scholarly journals White matter of perinatally HIV infected older youths shows low frequency fluctuations that may reflect glial cycling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj K. Sarma ◽  
Amrita Pal ◽  
Margaret A. Keller ◽  
Tamara Welikson ◽  
Joseph Ventura ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Activity ◽  
Low Frequency ◽  
Brain Regions ◽  
Cerebral White Matter ◽  
Frequency Fluctuations ◽  
And Gender ◽  
Latent Hiv ◽  
The Right ◽  
The Brain

AbstractIn perinatally HIV-infected (PHIV) children, neurodevelopment occurs in the presence of HIV-infection, and even with combination antiretroviral therapy (cART) the brain can be a reservoir for latent HIV. Consequently, patients often demonstrate long-term cognitive deficits and developmental delay, which may be reflected in altered functional brain activity. Our objective was to examine brain function in PHIV on cART by quantifying the amplitude of low frequency fluctuations (ALFF) and regional homogeneity (ReHo). Further, we studied ALFF and ReHo changes with neuropsychological performance and measures of immune health including CD4 count and viral loads in the HIV-infected youths. We found higher ALFF and ReHo in cerebral white matter in the medial orbital lobe for PHIV (N = 11, age mean ± sd = 22.5 ± 2.9 years) compared to controls (N = 16, age = 22.5 ± 3.0 years), with age and gender as co-variates. Bilateral cerebral white matter showed increased spontaneous regional activity in PHIV compared to healthy controls. No brain regions showed lower ALFF or ReHo in PHIV compared to controls. Higher log10 viral load was associated with higher ALFF and ReHo in PHIV in bilateral cerebral white matter and right cerebral white matter respectively after masking the outcomes intrinsic to the brain regions that showed significantly higher ALFF and ReHo in the PHIV compared to the control. Reductions in social cognition and abstract thinking in PHIV were correlated with higher ALFF at the left cerebral white matter in the left medial orbital gyrus and higher ReHo at the right cerebral white matter in the PHIV patients. Although neuroinflammation and associated neuro repair were not directly measured, the findings support their potential role in PHIV impacting neurodevelopment and cognition.

scholarly journals Altered Amplitude of Low-Frequency Fluctuations in Inactive Patients with Nonneuropsychiatric Systemic Lupus Erythematosus

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yang Yu ◽  
Liheng Chen ◽  
Qiaohong Wang ◽  
Lingzhen Hu ◽  
Qiuping Ding ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Brain Activity ◽  
Low Frequency ◽  
Brain Regions ◽  
Precentral Gyrus ◽  
Spontaneous Brain Activity ◽  
Low Frequency Oscillations ◽  
Postcentral Gyrus ◽  
Frequency Fluctuations ◽  
The Right

Objective.This study is aimed at investigating the characteristics of the spontaneous brain activity in inactive patients with nonneuropsychiatric systemic lupus erythematosus (non-NPSLE). Methods. Thirty-one female inactive patients with non-NPSLE and twenty healthy controls were examined by resting-state functional magnetic resonance imaging (RS-fMRI). Three amplitude methods including amplitude of low-frequency fluctuations (ALFF), fractional amplitude of low-frequency fluctuations (fALFF), and percent amplitude of fluctuation (PerAF) (with and without standardization) were applied to evaluate the spontaneous brain activity. The correlation was performed between low-frequency oscillations and clinical and neuropsychological factors in inactive patients with non-NPSLE. Results. Compared to healthy controls, patients with non-NPSLE showed increased standardized ALFF (mALFF) in the left inferior temporal gyrus and left putamen, decreased PerAF in the right postcentral gyrus and bilateral precentral gyrus, and increased standardized PerAF (mPerAF) in the left putamen and decreased mPerAF in the right postcentral gyrus and bilateral precentral gyrus. By standardized fALFF (mfALFF), no significant brain regions were found between the two groups. Correlation analysis revealed significantly positive correlations between glucocorticoid dose and PerAF in the right precentral gyrus and mPerAF in the left putamen, and Complement 3 (C3) and mPerAF in the right postcentral gyrus. There was a significant negative correlation between C3 and mALFF in the left putamen. Conclusion. Abnormal low-frequency oscillations in multiple brain regions were found in inactive patients with non-NPSLE, indicating that the alteration of mALFF, PerAF, and mPerAF in specific brain regions might be an imaging biomarker of brain dysfunction in inactive patients with non-NPSLE.

scholarly journals Investigation of changes in the activity and function of dry eye-associated brain regions using the amplitude of low frequency fluctuations(ALFF)method

2022 ◽  
Author(s):  
Tie Sun ◽  
Hui-Ye Shu ◽  
Jie-Li Wu ◽  
Ting Su ◽  
Yu-Ji Liu ◽  
...  
Keyword(s):  
Dry Eye ◽  
Brain Activity ◽  
Pearson Correlation ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Brain Regions ◽  
Middle Frontal Gyrus ◽  
Brain Areas ◽  
Spontaneous Brain Activity ◽  
Frequency Fluctuations

Objective: The local characteristics of spontaneous brain activity in patients with dry eye (DE) and its relationship with clinical characteristics were evaluated using the amplitude of low-frequency fluctuations (ALFF) method. Methods: A total of 27 patients with DE (10 males and 17 females) and 28 healthy controls (HCs) (10 males and 18 females) were recruited, matched according to sex, age, weight, and height, classified into the DE and HC groups, and examined using functional magnetic resonance imaging scans. Spontaneous brain activity changes were recorded using ALFF technology. Data were recorded and plotted on the receiver operating characteristic curve, reflecting changes in activity in different brain areas. Finally, Pearson correlation analysis was used to calculate the potential relationship between spontaneous brain activity abnormalities in multiple brain regions and clinical features in patients with DE. GraphPad Prism 8 (GraphPad Software, Inc.) was used to analyze the linear correlation between the Hospital Anxiety and Depression Scale and ALFF value. Results: Compared with HCs, the ALFF values of patients with DE were decreased in the right middle frontal gyrus/right inferior orbitofrontal cortex, left triangle inferior frontal gyrus, left middle frontal gyrus, and right superior frontal gyrus. In contrast, the ALFF value of patients with DE was increased in the left calcarine. Conclusion: There are significant fluctuations in the ALFF value of specific brain regions in patients with DE versus HCs. This corroborates previous evidence showing that the symptoms of ocular surface damage in patients with DE are related to dysfunction in specific brain areas.

Comparison of intrinsic brain activity in individuals with low/moderate myopia versus high myopia revealed by the amplitude of low-frequency fluctuations

2019 ◽  
Vol 61 (4) ◽  
pp. 496-507 ◽  
Author(s):  
Yi Cheng ◽  
Xin Huang ◽  
Yu-Xiang Hu ◽  
Mu-Hua Huang ◽  
Bo Yang ◽  
...  
Keyword(s):  
White Matter ◽  
High Myopia ◽  
Brain Activity ◽  
Low Frequency ◽  
Anterior Lobe ◽  
Frequency Fluctuation ◽  
Healthy Controls ◽  
Optic Radiation ◽  
Frequency Fluctuations ◽  
Intrinsic Brain Activity

Background Previous neuroimaging studies demonstrated that individuals with high myopia are associated with abnormalities in anatomy of the brain. Purpose The purpose of this study was to explore alterations in the intrinsic brain activity by studying the amplitude of low-frequency fluctuations. Material and Methods A total of 64 myopia individuals (41 with high myopia with a refractive error <–600 diopter [D], 23 with low/moderate myopia with a refractive error between –100 and –600 D, and similarly 59 healthy controls with emmetropia closely matched for age) were recruited. The amplitude of low-frequency fluctuations method was conducted to investigate the difference of intrinsic brain activity across three groups. Results Compared with the healthy controls, individuals with low/moderate myopia showed significantly decreased amplitude of low-frequency fluctuation values in the bilateral rectal gyrus, right cerebellum anterior lobe/calcarine, and bilateral thalamus and showed significantly increased amplitude of low-frequency fluctuation values in left white matter (optic radiation), right prefrontal cortex, and left primary motor cortex (M1)/primary somatosensory cortex (S1). In addition, individuals with high myopia showed significantly decreased amplitude of low-frequency fluctuation values in the right cerebellum anterior lobe/calcarine/bilateral parahippocampal gyrus, bilateral posterior cingulate cortex, and bilateral middle cingulate cortex and significantly increased amplitude of low-frequency fluctuation values in left white matter (optic radiation), bilateral frontal parietal cortex, and left M1/S1. Moreover, we found that the amplitude of low-frequency fluctuation values of the different brain areas was closely related to the clinical features in the high myopia group. Conclusion Our results demonstrated that individuals with low/moderate myopia and high myopia had abnormal intrinsic brain activities in various brain regions related to the limbic system, default mode network, and thalamo-occipital pathway.

Functional MRI

2018 ◽  
Keyword(s):  
Functional Mri ◽  
Resting State ◽  
Brain Activity ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Functional Brain Imaging ◽  
Fmri Signal ◽  
The Brain

Functional MRI with BOLD (Blood Oxygen Level Dependent) imaging is one of the commonly used modalities for studying brain function in neuroscience. The underlying source of the BOLD fMRI signal is the variation in oxyhemoglobin to deoxyhemoglobin ratio at the site of neuronal activity in the brain. fMRI is mostly used to map out the location and intensity of brain activity that correlate with mental activities. In recent years, a new approach to fMRI was developed that is called resting-state fMRI. The fMRI signal from this method does not require the brain to perform any goal-directed task; it is acquired with the subject at rest. It was discovered that there are low-frequency fluctuations in the fMRI signal in the brain at rest. The signals originate from spatially distinct functionally related brain regions but exhibit coherent time-synchronous fluctuations. Several of the networks have been identified and are called resting-state networks. These networks represent the strength of the functional connectivity between distinct functionally related brain regions and have been used as imaging markers of various neurological and psychiatric diseases. Resting-state fMRI is also ideally suited for functional brain imaging in disorders of consciousness and in subjects under anesthesia. This book provides a review of the basic principles of fMRI (signal sources, acquisition methods, and data analysis) and its potential clinical applications.

scholarly journals The Effects of Acupuncture at Real or Sham Acupoints on the Intrinsic Brain Activity in Mild Cognitive Impairment Patients

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Baohui Jia ◽  
Zhishun Liu ◽  
Baoquan Min ◽  
Zhenchang Wang ◽  
Aihong Zhou ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Activity ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Brain Network ◽  
Healthy Controls ◽  
The Difference ◽  
The Brain

Accumulating neuroimaging studies in humans have shown that acupuncture can modulate a widely distributed brain network in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) patients. Acupuncture at different acupoints could exert different modulatory effects on the brain network. However, whether acupuncture at real or sham acupoints can produce different effects on the brain network in MCI or AD patients remains unclear. Using resting-state fMRI, we reported that acupuncture at Taixi (KI3) induced amplitude of low-frequency fluctuation (ALFF) change of different brain regions in MCI patients from those shown in the healthy controls. In MCI patients, acupuncture at KI3 increased or decreased ALFF in the different regions from those activated by acupuncture in the healthy controls. Acupuncture at the sham acupoint in MCI patients activated the different brain regions from those in healthy controls. Therefore, we concluded that acupuncture displays more significant effect on neuronal activities of the above brain regions in MCI patients than that in healthy controls. Acupuncture at KI3 exhibits different effects on the neuronal activities of the brain regions from acupuncture at sham acupoint, although the difference is only shown at several regions due to the close distance between the above points.

Basic Principles of Functional MRI

2018 ◽  
pp. 20-29
Author(s):  
Cheuk Ying Tang
Keyword(s):  
Functional Mri ◽  
Resting State ◽  
Brain Activity ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Functional Brain Imaging ◽  
Basic Principles ◽  
Fmri Signal ◽  
The Brain

Blood oxygen level dependent (BOLD) MRI, also called functional MRI (fMRI), is one of the most widely used modalities for studying brain function. The underlying source of the fMRI signal is blood flow and the oxygenation state of hemoglobin. fMRI is mostly used to map out the location and intensity of brain activity that correlate with mental activities. In recent years, a new approach to fMRI has been developed that is called resting-state fMRI. The fMRI signal from this method does not require the brain to perform a goal-directed task; it is acquired with the subject at rest. It was discovered that there are low-frequency fluctuations in the fMRI signal in the brain at rest. These signals come from spatially distinct brain regions but exhibit coherent, time-synchronous fluctuations. Several of the networks have been identified and are called resting-state networks. The networks represent the strength of the functional connectivity between distinct brain regions and have been used as imaging biomarkers for various neurological and psychiatric diseases. Resting-state fMRI is also ideally suited for functional brain imaging in disorders of consciousness and in subjects under anesthesia. In this chapter, we provide an introductory review of the basic principles of fMRI: signal sources, acquisition methods, and data analysis.

Early Microstructure Changes of White Matter Fiber Bundles in Patients with Amnestic Mild Cognitive Impairment Predicts Progression of Mild Cognitive Impairment to Alzheimer’s Disease

2021 ◽  
pp. 1-14
Author(s):  
Fangmei He ◽  
Yuchen Zhang ◽  
Xiaofeng Wu ◽  
Youjun Li ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Brain Regions ◽  
Amnestic Mild Cognitive Impairment ◽  
Microstructure Changes ◽  
Disease Trajectory ◽  
Development Trajectory ◽  
The Right

Background: Amnestic mild cognitive impairment (aMCI) is the transitional stage between normal aging and Alzheimer’s disease (AD). Some aMCI patients will progress into AD eventually, whereas others will not. If the trajectory of aMCI can be predicted, it would enable early diagnosis and early therapy of AD. Objective: To explore the development trajectory of aMCI patients, we used diffusion tensor imaging to analyze the white matter microstructure changes of patients with different trajectories of aMCI. Methods: We included three groups of subjects:1) aMCI patients who convert to AD (MCI-P); 2) aMCI patients who remain in MCI status (MCI-S); 3) normal controls (NC). We analyzed the fractional anisotropy and mean diffusion rate of brain regions, and we adopted logistic binomial regression model to predicate the development trajectory of aMCI. Results: The fraction anisotropy value is significantly reduced, the mean diffusivity value is significantly increased in the two aMCI patient groups, and the MCI-P patients presented greater changes. Significant changes are mainly located in the cingulum, fornix, hippocampus, and uncinate fasciculus. These changed brain regions significantly correlated with the patient’s Mini-Mental State Examination scores. Conclusion: The study predicted the disease trajectory of different types of aMCI patients based on the characteristic values of the above-mentioned brain regions. The prediction accuracy rate can reach 90.2%, and the microstructure characteristics of the right cingulate band and the right hippocampus may have potential clinical application value to predict the disease trajectory.

scholarly journals Structural reorganization of the white matter pathways of the brain in patients with spastic diplegia after translingual neurostimulation

2021 ◽  
Vol 8 (4) ◽  
pp. 27-34
Author(s):  
K. S. Anpilogova ◽  
D. S. Chegina ◽  
T. S. Ignatova ◽  
A. Yu. Efimtsev ◽  
G. E. Trufanov
Keyword(s):  
White Matter ◽  
Motor Skills ◽  
Structural Changes ◽  
Muscle Tone ◽  
Controlled Study ◽  
Cerebral White Matter ◽  
Spastic Diplegia ◽  
Functional Impairments ◽  
The Brain ◽  
Stimulation Of

Background. Spastic diplegia (Little’s disease) is the most common form of infantile cerebral palsy (ICP), leading to persistent motor and functional impairments. One promising area of rehabilitation is a combination of physical therapy with methods of stimulation of various parts of the nervous system, among which functional electrical stimulation of muscles and nerves is the most prominent.Objective. To study structural changes of cerebral white matter conduction pathways in patients with spastic diplegia after translingual neurostimulation using magnetic resonance tractography.Materials and Methods. An open single center-controlled study was conducted. A total of 18 children were examined. All patients underwent comprehensive MRI in two time points, before and after a course of translingual neurostimulation, on a tomograph with magnetic field induction 3.0 Tesla, which included a traditional protocol in 3 mutually perpendicular planes), and diffusion-weighted imaging — DWI (Diffusion-Weight Imaging).Results. All patients after neurostimulation showed clinical improvement of movement coordination and decrease of muscle tone with formation of new motor skills, improvement of limb motor function. Statistically significant decrease of spasticity index was revealed up to 17% for arms and 23% for legs, improvement of motor skills on all three scales.Conclusion. Translingual neurostimulation allows to affect all components of motor activity, as a result of which neuroplasticity processes are activated and the brain of patients with spastic diplegia becomes more receptive to motor rehabilitation aimed at restoration of motor control and formation of new motor skills.

scholarly journals Glutamine synthetase expression in the brain during experimental acute liver failure (immunohistochemical study)

2021 ◽  
Vol 11 (10) ◽  
pp. 342-356
Author(s):  
T. Shulyatnikova ◽  
V. Tumanskiy
Keyword(s):  
White Matter ◽  
Glutamine Synthetase ◽  
Liver Failure ◽  
Acute Liver Failure ◽  
Caudate Nucleus ◽  
Immunohistochemical Study ◽  
Clinical Signs ◽  
Brain Regions ◽  
Progressive Increase ◽  
The Brain

The aim of the study was to determine the immunohistochemical level of glutamine synthetase (GS) expression in different brain regions in the conditions of experimental acute liver failure in rats. Materials and methods. The study was conducted in Wistar rats: 5 sham (control) animals and 10 rats with acetaminophen induced liver failure model (AILF). The immunohistochemical study of GS expression in the sensorimotor cortex, white matter, hippocampus, thalamus, caudate nucleus/putamen was carried out in the period of 12-24 h after acetaminophen treatment. Results. Beginning from the 6th hour after acetaminophen treatment all AILF-animals showed the progressive increase in clinical signs of acute brain disfunction finished in 6 rats by comatose state up to 24 h - they constituted subgroup AILF-B, “non-survived”. 4 animals survived until the 24 h - subgroup AILF-A, “survived”. In the AILF-B group, starting from 16 to 24 hours after treatment, a significant (relative to control) regionally-specific dynamic increase in the level of GS expression was observed in the brain: in the cortex – by 307.33 %, in the thalamus – by 249.47%, in the hippocampus – by 245.53%, in the subcortical white matter – by 126.08%, from 12th hour – in the caudate nucleus/putamen, by 191.66 %; with the most substantive elevation of GS expression in the cortex: by 4.07 times. Conclusion. Starting from the 16th hours after the acetaminophen treatment (from the 12th h in the caudate nucleus/putamen region) and up to 24 h, it is observed reliable compared to control dynamic increase in GS protein expression in the cortex, white matter, hippocampus, thalamus, caudate nucleus/putamen of the rat brain with the most significant elevation in the cortex among other regions. The heterogeneity in the degree of GS expression rising in different brain regions potentially may indicate regions more permeable for ammonia and/or other systemic toxic factors as well as heterogeneous sensitivity of brain regions to deleterious agents in conditions of AILF. Subsequently, revealed diversity in the GS expression reflects the specificity of reactive response of local astroglia in the condition of AILF-encephalopathy during specific time-period. The dynamic increase in the GS expression associated with impairment of animal state, indicates involvement of increased GS levels in the mechanisms of experimental acute hepatic encephalopathy.

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