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BOLD fMRI

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https://www.readbyqxmd.com/read/27911950/a-specialized-multi-transmit-head-coil-for-high-resolution-fmri-of-the-human-visual-cortex-at-7t
#1
Shubharthi Sengupta, Alard Roebroeck, Valentin G Kemper, Benedikt A Poser, Jan Zimmermann, Rainer Goebel, Gregor Adriany
PURPOSE: To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. METHODS: A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil...
2016: PloS One
https://www.readbyqxmd.com/read/27910126/gradient-echo-epi-using-a-high-degree-shim-insert-coil-at-7%C3%A2-t-implications-for-bold-fmri
#2
Tae Kim, Yoojin Lee, Tiejun Zhao, Hoby P Hetherington, Jullie W Pan
PURPOSE: To quantitatively assess the effects of high degree and order (1(st) -4(th+) ) relative to 1(st) -2(nd) degree B0 shimming at 7 Tesla (T) on gradient-echo echo planar imaging (GE-EPI) and blood-oxygen-level dependent (BOLD) activation. METHODS: Simulations and GE-EPI were performed at (2mm)(3) and (3mm)(3) resolution, evaluating the temporal signal-to-noise ratio (tSNR), transverse relaxivity ( R2*), BOLD % signal change and activated pixel counts in a breath-hold task...
December 1, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27908788/time-to-wake-up-studying-neurovascular-coupling-and-brain-wide-circuit-function-in-the-un-anesthetized-animal
#3
REVIEW
Yu-Rong Gao, Yuncong Ma, Qingguang Zhang, Aaron T Winder, Zhifeng Liang, Lilith Antinori, Patrick J Drew, Nanyin Zhang
Functional magnetic resonance imaging (fMRI) has allowed the noninvasive study of task-based and resting-state brain dynamics in humans by inferring neural activity from blood-oxygenation-level dependent (BOLD) signal changes. An accurate interpretation of the hemodynamic changes that underlie fMRI signals depends on the understanding of the quantitative relationship between changes in neural activity and changes in cerebral blood flow, oxygenation and volume. While there has been extensive study of neurovascular coupling in anesthetized animal models, anesthesia causes large disruptions of brain metabolism, neural responsiveness and cardiovascular function...
November 28, 2016: NeuroImage
https://www.readbyqxmd.com/read/27907094/continuous-descending-modulation-of-the-spinal-cord-revealed-by-functional-mri
#4
Patrick W Stroman, Rachael L Bosma, Andreea I Cotoi, Roxanne H Leung, Jennifer Kornelsen, Jane M Lawrence-Dewar, Caroline F Pukall, Roland Staud
Spontaneous variations in spinal cord activity may arise from regulation of any of a number of functions including sensory, motor, and autonomic control. Here, we use functional MRI (fMRI) of healthy participants to identify properties of blood oxygenation-level dependent (BOLD) variations in the spinal cord in response to knowledge that either a noxious stimulus is impending, or that no stimulus is to be expected. Expectation of a noxious stimulus, or no stimulus, is shown to have a significant effect on wide-spread BOLD signal variations in the spinal cord over the entire time period of the fMRI acquisition...
2016: PloS One
https://www.readbyqxmd.com/read/27903727/predicting-when-in-discourse-engages-the-human-dorsal-auditory-stream-an-fmri-study-using-naturalistic-stories
#5
Katerina Danae Kandylaki, Arne Nagels, Sarah Tune, Tilo Kircher, Richard Wiese, Matthias Schlesewsky, Ina Bornkessel-Schlesewsky
: The hierarchical organization of human cortical circuits integrates information across different timescales via temporal receptive windows, which increase in length from lower to higher levels of the cortical hierarchy (Hasson et al., 2015). A recent neurobiological model of higher-order language processing (Bornkessel-Schlesewsky et al., 2015) posits that temporal receptive windows in the dorsal auditory stream provide the basis for a hierarchically organized predictive coding architecture (Friston and Kiebel, 2009)...
November 30, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27902936/how-restful-is-it-with-all-that-noise-comparison-of-interleaved-silent-steady-state-isss-and-conventional-imaging-in-resting-state-fmri
#6
J Andoh, M Ferreira, I R Leppert, R Matsushita, B Pike, R J Zatorre
Resting-state fMRI studies have become very important in cognitive neuroscience because they are able to identify BOLD fluctuations in brain circuits involved in motor, cognitive, or perceptual processes without the use of an explicit task. Such approaches have been fruitful when applied to various disordered populations, or to children or the elderly. However, insufficient attention has been paid to the consequences of the loud acoustic scanner noise associated with conventional fMRI acquisition, which could be an important confounding factor affecting auditory and/or cognitive networks in resting-state fMRI...
November 27, 2016: NeuroImage
https://www.readbyqxmd.com/read/27900344/neurovascular-coupling-develops-alongside-neural-circuits-in-the-postnatal-brain
#7
COMMENT
Mariel G Kozberg, Elizabeth M C Hillman
In the adult brain, increases in local neural activity are accompanied by increases in regional blood flow. This relationship between neural activity and hemodynamics is termed neurovascular coupling and provides the blood flow-dependent contrast detected in functional magnetic resonance imaging (fMRI). Neurovascular coupling is commonly assumed to be consistent and reliable from birth; however, numerous studies have demonstrated markedly different hemodynamics in the early postnatal brain. Our recent study in J...
2016: Neurogenesis (Austin, Tex.)
https://www.readbyqxmd.com/read/27898705/the-role-of-the-amygdala-in-facial-trustworthiness-processing-a-systematic-review-and-meta-analyses-of-fmri-studies
#8
Sara Santos, Inês Almeida, Bárbara Oliveiros, Miguel Castelo-Branco
BACKGROUND: Faces play a key role in signaling social cues such as signals of trustworthiness. Although several studies identify the amygdala as a core brain region in social cognition, quantitative approaches evaluating its role are scarce. OBJECTIVES: This review aimed to assess the role of the amygdala in the processing of facial trustworthiness, by analyzing its amplitude BOLD response polarity to untrustworthy versus trustworthy facial signals under fMRI tasks through a Meta-analysis of effect sizes (MA)...
2016: PloS One
https://www.readbyqxmd.com/read/27898057/functional-brain-mapping-using-specific-sensory-circuit-stimulation-and-a-theoretical-graph-network-analysis-in-mice-with-neuropathic-allodynia
#9
Yuji Komaki, Keigo Hikishima, Shinsuke Shibata, Tsunehiko Konomi, Fumiko Seki, Masayuki Yamada, Naoyuki Miyasaka, Kanehiro Fujiyoshi, Hirotaka J Okano, Masaya Nakamura, Hideyuki Okano
Allodynia, a form of neuropathic pain, is defined as pain in response to a non-nociceptive stimulus. The brain regions responsible for pain, which are not normally activated, can be activated in allodynic mice by providing a suitable stimulus to Aβ-fibers, which transmit signals from tactile sensory fibers. Functional MRI (fMRI) can be used to objectively observe abnormal brain activation. In the present study, fMRI was conducted to investigate allodynia in mice; allodynia was generated by surgical injury at the L4 spinal nerve root, thus selectively stimulating sensory nerve fibers...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27897393/cancer-anorexia-hypothalamic-activity-and-its-association-with-inflammation-and-appetite-regulating-peptides-in-lung-cancer
#10
Alessio Molfino, Alessandro Iannace, Maria Chiara Colaiacomo, Alessio Farcomeni, Alessandra Emiliani, Gianfranco Gualdi, Alessandro Laviano, Filippo Rossi Fanelli
BACKGROUND: Energy homeostasis is mediated by the hypothalamus, whose inflammation-induced functional derangements contribute to the onset of anorexia in cancer. By using functional magnetic resonance imaging (fMRI), we determined the patterns of hypothalamic activation after oral intake in anorexic (A), non-anorexic (NA) cancer patients, and in controls (C). METHODS: Lung cancer patients were considered. Hypothalamic activation was recorded in A and NA patients and in C by fMRI, before (T0), immediately after (T1) the administration of an oral nutritional supplement, and after 15 min (T2)...
October 5, 2016: Journal of Cachexia, Sarcopenia and Muscle
https://www.readbyqxmd.com/read/27894892/longitudinal-functional-brain-imaging-study-in-early-course-schizophrenia-before-and-after-cognitive-enhancement-therapy
#11
Matcheri S Keshavan, Shaun M Eack, Konasale M Prasad, Chiara S Haller, Raymond Y Cho
OBJECTIVE: Schizophrenia is characterized by impaired -social and non social cognition both of which lead to functional deficits. These deficits may benefit from cognitive remediation, but the neural underpinnings of such improvements have not been clearly delineated. METHODS: We conducted a functional magnetic resonance (fMRI) study in early course schizophrenia patients randomly assigned to cognitive enhancement therapy (CET) or enriched supportive therapy (EST) and treated for two years...
November 25, 2016: NeuroImage
https://www.readbyqxmd.com/read/27893698/influence-of-acoustic-overstimulation-on-the-central-auditory-system-an-functional-magnetic-resonance-imaging-fmri-study
#12
Tomasz Wolak, Katarzyna Cieśla, Mateusz Rusiniak, Adam Piłka, Monika Lewandowska, Agnieszka Pluta, Henryk Skarżyński, Piotr H Skarżyński
BACKGROUND The goal of the fMRI experiment was to explore the involvement of central auditory structures in pathomechanisms of a behaviorally manifested auditory temporary threshold shift in humans. MATERIAL AND METHODS The material included 18 healthy volunteers with normal hearing. Subjects in the exposure group were presented with 15 min of binaural acoustic overstimulation of narrowband noise (3 kHz central frequency) at 95 dB(A). The control group was not exposed to noise but instead relaxed in silence...
November 28, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/27892484/environmental-factors-linked-to-depression-vulnerability-are-associated-with-altered-cerebellar-resting-state-synchronization
#13
Aldo Córdova-Palomera, Cristian Tornador, Carles Falcón, Nuria Bargalló, Paolo Brambilla, Benedicto Crespo-Facorro, Gustavo Deco, Lourdes Fañanás
Hosting nearly eighty percent of all human neurons, the cerebellum is functionally connected to large regions of the brain. Accumulating data suggest that some cerebellar resting-state alterations may constitute a key candidate mechanism for depressive psychopathology. While there is some evidence linking cerebellar function and depression, two topics remain largely unexplored. First, the genetic or environmental roots of this putative association have not been elicited. Secondly, while different mathematical representations of resting-state fMRI patterns can embed diverse information of relevance for health and disease, many of them have not been studied in detail regarding the cerebellum and depression...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27881788/brain-network-mechanisms-underlying-motor-enhancement-by-transcranial-entrainment-of-gamma-oscillations
#14
Marius Moisa, Rafael Polania, Marcus Grueschow, Christian C Ruff
: Gamma and beta oscillations are routinely observed in motor-related brain circuits during movement preparation and execution. Entrainment of gamma or beta oscillations via transcranial alternating current stimulation (tACS) over primary motor cortex (M1) has opposite effects on motor performance, suggesting a causal role of these brain rhythms for motor control. However, it is largely unknown which brain mechanisms characterize these changes in motor performance brought about by tACS...
November 23, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27881393/food-portion-size-and-energy-density-evoke-different-patterns-of-brain-activation-in-children
#15
Laural K English, S Nicole Fearnbach, Stephen J Wilson, Jennifer O Fisher, Jennifer S Savage, Barbara J Rolls, Kathleen L Keller
BACKGROUND: Large portions of food promote intake, but the mechanisms that drive this effect are unclear. Previous neuroimaging studies have identified the brain-reward and decision-making systems that are involved in the response to the energy density (ED) (kilocalories per gram) of foods, but few studies have examined the brain response to the food portion size (PS). OBJECTIVE: We used functional MRI (fMRI) to determine the brain response to food images that differed in PSs (large and small) and ED (high and low)...
November 23, 2016: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/27877115/insights-into-brain-architectures-from-the-homological-scaffolds-of-functional-connectivity-networks
#16
Louis-David Lord, Paul Expert, Henrique M Fernandes, Giovanni Petri, Tim J Van Hartevelt, Francesco Vaccarino, Gustavo Deco, Federico Turkheimer, Morten L Kringelbach
In recent years, the application of network analysis to neuroimaging data has provided useful insights about the brain's functional and structural organization in both health and disease. This has proven a significant paradigm shift from the study of individual brain regions in isolation. Graph-based models of the brain consist of vertices, which represent distinct brain areas, and edges which encode the presence (or absence) of a structural or functional relationship between each pair of vertices. By definition, any graph metric will be defined upon this dyadic representation of the brain activity...
2016: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/27876655/dorsal-root-ganglion-stimulation-attenuates-the-bold-signal-response-to-noxious-sensory-input-in-specific-brain-regions-insights-into-a-possible-mechanism-for-analgesia
#17
Christopher P Pawela, Jeffery M Kramer, Quinn H Hogan
Targeted dorsal root ganglion (DRG) electrical stimulation (i.e. ganglionic field stimulation - GFS) is an emerging therapeutic approach to alleviate chronic pain. Here we describe blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) responses to noxious hind-limb stimulation in a rat model that replicates clinical GFS using an electrode implanted adjacent to the DRG. Acute noxious sensory stimulation in the absence of GFS caused robust BOLD fMRI response in brain regions previously associated with sensory and pain-related response, such as primary/secondary somatosensory cortex, retrosplenial granular cortex, thalamus, caudate putamen, nucleus accumbens, globus pallidus, and amygdala...
November 19, 2016: NeuroImage
https://www.readbyqxmd.com/read/27870414/sex-differences-in-neural-responses-to-subliminal-sad-and-happy-faces-in-healthy-individuals-implications-for-depression
#18
Teresa A Victor, Wayne C Drevets, Masaya Misaki, Jerzy Bodurka, Jonathan Savitz
Twice as many women as men suffer from mood and anxiety disorders, yet the biological underpinnings of this phenomenon have been understudied and remain unclear. We and others have shown that the hemodynamic response to subliminally presented sad or happy faces during functional MRI (fMRI) is a robust biomarker for the attentional bias toward negative information classically observed in major depression. Here we used fMRI to compare the performance of healthy females (n = 28) and healthy males (n = 28) on a backward masking task using a fast event-related design with gradient-recalled, echoplanar imaging with sensitivity encoding...
January 2, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/27868422/correction-to-dennison-et-al-2016
#19
(no author information available yet)
Reports an error in "Neurobehavioral markers of resilience to depression amongst adolescents exposed to child abuse" by Meg J. Dennison, Margaret A. Sheridan, Daniel S. Busso, Jessica L. Jenness, Matthew Peverill, Maya L. Rosen and Katie A. McLaughlin (Journal of Abnormal Psychology, 2016[Nov], Vol 125[8], 1201-1212). In the original record, there was an error in the title. The word "Adolescents" was singular. The online version of this article has been corrected.(The following abstract of the original article appeared in record 2016-52992-014...
November 17, 2016: Journal of Abnormal Psychology
https://www.readbyqxmd.com/read/27867088/techniques-for-blood-volume-fmri-with-vaso-from-low-resolution-mapping-towards-sub-millimeter-layer-dependent-applications
#20
Laurentius Huber, Dimo Ivanov, Daniel A Handwerker, Sean Marrett, Maria Guidi, Kâmil Uludağ, Peter A Bandettini, Benedikt A Poser
Quantitative cerebral blood volume (CBV) fMRI has the potential to overcome several specific limitations of BOLD fMRI. It provides direct physiological interpretability and promises superior localization specificity in applications of sub-millimeter resolution fMRI applications at ultra-high magnetic fields (7T and higher). Non-invasive CBV fMRI using VASO (vascular space occupancy), however, is inherently limited with respect to its data acquisition efficiency, restricting its imaging coverage and achievable spatial and temporal resolution...
November 17, 2016: NeuroImage
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