Partly Separated Activations in the Spatial Distribution betweende-qiand Sharp Pain during Acupuncture Stimulation: An fMRI-Based Study

Nowadays, functional magnetic resonance imaging (fMRI) has become one of the most important ways to explore the central mechanism of acupuncture. Among these studies, activations around the somatosensory-related brain network had the most robust blood oxygen level-dependent (BOLD) responses. However, due to the insufficient control of the subjective sensations during acupuncture stimulation, whether these robust activations reflected the pattern ofde-qi, sharp pain, ormixed(de-qi+ sharp pain) sensations was largely unknown. The current study recruited 50 subjects and grouped them into two groups according to whether he/she experienced sharp pain during acupuncture stimulation to give a definite answer to the aforesaid question. Our results indicated that BOLD responses associated withde-qiduring acupuncture stimulation at ST36 were activation dominated. Furthermore, both the quantitative and qualitative differences of BOLD responses betweende-qiand mixed sensations evoked by acupuncture stimulation were significant. The pattern of BOLD responses of sharp pain might be partly separated from that ofde-qiin the spatial distribution. Therefore, we proposed that in order to explore the specific central mechanism of acupuncture, subjects with sharp pain should be excluded from those with onlyde-qi.

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Impact of Global Normalization in fMRI Acupuncture Studies

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2012/467061 ◽

2012 ◽

Vol 2012 ◽

pp. 1-22 ◽

Cited By ~ 7

Author(s):

Jinbo Sun ◽

Wei Qin ◽

Lingmin Jin ◽

Minghao Dong ◽

Xuejuan Yang ◽

...

Keyword(s):

Healthy Subjects ◽

Statistical Power ◽

Tactile Stimulation ◽

Brain Network ◽

Scaling Model ◽

Acupuncture Stimulation ◽

Bold Responses ◽

De Qi ◽

Statistical Results

Global normalization is often used as a preprocessing step for dispelling the “nuisance effects.” However, it has been shown in cognitive and emotion tasks that this preprocessing step might greatly distort statistical results when the orthogonality assumption of global normalization is violated. The present study examines this issue in fMRI acupuncture studies. Thirty healthy subjects were recruited to evaluate the impacts of the global normalization on the BOLD responses evoked by acupuncture stimulation duringDe-qisensation and tactile stimulation during nonpainful sensations. To this end, we compared results by conducting global normalization (PSGS) and not conducting global normalization (NO PSGS) based on a proportional scaling model. The orthogonality assumption of global normalization was violated, and significant changes between BOLD responses for NO PSGS and PSGS were shown in most subjects. Extensive deactivations of acupuncture in fMRI were the non-specifically pernicious consequences of global normalization. The central responses of acupuncture duringDe-qiare non-specifically activation-dominant at the somatosensory-related brain network, whose statistical power is specifically enhanced by PSGS. In conclusion, PSGS should be unjustified for acupuncture studies in fMRI. The differences including the global normalization or not may partly contribute to conflicting results and interpretations in previous fMRI acupuncture studies.

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

Journal of Neurophysiology ◽

10.1152/jn.00462.2010 ◽

2010 ◽

Vol 104 (4) ◽

pp. 2075-2081 ◽

Cited By ~ 16

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.

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Advanced Meditation Alters Resting-State Brain Network Connectivity Correlating With Improved Mindfulness

Frontiers in Psychology ◽

10.3389/fpsyg.2021.745344 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ramana V. Vishnubhotla ◽

Rupa Radhakrishnan ◽

Kestas Kveraga ◽

Rachael Deardorff ◽

Chithra Ram ◽

...

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Network Connectivity ◽

Blood Oxygen Level Dependent ◽

Brain Network ◽

Resting State Functional Connectivity ◽

Blood Oxygen Level ◽

Default Mode ◽

Before And After ◽

Brain Network Connectivity

Purpose: The purpose of this study was to investigate the effect of an intensive 8-day Samyama meditation program on the brain functional connectivity using resting-state functional MRI (rs-fMRI).Methods: Thirteen Samyama program participants (meditators) and 4 controls underwent fMRI brain scans before and after the 8-day residential meditation program. Subjects underwent fMRI with a blood oxygen level dependent (BOLD) contrast at rest and during focused breathing. Changes in network connectivity before and after Samyama program were evaluated. In addition, validated psychological metrics were correlated with changes in functional connectivity.Results: Meditators showed significantly increased network connectivity between the salience network (SN) and default mode network (DMN) after the Samyama program (p < 0.01). Increased connectivity within the SN correlated with an improvement in self-reported mindfulness scores (p < 0.01).Conclusion: Samyama, an intensive silent meditation program, favorably increased the resting-state functional connectivity between the salience and default mode networks. During focused breath watching, meditators had lower intra-network connectivity in specific networks. Furthermore, increased intra-network connectivity correlated with improved self-reported mindfulness after Samyama.Clinical Trials Registration: [https://clinicaltrials.gov], Identifier: [NCT04366544]. Registered on 4/17/2020.

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Low Frequency Stimulation of the Perforant Pathway Generates Anesthesia-Specific Variations in Neural Activity and BOLD Responses in the Rat Dentate Gyrus

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2011.126 ◽

2011 ◽

Vol 32 (2) ◽

pp. 291-305 ◽

Cited By ~ 12

Author(s):

Karla Krautwald ◽

Frank Angenstein

Keyword(s):

Dentate Gyrus ◽

Stimulus Frequency ◽

Low Frequency ◽

Blood Oxygen Level Dependent ◽

Bold Response ◽

Blood Oxygen Level ◽

Perforant Pathway ◽

Bold Responses ◽

Dependent Signal ◽

Frequency Stimulation

To study how various anesthetics affect the relationship between stimulus frequency and generated functional magnetic resonance imaging (fMRI) signals in the rat dentate gyrus, the perforant pathway was electrically stimulated with repetitive low frequency (i.e., 0.625, 1.25, 2.5, 5, and 10 Hz) stimulation trains under isoflurane/N2O, isoflurane, medetomidine, and α-chloralose. During stimulation, the blood oxygen level-dependent signal intensity (BOLD response) and local field potentials in the dentate gyrus were simultaneously recorded to prove whether the present anesthetic controls the generation of a BOLD response via targeting general hemodynamic parameters, by affecting mechanisms of neurovascular coupling, or by disrupting local signal processing. Using this combined electrophysiological/fMRI approach, we found that the threshold frequency (i.e., the minimal frequency required to trigger significant BOLD responses), the optimal frequency (i.e., the frequency that elicit the strongest BOLD response), and the spatial distribution of generated BOLD responses are specific for each anesthetic used. Concurrent with anesthetic-dependent characteristics of the BOLD response, we found the pattern of stimulus-induced neuronal activity in the dentate gyrus is also specific for each anesthetic. Consequently, the anesthetic-specific influence on local signaling processes is the underlying cause for the observation that an identical stimulus elicits different BOLD responses under various anesthetics.

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Inefficient cerebral recruitment as a vulnerability marker for schizophrenia

Psychological Medicine ◽

10.1017/s0033291712000992 ◽

2012 ◽

Vol 43 (1) ◽

pp. 169-182 ◽

Cited By ~ 11

Author(s):

E. B. Liddle ◽

A. T. Bates ◽

D. Das ◽

T. P. White ◽

M. J. Groom ◽

...

Keyword(s):

Frontal Cortex ◽

Reaction Times ◽

Blood Oxygen Level Dependent ◽

Medial Frontal Cortex ◽

Auditory Target ◽

Neural Activation ◽

Healthy Controls ◽

Blood Oxygen Level ◽

Brain Areas ◽

Bold Responses

BackgroundPatients with schizophrenia and their first-degree relatives exhibit both abnormally diminished and increased neural activation during cognitive tasks. In particular, excessive task-related activity is often observed when tasks are easy, suggesting that inefficient cerebral recruitment may be a marker of vulnerability for schizophrenia. This hypothesis might best be tested using a very easy task, thus avoiding confounding by individual differences in task difficulty.MethodEighteen people with schizophrenia, 18 unaffected full siblings of patients with schizophrenia and 26 healthy controls performed an easy auditory target-detection task in a 3-T magnetic resonance imaging (MRI) scanner. Groups were matched for accuracy on the task. Blood oxygen level-dependent (BOLD) responses to non-target stimuli in participants with vulnerability for schizophrenia (siblings and patients) were compared with those of healthy controls, and those of patients with those of unaffected siblings. BOLD responses to targets were compared with baseline, across groups.ResultsSubjects with vulnerability for schizophrenia showed significant hyperactivation to non-targets in brain areas activated by targets in all groups, in addition to reduced deactivation to non-targets in areas suppressed by targets in all groups. Siblings showed greater activation than patients to non-targets in the medial frontal cortex. Patients exhibited significantly longer reaction times (RTs) than unaffected siblings and healthy controls.ConclusionsInefficient cerebral recruitment is a vulnerability marker for schizophrenia, marked by reduced suppression of brain areas normally deactivated in response to task stimuli, and increased activation of areas normally activated in response to task stimuli. Moreover, siblings show additional activation in the medial frontal cortex that may be protective.

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

Journal of Neurophysiology ◽

10.1152/jn.00352.2017 ◽

2018 ◽

Vol 119 (3) ◽

pp. 979-989 ◽

Cited By ~ 2

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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Cortical Depth-Dependent Modeling of Visual Hemodynamic Responses

10.1101/2020.03.16.993154 ◽

2020 ◽

Author(s):

T.C. Lacy ◽

P.A. Robinson ◽

K.M. Aquino ◽

J.C. Pang

Keyword(s):

3D Model ◽

Three Dimensional ◽

Blood Oxygen Level Dependent ◽

Flow Dynamics ◽

Model Parameters ◽

Blood Oxygen ◽

Blood Oxygen Level ◽

Bold Responses ◽

Hemodynamic Model ◽

Blood Flow Dynamics

AbstractA physiologically based three-dimensional (3D) hemodynamic model is used to predict the experimentally observed blood oxygen level dependent (BOLD) responses versus the cortical depth induced by visual stimuli. Prior 2D approximations are relaxed in order to analyze 3D blood flow dynamics as a function of cortical depth. Comparison of the predictions with experimental data for typical stimuli demonstrates that the full 3D model matches at least as well as previous approaches while requiring significantly fewer assumptions and model parameters.

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What Is thede-qi-Related Pattern of BOLD Responses? A Review of Acupuncture Studies in fMRI

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/297839 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

Jinbo Sun ◽

Yuanqiang Zhu ◽

Yang Yang ◽

Lingmin Jin ◽

Karen M. von Deneen ◽

...

Keyword(s):

Neural Correlates ◽

Blood Oxygenation ◽

Therapeutic Effects ◽

Response Patterns ◽

Pain Stimulation ◽

Sharp Pain ◽

Grouping Strategy ◽

Bold Responses ◽

Oxygenation Level ◽

De Qi

de-qi, comprising mostly subjective sensations during acupuncture, is traditionally considered as a very important component for the possible therapeutic effects of acupuncture. However, the neural correlates ofde-qiare still unclear. In this paper, we reviewed previous fMRI studies from the viewpoint of the neural responses ofde-qi. We searched on Pubmed and identified 111 papers. Fourteen studies distinguishingde-qiand sharp pain and eight studies with the mixed sensations were included in further discussions. We found that the blood oxygenation level-dependent (BOLD) responses associated withde-qiwere activation dominated, mainly around cortical areas relevant to the processing of somatosensory or pain signals. More intense and extensive activations were shown for the mixed sensations. Specific activations of sharp pain were also shown. Similar BOLD response patterns betweende-qievoked by acupuncture stimulation andde-qi-like sensations evoked by deep pain stimulation were shown. We reckon that a standardized method of qualification and quantification ofde-qi, deeper understanding of grouping strategy ofde-qiand sharp pain, and making deep pain stimulation as a control, as well as a series of improvements in the statistical method, are crucial factors for revealing the neural correlates ofde-qiand neural mechanisms of acupuncture.

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Identification of Cerebral Networks by Classification of the Shape of BOLD Responses

Journal of Neurophysiology ◽

10.1152/jn.01040.2002 ◽

2003 ◽

Vol 90 (1) ◽

pp. 360-371 ◽

Cited By ~ 13

Author(s):

Giovanni d'Avossa ◽

Gordon L. Shulman ◽

Maurizio Corbetta

Keyword(s):

Formal Analysis ◽

Blood Oxygen Level Dependent ◽

Bold Response ◽

Blood Oxygen Level ◽

Match To Sample ◽

Sustained Activity ◽

Bold Responses ◽

Transient Activity ◽

Posterior Parietal ◽

Time Courses

Changes in regional blood oxygen level dependent (BOLD) signals in response to brief visual stimuli can exhibit a variety of time-courses. To demonstrate the anatomical distribution of BOLD response shapes during a match to sample task, a formal analysis of their time-courses is presented. An event-related design was used to estimate regional BOLD responses evoked by a cue word, which instructed the subject to attend to the motion or color of an upcoming target, and those evoked by a briefly presented moving target consisting of colored dots. Regional BOLD time-courses were adequately represented by the linear combination of three orthogonal waveforms. BOLD response shapes were then classified using a fuzzy clustering scheme. Three classes (sustained, phasic, and negative) best characterized cue responses. Four classes (sustained, sustained-phasic, phasic, and bi-phasic) best characterized target responses. In certain regions, the shape of the BOLD responses was modulated by the instruction to attend to the target's motion or color. A left frontal and a posterior parietal region showed sustained activity when motion was cued and transient activity when color was cued. A right thalamic and a left lateral occipital region showed sustained activity when color was cued and transient activity when motion was cued. Following the target several regions showed more sustained activity during motion than color trials. In summary, the effect of the task variable was focal following the cue and widespread following the target. We conclude that the temporal patterns of neural activity affected the shape of the BOLD signal.

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How instructed knowledge modulates the neural systems of reward learning

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1014938108 ◽

2010 ◽

Vol 108 (1) ◽

pp. 55-60 ◽

Cited By ~ 73

Author(s):

Jian Li ◽

Mauricio R. Delgado ◽

Elizabeth A. Phelps

Keyword(s):

Prefrontal Cortex ◽

Reinforcement Learning ◽

Blood Oxygen Level Dependent ◽

Brain Regions ◽

Reward Learning ◽

Behavioral Performance ◽

Blood Oxygen Level ◽

Economic Decision Making ◽

Bold Responses ◽

Dorsolateral Prefrontal

Recent research in neuroeconomics has demonstrated that the reinforcement learning model of reward learning captures the patterns of both behavioral performance and neural responses during a range of economic decision-making tasks. However, this powerful theoretical model has its limits. Trial-and-error is only one of the means by which individuals can learn the value associated with different decision options. Humans have also developed efficient, symbolic means of communication for learning without the necessity for committing multiple errors across trials. In the present study, we observed that instructed knowledge of cue-reward probabilities improves behavioral performance and diminishes reinforcement learning-related blood-oxygen level-dependent (BOLD) responses to feedback in the nucleus accumbens, ventromedial prefrontal cortex, and hippocampal complex. The decrease in BOLD responses in these brain regions to reward-feedback signals was functionally correlated with activation of the dorsolateral prefrontal cortex (DLPFC). These results suggest that when learning action values, participants use the DLPFC to dynamically adjust outcome responses in valuation regions depending on the usefulness of action-outcome information.

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