1
|
Lacroix A, Proteau-Lemieux M, Côté S, Near J, Hui SC, Edden RA, Lippé S, Çaku A, Corbin F, Lepage JF. Multimodal assessment of the GABA system in patients with fragile-X syndrome and neurofibromatosis of type 1. Neurobiol Dis 2022; 174:105881. [DOI: 10.1016/j.nbd.2022.105881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/12/2022] [Accepted: 10/02/2022] [Indexed: 11/24/2022] Open
|
2
|
Bell T, Stokoe M, Harris AD. Macromolecule suppressed GABA levels show no relationship with age in a pediatric sample. Sci Rep 2021; 11:722. [PMID: 33436899 PMCID: PMC7804253 DOI: 10.1038/s41598-020-80530-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/18/2020] [Indexed: 11/24/2022] Open
Abstract
The inhibitory neurotransmitter γ-Aminobutyric acid (GABA) plays a crucial role in cortical development. Therefore, characterizing changes in GABA levels during development has important implications for the study of healthy development and developmental disorders. Brain GABA levels can be measured non-invasively using GABA-edited magnetic resonance spectroscopy (MRS). However, the most commonly used editing technique to measure GABA results in contamination of the GABA signal with macromolecules (MM). Therefore, GABA measured using this technique is often referred to as GABA+ . While few in number, previous studies have shown GABA+ levels increase with age during development. However, these studies are unable to specify whether it is specifically GABA that is increasing or, instead, if levels of MM increase. In this study, we use a GABA-editing technique specifically designed to suppress the MM signal (MM-supp GABA). We find no relationship between MM-supp GABA and age in healthy children aged 7-14 years. These findings suggest that the relationship between GABA+ and age is driven by changes in MM levels, not by changes in GABA levels. Moreover, these findings highlight the importance of accounting for MM levels in MRS quantification.
Collapse
Affiliation(s)
- Tiffany Bell
- Department of Radiology, University of Calgary, Calgary, AB, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, 28 Oki Drive, Office B4-510, Calgary, AB, T3B 6A9, Canada.
| | - Mehak Stokoe
- Department of Radiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, 28 Oki Drive, Office B4-510, Calgary, AB, T3B 6A9, Canada
| | - Ashley D Harris
- Department of Radiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, 28 Oki Drive, Office B4-510, Calgary, AB, T3B 6A9, Canada
| |
Collapse
|
3
|
d'Almeida OC, Violante IR, Quendera B, Moreno C, Gomes L, Castelo-Branco M. The neurometabolic profiles of GABA and Glutamate as revealed by proton magnetic resonance spectroscopy in type 1 and type 2 diabetes. PLoS One 2020; 15:e0240907. [PMID: 33120406 PMCID: PMC7595380 DOI: 10.1371/journal.pone.0240907] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 10/05/2020] [Indexed: 01/06/2023] Open
Abstract
Glucose metabolism is pivotal for energy and neurotransmitter synthesis and homeostasis, particularly in Glutamate and GABA systems. In turn, the stringent control of inhibitory/excitatory tonus is known to be relevant in neuropsychiatric conditions. Glutamatergic neurotransmission dominates excitatory synaptic functions and is involved in plasticity and excitotoxicity. GABAergic neurochemistry underlies inhibition and predicts impaired psychophysical function in diabetes. It has also been associated with cognitive decline in people with diabetes. Still, the relation between metabolic homeostasis and neurotransmission remains elusive. Two 3T proton MR spectroscopy studies were independently conducted in the occipital cortex to provide insight into inhibitory/excitatory homeostasis (GABA/Glutamate) and to evaluate the impact of chronic metabolic control on the levels and regulation (as assessed by regression slopes) of the two main neurotransmitters of the CNS in type 2 diabetes (T2DM) and type 1 diabetes (T1DM). Compared to controls, participants with T2DM showed significantly lower Glutamate, and also GABA. Nevertheless, higher levels of GABA/Glx (Glutamate+Glutamine), and lower levels of Glutamate were associated with poor metabolic control in participants with T2DM. Importantly, the relationship between GABA/Glx and HbA1c found in T2DM supports a relationship between inhibitory/excitatory balance and metabolic control. Interestingly, this neurometabolic profile was undetected in T1DM. In this condition we found strong evidence for alterations in MRS surrogate measures of neuroinflammation (myo-Inositol), positively related to chronic metabolic control. Our results suggest a role for Glutamate as a global marker of T2DM and a sensitive marker of glycemic status. GABA/Glx may provide a signature of cortical metabolic state in poorly controlled patients as assessed by HbA1c levels, which indicate long-term blood Glucose control. These findings are consistent with an interplay between abnormal neurotransmission and metabolic control in particular in type 2 diabetes thereby revealing dissimilar contributions to the pathophysiology of neural dysfunction in both types of diabetes.
Collapse
Affiliation(s)
- Otília C d'Almeida
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CiBIT, Coimbra Institute for Biomedical Imaging and Translational Research, Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Ines R Violante
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Bruno Quendera
- CiBIT, Coimbra Institute for Biomedical Imaging and Translational Research, Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Carolina Moreno
- Department of Endocrinology, Coimbra University and Hospital Centre (CHUC), Coimbra, Portugal
| | - Leonor Gomes
- Department of Endocrinology, Coimbra University and Hospital Centre (CHUC), Coimbra, Portugal
| | - Miguel Castelo-Branco
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CiBIT, Coimbra Institute for Biomedical Imaging and Translational Research, Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| |
Collapse
|
4
|
Hong D, Rohani Rankouhi S, Thielen JW, van Asten JJA, Norris DG. A comparison of sLASER and MEGA-sLASER using simultaneous interleaved acquisition for measuring GABA in the human brain at 7T. PLoS One 2019; 14:e0223702. [PMID: 31603925 PMCID: PMC6788718 DOI: 10.1371/journal.pone.0223702] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 09/27/2019] [Indexed: 12/19/2022] Open
Abstract
γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter, is challenging to measure using proton spectroscopy due to its relatively low concentration, J-coupling and overlapping signals from other metabolites. Currently, the prevalent methods for detecting GABA at ultrahigh field strengths (≥ 7 T) are GABA-editing and model fitting of non-editing single voxel spectra. These two acquisition approaches have their own advantages: the GABA editing approach directly measures the GABA resonance at 3 ppm, whereas the fitting approach on the non-editing spectrum allows the detection of multiple metabolites, and has an SNR advantage over longer echo time (TE) acquisitions. This study aims to compare these approaches for estimating GABA at 7 T. We use an interleaved sequence of semi-LASER (sLASER: TE = 38 ms) and MEGA-sLASER (TE = 80 ms). This simultaneous interleaved acquisition minimizes the differential effect of extraneous factors, and enables an accurate comparison of the two acquisition methods. Spectra were acquired with an 8 ml isotropic voxel at six different brain regions: anterior-cingulate cortex, dorsolateral-prefrontal cortex, motor cortex, occipital cortex, posterior cingulate cortex, and precuneus. Spectral fitting with LCModel quantified the GABA to total Cr (tCr: Creatine + Phosphocreatine) concentration ratio. After correcting the T2 relaxation time variation, GABA/tCr ratios were similar between the two acquisition approaches. GABA editing showed smaller spectral fitting error according to Cramér-Rao lower bound than the sLASER approach for all regions examined. We conclude that both acquisition methods show similar accuracy but the precision of the MEGA-editing approach is higher for GABA measurement. In addition, the 2.28 ppm GABA resonance was found to be important for estimating GABA concentration without macromolecule contamination in the GABA-edited acquisition, when utilizing spectral fitting with LCModel.
Collapse
Affiliation(s)
- Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | | | - Jan-Willem Thielen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Jack J. A. van Asten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - David G. Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, Netherlands
| |
Collapse
|
5
|
Maes C, Hermans L, Pauwels L, Chalavi S, Leunissen I, Levin O, Cuypers K, Peeters R, Sunaert S, Mantini D, Puts NAJ, Edden RAE, Swinnen SP. Age-related differences in GABA levels are driven by bulk tissue changes. Hum Brain Mapp 2018; 39:3652-3662. [PMID: 29722142 DOI: 10.1002/hbm.24201] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 03/23/2018] [Accepted: 04/20/2018] [Indexed: 01/07/2023] Open
Abstract
Levels of GABA, the main inhibitory neurotransmitter in the brain, can be regionally quantified using magnetic resonance spectroscopy (MRS). Although GABA is crucial for efficient neuronal functioning, little is known about age-related differences in GABA levels and their relationship with age-related changes in brain structure. Here, we investigated the effect of age on GABA levels within the left sensorimotor cortex and the occipital cortex in a sample of 85 young and 85 older adults using the MEGA-PRESS sequence. Because the distribution of GABA varies across different brain tissues, various correction methods are available to account for this variation. Considering that these correction methods are highly dependent on the tissue composition of the voxel of interest, we examined differences in voxel composition between age groups and the impact of these various correction methods on the identification of age-related differences in GABA levels. Results indicated that, within both voxels of interest, older (as compared to young adults) exhibited smaller gray matter fraction accompanied by larger fraction of cerebrospinal fluid. Whereas uncorrected GABA levels were significantly lower in older as compared to young adults, this age effect was absent when GABA levels were corrected for voxel composition. These results suggest that age-related differences in GABA levels are at least partly driven by the age-related gray matter loss. However, as alterations in GABA levels might be region-specific, further research should clarify to what extent gray matter changes may account for age-related differences in GABA levels within other brain regions.
Collapse
Affiliation(s)
- Celine Maes
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Lize Hermans
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Lisa Pauwels
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Sima Chalavi
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Inge Leunissen
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Oron Levin
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Koen Cuypers
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.,REVAL Research Institute, Hasselt University, Agoralaan, Building A, Diepenbeek, B-3590, Belgium
| | - Ronald Peeters
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Department of Radiology, University Hospitals Leuven, Gasthuisberg, UZ, Leuven, Belgium
| | - Stefan Sunaert
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Department of Radiology, University Hospitals Leuven, Gasthuisberg, UZ, Leuven, Belgium
| | - Dante Mantini
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Nicolaas A J Puts
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Stephan P Swinnen
- Movement control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.,Leuven Brain Institute (LBI), Leuven, Belgium
| |
Collapse
|
6
|
Individual Differences in Resting Corticospinal Excitability Are Correlated with Reaction Time and GABA Content in Motor Cortex. J Neurosci 2017; 37:2686-2696. [PMID: 28179557 DOI: 10.1523/jneurosci.3129-16.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/04/2017] [Accepted: 01/31/2017] [Indexed: 01/14/2023] Open
Abstract
Individuals differ in the intrinsic excitability of their corticospinal pathways and, perhaps more generally, their entire nervous system. At present, we have little understanding of the mechanisms underlying these differences and how variation in intrinsic excitability relates to behavior. Here, we examined the relationship between individual differences in intrinsic corticospinal excitability, local cortical GABA levels, and reaction time (RT) in a group of 20 healthy human adults. We measured corticospinal excitability at rest with transcranial magnetic stimulation, local concentrations of basal GABA with magnetic resonance spectroscopy, and RT with a behavioral task. All measurements were repeated in two separate sessions, and tests of reliability confirmed the presence of stable individual differences. There was a negative correlation between corticospinal excitability and RT, such that larger motor-evoked potentials (MEPs) measured at rest were associated with faster RTs. Interestingly, larger MEPs were associated with higher levels of GABA in M1, but not in three other cortical regions. Together, these results suggest that individuals with more excitable corticospinal pathways are faster to initiate planned responses and have higher levels of GABA within M1, possibly to compensate for a more excitable motor system.SIGNIFICANCE STATEMENT This study brings together physiological, behavioral, and neurochemical evidence to examine variability in the excitability of the human motor system. Previous work has focused on state-based factors (e.g., preparedness, uncertainty), with little attention given to the influence of inherent stable characteristics. Here, we examined how the excitability of the motor system relates to reaction time and the regional content of the inhibitory neurotransmitter GABA. Importantly, motor pathway excitability and GABA concentrations were measured at rest, outside a task context, providing assays of intrinsic properties of the individuals. Individuals with more excitable motor pathways had faster reaction times and, paradoxically, higher concentrations of GABA. We propose that greater GABA capacity in the motor cortex counteracts an intrinsically more excitable motor system.
Collapse
|
7
|
Parto Dezfouli MA, Parto Dezfouli M, Ahmadian A, Frangi AF, Esmaeili Rad M, Saligheh Rad H. Quantification of 1 H-MRS signals based on sparse metabolite profiles in the time-frequency domain. NMR IN BIOMEDICINE 2017; 30:e3675. [PMID: 28052436 DOI: 10.1002/nbm.3675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
MRS is an analytical approach used for both quantitative and qualitative analysis of human body metabolites. The accurate and robust quantification capability of proton MRS (1 H-MRS) enables the accurate estimation of living tissue metabolite concentrations. However, such methods can be efficiently employed for quantification of metabolite concentrations only if the overlapping nature of metabolites, existing static field inhomogeneity and low signal-to-noise ratio (SNR) are taken into consideration. Representation of 1 H-MRS signals in the time-frequency domain enables us to handle the baseline and noise better. This is possible because the MRS signal of each metabolite is sparsely represented, with only a few peaks, in the frequency domain, but still along with specific time-domain features such as distinct decay constant associated with T2 relaxation rate. The baseline, however, has a smooth behavior in the frequency domain. In this study, we proposed a quantification method using continuous wavelet transformation of 1 H-MRS signals in combination with sparse representation of features in the time-frequency domain. Estimation of the sparse representations of MR spectra is performed according to the dictionaries constructed from metabolite profiles. Results on simulated and phantom data show that the proposed method is able to quantify the concentration of metabolites in 1 H-MRS signals with high accuracy and robustness. This is achieved for both low SNR (5 dB) and low signal-to-baseline ratio (-5 dB) regimes.
Collapse
Affiliation(s)
- Mohammad Ali Parto Dezfouli
- Department of Biomedical Engineering and Medical Physics, Tehran University of Medical Sciences, Tehran, Iran
- Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran, Iran
| | - Mohsen Parto Dezfouli
- School of Electrical Engineering, Faculty of Biomedical Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Alireza Ahmadian
- Department of Biomedical Engineering and Medical Physics, Tehran University of Medical Sciences, Tehran, Iran
| | - Alejandro F Frangi
- CISTIB Center for Computational Imaging and Simulation Technologies in Biomedicine, Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, UK
| | - Melika Esmaeili Rad
- Department of Electrical and Biomedical Engineering, Islamic Azad University of Qazvin, Qazvin, Iran
| | - Hamidreza Saligheh Rad
- Department of Biomedical Engineering and Medical Physics, Tehran University of Medical Sciences, Tehran, Iran
- Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran, Iran
| |
Collapse
|
8
|
Mikkelsen M, Singh KD, Brealy JA, Linden DEJ, Evans CJ. Quantification of γ-aminobutyric acid (GABA) in 1 H MRS volumes composed heterogeneously of grey and white matter. NMR IN BIOMEDICINE 2016; 29:1644-1655. [PMID: 27687518 DOI: 10.1002/nbm.3622] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/15/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
The quantification of γ-aminobutyric acid (GABA) concentration using localised MRS suffers from partial volume effects related to differences in the intrinsic concentration of GABA in grey (GM) and white (WM) matter. These differences can be represented as a ratio between intrinsic GABA in GM and WM: rM . Individual differences in GM tissue volume can therefore potentially drive apparent concentration differences. Here, a quantification method that corrects for these effects is formulated and empirically validated. Quantification using tissue water as an internal concentration reference has been described previously. Partial volume effects attributed to rM can be accounted for by incorporating into this established method an additional multiplicative correction factor based on measured or literature values of rM weighted by the proportion of GM and WM within tissue-segmented MRS volumes. Simulations were performed to test the sensitivity of this correction using different assumptions of rM taken from previous studies. The tissue correction method was then validated by applying it to an independent dataset of in vivo GABA measurements using an empirically measured value of rM . It was shown that incorrect assumptions of rM can lead to overcorrection and inflation of GABA concentration measurements quantified in volumes composed predominantly of WM. For the independent dataset, GABA concentration was linearly related to GM tissue volume when only the water signal was corrected for partial volume effects. Performing a full correction that additionally accounts for partial volume effects ascribed to rM successfully removed this dependence. With an appropriate assumption of the ratio of intrinsic GABA concentration in GM and WM, GABA measurements can be corrected for partial volume effects, potentially leading to a reduction in between-participant variance, increased power in statistical tests and better discriminability of true effects.
Collapse
Affiliation(s)
- Mark Mikkelsen
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
| | - Krish D Singh
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| | - Jennifer A Brealy
- MRC Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - David E J Linden
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
- MRC Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - C John Evans
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| |
Collapse
|
9
|
Hnilicová P, Považan M, Strasser B, Andronesi OC, Gajdošík M, Dydak U, Ukropec J, Dobrota D, Trattnig S, Bogner W. Spatial variability and reproducibility of GABA-edited MEGA-LASER 3D-MRSI in the brain at 3 T. NMR IN BIOMEDICINE 2016; 29:1656-1665. [PMID: 27717093 PMCID: PMC5095789 DOI: 10.1002/nbm.3613] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 07/27/2016] [Accepted: 08/02/2016] [Indexed: 05/06/2023]
Abstract
The reproducibility of gamma-aminobutyric acid (GABA) quantification results, obtained with MRSI, was determined on a 3 T MR scanner in healthy adults. In this study, a spiral-encoded, GABA-edited, MEGA-LASER MRSI sequence with real-time motion-scanner-instability corrections was applied for robust 3D mapping of neurotransmitters in the brain. In particular, the GABA+ (i.e. GABA plus macromolecule contamination) and Glx (i.e. glutamate plus glutamine contamination) signal was measured. This sequence enables 3D-MRSI with about 3 cm3 nominal resolution in about 20 min. Since reliable quantification of GABA is challenging, the spatial distribution of the inter-subject and intra-subject variability of GABA+ and Glx levels was studied via test-retest assessment in 14 healthy volunteers (seven men-seven women). For both inter-subject and intra-subject repeated measurement sessions a low coefficient of variation (CV) and a high intraclass correlation coefficient (ICC) were found for GABA+ and Glx ratios across all evaluated voxels (intra-/inter-subject: GABA+ ratios, CV ~ 8%-ICC > 0.75; Glx ratios, CV ~ 6%-ICC > 0.70). The same was found in selected brain regions for Glx ratios versus GABA+ ratios (CV varied from about 5% versus about 8% in occipital and parietal regions, to about 8% versus about 10% in the frontal area, thalamus, and basal ganglia). These results provide evidence that 3D mapping of GABA+ and Glx using the described methodology provides high reproducibility for application in clinical and neuroscientific studies.
Collapse
Affiliation(s)
- Petra Hnilicová
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Biomedical Center Martin, Division of Neurosciences, Martin, Slovakia
| | - Michal Považan
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Bernhard Strasser
- High Field MR Center, Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna, Austria
| | - Ovidiu C Andronesi
- Massachusetts General Hospital, Harvard Medical School, Martinos Center for Biomedical Imaging, Boston, Massachusetts, USA
| | - Martin Gajdošík
- High Field MR Center, Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna, Austria
| | - Ulrike Dydak
- Purdue University, School of Health Sciences, West Lafayette, IN, USA, Indiana University School of Medicine, Department of Radiology and Imaging Sciences, Indianapolis, Indiana, USA
| | - Jozef Ukropec
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Obesity Section, Diabetes and Metabolic Disease Laboratory, Bratislava, Slovakia
| | - Dušan Dobrota
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Department of Medical Biochemistry, Martin, Slovakia
| | - Siegfried Trattnig
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Wolfgang Bogner
- High Field MR Center, Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna, Austria.
| |
Collapse
|
10
|
Grewal M, Dabas A, Saharan S, Barker PB, Edden RAE, Mandal PK. GABA quantitation using MEGA-PRESS: Regional and hemispheric differences. J Magn Reson Imaging 2016; 44:1619-1623. [PMID: 27264205 DOI: 10.1002/jmri.25324] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/13/2016] [Accepted: 05/15/2016] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To measure in vivo brain gamma-aminobutyric acid (GABA) concentrations, and assess regional and hemispheric differences, using MR spectroscopy (1 H-MRS). MATERIALS AND METHODS GABA concentrations were measured bilaterally in the frontal cortex (FC), parietal cortex (PC), and occipital cortex (OC) of 21 healthy young subjects (age range 20-29 years) using 3 Tesla Philips scanner. A univariate general linear model analysis was carried out to assess the effect of region and hemisphere as well as their interaction on GABA concentrations while controlling for sex and gray matter differences. RESULTS Results indicated a significant regional dependence of GABA levels [F(2,89) = 11.725, P < 0.001, ηp2 = .209] with lower concentrations in the FC compared with both PC (P < 0.001) and OC (P < 0.001) regions. There was no significant hemispheric differences in GABA levels [F(1,89) = .172; P = 0.679; ηp2 = .002]. CONCLUSION This study reports the concentrations of GABA in the FC, PC, and OC brain regions of healthy young adults. GABA distribution exhibits hemispheric symmetry, but varies across regions; GABA levels in the FC are lower than those in the PC and OC. J. Magn. Reson. Imaging 2016;44:1619-1623.
Collapse
Affiliation(s)
- Monika Grewal
- Neuroimaging and Neurospectroscopy Laboratory, National Brain Research Centre, Gurgaon, India
| | - Aroma Dabas
- Neuroimaging and Neurospectroscopy Laboratory, National Brain Research Centre, Gurgaon, India
| | - Sumiti Saharan
- Neuroimaging and Neurospectroscopy Laboratory, National Brain Research Centre, Gurgaon, India
| | - Peter B Barker
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Richard A E Edden
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Pravat K Mandal
- Neuroimaging and Neurospectroscopy Laboratory, National Brain Research Centre, Gurgaon, India.,The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
11
|
Beta Peak Frequencies at Rest Correlate with Endogenous GABA+/Cr Concentrations in Sensorimotor Cortex Areas. PLoS One 2016; 11:e0156829. [PMID: 27258089 PMCID: PMC4892568 DOI: 10.1371/journal.pone.0156829] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 05/21/2016] [Indexed: 01/30/2023] Open
Abstract
Neuronal oscillatory activity in the beta band (15-30 Hz) is a prominent signal within the human sensorimotor cortex. Computational modeling and pharmacological modulation studies suggest an influence of GABAergic interneurons on the generation of beta band oscillations. Accordingly, studies in humans have demonstrated a correlation between GABA concentrations and power of beta band oscillations. It remains unclear, however, if GABA concentrations also influence beta peak frequencies and whether this influence is present in the sensorimotor cortex at rest and without pharmacological modulation. In the present study, we investigated the relation between endogenous GABA concentration (measured by magnetic resonance spectroscopy) and beta oscillations (measured by magnetoencephalography) at rest in humans. GABA concentrations and beta band oscillations were measured for left and right sensorimotor and occipital cortex areas. A significant positive linear correlation between GABA concentration and beta peak frequency was found for the left sensorimotor cortex, whereas no significant correlations were found for the right sensorimotor and the occipital cortex. The results show a novel connection between endogenous GABA concentration and beta peak frequency at rest. This finding supports previous results that demonstrated a connection between oscillatory beta activity and pharmacologically modulated GABA concentration in the sensorimotor cortex. Furthermore, the results demonstrate that for a predominantly right-handed sample, the correlation between beta band oscillations and endogenous GABA concentrations is evident only in the left sensorimotor cortex.
Collapse
|
12
|
Saleh MG, Alhamud A, Near J, van der Kouwe AJW, Meintjes EM. Volumetric navigated MEGA-SPECIAL for real-time motion and shim corrected GABA editing. NMR IN BIOMEDICINE 2016; 29:248-55. [PMID: 26663075 DOI: 10.1002/nbm.3454] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 05/28/2023]
Abstract
Mescher-Garwood (MEGA) editing with spin echo full intensity acquired localization (MEGA-SPECIAL, MSpc) is a technique to acquire γ-aminobutyric acid (GABA) without macromolecule (MM) contamination at a TE of 68 ms. However, due to the requirement of multiple shot-localization, it is often susceptible to subject motion and B0 inhomogeneity. A method is presented for real-time shim and motion correction (ShMoCo) using volumetric navigators to correct for motion and motion-related B0 inhomogeneity during MSpc acquisition. A phantom experiment demonstrates that ShMoCo restores the GABA peak and improves spectral quality in the presence of motion and zero- and first-order shim changes. The ShMoCo scans were validated in three subjects who performed up-down and left-right head rotations. Qualitative assessment of these scans indicates effective reduction of subtraction artefacts and well edited GABA peaks, while quantitative analysis indicates superior fitting and spectral quality relative to scans with no correction. Copyright © 2015 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Muhammad G Saleh
- Department of Human Biology, MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa
| | - A Alhamud
- Department of Human Biology, MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Jamie Near
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Canada
| | - André J W van der Kouwe
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
| | - Ernesta M Meintjes
- Department of Human Biology, MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa
| |
Collapse
|