highly heritable (61%) and linked to reduced leftward asymmetry of functional connectivity in the dorsal posterior superior temporal sulcus (dpSTS), a region interconnected with a left-lateralized language network. However, reduced dpSTS asymmetry had low heritability (16%) and was associated with lower cognitive performance suggesting that non-genetic factors, such as those mediating cognitive performance, might underlie its association with dpSTS asymmetry. Interventions that enhance cognition might help optimize brain function and reduce inattention.

PMID:40140344 | DOI:10.1038/s41398-025-03327-1

Neurobiol Aging. 2025 Mar 17;150:157-171. doi: 10.1016/j.neurobiolaging.2025.03.007. Online ahead of print.

ABSTRACT

Alzheimer's disease (AD) is characterized by a long preclinical stage during which molecular markers of amyloid beta and tau pathology rise, but there is minimal neurodegeneration or cognitive decline. Previous literature suggests that measures of brain function might be more sensitive to neuropathologic burden during the preclinical stage of AD than conventional measures of macrostructure, such as cortical thickness. Among studies that used resting-state functional Magnetic Resonance Imaging (fMRI) acquisitions with Blood Oxygenation Level Dependent (BOLD) contrast, most employed connectivity-based analytic approaches. Consequently, little is known about the effects of amyloid and tau pathology on amplitude of intrinsic BOLD signal fluctuations. To address this knowledge gap, we characterized the effects of preclinical and prodromal AD on the amplitude of low-frequency fluctuations (ALFF) of the BOLD signal both at the whole-brain level and at a more granular level focused on subregions of the medial temporal lobe. We observed reduced ALFF in both preclinical and prodromal AD. In preclinical AD, amyloid positivity was associated with a spatially diffuse ALFF reduction in the frontal, medial parietal, and lateral temporal association cortices. In contrast, tau pathology was negatively associated with ALFF in the entorhinal cortex. These ALFF effects were observed in the absence of observable macrostructural changes in preclinical AD and remained after adjusting for structural atrophy in prodromal AD, indicating that ALFF offers additional sensitivity to early disease processes beyond what is provided by traditional structural imaging biomarkers of neurodegeneration. We conclude that ALFF may be a promising imaging-based biomarker in preclinical AD.

PMID:40138942 | DOI:10.1016/j.neurobiolaging.2025.03.007

Brain Behav. 2025 Mar;15(3):e70440. doi: 10.1002/brb3.70440.

ABSTRACT

BACKGROUND AND PURPOSE: The nucleus accumbens (NAc), an important component of the reward circuit, is believed to play an indispensable role in Alzheimer's disease (AD). This study aimed to explore alterations in the functional connectivity (FC) of NAc subregions in AD patients and to explore their associations with neuropsychological profiles.

METHODS: Total 45 AD patients and 41 healthy controls (HCs) were recruited for this study. Four subregions of the NAc were used as regions of interest for whole-brain FC analysis. Correlation analyses were conducted to explore the relationships between the changed FC of brain regions with significant differences and neuropsychological profiles.

RESULTS: Compared with HCs, decreased FC was observed between NAc subregions and regions of the orbitofrontal cortex (OFC), precuneus (PCUN), insula (INS), cerebellum 8, and putamen in AD patients (Gaussian random field [GRF] corrected, voxel-level p < 0.001, cluster-level p < 0.05). Furthermore, the FC between the left core and left PCUN was correlated with the score of the auditory verbal learning test immediate recall task in AD patients (r = 0.441, p = 0.003, Bonferroni corrected).

CONCLUSION: Disruptions in connectivity between the NAc subregions and important cognitive-related areas may be related to the cognitive deficits observed in AD patients, especially episodic memory function.

PMID:40135639 | DOI:10.1002/brb3.70440

Brain Behav. 2025 Mar;15(3):e70434. doi: 10.1002/brb3.70434.

ABSTRACT

OBJECTIVE: This study utilized functional magnetic resonance imaging (fMRI) data to investigate cognitive function changes in trigeminal neuralgia (TN) patients and healthy controls (HCs), and to elucidate the potential mechanism.

MATERIALS AND METHODS: The cognitive function of 34 patients with TN and 30 HCs was evaluated. Afterward, we calculated the amplitude of low-frequency fluctuations (ALFFs), regional homogeneity (ReHo), and degree centrality (DC). These metrics were correlated with cognitive performance using the Spearman correlation analysis.

RESULTS: Patients with TN exhibited diminished cognitive performance compared to HCs. Increased mean ALFF (mALFF) levels were detected in the right temporal pole, superior temporal gyrus, and right insula in individuals with TN. These increases were negatively correlated with cognitive function. In contrast, decreased mALFF values were observed in the right lingual gyrus, bilateral calcarine, and left middle occipital gyrus, which were associated with improved cognitive function. Increased DC values were found in various areas, such as the right temporal pole, superior temporal gyrus, right opercular inferior frontal gyrus, bilateral medial superior frontal gyrus, left supplementary motor area, left anterior cingulum, and right middle cingulum in individuals with TN. These values negatively correlated with cognitive performance.

CONCLUSION: TN patients exhibited impairments in multiple cognitive areas, such as attention, memory, executive function, visual perception and executive ability, information processing speed, and motor speed. The metrics ALFF and DC exhibited alterations in TN patients, suggesting that cognitive impairments may be linked to decreased functional activity in specific brain regions. Concurrently, certain cerebral regions may exhibit increased functional activity as a compensatory response to cognitive deficits. These findings hold significant theoretical value and clinical application potential, providing novel methodologies and perspectives for early diagnosis, personalized treatment, and efficacy evaluation. Such advancements are poised to enhance the overall treatment outcomes and quality of life for TN patients.

PMID:40135636 | DOI:10.1002/brb3.70434

Commun Biol. 2025 Mar 25;8(1):488. doi: 10.1038/s42003-025-07876-5.

ABSTRACT

Neuronal hyperexcitation affects memory and neural processing across the Alzheimer's disease (AD) cognitive continuum. Levetiracetam, an antiepileptic, shows promise in improving cognitive impairment by restoring the neural excitation/inhibition balance in AD patients. We previously identified a hyper-excitable phenotype in cognitively unimpaired female APOE-ε4 carriers relative to male counterparts cross-sectionally. This sex difference lacks longitudinal validation; however, clarifying the vulnerability of female ε4-carriers could better inform antiepileptic treatment efficacy. Here, we investigated this sex-by-ε4 interaction using a longitudinal design. We used resting-state fMRI and diffusion tensor imaging collected longitudinally from 106 participants who were cognitively unimpaired for at least one scan event but may have been assessed to have clinical dementia ratings corresponding to early mild cognitive impairment over time. By including scan events where participants transitioned to mild cognitive impairment, we modeled the trajectory of the whole-brain excitation-inhibition ratio throughout the preclinical cognitively healthy continuum and extended to early impairment. A linear mixed model revealed a significant three-way interaction among sex, ε4-status, and time, with female ε4-carriers showing a significant hyper-excitable trajectory. These findings suggest a possible pathway for preventative therapy targeting preclinical hyperexcitation in female ε4-carriers.

PMID:40133608 | DOI:10.1038/s42003-025-07876-5

Neurol Sci. 2025 Mar 26. doi: 10.1007/s10072-025-08106-w. Online ahead of print.

ABSTRACT

OBJECTIVE: This study utilizes resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory analysis to identify key brain regions in vestibular migraine (VM), explore their associations with clinical symptoms, and examine the role of these functional network hubs in the pathophysiology of VM, offering novel insights and a theoretical basis for understanding its neural mechanisms and improving its clinical diagnosis and treatment.

METHODS: We enrolled patients diagnosed with VM, individuals with Migraine without Aura (MwoA), and healthy control subjects, collecting both clinical and sociodemographic data alongside MRI data. Employing graph theory analysis, we focused on identifying critical hub nodes and networks within VM patients, using metrics like degree, betweenness centrality, and eigenvector centrality for our analysis.

RESULTS: The study included 30 VM patients, 28 MwoA subjects, and 31 healthy controls. Analysis of rich-club coefficients across different levels of network sparsity indicated significantly lower normalized rich-club coefficients for VM and MwoA groups compared to healthy controls at a 65% sparsity threshold, particularly within a node degree range of 91 to 94. Notably, the temporal lobes, limbic system, and frontal lobes were predominant regions for rich-club nodes in the VM group, with significant increases in centrality metrics observed in the right posterior parahippocampal gyrus. These metrics in the hippocampus and parahippocampal gyrus showed a positive correlation with the intensity, duration, and progression of headache episodes in VM patients.

CONCLUSIONS: In vestibular migraine patients, critical hub nodes such as the hippocampus and parahippocampal gyrus are identified, potentially associated with emotional regulation, pain perception, and the memory of pain.

PMID:40133587 | DOI:10.1007/s10072-025-08106-w