scholarly journals Descending pain modulatory efficiency in healthy subjects is related to structure and resting connectivity of brain regions

NeuroImage ◽  
2021 ◽  
pp. 118742
Author(s):  
Vincent Huynh ◽  
Robin Lütolf ◽  
Jan Rosner ◽  
Roger Luechinger ◽  
Armin Curt ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Brain Regions

scholarly journals Scan–rescan and inter-vendor reproducibility of neurite orientation dispersion and density imaging metrics

2019 ◽  
Vol 62 (4) ◽  
pp. 483-494
Author(s):  
Christina Andica ◽  
Koji Kamagata ◽  
Takuya Hayashi ◽  
Akifumi Hagiwara ◽  
Wataru Uchida ◽  
...  
Keyword(s):  
Gray Matter ◽  
Healthy Subjects ◽  
Volume Fraction ◽  
Diffusion Tensor ◽  
Intraclass Correlation ◽  
Region Of Interest ◽  
Brain Regions ◽  
Automatic Extraction ◽  
Dispersion Index ◽  
Diffusion Tensor Imaging Dti

Abstract Purpose The reproducibility of neurite orientation dispersion and density imaging (NODDI) metrics in the human brain has not been explored across different magnetic resonance (MR) scanners from different vendors. This study aimed to evaluate the scan–rescan and inter-vendor reproducibility of NODDI metrics in white and gray matter of healthy subjects using two 3-T MR scanners from two vendors. Methods Ten healthy subjects (7 males; mean age 30 ± 7 years, range 23–37 years) were included in the study. Whole-brain diffusion-weighted imaging was performed with b-values of 1000 and 2000 s/mm2 using two 3-T MR scanners from two different vendors. Automatic extraction of the region of interest was performed to obtain NODDI metrics for whole and localized areas of white and gray matter. The coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were calculated to assess the scan–rescan and inter-vendor reproducibilities of NODDI metrics. Results The scan–rescan and inter-vendor reproducibility of NODDI metrics (intracellular volume fraction and orientation dispersion index) were comparable with those of diffusion tensor imaging (DTI) metrics. However, the inter-vendor reproducibilities of NODDI (CoV = 2.3–14%) were lower than the scan–rescan reproducibility (CoV: scanner A = 0.8–3.8%; scanner B = 0.8–2.6%). Compared with the finding of DTI metrics, the reproducibility of NODDI metrics was lower in white matter and higher in gray matter. Conclusion The lower inter-vendor reproducibility of NODDI in some brain regions indicates that data acquired from different MRI scanners should be carefully interpreted.

scholarly journals Building a database for brain 18 kDa translocator protein imaged using [11C]PBR28 in healthy subjects

2018 ◽  
Vol 39 (6) ◽  
pp. 1138-1147 ◽  
Author(s):  
Soumen Paul ◽  
Evan Gallagher ◽  
Jeih-San Liow ◽  
Sanche Mabins ◽  
Katharine Henry ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
High Performance ◽  
Patient Characteristics ◽  
Brain Regions ◽  
Distribution Volume ◽  
Translocator Protein ◽  
Blood Samples ◽  
Arterial Blood ◽  
Logan Plot ◽  
Translocator Protein 18 Kda

Translocator protein 18 kDa (TSPO) has been widely imaged as a marker of neuroinflammation using several radioligands, including [11C]PBR28. In order to study the effects of age, sex, and obesity on TSPO binding and to determine whether this binding can be accurately assessed using fewer radio high-performance liquid chromatography (radio-HPLC) measurements of arterial blood samples, we created a database of 48 healthy subjects who had undergone [11C]PBR28 scans (23 high-affinity binders (HABs) and 25 mixed-affinity binders (MABs), 20 F/28 M, age: 40.6 ± 16.8 years). After analysis by Logan plot using 23 metabolite-corrected arterial samples, total distribution volume ( VT) was found to be 1.2-fold higher in HABs across all brain regions. Additionally, the polymorphism plot estimated nondisplaceable uptake ( VND) as 1.40 mL · cm−3, which generated a specific-to-nondisplaceable ratio ( BPND) of 1.6 ± 0.6 in HABs and 1.1 ± 0.6 in MABs. VT increased significantly with age in nearly all regions and was well estimated with radio-HPLC measurements from six arterial samples. However, VT did not correlate with body mass index and was not affected by sex. These results underscore which patient characteristics should be accounted for during [11C]PBR28 studies and suggest ways to perform such studies more easily and with fewer blood samples.

scholarly journals Geometric renormalization unravels self-similarity of the multiscale human connectome

2020 ◽  
Vol 117 (33) ◽  
pp. 20244-20253 ◽  
Author(s):  
Muhua Zheng ◽  
Antoine Allard ◽  
Patric Hagmann ◽  
Yasser Alemán-Gómez ◽  
M. Ángeles Serrano
Keyword(s):  
Healthy Subjects ◽  
Multiple Scales ◽  
Structural Connectivity ◽  
Coarse Graining ◽  
Brain Regions ◽  
Self Similarity ◽  
Digital Reconstruction ◽  
Self Similar ◽  
The Brain ◽  
Organizing Principles

Structural connectivity in the brain is typically studied by reducing its observation to a single spatial resolution. However, the brain possesses a rich architecture organized over multiple scales linked to one another. We explored the multiscale organization of human connectomes using datasets of healthy subjects reconstructed at five different resolutions. We found that the structure of the human brain remains self-similar when the resolution of observation is progressively decreased by hierarchical coarse-graining of the anatomical regions. Strikingly, a geometric network model, where distances are not Euclidean, predicts the multiscale properties of connectomes, including self-similarity. The model relies on the application of a geometric renormalization protocol which decreases the resolution by coarse-graining and averaging over short similarity distances. Our results suggest that simple organizing principles underlie the multiscale architecture of human structural brain networks, where the same connectivity law dictates short- and long-range connections between different brain regions over many resolutions. The implications are varied and can be substantial for fundamental debates, such as whether the brain is working near a critical point, as well as for applications including advanced tools to simplify the digital reconstruction and simulation of the brain.

scholarly journals Morphological Neuroimaging Biomarkers for Tinnitus: Evidence Obtained by Applying Machine Learning

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yawen Liu ◽  
Haijun Niu ◽  
Jianming Zhu ◽  
Pengfei Zhao ◽  
Hongxia Yin ◽  
...  
Keyword(s):  
Machine Learning ◽  
Healthy Subjects ◽  
Morphological Changes ◽  
Gray Matter Volume ◽  
Brain Regions ◽  
Classification Model ◽  
Middle Temporal Gyrus ◽  
Support Vector ◽  
Svm Classifier ◽  
Neuroimaging Biomarkers

According to previous studies, many neuroanatomical alterations have been detected in patients with tinnitus. However, the results of these studies have been inconsistent. The objective of this study was to explore the cortical/subcortical morphological neuroimaging biomarkers that may characterize idiopathic tinnitus using machine learning methods. Forty-six patients with idiopathic tinnitus and fifty-six healthy subjects were included in this study. For each subject, the gray matter volume of 61 brain regions was extracted as an original feature pool. From this feature pool, a hybrid feature selection algorithm combining the F-score and sequential forward floating selection (SFFS) methods was performed to select features. Then, the selected features were used to train a support vector machine (SVM) model. The area under the curve (AUC) and accuracy were used to assess the performance of the classification model. As a result, a combination of 13 cortical/subcortical brain regions was found to have the highest classification accuracy for effectively differentiating patients with tinnitus from healthy subjects. These brain regions include the bilateral hypothalamus, right insula, bilateral superior temporal gyrus, left rostral middle frontal gyrus, bilateral inferior temporal gyrus, right inferior parietal lobule, right transverse temporal gyrus, right middle temporal gyrus, right cingulate gyrus, and left superior frontal gyrus. The accuracy in the training and test datasets was 80.49% and 80.00%, respectively, and the AUC was 0.8586. To the best of our knowledge, this is the first study to elucidate brain morphological changes in patients with tinnitus by applying an SVM classifier. This study provides validated cortical/subcortical morphological neuroimaging biomarkers to differentiate patients with tinnitus from healthy subjects and contributes to the understanding of neuroanatomical alterations in patients with tinnitus.

Counterfactual thinking in schizophrenia patients

2011 ◽  
Vol 26 (S2) ◽  
pp. 413-413 ◽  
Author(s):  
A. Caño ◽  
F. Contreras ◽  
J.M. Menchón
Keyword(s):  
Healthy Subjects ◽  
Mental Representations ◽  
Counterfactual Thinking ◽  
Brain Regions ◽  
Behavioral Regulation ◽  
Schizophrenic Patients ◽  
Healthy Control ◽  
Dsm Iv ◽  
The Mean

IntroductionCounterfactual thoughts (CFT) are mental representations of alternatives to past events, actions or states. For example, “If only I had studied, I would have passed the exam”).CFT in healthy subjects is associated with learning, behavioral regulation and planning.Damage to the prefrontal brain regions has been related to decreased generation and use of CFT. Due to the fact that frontal deficits are documented in patients with schizophrenia, it is expected that these patients could also present impairments in CFT.ObjectivesThe aim of our study was to examine the role of the generation of CFT in schizophrenia patients.MethodsForty subjects who met DSM-IV criteria for schizophrenia and 40 healthy control participants were recruited. The two groups were matched in age, education, and handedness.To investigate the generation of CTF we used an adaptation of the task made by Wells, Taylor & Turtle (1987). In this task, we presented to the subjects one history with 4 different scenarios. After the presentation of the history, we asked to the subjects that list alternatives to solve the problem presented in the history.ResultsThe schizophrenic patients generated less responses of CTF that controls. The patients obtained a mean of responses of 1.48 (1 SD). The mean for the controls was 2.08 (.971 SD). The control subjects generated significantly more counterfactual responses than schizophrenic patients ([t (78) = −2.670, p = .269]).ConclusionsOur findings indicate that patients with schizophrenia have impoverished the generation of CFT compared to normal control participants.

scholarly journals First in-human PET study of 3 novel tau radiopharmaceuticals: [11C]RO6924963, [11C]RO6931643, and [18F]RO6958948

2018 ◽  
Author(s):  
Dean F. Wong ◽  
Robert A. Comley ◽  
Hiroto Kuwabara ◽  
Paul B. Rosenberg ◽  
Susan M. Resnick ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Regional Analysis ◽  
Brain Regions ◽  
Whole Body ◽  
Kinetic Properties ◽  
Amyloid Pet ◽  
Significant Group ◽  
Pet Tracers ◽  
Arterial Blood

AbstractBackground[11C]RO-963, [11C]RO-643 and [18F]RO-948 (previously referred as [11C]RO6924963, [11C]RO6931643, and [18F]RO6958948, respectively) have been reported as promising PET tracers for tau imaging based on in vitro and preclinical PET data (1,2). Here we describe the first human evaluation of these novel radiotracers.MethodsAmyloid PET positive Alzheimer’s disease (AD) patients and young healthy subjects (YC) each received two different tau tracers. Dynamic 90 min scans were obtained after bolus injection of [11C]RO-963, [11C]RO-643 or [18F]RO-948. Arterial blood sampling was performed in 11 healthy controls (HC) and 11 AD. Regions were defined on MRI, and PET data were quantified by plasma reference graphical analysis (for VT) and target cerebellum ratio (SUVR60-90). SUVR images were also analyzed voxelwise. Five older healthy subjects (OC) each received two scans with [18F]RO-948 for evaluation of test-retest variability. Four AD subjects received a repeat [18F]RO-948 scan over about 1 year. Six additional HC (3M: 3F; 41-67y) each received one whole body dosimetry scan with [18F]RO-948.ResultsIn YC, peak SUV values were observed in the temporal lobe with values of approximately 3.0 for [11C]RO-963, 1.5 for [11C]RO-643 and 3.5 for [18F]RO-948. Over all brain regions and subjects, the trend was that [18F]RO-948 had the highest peak SUV value, followed by [11C]RO-963, and then [11C]RO-643. Regional analysis of SUVR and VT for [11C]RO-643 and [18F]RO-948 clearly discriminated AD and HC groups. Compartmental modeling confirmed that [11C]RO-643 had lower brain entry than both [18F]RO-963 and [18F]RO-948, and [18F]RO-948 showed a better contrast between (predicted) areas of high vs low tau accumulation. Thus, our subsequent analysis focused on [18F]RO-948. Both voxelwise and region-based analysis of [18F]RO-948 binding in HC vs AD revealed multiple areas where AD and HC significantly differed. Of 22 high-binding regions, 13 showed significant group difference (following ANOVA, F=45, p<10-5). Voxelwise analysis also revealed a set of symmetrical clusters where AD>HC (threshold of p<0.001, cluster size k>50).Conclusions[18F]RO-948 demonstrates superior characteristics to [11C]RO-643 and [18F]RO-963 for characterization of tau pathology in AD. Regional binding data and kinetic properties of RO-948 compare favorably with existing other tau PET tracers.

scholarly journals An fMRI Study Using a Combined Task of Interval Discrimination and Oddball Could Reveal Common Brain Circuits of Cognitive Change

2021 ◽  
Vol 12 ◽  
Author(s):  
María Sol Garcés ◽  
Irene Alústiza ◽  
Anton Albajes-Eizagirre ◽  
Javier Goena ◽  
Patricio Molero ◽  
...  
Keyword(s):  
Cognitive Processes ◽  
Healthy Subjects ◽  
Functional Neuroimaging ◽  
Meta Analysis ◽  
Brain Structures ◽  
Cognitive Change ◽  
Brain Regions ◽  
Task Type ◽  
Meta Analyses ◽  
The Brain

Recent functional neuroimaging studies suggest that the brain networks responsible for time processing are involved during other cognitive processes, leading to a hypothesis that time-related processing is needed to perform a range of tasks across various cognitive functions. To examine this hypothesis, we analyze whether, in healthy subjects, the brain structures activated or deactivated during performance of timing and oddball-detection type tasks coincide. To this end, we conducted two independent signed differential mapping (SDM) meta-analyses of functional magnetic resonance imaging (fMRI) studies assessing the cerebral generators of the responses elicited by tasks based on timing and oddball-detection paradigms. Finally, we undertook a multimodal meta-analysis to detect brain regions common to the findings of the two previous meta-analyses. We found that healthy subjects showed significant activation in cortical areas related to timing and salience networks. The patterns of activation and deactivation corresponding to each task type partially coincided. We hypothesize that there exists a time and change-detection network that serves as a common underlying resource used in a broad range of cognitive processes.

Altered Relationships Between rCBF in Different Brain Regions of Never-Treated Schizophrenics

1997 ◽  
Vol 36 (06) ◽  
pp. 194-201 ◽  
Author(s):  
R. Erkwoh ◽  
M. Schreckenberger ◽  
U. Cremerius ◽  
A. Owega ◽  
C. Diekmann ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Clinical Improvement ◽  
Healthy Subjects ◽  
Brain Regions ◽  
Regions Of Interest ◽  
Neuroleptic Treatment ◽  
Temporal Correlations ◽  
Schizophrenic Patients ◽  
Neuronal Functions

Summary Aim of this study was to investigate the relations between regiona cerebral blood flow (rCBF) of different brain regions in acute schizophrenia and following neuroleptic treatment. Methods: Twenty-two never-treated, acute schizophrenic patients were examined with HMPAO brain SPECT and assessed psychopathological-ly, and reexamined following neuroleptic treatment (over 96.8 days) and psychopathological remission. rCBF was determined by region/cerebel-lar count quotients obtained from 98 irregular regions of interest (ROIs), summed up to 11 ROIs on each hemisphere. In acute schizophrenics, interregional rCBF correlations of each ROI to every other ROI were compared to the interregional correlations following neuroleptic treatment and to those of controls. Results: All significant correlations of rCBF ratios of different brain regions were exclusively positive in controls and patients. In controls, all ROIs of one hemisphere except the mesial temporal ROI correlated significantly to its contralateral ROI. Each hemisphere showed significant frontal-temporal correlations, as well as cortical-subcortical and some cortico-limbic. In contrast, in acute schizophrenics nearly every ROI correlated significantly with every other ROI, without a grouping or relation of the rCBF of certain ROIs as in controls. After neuroleptic treatment and clinical improvement, this diffuse pattern of correlations remained. Conclusions: These results indicate differences in the neuronal interplay between regions in schizophrenic and healthy subjects. In never-treated schizophrenics, diffuse interregional rCBF correlations can be seen as a sign of change and dysfunction of the systems regulating specificity and diversity of the neuronal functions. Neuroleptic therapy and psychopathologic remission showed no normalizing effect on interregional correlations.

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