scholarly journals Reproducibility of swallow-induced cortical BOLD positive and negative fMRI activity

2012 ◽  
Vol 303 (5) ◽  
pp. G600-G609 ◽  
Author(s):  
Arash Babaei ◽  
B. Douglas Ward ◽  
Shahryar Ahmad ◽  
Anna Patel ◽  
Andrew Nencka ◽  
...  
Keyword(s):  
Multilevel Model ◽  
Cross Correlation ◽  
Group Analysis ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Blood Oxygen Level ◽  
Signal Change ◽  
Cortical Regions ◽  
Negative Bold ◽  
Task Positive Network

Functional MRI (fMRI) studies have demonstrated that a number of brain regions (cingulate, insula, prefrontal, and sensory/motor cortices) display blood oxygen level-dependent (BOLD) positive activity during swallow. Negative BOLD activations and reproducibility of these activations have not been systematically studied. The aim of our study was to investigate the reproducibility of swallow-related cortical positive and negative BOLD activity across different fMRI sessions. We studied 16 healthy volunteers utilizing an fMRI event-related analysis. Individual analysis using a general linear model was used to remove undesirable signal changes correlated with motion, white matter, and cerebrospinal fluid. The group analysis used a mixed-effects multilevel model to identify active cortical regions. The volume and magnitude of a BOLD signal within each cluster was compared between the two study sessions. All subjects showed significant clustered BOLD activity within the known areas of cortical swallowing network across both sessions. The cross-correlation coefficient of percent fMRI signal change and the number of activated voxels across both positive and negative BOLD networks were similar between the two studies ( r ≥ 0.87, P < 0.0001). Swallow-associated negative BOLD activity was comparable to the well-defined “default-mode” network, and positive BOLD activity had noticeable overlap with the previously described “task-positive” network. Swallow activates two parallel cortical networks. These include a positive and a negative BOLD network, respectively, correlated and anticorrelated with swallow stimulus. Group cortical activity maps, as well as extent and amplitude of activity induced by volitional swallowing in the cortical swallowing network, are reproducible between study sessions.

Modulation of cortical and subcortical brain areas at low and high exercise intensities

2019 ◽  
Vol 54 (2) ◽  
pp. 110-115 ◽  
Author(s):  
Eduardo Bodnariuc Fontes ◽  
Henrique Bortolotti ◽  
Kell Grandjean da Costa ◽  
Brunno Machado de Campos ◽  
Gabriela K Castanho ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Insular Cortex ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
Exercise Protocol ◽  
Brain Areas ◽  
Subcortical Brain ◽  
Negative Bold

IntroductionThe brain plays a key role in the perceptual regulation of exercise, yet neuroimaging techniques have only demonstrated superficial brain areas responses during exercise, and little is known about the modulation of the deeper brain areas at different intensities.Objectives/methodsUsing a specially designed functional MRI (fMRI) cycling ergometer, we have determined the sequence in which the cortical and subcortical brain regions are modulated at low and high ratings perceived exertion (RPE) during an incremental exercise protocol.ResultsAdditional to the activation of the classical motor control regions (motor, somatosensory, premotor and supplementary motor cortices and cerebellum), we found the activation of the regions associated with autonomic regulation (ie, insular cortex) (ie, positive blood-oxygen-level-dependent (BOLD) signal) during exercise. Also, we showed reduced activation (negative BOLD signal) of cognitive-related areas (prefrontal cortex), an effect that increased during exercise at a higher perceived intensity (RPE 13–17 on Borg Scale). The motor cortex remained active throughout the exercise protocol whereas the cerebellum was activated only at low intensity (RPE 6–12), not at high intensity (RPE 13–17).ConclusionsThese findings describe the sequence in which different brain areas become activated or deactivated during exercise of increasing intensity, including subcortical areas measured with fMRI analysis.

scholarly journals Key Aspects of Neurovascular Control Mediated by Specific Populations of Inhibitory Cortical Interneurons

2019 ◽  
Vol 30 (4) ◽  
pp. 2452-2464 ◽  
Author(s):  
L Lee ◽  
L Boorman ◽  
E Glendenning ◽  
C Christmas ◽  
P Sharp ◽  
...  
Keyword(s):  
Blood Volume ◽  
Neural Activity ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Cortical Inhibition ◽  
Blood Oxygen Level ◽  
Hemodynamic Changes ◽  
Cortical Interneurons ◽  
Negative Bold ◽  
Key Aspects

Abstract Inhibitory interneurons can evoke vasodilation and vasoconstriction, making them potential cellular drivers of neurovascular coupling. However, the specific regulatory roles played by particular interneuron subpopulations remain unclear. Our purpose was therefore to adopt a cell-specific optogenetic approach to investigate how somatostatin (SST) and neuronal nitric oxide synthase (nNOS)-expressing interneurons might influence the neurovascular relationship. In mice, specific activation of SST- or nNOS-interneurons was sufficient to evoke hemodynamic changes. In the case of nNOS-interneurons, robust hemodynamic changes occurred with minimal changes in neural activity, suggesting that the ability of blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) to reliably reflect changes in neuronal activity may be dependent on type of neuron recruited. Conversely, activation of SST-interneurons produced robust changes in evoked neural activity with shallow cortical excitation and pronounced deep layer cortical inhibition. Prolonged activation of SST-interneurons often resulted in an increase in blood volume in the centrally activated area with an accompanying decrease in blood volume in the surrounding brain regions, analogous to the negative BOLD signal. These results demonstrate the role of specific populations of cortical interneurons in the active control of neurovascular function.

scholarly journals Brain reactivity using fMRI to insomnia stimuli in insomnia patients with discrepancy between subjective and objective sleep

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young-Bo Kim ◽  
Nambeom Kim ◽  
Jae Jun Lee ◽  
Seo-Eun Cho ◽  
Kyoung-Sae Na ◽  
...  
Keyword(s):  
Brain Activity ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Cognitive Distortion ◽  
Sleep Diary ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
General Anxiety ◽  
Sleep Deficit ◽  
Perception Of Sleep

AbstractSubjective–objective discrepancy of sleep (SODS) might be related to the distorted perception of sleep deficit and hypersensitivity to insomnia-related stimuli. We investigated differences in brain activation to insomnia-related stimuli among insomnia patients with SODS (SODS group), insomnia patients without SODS (NOSODS group), and healthy controls (HC). Participants were evaluated for subjective and objective sleep using sleep diary and polysomnography. Functional magnetic resonance imaging was conducted during the presentation of insomnia-related (Ins), general anxiety-inducing (Gen), and neutral (Neu) stimuli. Brain reactivity to the contrast of Ins vs. Neu and Gen vs. Neu was compared among the SODS (n = 13), NOSODS (n = 15), and HC (n = 16) groups. In the SODS group compared to other groups, brain areas including the left fusiform, bilateral precuneus, right superior frontal gyrus, genu of corpus callosum, and bilateral anterior corona radiata showed significantly increased blood oxygen level dependent (BOLD) signal in the contrast of Ins vs. Neu. There was no brain region with significantly increased BOLD signal in the Gen vs. Neu contrast in the group comparisons. Increased brain activity to insomnia-related stimuli in several brain regions of the SODS group is likely due to these individuals being more sensitive to sleep-related threat and negative cognitive distortion toward insomnia.

Equal Degrees of Object Selectivity for Upper and Lower Visual Field Stimuli

2010 ◽  
Vol 104 (4) ◽  
pp. 2075-2081 ◽  
Author(s):  
Lars Strother ◽  
Adrian Aldcroft ◽  
Cheryl Lavell ◽  
Tutis Vilis
Keyword(s):  
Visual Field ◽  
Occipital Cortex ◽  
Recognition System ◽  
Blood Oxygen Level Dependent ◽  
Lower Visual Field ◽  
Blood Oxygen Level ◽  
Visual Areas ◽  
Bold Responses ◽  
Cortical Regions ◽  
Lateral Occipital Cortex

Functional MRI (fMRI) studies of the human object recognition system commonly identify object-selective cortical regions by comparing blood oxygen level–dependent (BOLD) responses to objects versus those to scrambled objects. Object selectivity distinguishes human lateral occipital cortex (LO) from earlier visual areas. Recent studies suggest that, in addition to being object selective, LO is retinotopically organized; LO represents both object and location information. Although LO responses to objects have been shown to depend on location, it is not known whether responses to scrambled objects vary similarly. This is important because it would suggest that the degree of object selectivity in LO does not vary with retinal stimulus position. We used a conventional functional localizer to identify human visual area LO by comparing BOLD responses to objects versus scrambled objects presented to either the upper (UVF) or lower (LVF) visual field. In agreement with recent findings, we found evidence of position-dependent responses to objects. However, we observed the same degree of position dependence for scrambled objects and thus object selectivity did not differ for UVF and LVF stimuli. We conclude that, in terms of BOLD response, LO discriminates objects from non-objects equally well in either visual field location, despite stronger responses to objects in the LVF.

The Relationship of Three Cortical Regions to an Information-Processing Model

2004 ◽  
Vol 16 (4) ◽  
pp. 637-653 ◽  
Author(s):  
John R. Anderson ◽  
Yulin Qin ◽  
V. Andrew Stenger ◽  
Cameron S. Carter
Keyword(s):  
Region Of Interest ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen Level ◽  
Information Processing Model ◽  
Response Hand ◽  
Equation Solving ◽  
Fmri Study ◽  
Cortical Regions ◽  
Relationship Of

This research tests a model of the computational role of three cortical regions in tasks like algebra equation solving. The model assumes that there is a left parietal region-of-interest (ROI) where the problem expression is represented and transformed, a left prefrontal ROI where information for solving the task is retrieved, and a motor ROI where hand movements to produce the answer are programmed. A functional magnetic resonance imaging (fMRI) study of an abstract symbolmanipulation task was performed to articulate the roles of these three regions. Participants learned to associate words with instructions for transforming strings of letters. The study manipulated the need to retrieve these instructions, the need to transform the strings, and whether there was a delay between calculation of the answer and the output of the answer. As predicted, the left parietal ROI mainly reflected the need for a transformation and the left prefrontal ROI the need for retrieval. Homologous right ROIs showed similar but weaker responses. Neither the prefrontal nor the parietal ROIs responded to delay, but the motor ROI did respond to delay, implying motor rehearsal over the delay. Except for the motor ROI, these patterns of activity did not vary with response hand. In an ACT-R model, it was shown that the activity of an imaginal buffer predicted the blood oxygen level-dependent (BOLD) response of the parietal ROI, the activity of a retrieval buffer predicted the response of the prefrontal ROI, and the activity of a manual buffer predicted the response of the motor ROI.

scholarly journals Functional magnetic resonance imaging evaluation of lumbosacral radiculopathic pain

2016 ◽  
Vol 25 (4) ◽  
pp. 517-522
Author(s):  
Alex J. Koefman ◽  
Melissa Licari ◽  
Michael Bynevelt ◽  
Christopher R. P. Lind
Keyword(s):  
Objective Assessment ◽  
Blood Oxygen Level Dependent ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
Imaging Evaluation ◽  
Pain Experience ◽  
Lumbosacral Radiculopathy ◽  
Signal Change ◽  
Left Parietal Cortex ◽  
Straight Leg Raise

OBJECTIVE An objective biomarker for pain is yet to be established. Functional MRI (fMRI) is a promising neuroimaging technique that may reveal an objective radiological biomarker. The purpose of this study was to evaluate fMRI technology in the setting of lumbosacral radiculopathy and discuss its application in revealing a biomarker for pain in the future. METHODS A prospective, within-participant control study was conducted. Twenty participants with painful lumbosacral radiculopathy from intervertebral disc pathology were recruited. Functional imaging of the brain was performed during a randomly generated series of nonprovocative and provocative straight leg raise maneuvers. RESULTS With a statistical threshold set at p < 0.000001, 3 areas showed significant blood oxygen level–dependent (BOLD) signal change: right superior frontal gyrus (x = 2, y = 13, z = 48, k = 29, Brodmann area 6 [BA6]), left supramarginal cortex (x = −37, y = −44, z = 33, k = 1084, BA40), and left parietal cortex (x = −19, y = −41, z = 63, k = 354, BA5). With a statistical threshold set at p < 0.0002, 2 structures showed significant BOLD signal change: right putamen (x = 29, y = −11, z = 6, k = 72) and bilateral thalami (right: x = 23, y = −11, z = 21, k = 29; x = 8, y = −11, z = 9, k = 274; and left: x = −28, y = −32, z = 6, k = 21). CONCLUSIONS The results in this study compare with those in previous studies and suggest that fMRI technology can provide an objective assessment of the pain experience.

scholarly journals Slowed Temporal and Parietal Cerebrovascular Response in Patients with Alzheimer’s Disease

2020 ◽  
Vol 47 (3) ◽  
pp. 366-373
Author(s):  
Kenneth R. Holmes ◽  
David Tang-Wai ◽  
Kevin Sam ◽  
Larissa McKetton ◽  
Julien Poublanc ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vascular Dysfunction ◽  
Intermediate Stage ◽  
Blood Oxygen Level Dependent ◽  
Cerebrovascular Reactivity ◽  
Blood Oxygen Level ◽  
Cerebrovascular Function ◽  
Anatomical Images ◽  
Cortical Regions

ABSTRACT:Background:Recent investigations now suggest that cerebrovascular reactivity (CVR) is impaired in Alzheimer’s disease (AD) and may underpin part of the disease’s neurovascular component. However, our understanding of the relationship between the magnitude of CVR, the speed of cerebrovascular response, and the progression of AD is still limited. This is especially true in patients with mild cognitive impairment (MCI), which is recognized as an intermediate stage between normal aging and dementia. The purpose of this study was to investigate AD and MCI patients by mapping repeatable and accurate measures of cerebrovascular function, namely the magnitude and speed of cerebrovascular response (τ) to a vasoactive stimulus in key predilection sites for vascular dysfunction in AD.Methods:Thirty-three subjects (age range: 52–83 years, 20 males) were prospectively recruited. CVR and τ were assessed using blood oxygen level-dependent MRI during a standardized carbon dioxide stimulus. Temporal and parietal cortical regions of interest (ROIs) were generated from anatomical images using the FreeSurfer image analysis suite.Results:Of 33 subjects recruited, 3 individuals were excluded, leaving 30 subjects for analysis, consisting of 6 individuals with early AD, 11 individuals with MCI, and 13 older healthy controls (HCs). τ was found to be significantly higher in the AD group compared to the HC group in both the temporal (p = 0.03) and parietal cortex (p = 0.01) following a one-way ANCOVA correcting for age and microangiopathy scoring and a Bonferroni post-hoc correction.Conclusion:The study findings suggest that AD is associated with a slowing of the cerebrovascular response in the temporal and parietal cortices.

Effective Connectivity During an Avoidance-Based Pavlovian-to-Instrumental Transfer Task

2021 ◽  
Author(s):  
Daniel Petrie ◽  
Sy-Miin Chow ◽  
Charles Geier
Keyword(s):  
Effective Connectivity ◽  
A Priori ◽  
Transfer Task ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Response Patterns ◽  
Multiple Model ◽  
Hemodynamic Response Function ◽  
Blood Oxygen Level ◽  
Psychological Phenomena

Pavlovian-to-instrumental transfer (PIT) refers to a phenomenon whereby a classically conditioned stimulus (CS) impacts the motivational salience of instrumental behavior. We examined behavioral response patterns and functional magnetic resonance imaging (fMRI) based effective connectivity during an avoidance-based PIT task. Eleven participants (8 females; Mage = 28.2, SD = 2.8, range = 25-32 years) completed the task. Effective connectivity between a priori brain regions engaged during the task was determined using hemodynamic response function group iterative multiple model estimation (HRF-GIMME). Behaviorally, participants exhibited specific PIT, a CS previously associated with a reinforcing outcome increased instrumental responding directed at the same outcome. We did not find evidence for general PIT; a CS did not significantly increase instrumental responding towards a different but related outcome. Using HRF-GIMME, we recovered effective connectivity maps among corticostriatal circuits engaged during the task. Group-level paths revealed directional effects from left putamen to right insula and from right putamen to right cingulate. Importantly, a direct effect of specific PIT stimuli on blood-oxygen-level-dependent (BOLD) activity in the left putamen was found. Results provide initial evidence of effective connectivity in key brain regions in an avoidance-based PIT task network. This study adds to the literature studying PIT effects in humans and employing GIMME models to understand how psychological phenomena are supported in the brain.

scholarly journals A Theoretical Investigation of the Relationship between Structural Equation Modeling and Partial Correlation in Functional MRI Effective Connectivity

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Guillaume Marrelec ◽  
Habib Benali
Keyword(s):  
Structural Equation Modeling ◽  
Structural Equation ◽  
Partial Correlation ◽  
Effective Connectivity ◽  
Real Data ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Equation Modeling ◽  
Blood Oxygen Level ◽  
Partial Correlations

An important field of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) is the investigation of effective connectivity, that is, the actions that a given set of regions exert on one another. We recently proposed a data-driven method based on the partial correlation matrix that could provide some insight regarding the pattern of functional interaction between brain regions as represented by structural equation modeling (SEM). So far, the efficiency of this approach was mostly based on empirical evidence. In this paper, we provide theoretical fundaments explaining why and in what measure structural equation modeling and partial correlations are related. This gives better insight regarding what parts of SEM can be retrieved by partial correlation analysis and what remains inaccessible. We illustrate the different results with real data.

scholarly journals Quantitative relations between BOLD responses, cortical energetics, and impulse firing

2018 ◽  
Vol 119 (3) ◽  
pp. 979-989 ◽  
Author(s):  
M. R. Bennett ◽  
L. Farnell ◽  
W. G. Gibson
Keyword(s):  
Neural Activity ◽  
Blood Oxygen Level Dependent ◽  
Bold Signal ◽  
Neural Firing ◽  
Functional Magnetic Resonance ◽  
Blood Oxygen Level ◽  
Baseline Activity ◽  
Bold Responses ◽  
Negative Bold ◽  
Quantitative Account

The blood oxygen level-dependent (BOLD) functional magnetic resonance imaging signal arises as a consequence of changes in blood flow and oxygen usage that in turn are modulated by changes in neural activity. Much attention has been given to both theoretical and experimental aspects of the energetics but not to the neural activity. Here we identify the best energetic theory for the steady-state BOLD signal on the basis of correct predictions of experimental observations. This theory is then used, together with the recently determined relationship between energetics and neural activity, to predict how the BOLD signal changes with activity. Unlike existing treatments, this new theory incorporates a nonzero baseline activity in a completely consistent way and is thus able to account for both sustained positive and negative BOLD signals. We also show that the increase in BOLD signal for a given increase in activity is significantly smaller the larger the baseline activity, as is experimentally observed. Furthermore, the decline of the positive BOLD signal arising from deeper cortical laminae in response to an increase in neural firing is shown to arise as a consequence of the larger baseline activity in deeper laminae. Finally, we provide quantitative relations integrating BOLD responses, energetics, and impulse firing, which among other predictions give the same results as existing theories when the baseline activity is zero. NEW & NOTEWORTHY We use a recently established relation between energetics and neural activity to give a quantitative account of BOLD dependence on neural activity. The incorporation of a nonzero baseline neural activity accounts for positive and negative BOLD signals, shows that changes in neural activity give BOLD changes that are smaller the larger the baseline, and provides a basis for the observed inverse relation between BOLD responses and the depth of cortical laminae giving rise to them.

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