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https://www.readbyqxmd.com/read/28213112/laminar-imaging-of-positive-and-negative-bold-in-human-visual-cortex-at-7t
#1
Alessio Fracasso, Peter R Luijten, Serge O Dumoulin, Natalia Petridou
Deciphering the direction of information flow is critical to understand the brain. Data from non-human primate histology shows that connections between lower to higher areas (e.g. retina→V1), and between higher to lower areas (e.g. V1←V2) can be dissociated based upon the distribution of afferent synapses at the laminar level. Ultra-high field scanners opened up the possibility to image brain structure and function at an unprecedented level of detail. Taking advantage of the increased spatial resolution available, it could theoretically be possible to disentangle activity from different cortical depths from human cerebral cortex, separately studying different compartments across depth...
February 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28186661/brain-neurochemical-and-hemodynamic-findings-in-the-ny1dd-mouse-model-of-mild-sickle-cell-disease
#2
Min-Hui Cui, Sandra M Suzuka, Nicholas A Branch, Kamalakar Ambadipudi, Sangeetha Thangaswamy, Seetharama A Acharya, Henny H Billett, Craig A Branch
To characterize the cerebral profile associated with sickle cell disease (SCD), we used in vivo proton MRI and MRS to quantify hemodynamics and neurochemicals in the thalamus of NY1DD mice, a mild model of SCD, and compared them with wild-type (WT) control mice. Compared with WT mice, NY1DD mice at steady state had elevated cerebral blood flow (CBF) and concentrations of N-acetylaspartate (NAA), glutamate (Glu), alanine, total creatine and N-acetylaspartylglutamate. Concentrations of glutathione (GSH) at steady state showed a negative correlation with BOLD signal change in response to 100% oxygen, a marker for oxidative stress, and mean diffusivity assessed using diffusion-tensor imaging, a marker for edematous inflammation...
February 10, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28179153/activation-of-npffr2-leads-to-hyperalgesia-through-the-spinal-inflammatory-mediator-cgrp-in-mice
#3
Ya-Tin Lin, Ho-Ling Liu, Yuan-Ji Day, Che-Chien Chang, Po-Hung Hsu, Jin-Chung Chen
Neuropeptide FF (NPFF) is recognized as an opioid modulating peptide that regulates morphine-induced analgesia. The aim of this study was to delineate the role of NPFFR2 in pain transmission. We found the expression levels of NPFF and NPFFR2 were increased in the lumbar dorsal horn of animals with CFA- and carrageenan-induced inflammation and both NPFFR2 over-expressing transgenic (NPFFR2-Tg) and NPFFR2 agonist-treated mice displayed hyperalgesia. BOLD signals from functional MRI showed that NPFFR2-Tg mice exhibited increased activation of pain-related brain regions after painful stimulation when compared to WT mice...
February 5, 2017: Experimental Neurology
https://www.readbyqxmd.com/read/28163122/comparison-of-bold-diffusion-weighted-fmri-and-adc-fmri-for-stimulation-of-the-primary-visual-system-with-a-block-paradigm
#4
R Nicolas, H Gros-Dagnac, F Aubry, P Celsis
The blood oxygen level-dependent (BOLD) effect is extensively used for functional MRI (fMRI) but presents some limitations. Diffusion-weighted fMRI (DfMRI) has been proposed as a method more tightly linked to neuronal activity. This work proposes a protocol of DfMRI acquired for several b-values and diffusion directions that is compared to gradient-echo BOLD (GE-BOLD) and to repeated spin-echo BOLD (SE-BOLD, acquisitions performed with b=0s/mm(2)), which was also used to ensure the reproducibility of the response...
February 2, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28162895/the-brain-basis-for-misophonia
#5
Sukhbinder Kumar, Olana Tansley-Hancock, William Sedley, Joel S Winston, Martina F Callaghan, Micah Allen, Thomas E Cope, Phillip E Gander, Doris-Eva Bamiou, Timothy D Griffiths
Misophonia is an affective sound-processing disorder characterized by the experience of strong negative emotions (anger and anxiety) in response to everyday sounds, such as those generated by other people eating, drinking, chewing, and breathing [1-8]. The commonplace nature of these sounds (often referred to as "trigger sounds") makes misophonia a devastating disorder for sufferers and their families, and yet nothing is known about the underlying mechanism. Using functional and structural MRI coupled with physiological measurements, we demonstrate that misophonic subjects show specific trigger-sound-related responses in brain and body...
February 1, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28161387/intranasal-oxytocin-but-not-vasopressin-augments-neural-responses-to-toddlers-in-human-fathers
#6
Ting Li, Xu Chen, Jennifer Mascaro, Ebrahim Haroon, James K Rilling
This study investigates paternal brain function with the hope of better understanding the neural basis for variation in caregiving involvement among men. The neuropeptides oxytocin (OT) and vasopressin (AVP) are implicated in paternal caregiving in humans and other species. In a double-blind, placebo-controlled, within-subject pharmaco-functional MRI experiment, we randomized 30 fathers of 1-2year old children to receive either 24IU intranasal OT before one scan and placebo before the other scan (n=15) or 20IU intranasal AVP before one scan and placebo before the other scan (n=15)...
February 1, 2017: Hormones and Behavior
https://www.readbyqxmd.com/read/28161312/exploring-structure-and-function-of-sensory-cortex-with-7t-mri
#7
Denis Schluppeck, Rosa-Maria Sanchez-Panchuelo, Susan T Francis
In this paper, we present an overview of 7T magnetic resonance imaging (MRI) studies of the detailed function and anatomy of sensory areas of the human brain. We discuss the motivation for the studies, with particular emphasis on increasing the spatial resolution of functional MRI (fMRI) using reduced field-of-view (FOV) data acquisitions. MRI at ultra-high-field (UHF) - defined here as 7T and above - has several advantages over lower field strengths. The intrinsic signal-to-noise ratio (SNR) of images is higher at UHF, and coupled with the increased blood-oxygen-level-dependent (BOLD) signal change, this results in increased BOLD contrast-to-noise ratio (CNR), which can be exploited to improve spatial resolution or detect weaker signals...
February 2, 2017: NeuroImage
https://www.readbyqxmd.com/read/28159686/resting-state-electrophysiology-links-classic-brain-rhythms-and-large-scale-functional-systems
#8
Carl D Hacker, Abraham Z Snyder, Mrinal Pahwa, Maurizio Corbetta, Eric C Leuthardt
Resting state functional MRI (R-fMRI) studies have shown that slow (< 0.1Hz), intrinsic fluctuations of the blood oxygen level dependent (BOLD) signal are temporally correlated within hierarchically organized functional systems known as resting state networks (RSNs) (Doucet et al., 2011). Most broadly, this hierarchy exhibits a dichotomy between two opposed systems (Fox et al., 2005). One system engages with the environment and includes the visual, auditory, and sensorimotor (SMN) networks as well as the dorsal attention network (DAN), which controls spatial attention...
January 31, 2017: NeuroImage
https://www.readbyqxmd.com/read/28152266/bold-fmri-with-median-nerve-electrical-stimulation-predict-hemodynamic-improvement-after-revascularization-in-patients-with-moyamoya-disease
#9
Peng-Gang Qiao, Cong Han, Tianyi Qian, Gong-Jie Li, Hong Yin
PURPOSE: To assess the severity of cerebral hemodynamic impairment and hemodynamic improvements, after revascularization in moyamoya disease (MMD) by means of blood-oxygen-level dependent functional magnetic resonance imaging (BOLD-fMRI). MATERIALS AND METHODS: BOLD-fMRI with median nerve electrical stimulation based on echo planar imaging was performed in 73 volunteers with MMD and 15 healthy volunteers using a 3.0 Tesla MRI scanner. Twenty-four MMD patients were reexamined after encephaloduroarteriosynangiosis...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152241/invalidation-of-fmri-experiments-secondary-to-neurovascular-uncoupling-in-patients-with-cerebrovascular-disease
#10
Andrea E Para, Kevin Sam, Julien Poublanc, Joseph A Fisher, Adrian P Crawley, David J Mikulis
PURPOSE: Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is a technique used to infer neuronal activity from the observed changes in blood flow. Cerebrovascular reactivity (CVR) is the ability of arterioles to increase blood flow in response to vasodilatory stimulus. We hypothesize that in areas of disease where there is exhausted vascular reserve and impaired CVR there will be diminished blood flow response following neuronal activation, and that these areas would appear as false-negative tests on BOLD fMRI...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152240/spatiotemporal-alignment-of-in-utero-bold-mri-series
#11
Esra Abaci Turk, Jie Luo, Borjan Gagoski, Javier Pascau, Carolina Bibbo, Julian N Robinson, P Ellen Grant, Elfar Adalsteinsson, Polina Golland, Norberto Malpica
PURPOSE: To present a method for spatiotemporal alignment of in-utero magnetic resonance imaging (MRI) time series acquired during maternal hyperoxia for enabling improved quantitative tracking of blood oxygen level-dependent (BOLD) signal changes that characterize oxygen transport through the placenta to fetal organs. MATERIALS AND METHODS: The proposed pipeline for spatiotemporal alignment of images acquired with a single-shot gradient echo echo-planar imaging includes 1) signal nonuniformity correction, 2) intravolume motion correction based on nonrigid registration, 3) correction of motion and nonrigid deformations across volumes, and 4) detection of the outlier volumes to be discarded from subsequent analysis...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152238/assessment-of-segmental-myocardial-blood-flow-and-myocardial-perfusion-reserve-by-adenosine-stress-myocardial-arterial-spin-labeling-perfusion-imaging
#12
Andrew J Yoon, Hung Phi Do, Steven Cen, Michael W Fong, Farhood Saremi, Mark L Barr, Krishna S Nayak
PURPOSE: To determine the feasibility of measuring increases in myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) on a per-segment basis using arterial spin labeled (ASL) magnetic resonance imaging (MRI) with adenosine vasodilator stress in normal human myocardium. MATERIALS AND METHODS: Myocardial ASL scans at rest and during adenosine infusion were incorporated into a routine 3T MR adenosine-induced vasodilator stress protocol and were performed in 10 healthy human volunteers...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28145075/biomarkers-designs-and-interpretations-of-resting-state-fmri-in-translational-pharmacological-research-a-review-of-state-of-the-art-challenges-and-opportunities-for-studying-brain-chemistry
#13
REVIEW
Najmeh Khalili-Mahani, Serge A R B Rombouts, Matthias J P van Osch, Eugene P Duff, Felix Carbonell, Lisa D Nickerson, Lino Becerra, Albert Dahan, Alan C Evans, Jean-Paul Soucy, Richard Wise, Alex P Zijdenbos, Joop M van Gerven
A decade of research and development in resting-state functional MRI (RSfMRI) has opened new translational and clinical research frontiers. This review aims to bridge between technical and clinical researchers who seek reliable neuroimaging biomarkers for studying drug interactions with the brain. About 85 pharma-RSfMRI studies using BOLD signal (75% of all) or arterial spin labeling (ASL) were surveyed to investigate the acute effects of psychoactive drugs. Experimental designs and objectives include drug fingerprinting dose-response evaluation, biomarker validation and calibration, and translational studies...
February 1, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28139701/the-value-of-resting-state-functional-mri-in-subacute-ischemic-stroke-comparison-with-dynamic-susceptibility-contrast-enhanced-perfusion-mri
#14
Ling Ni, Jingwei Li, Weiping Li, Fei Zhou, Fangfang Wang, Christopher G Schwarz, Renyuan Liu, Hui Zhao, Wenbo Wu, Xin Zhang, Ming Li, Haiping Yu, Bin Zhu, Arno Villringer, Yufeng Zang, Bing Zhang, Yating Lv, Yun Xu
To evaluate the potential clinical value of the time-shift analysis (TSA) approach for resting-state fMRI (rs-fMRI) blood oxygenation level-dependent (BOLD) data in detecting hypoperfusion of subacute stroke patients through comparison with dynamic susceptibility contrast perfusion weighted imaging (DSC-PWI). Forty patients with subacute stroke (3-14 days after neurological symptom onset) underwent MRI examination. Cohort A: 31 patients had MRA, DSC-PWI and BOLD data. Cohort B: 9 patients had BOLD and MRA data...
January 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28132008/compensatory-changes-in-energy-balance-during-dapagliflozin-treatment-in-type-2-diabetes-mellitus-a-randomised-double-blind-placebo-controlled-cross-over-trial-energize-study-protocol
#15
Surya Panicker Rajeev, Victoria S Sprung, Carl Roberts, Jo A Harrold, Jason C G Halford, Andrej Stancak, Emma J Boyland, Graham J Kemp, Daniel J Cuthbertson, John P H Wilding
INTRODUCTION: Sodium glucose cotransporter 2 (SGLT2) inhibitors are effective blood-glucose-lowering medications with beneficial effects on body weight in patients with type 2 diabetes mellitus (T2DM). However, observed weight loss is less than that predicted from quantified glycosuria, suggesting a compensatory increase in energy intake or a decrease in energy expenditure. Studies using dual-energy X-ray absorptiometry (DEXA) have suggested most body weight change is due to loss of adipose tissue, but organ-specific changes in fat content (eg, liver, skeletal muscle) have not been determined...
January 27, 2017: BMJ Open
https://www.readbyqxmd.com/read/28120404/functional-mri-of-human-pancreas-using-bold-contrast-responses-following-glucose-ingestion
#16
Bozhu Chen, Weibo Chen, Queenie Chan, Nan Zhou, Jian He, Zhengyang Zhou
PURPOSE: To evaluate the response of the pancreas to glucose ingestion in healthy volunteers by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). MATERIALS AND METHODS: This study was approved by the local Ethics Committee, and informed consent was obtained from all subjects. A multiple gradient recalled echo (mGRE) sequence was performed on a 3.0T MR scanner in 12 healthy volunteers before and after glucose or water ingestion. Pancreatic T2* values were calculated from it at each timepoint, and changes following stimulation were analyzed using summary measures...
January 24, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28119136/gabaergic-effect-on-resting-state-functional-connectivity-dynamics-under-pharmacological-antagonism
#17
Fatima A Nasrallah, Kavita Kaur D/O Ranjit Singh, Ling Yun Yeow, Kai-Hsiang Chuang
Resting state functional connectivity MRI measures synchronous activity among brain regions although the mechanisms governing the temporally coherent BOLD signals remain unclear. Recent studies suggest that γ-amino butyric acid (GABA) levels are correlated with functional connectivity. To understand whether changes in GABA transmission alter functional connectivity, we modulated the GABAergic activity by a GABAA receptor antagonist, bicuculline. Resting and evoked electrophysiology and BOLD signals were measured in isoflurane-anesthetized rats under infusion of low-dose bicuculline or vehicle individually...
January 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28119135/relative-latency-and-temporal-variability-of-hemodynamic-responses-at-the-human-primary-visual-cortex
#18
Fa-Hsuan Lin, Jonathan R Polimeni, Jo-Fu Lotus Lin, Kevin W-K Tsai, Ying-Hua Chu, Pu-Yeh Wu, Yi-Tien Li, Yi-Cheng Hsu, Shang-Yueh Tsai, Wen-Jui Kuo
The blood-oxygen-level-dependent (BOLD) functional MRI (fMRI) signal is a robust surrogate for local neuronal activity. However, it has been shown to vary substantially across subjects, brain regions, and repetitive measurements. This variability represents a limit to the precision of the BOLD response and the ability to reliably discriminate brain hemodynamic responses elicited by external stimuli or behavior that are nearby in time. While the temporal variability of the BOLD signal at human visual cortex has been found in the range of a few hundreds of milliseconds, the spatial distributions of the average and standard deviation of this temporal variability have not been quantitatively characterized...
January 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28116237/brain-correlates-of-spike-and-wave-discharges-in-glut1-deficiency-syndrome
#19
Anna Elisabetta Vaudano, Sara Olivotto, Andrea Ruggieri, Giuliana Gessaroli, Valentina De Giorgis, Antonia Parmeggiani, Pierangelo Veggiotti, Stefano Meletti
PURPOSE: To provide imaging biomarkers of generalized spike-and-wave discharges (GSWD) in patients with GLUT1 deficiency syndrome (GLUT1DS). METHODS: Eighteen GLUT1DS patients with pathogenetic mutation in SLC2A1 gene were studied by means of Video-EEG simultaneously recorded with functional MRI (VideoEEG-fMRI). A control group of sex and age-matched patients affected by Genetic Generalized Epilepsy (GGE) with GSWD were investigated with the same protocol. Within and between groups comparison was performed as appropriated...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28098938/towards-prognostic-biomarkers-from-bold-fluctuations-to-differentiate-a-first-epileptic-seizure-from-new-onset-epilepsy
#20
Lalit Gupta, Rick Janssens, Mariëlle C G Vlooswijk, Rob P W Rouhl, Anton de Louw, Albert P Aldenkamp, Shrutin Ulman, René M H Besseling, Paul A M Hofman, Vivianne H van Kranen-Mastenbroek, Danny M Hilkman, Jacobus F A Jansen, Walter H Backes
OBJECTIVE: The diagnosis of epilepsy cannot be reliably made prior to a patient's second seizure in most cases. Therefore, adequate diagnostic tools are needed to differentiate subjects with a first seizure from those with a seizure preceding the onset of epilepsy. The objective was to explore spontaneous blood oxygen level-dependent (BOLD) fluctuations in subjects with a first-ever seizure and patients with new-onset epilepsy (NOE), and to find characteristic biomarkers for seizure recurrence after the first seizure...
January 18, 2017: Epilepsia
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