Amplitude Of Low-frequency Fluctuation Research Articles

The role of cerebellar-cortical connectivity in modulating attentional abilities: insight from football athletes

Neuroplasticity, a phenomenon present throughout the lifespan, is thought to be influenced by physical training. However, the relationship between neuroplastic differences and attentional abilities remains unclear. This study explored the differences in brain function and attentional abilities between professional football athletes and novices, and further investigated the relationship between the two. To address this question, we included 49 football athletes and 63 novices in our study, collecting data on resting-state functional connectivity and Attention Network Test (ANT). Behavioral results from the ANT indicated that football experts had superior orienting attention but weaker alerting functions compared to novices, with no difference in executive control attention. fMRI results revealed that football experts exhibited higher fractional Amplitude of Low-Frequency Fluctuations (fALFF) values in the bilateral anterior cerebellar lobes, bilateral insula, and left superior temporal gyrus. Functional connectivity analysis showed increased connectivity between the left anterior cerebellar lobe and various cortical regions, including the right supramarginal gyrus, left precuneus, left superior frontal gyrus, bilateral posterior cerebellar lobes, and bilateral precentral gyri in experts compared to novices. More importantly, in the expert group but not in novice group, functional connectivity differences significantly predicted attentional orienting scores. Graph theoretical analysis showed that experts exhibited higher betweenness centrality and node efficiency in the right cerebellar lobule III (Cerebelum_3_R) node. Our findings demonstrate that long-term professional football training may significantly affect neuroplasticity and attentional functions. Importantly, our analysis reveals a substantive connection between these two aspects, suggesting that the integration of neuroplastic and attentional changes is likely mediated by cerebellar-cortical connectivity.

Gray matter structural and functional brain abnormalities in Parkinson's disease: a meta-analysis of VBM and ALFF data.

Previous studies based on resting-state functional imaging and voxel-based morphometry (VBM) have revealed structural and functional alterations in several brain regions in patients with Parkinson's disease (PD), but their results have been inconsistent. Furthermore, no studies have investigated specific and common functional and structural alterations in PD. The whole-brain voxel-wise meta-analyses on the VBM and amplitude of low-frequency fluctuation (ALFF) studies were conducted using the Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) software, respectively, with multimodal overlapping to comprehensively identify the gray matter volume (GMV) and spontaneous functional activity changes in patients with PD. A total of 30 independent studies for ALFF (1413 PD and 1424 HCs) and 27 independent studies for VBM (1236 PD and 1185 HCs) were included. Compared with HCs, patients with PD displayed significantly decreased spontaneous functional activity in the left striatum. For the VBM meta-analysis, patients with PD showed significantly decreased GMV in the right temporal pole: superior temporal gyrus (extending to the right hippocampus, parahippocampal gyrus, and amygdala), the left superior temporal gyrus (extending to the left insula, and temporal pole: superior temporal gyrus), and the left striatum. Furthermore, after overlapping functional and structural differences, patients with PD displayed a conjoint decrease of spontaneous functional activity and GMV in the left striatum. The multimodal meta-analysis revealed that PD showed similar pattern of aberrant brain functional activity and structure in the striatum. In addition, some brain regions within the within the temporal lobe and limbic system displayed only structural deficits. These findings provide useful insights for understanding the underlying pathophysiology of PD.

Voxel-based alterations in spontaneous brain activity among very-late-onset schizophrenia-like psychosis: A preliminary resting-state functional magnetic resonance imaging study.

Very late-onset schizophrenia-like psychosis (VLOSLP) is a subtype of schizophrenia spectrum disorders in which individuals experience psychotic symptoms for the first time after the age of 60. The incidence of VLOSLP shows a linear relationship with increasing age. However, no studies have reported alterations in spontaneous brain activity among VLOSLP patients and their correlation with cognitive function and clinical symptoms. To explore VLOSLP brain activity and correlations with cognitive function and clinical symptoms using resting-state functional magnetic resonance imaging. This study included 33 VLOSLP patients and 34 healthy controls. The cognitive assessment utilized the Mini Mental State Examination, Montreal Cognitive Assessment, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Clinical characteristic acquisition was performed via the Positive and Negative Syndrome Scale (PANSS). All participants were scanned via resting-state functional magnetic resonance imaging, and the data were processed using amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), regional homogeneity, and voxel-mirrored homotopic connectivity (VMHC). The VLOSLP group presented decreased ALFF values in the left cuneus, right precuneus, right precentral gyrus, and left paracentral lobule; increased fALFF values in the left caudate nucleus; decreased fALFF values in the right calcarine fissure and surrounding cortex (CAL) and right precuneus; increased regional homogeneity values in the right putamen; and decreased VMHC values in the bilateral CAL, bilateral superior temporal gyrus, and bilateral cuneus. In the VLOSLP group, ALFF values in the right precuneus were negatively correlated with Mini Mental State Examination score and PANSS positive subscale score, and VMHC values in the bilateral CAL were negatively correlated with the RBANS total score, RBANS delayed memory score, and PANSS positive subscale score. The changes of brain activity in VLOSLP are concentrated in the right precuneus and bilateral CAL regions, which may be associated with cognitive impairment and clinically positive symptoms.

Abnormal Local Cortical Functional Connectivity due to Interneuron Dysmaturation after Neonatal Intermittent Hypoxia.

Prematurely born infants often experience frequent hypoxic episodes due to immaturity of respiratory control resulting in disturbances of cortical development and long-term cognitive and behavioral abnormalities. We hypothesize that neonatal intermittent hypoxia alters maturation of cortical excitatory and inhibitory circuits that can be detected early with functional MRI. C57BL/6 mouse male and female pups were exposed to an intermittent hypoxia (IH) regimen from P3 to P7, corresponding to preterm humans. Adult mice after neonatal IH exhibited motor hyperactivity and impaired motor learning in complex wheel tests. Patch-clamp and evoked field potential recordings revealed increased glutamatergic synaptic transmission. To investigate the role of GABAergic inhibition on glutamatergic transmission during the developmental, we applied a selective GABAA receptor inhibitor picrotoxin. A decreased synaptic inhibitory drive in the motor cortex was evidenced by miniature IPSC frequency on pyramidal cells, multi-unit activity recording in vivo with picrotoxin injection, and decreased interneuron density. There was also an increased tonic depolarizing effect of picrotoxin after IH on Betz cells' membrane potential on patch-clamp and direct current potential in extracellular recordings. The amplitude of low-frequency fluctuation on resting-state fMRI was larger, with a larger increase in regional homogeneity index after picrotoxin injection in the IH group. The increased glutamatergic transmission, decreased numbers, and activity of inhibitory interneurons after neonatal IH may affect the maturation of connectivity in cortical networks, resulting in long-term cognitive and behavioral changes. Functional MRI reveals increased intrinsic connectivity in the sensorimotor cortex, suggesting neuronal dysfunction in cortical maturation after neonatal IH.

Study on Intermittent Theta Burst Stimulation Improves Expression Function and Mechanism in Patients With Aphasia After Stroke.

To explore the effects of Intermittent Theta Burst Stimulation (iTBS) on the posterior inferior frontal gyrus of the left hemisphere on the expression function of patients with aphasia after stroke, and to explore the specific mechanism of fractional amplitude of low-frequency fluctuation (fALFF) analysis and degree centrality (DC) analysis of resting-state functional MRI. According to the inclusion and exclusion criteria, 40 patients with poststroke aphasia were randomized into a treatment group (iTBS group) and a control group (S-iTBS group). Patients in the iTBS group received iTBS +speech training, and patients in the S-iTBS group received sham iTBS + speech training. The Western aphasia test (Chinese version) was used to assess spontaneous language, naming, retelling, and aphasia quotient before and after treatment; resting-state fMRI scans were performed before and after treatment, and the scanned image data were analyzed to explore specific activated or suppressed brain regions. Compared with before and after treatment, the scores of spontaneous language, naming, retelling, and aphasia quotient of the patients in iTBS group improved significantly, and the spontaneous language, naming, retelling, and aphasia quotient of the patients in S-iTBS group also improved. After the treatment, the scores of naming, retelling and aphasia quotient of the patients in the iTBS group improved significantly compared with that of the patients in the S-iTBS group. The resting-state fMRI results of the 2 groups before and after treatment were fALFF analysis found that the fALFF value increased in multiple brain regions in the left frontal and temporal lobes of the patients in iTBS group. Meanwhile, DC analysis also found increased DC values in multiple frontotemporal brain regions of the left hemisphere of patients in the iTBS group, indicating that the improved activation of the above brain regions of the patients in the iTBS group was significantly compared with that of the patients in the S-iTBS group. iTBS combined with conventional speech training significantly improved the expression function of patients with aphasia after stroke. After iTBS action on the left hemisphere, increased activation of multiple brain regions in the left hemisphere may be one of the important mechanisms by which iTBS improves expression function in poststroke aphasia patients.

Dynamic changes of spontaneous brain activity in patients after LASIK: a resting-state fMRI study.

To investigate changes in local brain activity after laser assisted in situ keratomileusis (LASIK) in myopia patients, and further explore whether post-LASIK (POL) patients and healthy controls (HCs) can be distinguished by differences in dynamic amplitude of low-frequency fluctuations (dALFF) in specific brain regions. The resting-state functional magnetic resonance imaging (rs-fMRI) data were collected from 15 myopic patients who underwent LASIK and 15 matched healthy controls. This method was selected to calculate the corresponding dALFF values of each participant, to compare dALFF between the groups and to determine whether dALFF distinguishes reliably between myopic patients after LASIK and HCs using the linear support vector machine (SVM) permutation test (5000 repetitions). dALFF was lower in POL than in HCs at the right precentral gyrus and right insula. Classification accuracy of the SVM was 89.1% (P<0.001). The activity of spontaneous neurons in the right precentral gyrus and right insula of myopic patients change significantly after LASIK. SVM can correctly classify POL patients and HCs based on dALFF differences.

Comparative Effects of Temporal Interference and High-Definition Transcranial Direct Current Stimulation on Spontaneous Neuronal Activity in the Primary Motor Cortex: A Randomized Crossover Study

Background: Modulating spontaneous neuronal activity is critical for understanding and potentially treating neurological disorders, yet the comparative effects of different non-invasive brain stimulation techniques remain underexplored. Objective: This study aimed to systematically compare the effects of temporal interference (TI) stimulation and high-definition transcranial direct current stimulation (HD-tDCS) on spontaneous neuronal activity in the primary motor cortex. Methods: In a randomized, crossover design, forty right-handed participants underwent two 20 min sessions of either TI or HD-tDCS. Resting-state fMRI data were collected at four stages: pre-stimulus baseline (S1), first half of stimulation (S2), second half of stimulation (S3), and post-stimulation (S4). We analyzed changes in regional homogeneity (ReHo), dynamic ReHo (dReHo), fractional amplitude of low-frequency fluctuations (fALFFs), and dynamic fALFFs (dfALFFs) to assess the impact on spontaneous neuronal activity. Results: The analysis revealed that TI had a more significant impact on ReHo, especially in the left superior temporal gyrus and postcentral gyrus, compared with HD-tDCS. Both stimulation methods exhibited their strongest effects during the second half of the stimulation period, but only TI maintained significant activity in the post-stimulation phase. Additionally, both TI and HD-tDCS enhanced fALFFs in real-time, with TI showing more pronounced effects in sensorimotor regions. Conclusions: These findings suggest that TI exerts a more potent and sustained influence on spontaneous neuronal activity than HD-tDCS. This enhanced understanding of their differential effects provides valuable insights for optimizing non-invasive brain stimulation protocols for therapeutic applications.

Changes in the functional brain networks and graph theory analysis of patients with epilepsy and comorbid migraine without aura.

This study aims to evaluate the changes in the functional brain networks and graph theory analysis of patients with epilepsy and comorbid migraine without aura (EM). We included 30 patients with EM, 20 healthy controls (HC) and 30 epilepsy controls (EC) without migraine. Resting-state functional magnetic resonance imaging was performed to obtain imaging data. The fractional amplitude of low-frequency fluctuations (fALFF) value of the left superior temporal gyrus was higher in the EM group than in the HC group. The regional homogeneity (ReHo) values of the right orbital superior frontal gyrus were higher in the EM group than in the EC group. The functional connectivity between left superior occipital gyrus and left orbital part of the superior frontal gyrus, left middle temporal gyrus, right orbital part of middle frontal gyruss, left medial superior frontal gyrus (cluster 2), right middle frontal gyrus, left middle frontal gyrus, left median cingulate and paracingulate gyri was enhanced in the EM group compared with the HC group; the functional connectivity between the left superior occipital and left medial superior frontal gyri (cluster 1) was weakened. The functional connectivity was weakened between the posterior default mode network (pDMN) and dorsal sensorimotor network (dSMN) and the left frontoparietal network (LFPN) and right frontoparietal network. The functional connectivity between pDMN and LFPN was enhanced in the EM group compared with the EC group. Graph theory analysis revealed that the area under the curve of the standardized characteristic path length of the EM group was smaller than that of the HC and EM groups. The abnormal functional brain networks associated with pain regulation, and changes in topological properties may be involved in the mechanisms underlying migraine without aura occurrence in patients with epilepsy.

Neuroimaging differences between chronic migraine with and without medication overuse headache: a 7 Tesla multimodal MRI study

BackgroundChronic migraine (CM) patients with medication overuse headache (MOH) exhibit distinct neurobiological alterations compared to those without MOH. However, prior studies, often limited to single imaging modalities, have yielded inconsistent findings. This study employs multimodal MRI—combining structural, diffusion tensor, and functional imaging—to characterize brain abnormalities in CM patients with and without MOH, while investigating the relationship between acute analgesic use frequency and these changes.MethodsThe study employed comparative analyses to examine differences in gray matter volume, white matter integrity, and spontaneous brain activity between CM patients with (CM + MOH) and without (CM − MOH) medication overuse headache, as well as healthy controls. Additionally, brain regions associated with the frequency of acute medication use were identified and further investigated.ResultsNineteen CM − MOH patients, twenty-five CM + MOH patients, and nineteen healthy controls were enrolled. Compared to CM − MOH patients, CM + MOH patients exhibited significantly reduced gray matter volume in the parahippocampal gyrus and middle occipital gyrus, alongside markedly lower fractional anisotropy (FA) in the left cingulum bundle. Moreover, fractional amplitude of low-frequency fluctuations (fALFF) values in the right putamen were significantly decreased and demonstrated a negative correlation with the frequency of acute pain medication use. Functional connectivity analysis further revealed significantly enhanced connectivity between the right putamen and regions such as the frontal lobe, middle cingulate gyrus, lingual gyrus, and precuneus, which positively correlated with the frequency of acute analgesic use.ConclusionCompared to CM − MOH patients, those with MOH exhibit distinct patterns of gray matter volume reduction in regions associated with memory and visual processing, accompanied by significant white matter disruption. Additionally, decreased spontaneous activity in the right putamen and heightened functional connectivity between the putamen and multiple brain regions are strongly correlated with the frequency of acute medication use. These results highlight the significant impact of medication overuse on brain structure and function, shedding light on the mechanisms of migraine chronification.

Common neural correlates of chronic pain - A systematic review and meta-analysis of resting-state fMRI studies.

Common neural correlates of chronic pain - A systematic review and meta-analysis of resting-state fMRI studies.

Multi-feature fusion RFE random forest for schizophrenia classification and treatment response prediction

Schizophrenia(SZ) classification and treatment response prediction hold substantial clinical application value. However, only a limited number of researchers have exploited the multi-feature information derived from resting-state functional magnetic resonance imaging (rs-fMRI) to achieve short-term drug-treatment SZ classification and treatment response prediction. We developed a multi-feature fusion recursive feature elimination random forest (RFE-RF) approach for SZ classification and treatment response prediction. Initially, we computed multiple features, such as regional homogeneity, fractional amplitude of low-frequency fluctuations, and functional connectivity. Subsequently, the RFE-RF method was employed to conduct SZ classification. Moreover, we utilized the rate of score reduction (RR) of the Positive and Negative Symptom Scale (PANSS) to forecast the treatment response of individual patients. Finally, we identified the neuroimaging biomarkers for SZ classification and drug-treatment response prediction. This method achieved the classification results (accuracy = 91.7%, sensitivity = 90.9%, and specificity = 92.6%), and the abnormalities in the visual and default mode networks emerged as potential neuroimaging biomarkers for differentiating SZ from healthy controls (HC). Additionally, we predicted the drug-treatment response of SZ patients in terms of their total PANSS scores, as well as negative and positive symptom scores after eight weeks of treatment. Specifically, the abnormalities in the visual network, sensorimotor network, and right superior frontal gyrus are crucial biomarkers for the short-term drug-treatment response of negative symptoms in SZ patients. Meanwhile, the abnormalities in the visual and default mode networks serve as important biomarkers of the short-term drug-treatment response of positive symptoms. There findings offer novel insights into the neural mechanisms underlying SZ following eight weeks of short-term drug treatment. With further clinical validation in the future, this research may provide potential biomarkers and intervention targets for personalized treatment of SZ.

A role for the insula in establishing social dominance: structural and functional MRI studies in nonhuman primates.

Awareness of one's position in the social hierarchy is essential for survival. Conversely, poor social cognition is associated with several neuropsychiatric diseases. Although brain regions that mediate understanding of the social hierarchy are poorly understood, recent evidence implicates the insula. Magnetic resonance imaging (MRI) scans were acquired in twelve individually housed male cynomolgus monkeys to determine whether structural and functional characteristics of the insular cortex predicted the social rank that monkeys would attain once they formed stable social hierarchies. Structural MRI revealed that left insular volume was significantly larger in monkeys that would become dominant vs. subordinate. No differences were observed in other areas including amygdala, caudate nucleus, or prefrontal cortex. Volumetric differences were localized to dorsal anterior regions of both left and right insulae. Functional MRI revealed that global correlation, a measure of connectedness to the rest of the brain, was significantly lower in the left insula of monkeys who would become dominant vs. subordinate. Moreover, the fractional amplitude of low-frequency fluctuations, a reflection of spontaneous brain activity, trended lower in bilateral insula in the future dominant monkeys. This prospective study provides evidence for a role of the insula in the establishment and maintenance of social dominance relationships.

Dissecting biological heterogeneity in major depressive disorder based on neuroimaging subtypes with multi-omics data

The heterogeneity of Major Depressive Disorder (MDD) has been increasingly recognized, challenging traditional symptom-based diagnostics and the development of mechanism-targeted therapies. This study aims to identify neuroimaging-based MDD subtypes and dissect their predominant biological characteristics using multi-omics data. A total of 807 participants were included in this study, comprising 327 individuals with MDD and 480 healthy controls (HC). The amplitude of low-frequency fluctuations (ALFF), a functional neuroimaging feature, was extracted for each participant and used to identify MDD subtypes through machine learning clustering. Multi-omics data, including profiles of genetic, epigenetics, metabolomics, and pro-inflammatory cytokines, were obtained. Comparative analyses of multi-omics data were conducted between each MDD subtype and HC to explore the molecular underpinnings involved in each subtype. We identified three neuroimaging-based MDD subtypes, each characterized by unique ALFF pattern alterations compared to HC. Multi-omics analysis showed a strong genetic predisposition for Subtype 1, primarily enriched in neuronal development and synaptic regulation pathways. This subtype also exhibited the most severe depressive symptoms and cognitive decline compared to the other subtypes. Subtype 2 is characterized by immuno-inflammation dysregulation, supported by elevated IL-1 beta levels, altered epigenetic inflammatory measures, and differential metabolites correlated with IL-1 beta levels. No significant biological markers were identified for Subtype 3. Our results identify neuroimaging-based MDD subtypes and delineate the distinct biological features of each subtype. This provides a proof of concept for mechanism-targeted therapy in MDD, highlighting the importance of personalized treatment approaches based on neurobiological and molecular profiles.

Altered functional activity and connectivity in Parkinson's disease with chronic pain: a resting-state fMRI study.

Chronic pain is a common non-motor symptom of Parkinson's disease (PD) that significantly impacts patients' quality of life, but its neural mechanisms remain poorly understood. This study investigated changes in spontaneous neuronal activity and functional connectivity (FC) associated with chronic pain in PD patients. The study included 41 PD patients with chronic pain (PDP), 41 PD patients without pain (nPDP), and 29 healthy controls. Pain severity was assessed using the visual analog scale (VAS). Resting-state fMRI images were used to measure the amplitude of low-frequency fluctuations (ALFF) as an indicator of regional brain activity. Subsequently, FC analysis was performed to evaluate synchronization between ALFF-identified regions and the entire brain. Compared to nPDP patients, PDP patients exhibited decreased ALFF in the right putamen, and increased ALFF in motor regions, including the right superior frontal gyrus/supplementary motor area and the left paracentral lobule/primary motor cortex. Additionally, PDP patients exhibited diminished right putamen-based FC in the midbrain, anterior cingulate cortex, orbitofrontal cortex, middle frontal gyrus, middle temporal gyrus, and posterior cerebellar lobe. The correlation analysis revealed that ALFF values in the right putamen were negatively associated with VAS scores in PDP patients. This study demonstrates that chronic pain in PD is associated with reduced ALFF in the putamen and disrupted FC with brain regions involved in pain perception and modulation, highlighting the critical role of dopaminergic degeneration in the development and maintenance of pain in PD.

Multimodal magnetic resonance imaging analysis of early mild cognitive impairment.

Early mild cognitive impairment (EMCI) represents a prodromal stage of dementia, and early detection is crucial for delaying dementia progression. However, accurately identifying its neuroimaging features remains challenging. To comprehensively evaluate structural and functional neuroimaging changes in EMCI using multimodal magnetic resonance imaging (MRI) techniques. One hundred and eleven participants were included from the Alzheimer's Disease Neuroimaging Initiative (ADNI): 36 with cognitively normal (CN), 30 with EMCI, 32 with late mild cognitive impairment (LMCI), and 13 with Alzheimer's disease (AD). FreeSurfer software was employed to segment hippocampal and amygdala subregions. The amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), and functional connectivity were processed using Data Processing & Analysis for Brain Imaging toolbox. Graph Theoretical Network Analysis toolbox was utilized to evaluate global functional network. The volume of most hippocampal and amygdala subregions was decreased in AD group than those of EMCI group in structural MRI. Significant differences were found between EMCI and AD group in fALFF (right insula) and ReHo (bilateral caudate regions). EMCI group exhibited stronger functional connectivity between left hippocampus and right inferior temporal gyrus (compared to CN), left inferior temporal gyrus (compared to LMCI), and cerebellum crus 8 (compared to AD). EMCI group exhibited stronger connectivity between right hippocampus and left anterior cingulate gyrus compared to AD. Network metrics showed no significant differences among these groups, but all exhibited small-world properties. Multimodal MRI analysis revealed the neuroimaging characteristics of EMCI and promoted the understanding of the mechanisms underlying neuroimaging changes in EMCI.

Transcranial vibration stimulation at 40 Hz induced neural activity and promoted the coupling of global brain activity and cerebrospinal fluid flow.

Transcranial vibration stimulation at 40 Hz induced neural activity and promoted the coupling of global brain activity and cerebrospinal fluid flow.

Dynamic alterations in spontaneous neural activity in patients with attention-deficit/hyperactivity disorder: A resting-state fMRI study.

Dynamic alterations in spontaneous neural activity in patients with attention-deficit/hyperactivity disorder: A resting-state fMRI study.

CD8+T cells and monocytes were associated with brain alterations in human immunodeficiency virus-infected individuals with cognitive impairment.

CD8+T cells and monocytes were associated with brain alterations in human immunodeficiency virus-infected individuals with cognitive impairment.

Neurovascular coupling dysfunction associated with inflammatory factors in sudden sensorineural hearing loss.

Neurovascular coupling dysfunction associated with inflammatory factors in sudden sensorineural hearing loss.

Altered cerebellar activity and cognitive deficits in Type 2 diabetes: Insights from resting-state fMRI.

Altered cerebellar activity and cognitive deficits in Type 2 diabetes: Insights from resting-state fMRI.