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Magnetic resonance spectroscopy (MRS) allows measurement of neurotransmitter concentrations within a region of interest in the brain. Inter-individual variation in MRS-measured GABA levels have been related to variation in task performance in a number of regions. However, it is not clear how MRS-assessed measures of GABA relate to cortical excitability or(More)
Coordination between glutamatergic excitatory neurons and gamma-aminobutyric acid (GABA)-ergic inhibitory interneurons is fundamental to the regulation of neuronal firing rates and is believed to have relevance to functional magnetic resonance imaging (fMRI) contrast. While much is known regarding the molecular behavior of excitatory and inhibitory(More)
Although the ventromedial prefrontal cortex (vmPFC) has long been implicated in reward-guided decision making, its exact role in this process has remained an unresolved issue. Here we show that, in accordance with models of decision making, vmPFC concentrations of GABA and glutamate in human volunteers predict both behavioral performance and the dynamics of(More)
ATP citrate-lyase is the primary enzyme responsible for the synthesis of cytosolic acetyl-CoA in many tissues. We have isolated a full-length cDNA copy of 4.3 kilobase pairs encoding the ATP-citrate lyase mRNA by screening rat liver cDNA library using oligonucleotide probes designed from peptide sequences obtained from the purified rat enzyme. Expression of(More)
One of the most commonly used methods for in vivo MRS detection of γ-aminobutyric acid (GABA) is the MEGA-point-resolved spectroscopy (MEGA-PRESS) technique. However, accurate quantification of GABA using MEGA-PRESS is complicated by spectral co-editing of macromolecular resonances. In this article, a new pulse sequence is presented which enables GABA(More)
The brain has limited capacity, and so selective attention enhances relevant incoming information while suppressing irrelevant information. This process is not always successful, and the frequency of such cognitive failures varies to a large extent between individuals. Here we hypothesised that individual differences in cognitive failures might be reflected(More)
A full-length cDNA clone of 4.3 kb encoding the human ATP-citrate lyase enzyme has been isolated by screening a human cDNA library with the recently isolated rat ATP-citrate lyase cDNA clone [Elshourbagy et al. (1990) J. Biol. Chem. 265, 1430]. Nucleic-acid sequence data indicate that the cDNA contains the complete coding region for the enzyme, which is(More)
PURPOSE Frequency and phase drifts are a common problem in the acquisition of in vivo magnetic resonance spectroscopy (MRS) data. If not accounted for, frequency and phase drifts will result in artifactual broadening of spectral peaks, distortion of spectral lineshapes, and a reduction in signal-to-noise ratio (SNR). We present herein a new method for(More)
PURPOSE To introduce a new toolkit for simulation and processing of magnetic resonance spectroscopy (MRS) data, and to demonstrate some of its novel features. METHODS The FID appliance (FID-A) is an open-source, MATLAB-based software toolkit for simulation and processing of MRS data. The software is designed specifically for processing data with multiple(More)
We previously demonstrated that network level functional connectivity in the human brain could be related to levels of inhibition in a major network node at baseline (Stagg et al., 2014). In this study, we build upon this finding to directly investigate the effects of perturbing M1 GABA and resting state functional connectivity using transcranial direct(More)