Accuracy and stability of measuring GABA, glutamate, and glutamine by proton magnetic resonance spectroscopy: A phantom study at 4Tesla

Henry, Michael E.; Lauriat, Tara L.; Shanahan, Meghan; Renshaw, Perry F.; Jensen, J. Eric

doi:10.1016/j.jmr.2010.11.003

Cited by 65 publications

(65 citation statements)

References 32 publications

(38 reference statements)

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“…Using our previously published methods, every J-resolved spectral extraction (64 in total) within the 67 Hz bandwith was fitted with LCModel and its theoretically-correct template, which is optimized GAMMA-simulated J-resolved basis sets modeled for 2.89 T (Friedman et al, 2013; Henry et al, 2011; Jensen et al, 2009). All spectral data were modeled for 2.89 T field strength (123.05 MHz) to match that of our TRIO scanner.…”

Section: Methodsmentioning

confidence: 99%

Dorsal anterior cingulate glutamate is associated with engagement of the default mode network during exposure to smoking cues

Janes

Betts

Jensen

et al. 2016

Drug and Alcohol Dependence

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Background When exposed to smoking cues, nicotine dependent individuals activate brain regions overlapping with the default mode network (DMN), a network of regions involved in internally-focused cognition. The salience network (SN), which includes the dorsal anterior cingulate cortex (dACC), is thought to interact with the DMN and aids in directing attention toward salient internal or external stimuli. One possibility is that neurochemical variation in SN regions such as the dACC impact DMN reactivity to personally relevant stimuli such as smoking cues. This is consistent with emerging evidence suggesting an association between midline cortical glutamate (Glu) and activity in brain regions overlapping with the DMN. Methods In 18 nicotine-dependent individuals, we assessed the relationship between DMN activation to smoking relative to neutral cues using functional magnetic resonance imaging and dACC Glu as measured by magnetic resonance spectroscopy. This association also was tested in a replication sample of 14 nicotine-dependent participants. Results Not only was the DMN significantly less suppressed during smoking cue exposure, but also there was a positive association between DMN reactivity to smoking relative to neutral cues and dACC Glu (r = 0.56, p < 0.02). This finding was confirmed in the independent replication cohort (r = 0.64, p < 0.02). Conclusions The current findings confirm that the DMN is less suppressed when smokers view smoking relative to neutral cues, suggesting that smoking cues engage self-relevant processing. Furthermore, these results indicate that dACC Glu is associated with enhanced DMN engagement when nicotine-dependent individuals are exposed to self-relevant smoking cues.

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Section: Methodsmentioning

confidence: 99%

Dorsal anterior cingulate glutamate is associated with engagement of the default mode network during exposure to smoking cues

Janes

Betts

Jensen

et al. 2016

Drug and Alcohol Dependence

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“…In order to quantify GABA with the JPRESS data, the 22 TE-stepped free-induction decay was first zerofilled out to 64 points, Gaussian-filtered, and Fourier transformed. Consistent with our validated methods, every J-resolved spectral extraction within a bandwidth of 67 Hz was fitted with LCModel and its theoretically-correct template, which used an optimized GAMMA-simulated J-resolved basis sets modeled for 2.89 T (Friedman et al, 2012;Henry et al, 2011;Jensen et al, 2009). The integrated area under the entire 2D surface for each metabolite was calculated by summing the raw peak areas across all 64 J-resolved extractions for each metabolite.…”

Section: Magnetic Resonance Spectroscopymentioning

confidence: 99%

GABA Levels in The Dorsal Anterior Cingulate Cortex Associated with Difficulty Ignoring Smoking-Related Cues in Tobacco-Dependent Volunteers

Janes

Jensen

Farmer

et al. 2013

Neuropsychopharmacol

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Substance abusers have difficulty ignoring drug-related cues, which is associated with relapse vulnerability. This 'attentional bias' towards drug cues translates into an inability to ignore drug-related stimuli and may reflect deficits in the brain regions, such as the dorsal anterior cingulate cortex (dACC)-a key region in cognitive control and adaptive decision making. Quantifying relationships between attentional biases to drug cues and dACC neurochemistry could aid in identifying neurobiological mechanisms associated with increased relapse vulnerability precipitated by drug cues. As gamma-aminobutyric acid (GABA) deficits have been linked to impaired cognition and addictive disorders, we hypothesized that reduced GABA in the dACC would be associated with increased attentional biases towards smoking-related cues. We confirmed this hypothesis among nicotine-dependent tobacco smokers by combining an offline behavioral measure of attentional bias with magnetic resonance spectroscopy. Smokers with the greatest attentional bias also experienced more negative affect during early nicotine withdrawal. Findings revealed a relationship between heightened reactivity to drug cues, and both decreasing dACC GABA and early withdrawal symptoms. Because reduced GABA function in frontal brain regions disrupt cognitive function, our findings suggest that smokers with diminished dACC GABA may lack the cognitive resources to successfully ignore highly salient distractors such as tobacco-related stimuli and therefore might be more prone to cue-induced relapse. This newly discovered relationship between dACC GABA and attentional bias provides evidence for a neurochemical target, which may aid smoking cessation in highly cue-reactive individuals.

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“…Also the measured Glu signal is contaminated by glutamine and glutathione and, thus, often abbreviated as Glx. Nevertheless, the difference (OFF-ON) spectrum allows accurate and stable quantification of GABA and good quantification of Glx (Henry et al, 2011). …”

Section: Introductionmentioning

confidence: 99%

3D GABA imaging with real-time motion correction, shim update and reacquisition of adiabatic spiral MRSI

et al. 2014

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Gamma-aminobutyric acid (GABA) and glutamate (Glu) are the major neurotransmitters in the brain. They are crucial for the functioning of healthy brain and their alteration is a major mechanism in the pathophysiology of many neuro-psychiatric disorders. Magnetic resonance spectroscopy (MRS) is the only way to measure GABA and Glu non-invasively in vivo. GABA detection is particularly challenging and requires special MRS techniques. The most popular is MEscher-GArwood (MEGA) difference editing with single-voxel Point RESolved Spectroscopy (PRESS) localization. This technique has three major limitations: a) MEGA editing is a subtraction technique, hence is very sensitive to scanner instabilities and motion artifacts. b) PRESS is prone to localization errors at high fields (≥3T) that compromise accurate quantification. c) Single-voxel spectroscopy can (similar to a biopsy) only probe average GABA and Glu levels in a single location at a time. To mitigate these problems, we implemented a 3D MEGA-editing MRS imaging sequence with the following three features: a) Real-time motion correction, dynamic shim updates, and selective reacquisition to eliminate subtraction artifacts due to scanner instabilities and subject motion. b) Localization by Adiabatic SElective Refocusing (LASER) to improve the localization accuracy and signal-to-noise ratio. c) K-space encoding via a weighted stack of spirals provides 3D metabolic mapping with flexible scan times. Simulations, phantom and in vivo experiments prove that our MEGA-LASER sequence enables 3D mapping of GABA+ and Glx (Glutamate + Gluatmine), by providing 1.66 times larger signal for the 3.02 ppm multiplet of GABA+ compared to MEGA-PRESS, leading to clinically feasible scan times for 3D brain imaging. Hence, our sequence allows accurate and robust 3D-mapping of brain GABA+ and Glx levels to be performed at clinical 3T MR scanners for use in neuroscience and clinical applications.

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Accuracy and stability of measuring GABA, glutamate, and glutamine by proton magnetic resonance spectroscopy: A phantom study at 4Tesla

Cited by 65 publications

References 32 publications

Dorsal anterior cingulate glutamate is associated with engagement of the default mode network during exposure to smoking cues

Dorsal anterior cingulate glutamate is associated with engagement of the default mode network during exposure to smoking cues

GABA Levels in The Dorsal Anterior Cingulate Cortex Associated with Difficulty Ignoring Smoking-Related Cues in Tobacco-Dependent Volunteers

3D GABA imaging with real-time motion correction, shim update and reacquisition of adiabatic spiral MRSI

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