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BOLD fMRI

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https://www.readbyqxmd.com/read/28634048/activation-volume-vs-bold-signal-change-as-measures-of-fmri-activation-its-impact-on-gaba-fmri-activation-correlation
#1
Pallab K Bhattacharyya, Micheal D Phillips, Lael A Stone, Mark J Lowe
PURPOSE: To explore the relative robustness of functional MRI (fMRI) activation volume and blood oxygen level-dependent (BOLD) signal change as fMRI metric, and to study the effect of relative robustness on the correlation between fMRI activation and cortical gamma amino butyric acid (GABA) in healthy controls and patients with multiple sclerosis (MS). METHODS: fMRI data were acquired from healthy controls and patients with MS, with the subjects peforming self paced bilateral finger tapping in block design...
June 17, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28629975/anatomical-and-functional-properties-of-the-foot-and-leg-representation-in-areas-3b-1-and-2-of-primary-somatosensory-cortex-in-humans-a-7t-fmri-study
#2
Michel Akselrod, Roberto Martuzzi, Andrea Serino, Wietske van der Zwaag, Roger Gassert, Olaf Blanke
Primary somatosensory cortex (S1) processes somatosensory information and is composed of multiple subregions. In particular, tactile information from the skin is encoded in three subregions, namely Brodmann areas (BAs) 3b, 1 and 2, with each area representing a complete map of the contralateral body. Although, much is known about the somatotopic organization of the hand in human S1, less research has been carried out regarding the somatotopic maps of the foot and leg in S1. Moreover, a latero-medial S1 organization along the superior part of the postcentral gyrus has been reported when moving from hip to toes, yet to date there is no study investigating leg/foot maps within the different subregions of S1...
June 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28628224/human-exposure-to-power-frequency-magnetic-fields-up-to-7-6%C3%A2-mt-an-integrated-eeg-fmri-study
#3
Julien Modolo, Alex W Thomas, Alexandre Legros
We assessed the effects of power-line frequency (60 Hz in North America) magnetic fields (MF) in humans using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Twenty-five participants were enrolled in a pseudo-double-blind experiment involving "real" or "sham" exposure to sinusoidal 60 Hz MF exposures delivered using the gradient coil of an MRI scanner following two conditions: (i) 10 s exposures at 3 mT (10 repetitions); (ii) 2 s exposures at 7.6 mT (100 repetitions)...
June 19, 2017: Bioelectromagnetics
https://www.readbyqxmd.com/read/28626199/oxygen-and-glucose-as-stimulation-agents-for-bold-functional-mr-imaging-of-rabbit-liver-a-feasibility-study
#4
Fang Yuan, Bin Song, Zixing Huang, Xijiao Liu, Chunchao Xia
PURPOSE: To assess the feasibility of using oxygen and glucose as stimulating agents in blood-oxygen-level-dependent (BOLD) Functional Magnetic Resonance Imaging (fMRI) of rabbit liver and analyze the impacts by blood flow. METHODS: Pure oxygen inhalation, intravenous injection and oral administration of glucose were given to 11 New Zealand white rabbits to compare the differences of liver T2*, aortic flow (AF), portal vein flow (PVF), aortic area (AA) and portal vein area (PVA) before and at 5 min, 10 min, 20 min, 30 min after administrations...
June 16, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28625875/individual-differences-in-functional-connectivity-during-naturalistic-viewing-conditions
#5
Tamara Vanderwal, Jeffrey Eilbott, Emily S Finn, R Cameron Craddock, Adam Turnbull, F Xavier Castellanos
Naturalistic viewing paradigms such as movies have been shown to reduce participant head motion and improve arousal during fMRI scanning relative to task-free rest, and have been used to study both functional connectivity and stimulus-evoked BOLD-signal changes. These task-based hemodynamic changes are synchronized across subjects and involve large areas of the cortex, and it is unclear whether individual differences in functional connectivity are enhanced or diminished under such naturalistic conditions. This work first aims to characterize variability in BOLD-signal based functional connectivity (FC) across 2 distinct movie conditions and eyes-open rest (n=31 healthy adults, 2 scan sessions each)...
June 15, 2017: NeuroImage
https://www.readbyqxmd.com/read/28616455/ultra-high-field-7%C3%A2-t-multi-resolution-fmri-data-for-orientation-decoding-in-visual-cortex
#6
Ayan Sengupta, Renat Yakupov, Oliver Speck, Stefan Pollmann, Michael Hanke
Multivariate pattern classification methods have been successfully applied to decode orientation of visual grating stimuli from BOLD fMRI activity recorded in human visual cortex (Kamitani and Tong, 2005; Haynes and Rees, 2005) [12], [10]. Though there has been extensive research investigating the true spatial scale of the orientation specific signals (Op de Beeck, 2010; Swisher et al., 2010; Alink et al., 2013; Freeman et al., 2011, 2013) [2], [15], [1], [4], [5], it remained inconclusive what spatial acquisition resolution is required, or is optimal, for decoding analyses...
August 2017: Data in Brief
https://www.readbyqxmd.com/read/28611613/simultaneous-processing-of-noun-cue-and-to-be-produced-verb-in-verb-generation-task-electromagnetic-evidence
#7
Anna V Butorina, Anna A Pavlova, Anastasia Y Nikolaeva, Andrey O Prokofyev, Denis P Bondarev, Tatiana A Stroganova
A long-standing but implicit assumption is that words strongly associated with a presented cue are automatically activated in the memory through rapid spread of activation within brain semantic networks. The current study was aimed to provide direct evidence of such rapid access to words' semantic representations and to investigate its neural sources using magnetoencephalography (MEG) and distributed source localization technique. Thirty-three neurotypical subjects underwent the MEG recording during verb generation task, which was to produce verbs related to the presented noun cues...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28611513/brain-changes-detected-by-functional-magnetic-resonance-imaging-and-spectroscopy-in-patients-with-crohn-s-disease
#8
REVIEW
Kun Lv, Yi-Hong Fan, Li Xu, Mao-Sheng Xu
Crohn's disease (CD) is a chronic, non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease (IBD). CD is prone to relapse, and its incidence displays a persistent increase in developing countries. However, the pathogenesis of CD is poorly understood, with some studies emphasizing the link between CD and the intestinal microbiota. Specifically, studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD...
May 28, 2017: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/28610902/post-stimulus-fmri-and-eeg-responses-evidence-for-a-neuronal-origin-hypothesised-to-be-inhibitory
#9
K J Mullinger, M T Cherukara, R B Buxton, S T Francis, S D Mayhew
Post-stimulus undershoots, negative responses following cessation of stimulation, are widely observed in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) data. However, the debate surrounding whether the origin of this response phase is neuronal or vascular, and whether it provides functionally relevant information, that is additional to what is contained in primary response, means that undershoots are widely overlooked. We simultaneously recorded electroencephalography (EEG), BOLD and cerebral blood-flow (CBF) [obtained from arterial spin labelled (ASL) fMRI] fMRI responses to hemifield checkerboard stimulation to test the potential neural origin of the fMRI post-stimulus undershoot...
June 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28602661/brain-arteriovenous-malformations-located-in-language-area-surgical-outcomes-and-risk-factors-for-postoperative-language-deficits
#10
Yuming Jiao, Fuxin Lin, Jun Wu, Hao Li, Xin Chen, Zhicen Li, Ji Ma, Yong Cao, Shuo Wang, Jizong Zhao
OBJECT: Case selection for surgical treatment of language area brain arteriovenous malformations (L-BAVMs) remains difficult. This study aimed to determine the surgical outcomes and risk factors for postoperative language deficits (LD) in patients with L-BAVMs. METHODS: Patients with L-BAVMs who underwent microsurgical resection between September 2012 and June 2016 were reviewed. All patients had undergone preoperative functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI)...
June 7, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28599964/resting-state-fmri-correlations-from-link-wise-unreliability-to-whole-brain-stability
#11
Mario Pannunzi, Rikkert Hindriks, Ruggero G Bettinardi, Elisabeth Wenger, Nina Lisofsky, Johan Martensson, Oisin Butler, Elisa Filevich, Maxi Becker, Martyna Lochstet, Simone Kühn, Gustavo Deco
The functional architecture of spontaneous BOLD fluctuations has been characterized in detail by numerous studies, demonstrating its potential relevance as a biomarker. However, the systematic investigation of its consistency is still in its infancy. Here, we analyze within- and between-subject variability and test-retest reliability of resting-state functional connectivity (FC) in a unique data set comprising multiple fMRI scans (42) from 5 subjects, and 50 single scans from 50 subjects. We adopt a statistical framework that enables us to identify different sources of variability in FC...
June 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28599147/integration-of-identity-and-emotion-information-in-faces-fmri-evidence
#12
Alla Yankouskaya, Moritz Stolte, Zargol Moradi, Pia Rotshtein, Glyn Humphreys
Separate neural systems have been implicated in the recognition of facial identity and emotional expression. A growing number of studies now provide evidence against this modular view by demonstrating that integration of identity and emotion information enhances face processing. Yet, the neural mechanisms that shape this integration remain largely unknown. We hypothesize that the presence of both personal and emotional expression target information triggers changes in functional connectivity between frontal and extrastriate areas in the brain...
August 2017: Brain and Cognition
https://www.readbyqxmd.com/read/28592696/visual-working-memory-enhances-the-neural-response-to-matching-visual-input
#13
Surya Gayet, Matthias Guggenmos, Thomas B Christophel, John-Dylan Haynes, Chris L E Paffen, Stefan Van der Stigchel, Philipp Sterzer
Visual working memory (VWM) is used to maintain visual information available for subsequent goal-directed behavior. The content of VWM has been shown to affect the behavioral response to concurrent visual input, suggesting that visual representations originating from VWM and from sensory input draw upon a shared neural substrate (i.e., a sensory recruitment stance on VWM storage). Here, we hypothesized that visual information maintained in VWM would enhance the neural response to concurrent visual input that matches the content of VWM...
June 7, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28588478/lower-activation-in-frontal-cortex-and-posterior-cingulate-cortex-observed-during-sex-determination-test-in-early-stage-dementia-of-the-alzheimer-type
#14
Ravi Rajmohan, Ronald C Anderson, Dan Fang, Austin G Meyer, Pavis Laengvejkal, Parunyou Julayanont, Greg Hannabas, Kitten Linton, John Culberson, Hafiz Khan, John De Toledo, P Hemachandra Reddy, Michael W O'Boyle
Face-labeling refers to the ability to classify faces into social categories. This plays a critical role in human interaction as it serves to define concepts of socially acceptable interpersonal behavior. The purpose of the current study was to characterize, what, if any, impairments in face-labeling are detectable in participants with early-stage clinically diagnosed dementia of the Alzheimer type (CDDAT) through the use of the sex determination test (SDT). In the current study, four (1 female, 3 males) CDDAT and nine (4 females, 5 males) age-matched neurotypicals (NT) completed the SDT using chimeric faces while undergoing BOLD fMRI...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28588363/blood-oxygenation-level-dependent-functional-mri-of-early-evidences-of-brain-plasticity-after-hemodialysis-session-by-helixone-membrane-of-patients-with-indices-of-adrenal-deficiency
#15
Saïd Boujraf, Rachida Belaïch, Abdelkhalek Housni, Mustapha Maaroufi, Siham Tizniti, Tarik Sqalli, Mohammed Benzagmout
BACKGROUND: Various alterations of hypothalamic-pituitary-adrenal axis function have been described in patients with chronic renal failure. Nevertheless, controversial evidences were stated about the association between adrenal function deficiency (AD) and hemodialysis (HD). PURPOSE: The goal of this paper was to estimate indirect indices of the adrenal gland dysfunction which is potentially influenced by oxidative stress (OS) that still generates brain plasticity and reorganization of the functional control...
May 2017: Annals of Neurosciences
https://www.readbyqxmd.com/read/28588065/the-hierarchical-cortical-organization-of-human-speech-processing
#16
Wendy A de Heer, Alexander G Huth, Thomas L Griffiths, Jack L Gallant, Frédéric E Theunissen
Speech comprehension requires that the brain extract semantic meaning from the spectral features represented at the cochlea. To investigate this process, we performed an fMRI experiment in which five men and two women passively listened to several hours of natural narrative speech. We then used voxel-wise modeling to predict BOLD responses based on three different feature spaces that represent the spectral, articulation, and semantic properties of speech. The amount of variance explained by each feature space was then assessed using a separate validation dataset...
June 6, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28582450/spontaneous-low-frequency-bold-signal-variations-from-resting-state-fmri-are-decreased-in-alzheimer-disease
#17
Samaneh Kazemifar, Kathryn Y Manning, Nagalingam Rajakumar, Francisco A Gómez, Andrea Soddu, Michael J Borrie, Ravi S Menon, Robert Bartha
Previous studies have demonstrated altered brain activity in Alzheimer's disease using task based functional MRI (fMRI), network based resting-state fMRI, and glucose metabolism from 18F fluorodeoxyglucose-PET (FDG-PET). Our goal was to define a novel indicator of neuronal activity based on a first-order textural feature of the resting state functional MRI (RS-fMRI) signal. Furthermore, we examined the association between this neuronal activity metric and glucose metabolism from 18F FDG-PET. We studied 15 normal elderly controls (NEC) and 15 probable Alzheimer disease (AD) subjects from the AD Neuroimaging Initiative...
2017: PloS One
https://www.readbyqxmd.com/read/28582399/effect-of-verbal-task-complexity-in-a-working-memory-paradigm-in-patients-with-type-1-diabetes-a-fmri-study
#18
Joan Guàrdia-Olmos, Geisa B Gallardo-Moreno, Esteve Gudayol-Ferré, Maribel Peró-Cebollero, Andrés A González-Garrido
Type 1 diabetes (T1D) is commonly diagnosed in childhood and adolescence, and the developing brain has to cope with its deleterious effects. Although brain adaptation to the disease may not result in evident cognitive dysfunction, the effects of T1D on neurodevelopment could alter the pattern of BOLD fMRI activation. The aim of this study was to explore the neural BOLD activation pattern in patients with T1D versus that of healthy matched controls while performing two visuospatial working memory tasks, which included a pair of assignments administered through a block design...
2017: PloS One
https://www.readbyqxmd.com/read/28580293/acupuncture-modulates-the-abnormal-brainstem-activity-in-migraine-without-aura-patients
#19
Zhengjie Li, Fang Zeng, Tao Yin, Lei Lan, Nikos Makris, Kristen Jorgenson, Taipin Guo, Feng Wu, Yujie Gao, Mingkai Dong, Mailan Liu, Jie Yang, Ying Li, Qiyong Gong, Fanrong Liang, Jian Kong
Migraine is a common neurological disease with a high prevalence and unsatisfactory treatment options. The specific pathophysiological mechanisms of migraine remain unclear, which restricts the development of effective treatments for this prevalent disorder. The aims of this study were to 1) compare the spontaneous brain activity differences between Migraine without Aura (MwoA) patients and healthy controls (HCs), using amplitude of low-frequency fluctuations (ALFF) calculation method, and 2) explore how an effective treatment (verum acupuncture) could modulate the ALFF of MwoA patients...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28579187/functional-mri-bold-response-in-sickle-mice-with-hyperalgesia
#20
Ying Wang, Xiao Wang, Wei Chen, Kalpna Gupta, Xiao-Hong Zhu
Patients with sickle cell anemia (SCA) have abnormal hemoglobin (sickle hemoglobin S) leading to the crystallization of hemoglobin chains in red blood cells (RBCs), which assume sickle shape and display reduced flexibility. Sickle RBCs (sRBCs) adhere to vessel walls and block blood flow, thus preventing oxygen delivery to the tissues leading to vaso-occlusive crises (VOC), acute pain and organ damage. SCA patients often have chronic pain that can be attributed to inflammation, vasculopathy, neuropathy, ischemia-reperfusion injury and organ damage...
June 2017: Blood Cells, Molecules & Diseases
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