Brain Imaging and Behavior最新文献

Aerobic exercise has been proved to reduce the risk of major depression in subthreshold depression (StD) individuals effectively, yet previous studies ignored the different functions of amygdala subregions. In this study, 44 StD individuals and 34 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging before and after eight weeks of aerobic exercise respectively. Transverse and longitudinal analyses were conducted based on the seed-based functional connectivity (FC) analysis between amygdala subregions and the whole brain of the two groups. The transverse analyses showed that compared to HCs, StD individuals showed abnormal FC between the right dorsal amygdala (DA) and right superior frontal gyrus, the left medial amygdala (MA) and left gyrus rectus, right caudate, as well as the right ventrolateral amygdala (VA) and right angular gyrus before the exercise intervention, while increased FC between the right DA and left supramarginal gyrus after the exercise intervention. The longitudinal analysis showed decreased FC between the left DA and left caudate, left middle frontal gyrus, while increased FC between the right MA and posterior central gyrus in StD individuals after exercise intervention. As for HCs, the DA showed FC differences with the insula, frontal lobe, parietal lobe, temporal lobe and thalamus. The MA showed FC differences with the central posterior gyrus, occipital lobe and thalamus. The VA showed FC differences with the calcarine cortex and parietal lobe. The findings demonstrated the alleviative effect of aerobic exercise on depression from the perspective of brain function.

This study aims to determine if the six different types of communication (Directive, Imaginative, Reflective, Persuasive, Harmonizing, Promoting), as presented in the Process Communication Model, correlate with a respective neural pathway. Participants were 30 medical students with no past medical history. They underwent functional magnetic resonance imaging (fMRI) while watching videos typical of each communication type. By comparing each of the six experimental conditions with all the other ones, common activations were detected in the core memory network. Assertive communication styles (Directive, Imaginative) generated activations in conflict detection and resolution related areas, with a predominance in the frontal lobe. Emotive communication (Harmonizing, Promoting) highlighted activations associated with the interpretation of social and emotional cues, with a temporo-occipital predominance. There were no significant activations for the Reflective and Persuasive channel, the two channels that were most coherent with the subjects' base patterns and communication. This study indicated that out of the six communication types that were analyzed, four have a specific and congruous underlying cerebral process. This shows that neural response patterns vary across different communication styles, reflecting differences in cognitive and emotional processing.

Objectives: Tinnitus affects millions worldwide. Its neural mechanisms remain unclear. This study aimed to explore the causal relationships between brain functional networks and tinnitus risk using Mendelian randomization (MR) analyses.

Methods: We performed MR analyses using brain activity data from resting-state functional magnetic resonance imaging (rs-fMRI) and genetic data from genome-wide association studies (GWAS). A total of 191 brain features, including amplitude traits and functional connectivity measures, were selected based on their genetic associations.

Results: Forward MR analyses showed that increased activity in the parietal and inferior frontal regions was associated with a 41% reduction in tinnitus risk (OR = 0.59, p = 1.8 × 10^-4). In contrast, increased activity in the precuneus, angular gyrus, and frontal areas was linked to a 49% increase in tinnitus risk (OR = 1.49, p = 8.9 × 10^-4). Activities in the parietal and inferior frontal regions were negatively correlated with tinnitus risk (OR = 0.72, p = 0.0037). Additionally, higher activity in the parietal, frontal, and temporal regions doubled the risk (OR = 2.02, p = 0.015). Reverse MR showed that stronger connectivity between frontal and temporal regions was inversely related to tinnitus risk (beta = - 0.056, p = 0.049).

Conclusions: Specific brain activity and connectivity patterns are causally linked to tinnitus.

Aging is associated with marked declines in episodic memory corresponding with decreased volume in studies of morphology and reduced network response in studies of functional connectomics. Furthermore, recent research has demonstrated that reductions in resting state network connectivity are related to declines in episodic memory, specifically in the default mode and frontoparietal cortical networks. Additionally, the interactive effects of aging and traumatic brain injury (TBI) are associated with increased risk for neurodegeneration and episodic memory impairments. However, there is a gap in the literature examining episodic memory and hippocampal-subcortical resting state connectivity differences related to aging with and without TBI. The current work aims to investigate episodic memory differences between older adults with TBI (N = 45) and older adults with no history of TBI (N = 28) and how that relates to hippocampal-subcortical network differences at rest. We demonstrate a positive relationship between default mode and frontoparietal network connectivity and memory performance differentially between those aging with and without moderate-severe TBI (msTBI). Additionally, we demonstrate that reliability in the strength of resting state functional connectivity between parcellations is weakest among connections to the hippocampus compared to other cortical connections but is generally reliable across other connections.

Autism spectrum disorder (ASD) is a neurodevelopmental condition with high structural and functional heterogeneity. Multimodal fusion of structural and functional magnetic resonance imaging (MRI) allows better integration of ASD features from multiple perspectives. This study aimed to uncover the potential ASD subtypes by fusing the features of brain structure and function. An unsupervised learning method, similarity network fusion (SNF), was used. Resting-state functional MRI and structural MRI from the Autism Brain Imaging Data Exchange database of 207 male children were included in this study (105 ASD; 102 healthy controls (HC)). Gray matter volume (GMV) and amplitude of low-frequency fluctuation (ALFF) were utilized to represent structural and functional features separately. Structural and functional distance networks were constructed and fused by SNF. Then spectral clustering was carried out on the fused network. At last, the multivariate support vector regression analysis was used to investigate the relationship between the multimodal alterations and symptom severity of ASD subtypes. Two ASD subtypes were identified. Compared to HC, the two ASD subtypes demonstrated opposite GMV changes and distinct ALFF alterations. Furthermore, the alterations of ALFF predicted the severity of social communication impairments in ASD subtype 1. However, no significant associations were found between the multimodal alterations and symptoms in ASD subtype 2. These findings demonstrate the existence of heterogeneity with distinct structural and functional patterns in ASD and highlight the crucial role of combining multimodal features in investigating the neural mechanism underlying ASD.

Lesions in the basal ganglia present different neuroimaging manifestations compared to other regions. The functional connectivity and white matter (WM) microstructural alterations in patients with left basal ganglia acute ischemic stroke (AIS) remain unknown. This study aimed to explore the alterations of functional connectivity and WM microstructure, as well as their relationship with cognitive performance in patients with left basal ganglia AIS. We acquired resting-state functional MRI (rs-fMRI) and diffusion kurtosis imaging (DKI) data from 41 individuals with left basal ganglia AIS and 41 healthy controls (HC). The degree centrality (DC) method was applied to calculate the functional connectivity and Tract-Based Spatial Statistics was employed to evaluate the voxel-based group differences of diffusion metrics for the values of fractional anisotropy (FA), mean diffusivity, axial diffusivity (AD), radial diffusivity, mean kurtosis (MK), axial kurtosis, and radial kurtosis (RK). AIS showed attenuated DC in the bilateral precuneus and enhanced DC in the left caudate nucleus, compared with HC. In AIS, DC in the left caudate nucleus correlated positively with the Montreal Cognitive Assessment (MoCA) score (r = 0.681, p < 0.05). AIS had significantly decreased FA, AD, MK, and RK in WM tracts, including the internal capsule (IC), genu of corpus callosum (CC), body of CC, left superior longitudinal fasciculus (SLF), left cerebral peduncle, left corticospinal tract, anterior corona radiata (ACR), and left cingulum gyrus (CG). The MK in a cluster including the body of CC, right IC, left cingulate, SLF, ACR, and left CG was also significantly negatively correlated with MoCA scores (r = -0.508, p < 0.05). This study revealed that left basal ganglia AIS not only disrupted the functional connectivity of the whole brain but also had a pervasive impact on the WM microstructure of the whole brain. These findings provide novel insights into the underlying neural mechanisms of early cognitive decline in patients after AIS.

This study aimed to evaluate changes in gray matter nuclei iron deposition in chronic kidney disease (CKD) patients using the quantitative susceptibility mapping (QSM) threshold method, and analyze the relationship between brain iron levels and cognitive function. A total of fifty-three CKD patients were prospectively recruited, comprising 35 hemodialysis (HD, 57.54 ± 10.42 years, 21 males) and 18 non-hemodialysis (NHD, 55.06 ± 11.47 years, 10 males ), and were compared to 43 healthy controls (HC, 55.67 ± 7.79 years, 18 males). All participants underwent clinical assessments, neuropsychological tests, and QSM scans. The mean magnetic susceptibility value (MSV) and volume of the whole nuclei (MSV_M, V_M) and high iron region (MSV_RII, V_RII) were measured. Correlations between QSM data, neuropsychological scores, and clinical variables in HD group were analyzed. Linear regression analysis was performed to explore the effect of iron deposition on cognition and emotional well-being in HD group. A statistically significant P-value was set at 0.05. HD patients exhibited higher MSV_M in the right red nucleus (RN) compared to HCs (P = 0.006). Additionally, significant differences in the MSV_RII were observed in the left caudate nucleus (CN), bilateral putamen (Put), and right RN among the three groups (all P = 0.027, FDR-corrected). MSV_RII of the left Put was positively correlated with creatinine and uric acid levels, while the MSV_RII of the right Put was negatively correlated with mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Regression analysis revealed that iron deposition in left CN was independently associated with depression, while iron deposition in left Put and right RN were independently positively associated with delayed recall performance. Conversely, iron deposition in bilateral Put and right RN were negatively associated with orientation ability, after controlling for age, sex, years of education and duration of dialysis. Brain iron deposition is often excessive and uneven in CKD patients, particularly those undergoing hemodialysis. Assessing regional high-iron deposition can provide valuable insights into the distribution of iron, which is associated with cognitive dysfunction and emotional disorders.

Here, we explore the relationship between transcranial direct current stimulation (tDCS) and brain-behavior interactions. We propose that tDCS perturbation allows for the investigation of relationships between brain volume and behavior. We focused on the hippocampus (HPC) and cerebellum (CB) regions that are implicated in our understanding of memory and motor skill acquisition. Seventy-four young adults (mean age: 22 ± 0.42 years, mean education: 14.7 ± 0.25 years) were randomly assigned to receive either anodal, cathodal, or sham stimulation. Following stimulation, participants completed computerized tasks assessing working memory and sequence learning in a magnetic resonance imaging (MRI) environment. We investigated the statistical interaction between CB and HPC volumes. Our findings showed that individuals with larger cerebellar volumes had shorter reaction times (RT) on a high-load working memory task in the sham stimulation group. In contrast, the anodal stimulation group exhibited faster RTs during the low-load working memory condition. These RT differences were associated with the cortical volumetric interaction between CB-HPC. Literature suggests that anodal stimulation down-regulates the CB and here, those with larger volumes perform more quickly, suggesting the potential need for additional cognitive resources to compensate for cerebellar downregulation or perturbation. This new insight suggests that tDCS can aid in revealing structure-function relationships, due to greater performance variability, especially in young adults. It may also reveal new targets of interest in the study of aging or in diseases where there is also greater behavioral variability.

Vascular Endothelial Growth Factor A (VEGF-A) is an angiogenic signaling protein involved in the maintenance of the cerebral vasculature. No prior study has explored whether plasma VEGF-A levels may be associated with brain functional connectivity changes, such as disruption of the default mode network (DMN), which often precedes the development of cognitive changes in aging. Seventy-six independently living older adults (mean age = 70.3 years; SD = 7.5; 31.6% male) free of dementia or clinical stroke underwent venipuncture and brain MRI. Plasma was assayed for VEGF-A. Using resting state functional MRI, region of interest (ROI) to ROI connectivity and graph theory analysis were conducted to determine average connectivity and global efficiency between each of the following ROIs comprising the DMN: medial prefrontal cortex, lateral parietal cortex and precuneus cortex. Multiple linear regression analysis revealed a significant negative association between VEGF-A levels and DMN connectivity (B = - 0.14, 95% CI (-0.26, - 0.01), p =.038), accounting for age, sex, education, and vascular risk factors. Graph theory analysis similarly revealed that VEGF-A levels are associated with global efficiency of the entire network (B = - 0.18, p =.004). These findings suggest that VEGF-A may be elevated early in the progression of neurocognitive disorders. Whether higher levels of VEGF-A contribute to the pathogenesis of neurocognitive disorders or play a protective role in preserving cognitive function warrants further investigation. Clinical Trial Number: N/A; None.

Resting-state functional connectivity has become a valuable tool in studying post-stroke aphasia (PSA). However, the specific distribution of increased functional connectivity areas (IFCAs) in PSA patients after speech-language therapy (SLT) remains unclear, particularly compared with the intrinsic brain network (IBN) observed in healthy controls. This study aimed to explore the effects of SLT and spontaneous recovery on functional connectivity changes in the brain. We recruited twenty healthy controls and twelve PSA patients, each of whom underwent one month of SLT. The Chinese version of the Western Aphasia Battery (WAB) was administered to assess language function recovery. The Dice coefficients were calculated between each patient's lesion and the reference lesion, which showed moderate to high intensity. The results revealed a close association between the spatial distribution of IFCAs and improvements in specific language functions. Our findings indicate that the distribution pattern of IFCAs may serve as a significant marker of recovery in PSA patients.