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VanElzakker MB, Brumfield SA, Lara Mejia PS. Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods. Front Neurol 2019; 9:1033. [PMID: 30687207 PMCID: PMC6335565 DOI: 10.3389/fneur.2018.01033] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 11/16/2018] [Indexed: 01/18/2023] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the label given to a syndrome that can include long-term flu-like symptoms, profound fatigue, trouble concentrating, and autonomic problems, all of which worsen after exertion. It is unclear how many individuals with this diagnosis are suffering from the same condition or have the same underlying pathophysiology, and the discovery of biomarkers would be clarifying. The name "myalgic encephalomyelitis" essentially means "muscle pain related to central nervous system inflammation" and many efforts to find diagnostic biomarkers have focused on one or more aspects of neuroinflammation, from periphery to brain. As the field uncovers the relationship between the symptoms of this condition and neuroinflammation, attention must be paid to the biological mechanisms of neuroinflammation and issues with its potential measurement. The current review focuses on three methods used to study putative neuroinflammation in ME/CFS: (1) positron emission tomography (PET) neuroimaging using translocator protein (TSPO) binding radioligand (2) magnetic resonance spectroscopy (MRS) neuroimaging and (3) assays of cytokines circulating in blood and cerebrospinal fluid. PET scanning using TSPO-binding radioligand is a promising option for studies of neuroinflammation. However, methodological difficulties that exist both in this particular technique and across the ME/CFS neuroimaging literature must be addressed for any results to be interpretable. We argue that the vast majority of ME/CFS neuroimaging has failed to use optimal techniques for studying brainstem, despite its probable centrality to any neuroinflammatory causes or autonomic effects. MRS is discussed as a less informative but more widely available, less invasive, and less expensive option for imaging neuroinflammation, and existing studies using MRS neuroimaging are reviewed. Studies seeking to find a peripheral circulating cytokine "profile" for ME/CFS are reviewed, with attention paid to the biological and methodological reasons for lack of replication among these studies. We argue that both the biological mechanisms of cytokines and the innumerable sources of potential variance in their measurement make it unlikely that a consistent and replicable diagnostic cytokine profile will ever be discovered.
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Affiliation(s)
- Michael B. VanElzakker
- Division of Neurotherapeutics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
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Moser P, Hingerl L, Strasser B, Považan M, Hangel G, Andronesi OC, van der Kouwe A, Gruber S, Trattnig S, Bogner W. Whole-slice mapping of GABA and GABA + at 7T via adiabatic MEGA-editing, real-time instability correction, and concentric circle readout. Neuroimage 2019; 184:475-489. [PMID: 30243974 PMCID: PMC7212034 DOI: 10.1016/j.neuroimage.2018.09.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 08/20/2018] [Accepted: 09/15/2018] [Indexed: 01/29/2023] Open
Abstract
An adiabatic MEscher-GArwood (MEGA)-editing scheme, using asymmetric hyperbolic secant editing pulses, was developed and implemented in a B1+-insensitive, 1D-semiLASER (Localization by Adiabatic SElective Refocusing) MR spectroscopic imaging (MRSI) sequence for the non-invasive mapping of γ-aminobutyric acid (GABA) over a whole brain slice. Our approach exploits the advantages of edited-MRSI at 7T while tackling challenges that arise with ultra-high-field-scans. Spatial-spectral encoding, using density-weighted, concentric circle echo planar trajectory readout, enabled substantial MRSI acceleration and an improved point-spread-function, thereby reducing extracranial lipid signals. Subject motion and scanner instabilities were corrected in real-time using volumetric navigators optimized for 7T, in combination with selective reacquisition of corrupted data to ensure robust subtraction-based MEGA-editing. Simulations and phantom measurements of the adiabatic MEGA-editing scheme demonstrated stable editing efficiency even in the presence of ±0.15 ppm editing frequency offsets and B1+ variations of up to ±30% (as typically encountered in vivo at 7T), in contrast to conventional Gaussian editing pulses. Volunteer measurements were performed with and without global inversion recovery (IR) to study regional GABA levels and their underlying, co-edited, macromolecular (MM) signals at 2.99 ppm. High-quality in vivo spectra allowed mapping of pure GABA and MM-contaminated GABA+ (GABA + MM) along with Glx (Glu + Gln), with high-resolution (eff. voxel size: 1.4 cm3) and whole-slice coverage in 24 min scan time. Metabolic ratio maps of GABA/tNAA, GABA+/tNAA, and Glx/tNAA were correlated linearly with the gray matter fraction of each voxel. A 2.15-fold increase in gray matter to white matter contrast was observed for GABA when enabling IR, which we attribute to the higher abundance of macromolecules at 2.99 ppm in the white matter than in the gray matter. In conclusion, adiabatic MEGA-editing with 1D-semiLASER selection is as a promising approach for edited-MRSI at 7T. Our sequence capitalizes on the benefits of ultra-high-field MRSI while successfully mitigating the challenges related to B0/B1+ inhomogeneities, prolonged scan times, and motion/scanner instability artifacts. Robust and accurate 2D mapping has been shown for the neurotransmitters GABA and Glx.
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Affiliation(s)
- Philipp Moser
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MRI, Vienna, Austria.
| | - Lukas Hingerl
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria.
| | - Bernhard Strasser
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Michal Považan
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Gilbert Hangel
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria.
| | - Ovidiu C Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Andre van der Kouwe
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Stephan Gruber
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria.
| | - Siegfried Trattnig
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria.
| | - Wolfgang Bogner
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, A-1090, Vienna, Austria.
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53
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Kolasinski J, Hinson EL, Divanbeighi Zand AP, Rizov A, Emir UE, Stagg CJ. The dynamics of cortical GABA in human motor learning. J Physiol 2018; 597:271-282. [PMID: 30300446 PMCID: PMC6312422 DOI: 10.1113/jp276626] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/04/2018] [Indexed: 12/20/2022] Open
Abstract
Key points The ability to learn new motor skills is supported by plasticity in the structural and functional organisation of the primary motor cortex in the human brain. Changes inhibitory to signalling by GABA are thought to be crucial in inducing motor cortex plasticity. This study used magnetic resonance spectroscopy (MRS) to quantify the concentration of GABA in human motor cortex during a period of motor learning, as well as during a period of movement and a period at rest. We report evidence for a reduction in the MRS‐measured concentration of GABA specific to learning. Further, the GABA concentration early in the learning task was strongly correlated with the magnitude of subsequent learning: higher GABA concentrations were associated with poorer learning. The results provide initial insight into the neurochemical correlates of cortical plasticity associated with motor learning, specifically relevant in therapeutic efforts to induce cortical plasticity during recovery from stroke.
Abstract The ability to learn novel motor skills is a central part of our daily lives and can provide a model for rehabilitation after a stroke. However, there are still fundamental gaps in our understanding of the physiological mechanisms that underpin human motor plasticity. The acquisition of new motor skills is dependent on changes in local circuitry within the primary motor cortex (M1). This reorganisation has been hypothesised to be facilitated by a decrease in local inhibition via modulation of the neurotransmitter GABA, but this link has not been conclusively demonstrated in humans. Here, we used 7 T magnetic resonance spectroscopy to investigate the dynamics of GABA concentrations in human M1 during the learning of an explicit, serial reaction time task. We observed a significant reduction in GABA concentration during motor learning that was not seen in an equivalent motor task lacking a learnable sequence, nor during a passive resting task of the same duration. No change in glutamate was observed in any group. Furthermore, M1 GABA measured early in task performance was strongly correlated with the degree of subsequent learning, such that greater inhibition was associated with poorer subsequent learning. This result suggests that higher levels of cortical inhibition may present a barrier that must be surmounted in order to achieve an increase in M1 excitability, and hence encoding of a new motor skill. These results provide strong support for the mechanistic role of GABAergic inhibition in motor plasticity, raising questions regarding the link between population variability in motor learning and GABA metabolism in the brain. The ability to learn new motor skills is supported by plasticity in the structural and functional organisation of the primary motor cortex in the human brain. Changes inhibitory to signalling by GABA are thought to be crucial in inducing motor cortex plasticity. This study used magnetic resonance spectroscopy (MRS) to quantify the concentration of GABA in human motor cortex during a period of motor learning, as well as during a period of movement and a period at rest. We report evidence for a reduction in the MRS‐measured concentration of GABA specific to learning. Further, the GABA concentration early in the learning task was strongly correlated with the magnitude of subsequent learning: higher GABA concentrations were associated with poorer learning. The results provide initial insight into the neurochemical correlates of cortical plasticity associated with motor learning, specifically relevant in therapeutic efforts to induce cortical plasticity during recovery from stroke.
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Affiliation(s)
- James Kolasinski
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK.,Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Emily L Hinson
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK.,Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, OX3 7JX, UK
| | - Amir P Divanbeighi Zand
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK
| | - Assen Rizov
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK
| | - Uzay E Emir
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK.,Purdue University School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN, 47907, USA
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging, Oxford Centre for fMRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 7DU, UK.,Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, OX3 7JX, UK
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The Neurochemistry of Mathematical Genius: Reduced Frontal Excitation/Inhibition Balance in an Expert Calculator. Neuroscience 2018; 392:252-257. [DOI: 10.1016/j.neuroscience.2018.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 07/24/2018] [Accepted: 08/05/2018] [Indexed: 11/23/2022]
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Inhibitory and excitatory mechanisms in the human cingulate-cortex support reinforcement learning: A functional Proton Magnetic Resonance Spectroscopy study. Neuroimage 2018; 184:25-35. [PMID: 30201464 DOI: 10.1016/j.neuroimage.2018.09.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 08/10/2018] [Accepted: 09/07/2018] [Indexed: 12/26/2022] Open
Abstract
The dorsal anterior cingulate cortex (dACC) is crucial for motivation, reward- and error-guided decision-making, yet its excitatory and inhibitory mechanisms remain poorly explored in humans. In particular, the balance between excitation and inhibition (E/I), demonstrated to play a role in animal studies, is difficult to measure in behaving humans. Here, we used functional magnetic-resonance-spectroscopy (1H-fMRS) to measure the brain's major inhibitory (GABA) and excitatory (Glutamate) neurotransmitters during reinforcement learning with three different conditions: high cognitive load (uncertainty); probabilistic discrimination learning; and a control null-condition. Participants learned to prefer the gain option in the discrimination phase and had no preference in the other conditions. We found increased GABA levels during the uncertainty condition, potentially reflecting recruitment of inhibitory systems during high cognitive load when trying to learn. Further, higher GABA levels during the null (baseline) condition correlated with improved discrimination learning. Finally, glutamate and GABA levels were correlated during high cognitive load. These results suggest that availability of dACC inhibitory resources enables successful learning. Our approach helps elucidate the potential contribution of the balance between excitation and inhibition to learning and motivation in behaving humans.
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56
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Thiaucourt M, Shabes P, Schloss N, Sack M, Baumgärtner U, Schmahl C, Ende G. Posterior Insular GABA Levels Inversely Correlate with the Intensity of Experimental Mechanical Pain in Healthy Subjects. Neuroscience 2018; 387:116-122. [DOI: 10.1016/j.neuroscience.2017.09.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/21/2017] [Accepted: 09/24/2017] [Indexed: 02/07/2023]
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Andersson JD, Matuskey D, Finnema SJ. Positron emission tomography imaging of the γ-aminobutyric acid system. Neurosci Lett 2018; 691:35-43. [PMID: 30102960 DOI: 10.1016/j.neulet.2018.08.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 01/08/2023]
Abstract
In this review, we summarize the recent development of positron emission tomography (PET) radioligands for γ-aminobutyric acid A (GABAA) receptors and their potential to measure changes in endogenous GABA levels and highlight the clinical and translational applications of GABA-sensitive PET radioligands. We review the basic physiology of the GABA system with a focus on the importance of GABAA receptors in the brain and specifically the benzodiazepine binding site. Challenges for the development of central nervous system radioligands and particularly for radioligands with increased GABA sensitivity are outlined, as well as the status of established benzodiazepine site PET radioligands and agonist GABAA radioligands. We underline the challenge of using allosteric interactions to measure GABA concentrations and review the current state of PET imaging of changes in GABA levels. We conclude that PET tracers with increased GABA sensitivity are required to efficiently measure GABA release and that such a tool could be broadly applied to assess GABA transmission in vivo across several disorders.
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Affiliation(s)
- Jan D Andersson
- University of Alberta, Medical Isotope and Cyclotron Facility, Edmonton, Canada
| | - David Matuskey
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Sjoerd J Finnema
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA; Center for Psychiatric Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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58
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Garside T, Wood FM, Vallence AM. Case series investigating the cortical silent period after burns using transcranial magnetic stimulation. Burns 2018; 44:1195-1202. [DOI: 10.1016/j.burns.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/02/2018] [Accepted: 04/10/2018] [Indexed: 12/25/2022]
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59
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Polymorphisms that affect GABA neurotransmission predict processing of aversive prediction errors in humans. Neuroimage 2018; 176:179-192. [DOI: 10.1016/j.neuroimage.2018.04.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/26/2018] [Accepted: 04/25/2018] [Indexed: 12/28/2022] Open
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60
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Sumner RL, McMillan RL, Shaw AD, Singh KD, Sundram F, Muthukumaraswamy SD. Peak visual gamma frequency is modified across the healthy menstrual cycle. Hum Brain Mapp 2018; 39:3187-3202. [PMID: 29665216 PMCID: PMC6055613 DOI: 10.1002/hbm.24069] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 12/14/2022] Open
Abstract
Fluctuations in gonadal hormones over the course of the menstrual cycle are known to cause functional brain changes and are thought to modulate changes in the balance of cortical excitation and inhibition. Animal research has shown this occurs primarily via the major metabolite of progesterone, allopregnanolone, and its action as a positive allosteric modulator of the GABAA receptor. Our study used EEG to record gamma oscillations induced in the visual cortex using stationary and moving gratings. Recordings took place during twenty females' mid-luteal phase when progesterone and estradiol are highest, and early follicular phase when progesterone and estradiol are lowest. Significantly higher (∼5 Hz) gamma frequency was recorded during the luteal compared to the follicular phase for both stimuli types. Using dynamic causal modeling, these changes were linked to stronger self-inhibition of superficial pyramidal cells in the luteal compared to the follicular phase. In addition, the connection from inhibitory interneurons to deep pyramidal cells was found to be stronger in the follicular compared to the luteal phase. These findings show that complex functional changes in synaptic microcircuitry occur across the menstrual cycle and that menstrual cycle phase should be taken into consideration when including female participants in research into gamma-band oscillations.
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Affiliation(s)
- Rachael L. Sumner
- School of PsychologyThe University of AucklandAuckland1142New Zealand
| | | | | | - Krish D. Singh
- CUBRIC, School of PsychologyCardiff UniversityCardiffCF24 4HQUK
| | - Fred Sundram
- Department of Psychological MedicineThe University of AucklandAuckland1142New Zealand
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Wyss C, Tse DHY, Boers F, Shah NJ, Neuner I, Kawohl W. Association between Cortical GABA and Loudness Dependence of Auditory Evoked Potentials (LDAEP) in Humans. Int J Neuropsychopharmacol 2018; 21:809-813. [PMID: 29917080 PMCID: PMC6119294 DOI: 10.1093/ijnp/pyy056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 06/14/2018] [Indexed: 11/13/2022] Open
Abstract
Loudness dependence of auditory evoked potentials (LDAEP) is a widely used EEG-based biomarker for central serotonergic activity. Serotonin has been shown to be associated with different psychiatric disorders such as depression and schizophrenia. Despite its clinical significance, the underlying neurochemical mechanism of this promising marker is not fully understood, and further research is needed to improve its validity. Other neurotransmitters might have a significant impact on this measure. Thus, we assessed the inhibitory action through individual GABA/H20 concentrations and GABA/glutamate ratios by means of magnetic resonance spectroscopy at 3T in healthy subjects. The measurements were assessed in the primary auditory cortex to investigate the association with the LDAEP, whose generators are mainly in the primary auditory cortex. For the first time, this study examines the link between GABAergic neurotransmission and LDAEP, and the data preliminary show that GABA may not contribute to the generation of EEG-based LDAEP.
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Affiliation(s)
- Christine Wyss
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland,Correspondence: Christine Wyss, PhD, Hospital of Psychiatry, University of Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Militärstrasse 8, P.O. Box 2019, 8021 Zurich, Switzerland ()
| | - Desmond H Y Tse
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Jülich, Germany
| | - Frank Boers
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Jülich, Germany
| | - Nadim J Shah
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Jülich, Germany,JARA-Brain, Translational Medicine, Jülich, Germany,Department of Neurology, RWTH Aachen University, Aachen, Germany
| | - Irene Neuner
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Jülich, Germany,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany,JARA-Brain, Translational Medicine, Jülich, Germany
| | - Wolfram Kawohl
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
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Coxon JP, Cash RFH, Hendrikse JJ, Rogasch NC, Stavrinos E, Suo C, Yücel M. GABA concentration in sensorimotor cortex following high-intensity exercise and relationship to lactate levels. J Physiol 2017; 596:691-702. [PMID: 29159914 DOI: 10.1113/jp274660] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 11/06/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Magnetic resonance spectroscopy was conducted before and after high-intensity interval exercise. Sensorimotor cortex GABA concentration increased by 20%. The increase was positively correlated with the increase in blood lactate. There was no change in dorsolateral prefrontal cortex. There were no changes in the glutamate-glutamine-glutathione peak. ABSTRACT High-intensity exercise increases the concentration of circulating lactate. Cortical uptake of blood borne lactate increases during and after exercise; however, the potential relationship with changes in the concentration of neurometabolites remains unclear. Although changes in neurometabolite concentration have previously been demonstrated in primary visual cortex after exercise, it remains unknown whether these changes extend to regions such as the sensorimotor cortex (SM) or executive regions such as the dorsolateral prefrontal cortex (DLPFC). In the present study, we explored the acute after-effects of high-intensity interval training (HIIT) on the concentration of gamma-Aminobutyric acid (GABA) and the combined glutamate-glutamine-glutathione (Glx) spectral peak in the SM and DLPFC, as well as the relationship with blood lactate levels. Following HIIT, there was a robust increase in GABA concentration in the SM, as evident across the majority of participants. This change was not observed in the DLPFC. Furthermore, the increase in SM GABA was positively correlated with an increase in blood lactate. There were no changes in Glx concentration in either region. The observed increase in SM GABA concentration implies functional relevance, whereas the correlation with lactate levels may relate to the metabolic fate of exercise-derived lactate that crosses the blood-brain barrier.
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Affiliation(s)
- James P Coxon
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Robin F H Cash
- Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School and The Alfred, Melbourne, VIC, Australia
| | - Joshua J Hendrikse
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Nigel C Rogasch
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Ellen Stavrinos
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Chao Suo
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Murat Yücel
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
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63
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Hippocampal GABA enables inhibitory control over unwanted thoughts. Nat Commun 2017; 8:1311. [PMID: 29101315 PMCID: PMC5670182 DOI: 10.1038/s41467-017-00956-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 08/08/2017] [Indexed: 02/02/2023] Open
Abstract
Intrusive memories, images, and hallucinations are hallmark symptoms of psychiatric disorders. Although often attributed to deficient inhibitory control by the prefrontal cortex, difficulty in controlling intrusive thoughts is also associated with hippocampal hyperactivity, arising from dysfunctional GABAergic interneurons. How hippocampal GABA contributes to stopping unwanted thoughts is unknown. Here we show that GABAergic inhibition of hippocampal retrieval activity forms a key link in a fronto-hippocampal inhibitory control pathway underlying thought suppression. Subjects viewed reminders of unwanted thoughts and tried to suppress retrieval while being scanned with functional magnetic resonance imaging. Suppression reduced hippocampal activity and memory for suppressed content. 1H magnetic resonance spectroscopy revealed that greater resting concentrations of hippocampal GABA predicted better mnemonic control. Higher hippocampal, but not prefrontal GABA, predicted stronger fronto-hippocampal coupling during suppression, suggesting that interneurons local to the hippocampus implement control over intrusive thoughts. Stopping actions did not engage this pathway. These findings specify a multi-level mechanistic model of how the content of awareness is voluntarily controlled. It is not fully understood how intrusive or unwanted memories are regulated. Here the authors show that hippocampal GABA concentrations, and coupling between the dorsolateral prefrontal cortex and hippocampus, predict how well subjects can suppress unwanted memories when presented with a reminder.
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64
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de Matos NM, Hock A, Wyss M, Ettlin DA, Brügger M. Neurochemical dynamics of acute orofacial pain in the human trigeminal brainstem nuclear complex. Neuroimage 2017; 162:162-172. [DOI: 10.1016/j.neuroimage.2017.08.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 08/28/2017] [Accepted: 08/30/2017] [Indexed: 01/25/2023] Open
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65
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Mikkelsen M, Barker PB, Bhattacharyya PK, Brix MK, Buur PF, Cecil KM, Chan KL, Chen DYT, Craven AR, Cuypers K, Dacko M, Duncan NW, Dydak U, Edmondson DA, Ende G, Ersland L, Gao F, Greenhouse I, Harris AD, He N, Heba S, Hoggard N, Hsu TW, Jansen JFA, Kangarlu A, Lange T, Lebel RM, Li Y, Lin CYE, Liou JK, Lirng JF, Liu F, Ma R, Maes C, Moreno-Ortega M, Murray SO, Noah S, Noeske R, Noseworthy MD, Oeltzschner G, Prisciandaro JJ, Puts NAJ, Roberts TPL, Sack M, Sailasuta N, Saleh MG, Schallmo MP, Simard N, Swinnen SP, Tegenthoff M, Truong P, Wang G, Wilkinson ID, Wittsack HJ, Xu H, Yan F, Zhang C, Zipunnikov V, Zöllner HJ, Edden RAE. Big GABA: Edited MR spectroscopy at 24 research sites. Neuroimage 2017; 159:32-45. [PMID: 28716717 PMCID: PMC5700835 DOI: 10.1016/j.neuroimage.2017.07.021] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/20/2017] [Accepted: 07/11/2017] [Indexed: 12/14/2022] Open
Abstract
Magnetic resonance spectroscopy (MRS) is the only biomedical imaging method that can noninvasively detect endogenous signals from the neurotransmitter γ-aminobutyric acid (GABA) in the human brain. Its increasing popularity has been aided by improvements in scanner hardware and acquisition methodology, as well as by broader access to pulse sequences that can selectively detect GABA, in particular J-difference spectral editing sequences. Nevertheless, implementations of GABA-edited MRS remain diverse across research sites, making comparisons between studies challenging. This large-scale multi-vendor, multi-site study seeks to better understand the factors that impact measurement outcomes of GABA-edited MRS. An international consortium of 24 research sites was formed. Data from 272 healthy adults were acquired on scanners from the three major MRI vendors and analyzed using the Gannet processing pipeline. MRS data were acquired in the medial parietal lobe with standard GABA+ and macromolecule- (MM-) suppressed GABA editing. The coefficient of variation across the entire cohort was 12% for GABA+ measurements and 28% for MM-suppressed GABA measurements. A multilevel analysis revealed that most of the variance (72%) in the GABA+ data was accounted for by differences between participants within-site, while site-level differences accounted for comparatively more variance (20%) than vendor-level differences (8%). For MM-suppressed GABA data, the variance was distributed equally between site- (50%) and participant-level (50%) differences. The findings show that GABA+ measurements exhibit strong agreement when implemented with a standard protocol. There is, however, increased variability for MM-suppressed GABA measurements that is attributed in part to differences in site-to-site data acquisition. This study's protocol establishes a framework for future methodological standardization of GABA-edited MRS, while the results provide valuable benchmarks for the MRS community.
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Affiliation(s)
- Mark Mikkelsen
- 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
| | - Peter B Barker
- 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
| | - Pallab K Bhattacharyya
- Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Radiology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Maiken K Brix
- Department of Radiology, Haukeland University Hospital, Bergen, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Pieter F Buur
- Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands
| | - Kim M Cecil
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kimberly L Chan
- 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; Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David Y-T Chen
- Department of Radiology, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Alexander R Craven
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; NORMENT - Norwegian Center for Mental Disorders Research, University of Bergen, Bergen, Norway
| | - Koen Cuypers
- Department of Kinesiology, KU Leuven, Leuven, Belgium; REVAL Rehabilitation Research Center, Hasselt University, Diepenbeek, Belgium
| | - Michael Dacko
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Niall W Duncan
- Brain and Consciousness Research Centre, Taipei Medical University, Taipei, Taiwan
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - David A Edmondson
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Gabriele Ende
- Department of Neuroimaging, Central Institute of Mental Health, Mannheim, Germany
| | - Lars Ersland
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; NORMENT - Norwegian Center for Mental Disorders Research, University of Bergen, Bergen, Norway; Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway
| | - Fei Gao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Ian Greenhouse
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Ashley D Harris
- Department of Radiology, University of Calgary, Calgary, AB, Canada
| | - Naying He
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Stefanie Heba
- Department of Neurology, BG University Hospital Bergmannsheil, Bochum, Germany
| | - Nigel Hoggard
- Academic Unit of Radiology, University of Sheffield, Sheffield, UK
| | - Tun-Wei Hsu
- Department of Radiology, Taipei Veterans General Hospital, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Jacobus F A Jansen
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alayar Kangarlu
- Department of Psychiatry, Columbia University, New York, NY, USA; New York State Psychiatric Institute, New York, NY, USA
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | | | - Yan Li
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | | | - Jy-Kang Liou
- Department of Radiology, Taipei Veterans General Hospital, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Jiing-Feng Lirng
- Department of Radiology, Taipei Veterans General Hospital, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Feng Liu
- New York State Psychiatric Institute, New York, NY, USA
| | - Ruoyun Ma
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Celine Maes
- Department of Kinesiology, KU Leuven, Leuven, Belgium
| | | | - Scott O Murray
- Department of Psychology, University of Washington, Seattle, WA, USA
| | - Sean Noah
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | | | - Michael D Noseworthy
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada
| | - Georg Oeltzschner
- 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
| | - James J Prisciandaro
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Nicolaas A J Puts
- 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
| | - Timothy P L Roberts
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Markus Sack
- Department of Neuroimaging, Central Institute of Mental Health, Mannheim, Germany
| | - Napapon Sailasuta
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Muhammad G Saleh
- 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
| | | | - Nicholas Simard
- School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
| | - Stephan P Swinnen
- Department of Kinesiology, KU Leuven, Leuven, Belgium; Leuven Research Institute for Neuroscience & Disease (LIND), KU Leuven, Leuven, Belgium
| | - Martin Tegenthoff
- Department of Neurology, BG University Hospital Bergmannsheil, Bochum, Germany
| | - Peter Truong
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Guangbin Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Iain D Wilkinson
- Academic Unit of Radiology, University of Sheffield, Sheffield, UK
| | - Hans-Jörg Wittsack
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany
| | - Hongmin Xu
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chencheng Zhang
- Department of Functional Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Vadim Zipunnikov
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Helge J Zöllner
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany; Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University, Duesseldorf, Germany
| | - Richard A E Edden
- 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.
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66
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Divergent influences of anterior cingulate cortex GABA concentrations on the emotion circuitry. Neuroimage 2017; 158:136-144. [DOI: 10.1016/j.neuroimage.2017.06.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/18/2017] [Accepted: 06/21/2017] [Indexed: 01/15/2023] Open
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67
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Ford TC, Nibbs R, Crewther DP. Increased glutamate/GABA+ ratio in a shared autistic and schizotypal trait phenotype termed Social Disorganisation. Neuroimage Clin 2017; 16:125-131. [PMID: 28794973 PMCID: PMC5537407 DOI: 10.1016/j.nicl.2017.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/19/2017] [Accepted: 07/12/2017] [Indexed: 01/01/2023]
Abstract
Autism and schizophrenia are multi-dimensional spectrum disorders that have substantial phenotypic overlap. This overlap is readily identified in the non-clinical population, and has been conceptualised as Social Disorganisation (SD). This study investigates the balance of excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) concentrations in a non-clinical sample with high and low trait SD, as glutamate and GABA abnormalities are reported across the autism and schizophrenia spectrum disorders. Participants were 18 low (10 females) and 19 high (9 females) SD scorers aged 18 to 40 years who underwent 1H-MRS for glutamate and GABA+macromolecule (GABA+) concentrations in right and left hemisphere superior temporal (ST) voxels. Reduced GABA+ concentration (p = 0.03) and increased glutamate/GABA+ ratio (p = 0.003) in the right ST voxel for the high SD group was found, and there was increased GABA+ concentration in the left compared to right ST voxel (p = 0.047). Bilateral glutamate concentration was increased for the high SD group (p = 0.006); there was no hemisphere by group interaction (p = 0.772). Results suggest that a higher expression of the SD phenotype may be associated with increased glutamate/GABA+ ratio in the right ST region, which may affect speech prosody processing, and lead behavioural characteristics that are shared within the autistic and schizotypal spectra.
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Affiliation(s)
- Talitha C. Ford
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Richard Nibbs
- Swinburne Neuroimaging, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - David P. Crewther
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
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68
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Age-dependent, lasting effects of methylphenidate on the GABAergic system of ADHD patients. NEUROIMAGE-CLINICAL 2017; 15:812-818. [PMID: 28725548 PMCID: PMC5506880 DOI: 10.1016/j.nicl.2017.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/19/2017] [Accepted: 06/01/2017] [Indexed: 12/14/2022]
Abstract
Stimulants are the main pharmacological treatment for patients with attention-deficit/hyperactivity disorder (ADHD). Their current prescription rates are rising, both in children, adolescents and adults. Related to the impulse control phenotype, both preclinical and clinical studies have demonstrated lower γ-amino butyric acid (GABA) levels in prefrontal brain regions in ADHD. Whereas stimulant treatment increases GABA levels, preclinical studies have suggested that stimulant treatment effects may be age-dependent. As the long-term consequences of stimulant use in ADHD children and adolescents have so far been poorly studied, we used magnetic resonance spectroscopy to assess GABA+ and glutamate + glutamine (Glx) levels in the medial prefrontal cortex (mPFC) of adult ADHD patients, both before and after an oral methylphenidate (MPH) challenge. Three groups were studied: 1) ADHD patients who were first treated with stimulants before 16 years of age, i.e. during periods of ongoing brain development (early-stimulant-treated, EST); 2) patients first treated with stimulants in adulthood (i.e. > 23 years) (late-stimulant-treated, LST), and 3) stimulant-treatment-naive (STN) ADHD patients. Reduced basal GABA+ levels were found in EST compared to LST patients (p = 0.04), while after an MPH challenge, only the EST patients showed significant increases in GABA+ (p = 0.01). For Glx, no differences were found at baseline, nor after an MPH challenge. First stimulant exposure at a young age is thus associated with lower baseline levels of GABA+ and increased responsivity in adulthood. This effect could not be found in patients that started treatment at an adult age. Hence, while adult stimulant treatment seems to exert no major effects on GABA+ levels in the mPFC, MPH may induce long-lasting alterations in the adult mPFC GABAergic system when treatment was started at a young age.
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69
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Tapper S, Tisell A, Lundberg P. How does motion affect GABA-measurements? Order statistic filtering compared to conventional analysis of MEGA-PRESS MRS. PLoS One 2017; 12:e0177795. [PMID: 28520793 PMCID: PMC5433745 DOI: 10.1371/journal.pone.0177795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/03/2017] [Indexed: 01/07/2023] Open
Abstract
Purpose The aim of this study was to evaluate two post-processing techniques applied to MRS MEGA-PRESS data influenced by motion-induced artifacts. In contrast to the conventional averaging technique, order statistic filtering (OSF) is a known method for artifact reduction. Therefore, this method may be suitable to incorporate in the GABA quantification. Methods Twelve healthy volunteers were scanned three times using a 3 T MR system. One measurement protocol consisted of two MEGA-PRESS measurements, one reference measurement and one measurement including head motions. The resulting datasets were analyzed with the standard averaging technique and with the OSF-technique in two schemes; filtering phase cycles ‘RAW PC’ and filtering dynamics ‘RAW Dyn’. Results The datasets containing artifacts resulted in an underestimation of the concentrations. There was a trend for the OSF-technique to compensate for this reduction when quantifying SNR-intense signals. However, there was no indication that OSF improved the estimated GABA concentrations. Moreover, when only considering the reference measurements, the OSF technique was equally as effective as averaging, which suggests that the techniques are interchangeable. Conclusion OSF performed equally well as the conventional averaging technique for low-SNR signals. For high-SNR signals, OSF performed better and thus could be considered for routine usage.
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Affiliation(s)
- Sofie Tapper
- Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden
- Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- * E-mail:
| | - Anders Tisell
- Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden
- Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- Radiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Peter Lundberg
- Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden
- Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- Radiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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70
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Wyss C, Tse DHY, Kometer M, Dammers J, Achermann R, Shah NJ, Kawohl W, Neuner I. GABA metabolism and its role in gamma-band oscillatory activity during auditory processing: An MRS and EEG study. Hum Brain Mapp 2017; 38:3975-3987. [PMID: 28480987 DOI: 10.1002/hbm.23642] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) and glutamate are believed to have inhibitory and exhibitory neuromodulatory effects that regulate the brain's response to sensory perception. Furthermore, frequency-specific synchronization of neuronal excitability within the gamma band (30-80 Hz) is attributable to a homeostatic balance between excitation and inhibition. However, our understanding of the physiological mechanism underlying gamma rhythms is based on animal models. Investigations of the relationship between GABA concentrations, glutamate concentrations, and gamma band activity in humans were mostly restricted to the visual cortex and are conflicting. Here, we performed a multimodal imaging study combining magnetic resonance spectroscopy (MRS) with electroencephalography (EEG) in the auditory cortex. In 14 healthy subjects, we investigated the impact of individual differences in GABA and glutamate concentration on gamma band response (GBR) following auditory stimulus presentation. We explored the effects of bulk GABA on the GBR across frequency (30-200 Hz) and time (-200 to 600 ms) and found no significant relationship. Furthermore, no correlations were found between gamma peak frequency or power measures and metabolite concentrations (GABA, glutamate, and GABA/glutamate ratio). These findings suggest that, according to MRS measurements, and given the auditory stimuli used in this study, GABA and glutamate concentrations are unlikely to play a significant role in the inhibitory and excitatory drive in the generation of gamma band activity in the auditory cortex. Hum Brain Mapp 38:3975-3987, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Christine Wyss
- Department of Psychiatry, Psychotherapie and Psychosomatics, Hospital of Psychiatry, University of Zurich, Switzerland
| | - Desmond H Y Tse
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Germany
| | - Michael Kometer
- Department of Psychiatry, Psychotherapie and Psychosomatics, Hospital of Psychiatry, University of Zurich, Switzerland
| | - Jürgen Dammers
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Germany
| | - Rita Achermann
- Psychological Methods, Evaluation and Statistics, Department of Psychology, University of Zurich, Switzerland
| | - N Jon Shah
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Germany.,JARA-Brain, Translational Medicine, Jülich, Germany.,Department of Neurology, RWTH Aachen University, Germany
| | - Wolfram Kawohl
- Department of Psychiatry, Psychotherapie and Psychosomatics, Hospital of Psychiatry, University of Zurich, Switzerland
| | - Irene Neuner
- Institute of Neuroscience and Medicine, INM4, Forschungszentrum Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Germany.,JARA-Brain, Translational Medicine, Jülich, Germany
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71
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Levar N, van Leeuwen JMC, Puts NAJ, Denys D, van Wingen GA. GABA Concentrations in the Anterior Cingulate Cortex Are Associated with Fear Network Function and Fear Recovery in Humans. Front Hum Neurosci 2017; 11:202. [PMID: 28496404 PMCID: PMC5406467 DOI: 10.3389/fnhum.2017.00202] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 04/07/2017] [Indexed: 12/03/2022] Open
Abstract
Relapse of fear after successful treatment is a common phenomenon in patients with anxiety disorders. Animal research suggests that the inhibitory neurotransmitter γ-aminobutyric acid (GABA) plays a key role in the maintenance of extinguished fear. Here, we combined magnetic resonance spectroscopy and functional magnetic resonance imaging to investigate the role of GABA in fear recovery in 70 healthy male participants. We associated baseline GABA levels in the dorsal anterior cingulate cortex (dACC) to indices of fear recovery as defined by changes in skin conductance responses (SCRs), blood oxygen level dependent responses, and functional connectivity from fear extinction to fear retrieval. The results showed that high GABA levels were associated with increased SCRs, enhanced activation of the right amygdala, and reduced amygdala-ventromedial prefrontal cortex connectivity during fear recovery. Follow-up analyses exclusively for the extinction phase showed that high GABA levels were associated with reduced amygdala activation and enhanced amygdala-ventromedial prefrontal cortex connectivity, despite the absence of correlations between GABA and physiological responses. Follow-up analyses for the retrieval phase did not show any significant associations with GABA. Together, the association between GABA and increases in SCRs from extinction to retrieval, without associations during both phases separately, suggests that dACC GABA primarily inhibits the consolidation of fear extinction. In addition, the opposite effects of GABA on amygdala activity and connectivity during fear extinction compared to fear recovery suggest that dACC GABA may initially facilitate extinction learning.
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Affiliation(s)
- Nina Levar
- Department of Psychiatry, Academic Medical CenterAmsterdam, Netherlands.,Brain Imaging Center, Academic Medical CenterAmsterdam, Netherlands.,Amsterdam Brain and Cognition, University of AmsterdamAmsterdam, Netherlands.,Spinoza Center for NeuroimagingAmsterdam, Netherlands
| | - Judith M C van Leeuwen
- Department of Psychiatry, Academic Medical CenterAmsterdam, Netherlands.,Department of Psychiatry, University Medical Center UtrechtUtrecht, Netherlands
| | - Nicolaas A J Puts
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins UniversityBaltimore, MD, USA.,FM Kirby Center for Functional Brain Imaging, Kennedy Krieger InstituteBaltimore, MD, USA
| | - Damiaan Denys
- Department of Psychiatry, Academic Medical CenterAmsterdam, Netherlands.,Brain Imaging Center, Academic Medical CenterAmsterdam, Netherlands.,Amsterdam Brain and Cognition, University of AmsterdamAmsterdam, Netherlands.,Spinoza Center for NeuroimagingAmsterdam, Netherlands
| | - Guido A van Wingen
- Department of Psychiatry, Academic Medical CenterAmsterdam, Netherlands.,Brain Imaging Center, Academic Medical CenterAmsterdam, Netherlands.,Amsterdam Brain and Cognition, University of AmsterdamAmsterdam, Netherlands.,Spinoza Center for NeuroimagingAmsterdam, Netherlands
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72
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Liu B, Yang H, Gao F, Wang Q, Zhao B, Gong T, Wang Z, Chen W, Wang G, Edden RA. Investigation of brain GABA+ in primary hypothyroidism using edited proton MR spectroscopy. Clin Endocrinol (Oxf) 2017; 86:256-262. [PMID: 27581339 PMCID: PMC5512100 DOI: 10.1111/cen.13177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 07/17/2016] [Accepted: 08/30/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Evidence indicates that thyroid hormones have effects on the inhibitory GABAergic system. The aim of this study was to investigate whether brain GABA levels are altered in patients with hypothyroidism compared with healthy controls. DESIGN/METHODS Fifteen patients with primary hypothyroidism and 15 matched healthy controls underwent single-voxel MEGA-PRESS magnetic resonance spectroscopy at 3T, to quantify GABA levels in the median prefrontal cortex (mPFC) and posterior cingulate cortex (PCC). All participants underwent thyroid function test. Neuropsychological performances were evaluated by administration of the Montreal Cognitive Assessment (MoCA) and the 21-item Beck Depression Inventory-II (BDI-II). RESULTS The patients with hypothyroidism had significantly lower GABA+ levels in the mPFC compared with healthy controls (P = 0·016), whereas no significant difference (P = 0·214) was observed in the PCC. Exploratory analyses revealed that mPFC GABA+ levels were negatively correlated with the BDI-II scores in patient group (r = -0·60, P = 0·018). No correlations were found between GABA+ levels and TSH or fT3 or fT4 levels in either region (all P > 0·05). CONCLUSION This study suggests that alteration of GABAergic neurotransmission may play an important role in the pathophysiology of primary hypothyroidism, providing intriguing neurochemical clues to understand thyroid-brain interactions.
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Affiliation(s)
- Bo Liu
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Huan Yang
- Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China
| | - Fei Gao
- Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China
| | - Qing Wang
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Bin Zhao
- Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China
| | - Tao Gong
- Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China
| | - Zhensong Wang
- Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | | | - Guangbin Wang
- Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China
| | - Richard A.E. Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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73
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Wilke S, List J, Mekle R, Lindenberg R, Bukowski M, Ott S, Schubert F, Ittermann B, Flöel A. No Effect of Anodal Transcranial Direct Current Stimulation on Gamma-Aminobutyric Acid Levels in Patients with Recurrent Mild Traumatic Brain Injury. J Neurotrauma 2017; 34:281-290. [DOI: 10.1089/neu.2016.4399] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Skadi Wilke
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Jonathan List
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Ralf Mekle
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Robert Lindenberg
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Martin Bukowski
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Stefanie Ott
- Department of Neurology, Charité–University Hospital, Berlin, Germany
| | - Florian Schubert
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Berlin, Germany
| | - Agnes Flöel
- Department of Neurology, Charité–University Hospital, Berlin, Germany
- Center for Stroke Research Berlin, Charité–University Hospital, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité–University Hospital, Berlin, Germany
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Van Horn JD, Bhattrai A, Irimia A. Multimodal Imaging of Neurometabolic Pathology due to Traumatic Brain Injury. Trends Neurosci 2016; 40:39-59. [PMID: 27939821 DOI: 10.1016/j.tins.2016.10.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 12/28/2022]
Abstract
The impact of traumatic brain injury (TBI) involves a combination of complex biochemical processes beginning with the initial insult and lasting for days, months and even years post-trauma. These changes range from neuronal integrity losses to neurotransmitter imbalance and metabolite dysregulation, leading to the release of pro- or anti-apoptotic factors which mediate cell survival or death. Such dynamic processes affecting the brain's neurochemistry can be monitored using a variety of neuroimaging techniques, whose combined use can be particularly useful for understanding patient-specific clinical trajectories. Here, we describe how TBI changes the metabolism of essential neurochemical compounds, summarize how neuroimaging approaches facilitate the study of such alterations, and highlight promising ways in which neuroimaging can be used to investigate post-TBI changes in neurometabolism.
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Affiliation(s)
- John Darrell Van Horn
- USC Mark and Mary Stevens Neuroimaging and Informatics Institute, 2025 Zonal Avenue, Keck School of Medicine of USC, University of Southern California, Los Angeles, California 90033, USA.
| | - Avnish Bhattrai
- USC Mark and Mary Stevens Neuroimaging and Informatics Institute, 2025 Zonal Avenue, Keck School of Medicine of USC, University of Southern California, Los Angeles, California 90033, USA
| | - Andrei Irimia
- USC Mark and Mary Stevens Neuroimaging and Informatics Institute, 2025 Zonal Avenue, Keck School of Medicine of USC, University of Southern California, Los Angeles, California 90033, USA
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75
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Reckziegel D, Raschke F, Cottam WJ, Auer DP. Cingulate GABA levels inversely correlate with the intensity of ongoing chronic knee osteoarthritis pain. Mol Pain 2016; 12:12/0/1744806916650690. [PMID: 27206661 PMCID: PMC4956171 DOI: 10.1177/1744806916650690] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 04/15/2016] [Indexed: 11/16/2022] Open
Abstract
Background This study aims to investigate the role of the mid-anterior cingulate cortex γ-aminobutyric acid levels in chronic nociceptive pain. The molecular mechanisms of pain chronification are not well understood. In fibromyalgia, low mid-anterior cingulate cortex γ-aminobutyric acid was associated with high pain suggesting a role of prefrontal disinhibition. We hypothesize that mid-anterior cingulate cortex GABAergic disinhibition may underpin chronic pain independent of the pain etiology and comorbid negative affect. Proton magnetic resonance spectra were acquired at 3T from the mid-anterior cingulate cortex in 20 patients with chronic painful knee osteoarthritis, and 19 healthy pain-free individuals using a point resolved spectroscopy sequence optimized for detection of γ-aminobutyric acid. Participants underwent questionnaires for negative affect (depression and anxiety) and psychophysical pain phenotyping. Results No differences in mid-anterior cingulate cortex γ-aminobutyric acid or other metabolite levels were detected between groups. Ratings of perceived intensity of ongoing osteoarthritis pain were inversely correlated with γ-aminobutyric acid (r = −0.758, p < 0.001), but no correlations were seen for negative affect or pain thresholds. The pain γ-aminobutyric acid interrelation remained strong when controlling for depression (r = −0.820, p < 0.001). Combined levels of glutamine and glutamate were unrelated to psychometric or to pain thresholds. Conclusion Our study supports mid-anterior cingulate cortex γ-aminobutyric acid as a potential marker of pain severity in chronic nociceptive pain states independent of negative affect. The findings suggest that GABAergic disinhibition of the salience network may underlie sensitization to averse stimuli as a mechanism contributing to pain chronification.
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Affiliation(s)
- Diane Reckziegel
- Arthritis Research UK Pain Centre, University of Nottingham, UK Sir Peter Mansfield Imaging Centre, University of Nottingham, UK Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, UK
| | - Felix Raschke
- Sir Peter Mansfield Imaging Centre, University of Nottingham, UK Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, UK
| | - William J Cottam
- Arthritis Research UK Pain Centre, University of Nottingham, UK Sir Peter Mansfield Imaging Centre, University of Nottingham, UK Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, UK
| | - Dorothee P Auer
- Arthritis Research UK Pain Centre, University of Nottingham, UK Sir Peter Mansfield Imaging Centre, University of Nottingham, UK Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, UK
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76
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Myers JF, Nutt DJ, Lingford-Hughes AR. γ-aminobutyric acid as a metabolite: Interpreting magnetic resonance spectroscopy experiments. J Psychopharmacol 2016; 30:422-7. [PMID: 27005308 DOI: 10.1177/0269881116639298] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The current rise in the prevalence of magnetic resonance spectroscopy experiments to measure γ-aminobutyric acid in the living human brain is an exciting and productive area of research. As research spreads into clinical populations and cognitive research, it is important to fully understand the source of the magnetic resonance spectroscopy signal and apply appropriate interpretation to the results of the experiments. γ-aminobutyric acid is present in the brain not only as a neurotransmitter, but also in high intracellular concentrations, both as a transmitter precursor and a metabolite. γ-aminobutyric acid concentrations measured by magnetic resonance spectroscopy are not necessarily implicated in neurotransmission and therefore may reflect a very different brain activity to that commonly suggested. In this perspective, we examine some of the considerations to be taken in the interpretation of any γ-aminobutyric acid signal measured by magnetic resonance spectroscopy.
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Affiliation(s)
- James Fm Myers
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
| | - David J Nutt
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
| | - Anne R Lingford-Hughes
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, UK
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77
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Carmichael ST. Emergent properties of neural repair: elemental biology to therapeutic concepts. Ann Neurol 2016; 79:895-906. [PMID: 27043816 PMCID: PMC4884133 DOI: 10.1002/ana.24653] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 03/28/2016] [Accepted: 03/29/2016] [Indexed: 12/20/2022]
Abstract
Stroke is the leading cause of adult disability. The past decade has seen advances in basic science research of neural repair in stroke. The brain forms new connections after stroke, which have a causal role in recovery of function. Brain progenitors, including neuronal and glial progenitors, respond to stroke and initiate a partial formation of new neurons and glial cells. The molecular systems that underlie axonal sprouting, neurogenesis, and gliogenesis after stroke have recently been identified. Importantly, tractable drug targets exist within these molecular systems that might stimulate tissue repair. These basic science advances have taken the field to its first scientific milestone; the elemental principles of neural repair in stroke have been identified. The next stages in this field involve understanding how these elemental principles of recovery interact in the dynamic cellular systems of the repairing brain. Emergent principles arise out of the interaction of the fundamental or elemental principles in a system. In neural repair, the elemental principles of brain reorganization after stroke interact to generate higher order and distinct concepts of regenerative brain niches in cellular repair, neuronal networks in synaptic plasticity, and the distinction of molecular systems of neuroregeneration. Many of these emergent principles directly guide the development of new therapies, such as the necessity for spatial and temporal control in neural repair therapy delivery and the overlap of cancer and neural repair mechanisms. This review discusses the emergent principles of neural repair in stroke as they relate to scientific and therapeutic concepts in this field. Ann Neurol 2016;79:895–906
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Affiliation(s)
- S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA and UCLA Broad Stem Cell Center, University of California, Los Angeles, Los Angeles, CA
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78
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Ford TC, Crewther DP. A Comprehensive Review of the (1)H-MRS Metabolite Spectrum in Autism Spectrum Disorder. Front Mol Neurosci 2016; 9:14. [PMID: 27013964 PMCID: PMC4783404 DOI: 10.3389/fnmol.2016.00014] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/16/2016] [Indexed: 01/11/2023] Open
Abstract
Neuroimaging studies of neuropsychiatric behavior biomarkers across spectrum disorders are typically based on diagnosis, thus failing to account for the heterogeneity of multi-dimensional spectrum disorders such as autism (ASD). Control group trait phenotypes are also seldom reported. Proton magnetic resonance spectroscopy (1H-MRS) measures the abundance of neurochemicals such as neurotransmitters and metabolites and hence can probe disorder phenotypes at clinical and sub-clinical levels. This detailed review summarizes and critiques the current 1H-MRS research in ASD. The literature reports reduced N-acetylaspartate (NAA), glutamate and glutamine (Glx), γ-aminobutyric acid (GABA), creatine and choline, and increased glutamate for children with ASD. Adult studies are few and results are inconclusive. Overall, the literature has several limitations arising from differences in 1H-MRS methodology and sample demographics. We argue that more consistent methods and greater emphasis on phenotype studies will advance understanding of underlying cortical metabolite disturbance in ASD, and the detection, diagnosis, and treatment of ASD and other multi-dimensional psychiatric disorders.
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Affiliation(s)
- Talitha C Ford
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
| | - David P Crewther
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
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79
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Oeltzschner G, Butz M, Baumgarten TJ, Hoogenboom N, Wittsack HJ, Schnitzler A. Low visual cortex GABA levels in hepatic encephalopathy: links to blood ammonia, critical flicker frequency, and brain osmolytes. Metab Brain Dis 2015; 30:1429-38. [PMID: 26359122 DOI: 10.1007/s11011-015-9729-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/03/2015] [Indexed: 12/22/2022]
Abstract
The pathogenesis of hepatic encephalopathy (HE) is not fully understood yet. Hyperammonemia due to liver failure and subsequent disturbance of cerebral osmolytic balance is thought to play a pivotal role in the emergence of HE. The aim of this in-vivo MR spectroscopy study was to investigate the levels of γ-aminobutyric acid (GABA) and its correlations with clinical symptoms of HE, blood ammonia, critical flicker frequency, and osmolytic levels. Thirty patients with minimal HE or HE1 and 16 age-matched healthy controls underwent graduation of HE according to the West-Haven criteria and including the critical flicker frequency (CFF), neuropsychometric testing and blood testing. Edited proton magnetic resonance spectroscopy ((1)H MRS) was used to non-invasively measure the concentrations of GABA, glutamate (Glu), glutamine (Gln), and myo-inositol (mI) - all normalized to creatine (Cr) - in visual and sensorimotor cortex. GABA/Cr in the visual area was significantly decreased in mHE and HE1 patients and correlated both to the CFF (r = 0.401, P = 0.013) and blood ammonia levels (r = -0.434, P = 0.006). Visual GABA/Cr was also strongly linked to mI/Cr (r = 0.720, P < 0.001) and Gln/Cr (r = -0.699, P < 0.001). No group differences or correlations were found for GABA/Cr in the sensorimotor area. Hepatic encephalopathy is associated with a regional specific decrease of GABA levels in the visual cortex, while no changes were revealed for the sensorimotor cortex. Correlations of visual GABA/Cr with CFF, blood ammonia, and osmolytic regulators mI and Gln indicate that decreased visual GABA levels might contribute to HE symptoms, most likely as a consequence of hyperammonemia.
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Affiliation(s)
- Georg Oeltzschner
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany.
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University Düsseldorf, D-40225, Düsseldorf, Germany.
| | - Markus Butz
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
| | - Thomas J Baumgarten
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
| | - Nienke Hoogenboom
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
| | - Hans-Jörg Wittsack
- Medical Faculty, Department of Diagnostic and Interventional Radiology, University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
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80
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Kujala J, Jung J, Bouvard S, Lecaignard F, Lothe A, Bouet R, Ciumas C, Ryvlin P, Jerbi K. Gamma oscillations in V1 are correlated with GABA(A) receptor density: A multi-modal MEG and Flumazenil-PET study. Sci Rep 2015; 5:16347. [PMID: 26572733 PMCID: PMC4647220 DOI: 10.1038/srep16347] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/12/2015] [Indexed: 12/02/2022] Open
Abstract
High-frequency oscillations in the gamma-band reflect rhythmic synchronization of spike timing in active neural networks. The modulation of gamma oscillations is a widely established mechanism in a variety of neurobiological processes, yet its neurochemical basis is not fully understood. Modeling, in-vitro and in-vivo animal studies suggest that gamma oscillation properties depend on GABAergic inhibition. In humans, search for evidence linking total GABA concentration to gamma oscillations has led to promising -but also to partly diverging- observations. Here, we provide the first evidence of a direct relationship between the density of GABAA receptors and gamma oscillatory gamma responses in human primary visual cortex (V1). By combining Flumazenil-PET (to measure resting-levels of GABAA receptor density) and MEG (to measure visually-induced gamma oscillations), we found that GABAA receptor densities correlated positively with the frequency and negatively with amplitude of visually-induced gamma oscillations in V1. Our findings demonstrate that gamma-band response profiles of primary visual cortex across healthy individuals are shaped by GABAA-receptor-mediated inhibitory neurotransmission. These results bridge the gap with in-vitro and animal studies and may have future clinical implications given that altered GABAergic function, including dysregulation of GABAA receptors, has been related to psychiatric disorders including schizophrenia and depression.
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Affiliation(s)
- Jan Kujala
- Department of Neuroscience and Biomedical Engineering, Aalto University, 02150 Espoo, Finland.,Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France
| | - Julien Jung
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France.,Department of Epileptology and Functional Neurology, Lyon Neurological Hospital, F-69000, Lyon, France
| | - Sandrine Bouvard
- CERMEP imaging center, F-69003, Bron, France.,Institute for Child and Adolescent with Epilepsy (IDEE), F-69000, Lyon, France
| | - Françoise Lecaignard
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France.,CERMEP imaging center, F-69003, Bron, France
| | - Amélie Lothe
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France
| | - Romain Bouet
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France
| | - Carolina Ciumas
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France.,Institute for Child and Adolescent with Epilepsy (IDEE), F-69000, Lyon, France
| | - Philippe Ryvlin
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France.,Institute for Child and Adolescent with Epilepsy (IDEE), F-69000, Lyon, France.,Department of Clinical Neurosciences, CHUV, 1011, Lausanne, Switzerland
| | - Karim Jerbi
- Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR5292, F-69000, Lyon, France.,Department of Psychology, University of Montreal, H3C 3J7 Montreal, Québec, Canada
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81
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Huang Z, Davis HH, Yue Q, Wiebking C, Duncan NW, Zhang J, Wagner NF, Wolff A, Northoff G. Increase in glutamate/glutamine concentration in the medial prefrontal cortex during mental imagery: A combined functional mrs and fMRI study. Hum Brain Mapp 2015; 36:3204-12. [PMID: 26059006 DOI: 10.1002/hbm.22841] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 03/24/2015] [Accepted: 04/27/2015] [Indexed: 02/05/2023] Open
Abstract
Recent functional magnetic resonance spectroscopy (fMRS) studies have shown changes in glutamate/glutamine (Glx) concentrations between resting-state and active-task conditions. However, the types of task used have been limited to sensory paradigms, and the regions from which Glx concentrations have been measured limited to sensory ones. This leaves open the question as to whether the same effect can be seen in higher-order brain regions during cognitive tasks. Cortical midline structures, especially the medial prefrontal cortex (MPFC), have been suggested to be involved in various such cognitive tasks. We, therefore set out to use fMRS to investigate the dynamics of Glx concentrations in the MPFC between resting-state and mental imagery task conditions. The auditory cortex was used as a control region. In addition, functional magnetic resonance imaging was used to explore task-related neural activity changes. The mental imagery task consisted of imagining swimming and was applied to a large sample of healthy participants (n = 46). The participants were all competitive swimmers, ensuring proficiency in mental-swimming. Glx concentrations in the MPFC increased during the imagery task, as compared to resting-state periods preceding and following the task. These increases mirror BOLD activity changes in the same region during the task. No changes in either Glx concentrations or BOLD activity were seen in the auditory cortex. These findings contribute to our understanding of the biochemical basis of generating or manipulating mental representations and the MPFC's role in this.
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Affiliation(s)
- Zirui Huang
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada
| | | | - Qiang Yue
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, People's Republic of China
| | - Christine Wiebking
- Cluster of Excellence in Cognitive Sciences, Department of Sociology of Physical Activity and Health, University of Potsdam, Potsdam, 14469, Germany
| | - Niall W Duncan
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.,Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.,Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, 10001, Taiwan.,Brain and Consciousness Research Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City, 23561, Taiwan
| | - Jianfeng Zhang
- Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University, Hangzhou, 310015, People's Republic of China
| | - Nils-Frederic Wagner
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada
| | - Annemarie Wolff
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada
| | - Georg Northoff
- Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, K1Z 7K4, Canada.,Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, 310003, People's Republic of China.,Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, 10001, Taiwan.,Brain and Consciousness Research Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City, 23561, Taiwan.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University, Hangzhou, 310015, People's Republic of China.,Research Center for Mind, Brain and Learning, National Chengchi University, Taipei, 10001, Taiwan.,Department of Psychology, National Chengchi University, Taipei, 10001, Taiwan
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82
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Harris AD, Puts NAJ, Anderson BA, Yantis S, Pekar JJ, Barker PB, Edden RAE. Multi-regional investigation of the relationship between functional MRI blood oxygenation level dependent (BOLD) activation and GABA concentration. PLoS One 2015; 10:e0117531. [PMID: 25699994 PMCID: PMC4336183 DOI: 10.1371/journal.pone.0117531] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 12/06/2014] [Indexed: 11/19/2022] Open
Abstract
Several recent studies have reported an inter-individual correlation between regional GABA concentration, as measured by MRS, and the amplitude of the functional blood oxygenation level dependent (BOLD) response in the same region. In this study, we set out to investigate whether this coupling generalizes across cortex. In 18 healthy participants, we performed edited MRS measurements of GABA and BOLD-fMRI experiments using regionally related activation paradigms. Regions and tasks were the: occipital cortex with a visual grating stimulus; auditory cortex with a white noise stimulus; sensorimotor cortex with a finger-tapping task; frontal eye field with a saccade task; and dorsolateral prefrontal cortex with a working memory task. In contrast to the prior literature, no correlation between GABA concentration and BOLD activation was detected in any region. The origin of this discrepancy is not clear. Subtle differences in study design or insufficient power may cause differing results; these and other potential reasons for the discrepant results are discussed. This negative result, although it should be interpreted with caution, has a larger sample size than prior positive results, and suggests that the relationship between GABA and the BOLD response may be more complex than previously thought.
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Affiliation(s)
- Ashley D. Harris
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, United States of America
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
- * E-mail:
| | - Nicolaas A. J. Puts
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, United States of America
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
| | - Brian A. Anderson
- Department of Psychological and Brain Sciences, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Steven Yantis
- Department of Psychological and Brain Sciences, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - James J. Pekar
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, United States of America
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
| | - Peter B. Barker
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, United States of America
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
| | - Richard A. E. Edden
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, United States of America
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
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83
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Bridge H, Stagg CJ, Near J, Lau CI, Zisner A, Cader MZ. Altered neurochemical coupling in the occipital cortex in migraine with visual aura. Cephalalgia 2015; 35:1025-30. [PMID: 25631169 DOI: 10.1177/0333102414566860] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 12/06/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND Visual aura is present in about one-third of migraine patients and triggering by bright or flickering lights is frequently reported. METHOD Using migraine with visual aura patients, we investigated the neurochemical profile of the visual cortex using magnetic resonance spectroscopy. Specifically, glutamate/creatine and GABA/creatine ratios were quantified in the occipital cortex of female migraine patients. RESULTS GABA levels in the occipital cortex of migraine patients were lower than that of controls. Glutamate levels in migraine patients, but not controls, correlated with the blood-oxygenation-level-dependent (BOLD) signal in the primary visual cortex during visual stimulation. CONCLUSION Migraine with visual aura appears to disrupt the excitation-inhibition coupling in the occipital cortex.
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Affiliation(s)
- Holly Bridge
- Nuffield Department of Clinical Neuroscience, University of Oxford, UK Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, UK
| | - Charlotte J Stagg
- Nuffield Department of Clinical Neuroscience, University of Oxford, UK Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, UK Oxford Centre for Human Brain Activity, University of Oxford, UK
| | - Jamie Near
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Canada
| | - Chi-ieong Lau
- Department of Neurology, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Aimee Zisner
- Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, UK
| | - M Zameel Cader
- Nuffield Department of Clinical Neuroscience, University of Oxford, UK Oxford Headache Centre, John Radcliffe Hospital, Oxford, UK
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84
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Gao F, Wang G, Ma W, Ren F, Li M, Dong Y, Liu C, Liu B, Bai X, Zhao B, Edden RAE. Decreased auditory GABA+ concentrations in presbycusis demonstrated by edited magnetic resonance spectroscopy. Neuroimage 2014; 106:311-6. [PMID: 25463460 DOI: 10.1016/j.neuroimage.2014.11.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/02/2014] [Accepted: 11/11/2014] [Indexed: 12/14/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central auditory system. Altered GABAergic neurotransmission has been found in both the inferior colliculus and the auditory cortex in animal models of presbycusis. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, to date there has been a paucity of studies exploring changes to the GABA concentrations in the auditory region of patients with presbycusis. In this study, sixteen patients with presbycusis (5 males/11 females, mean age 63.1 ± 2.6 years) and twenty healthy controls (6 males/14 females, mean age 62.5 ± 2.3 years) underwent audiological and MRS examinations. Pure tone audiometry from 0.125 to 8 kHz and tympanometry were used to assess the hearing abilities of all subjects. The pure tone average (PTA; the average of hearing thresholds at 0.5, 1, 2 and 4 kHz) was calculated. The MEGA-PRESS sequence was used to measure GABA+ concentrations in 4 × 3 × 3 cm(3) volumes centered on the left and right Heschl's gyri. GABA+ concentrations were significantly lower in the presbycusis group compared to the control group (left auditory regions: p = 0.002, right auditory regions: p = 0.008). Significant negative correlations were observed between PTA and GABA+ concentrations in the presbycusis group (r = -0.57, p = 0.02), while a similar trend was found in the control group (r = -0.40, p = 0.08). These results are consistent with a hypothesis of dysfunctional GABAergic neurotransmission in the central auditory system in presbycusis and suggest a potential treatment target for presbycusis.
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Affiliation(s)
- Fei Gao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Guangbin Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Wen Ma
- The Central Hospital of Jinan City, Shandong University, Jinan, China
| | - Fuxin Ren
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Muwei Li
- College of Electronics and Information Engineering, Sichuan University, Chengdu, China
| | - Yuling Dong
- The Central Hospital of Jinan City, Shandong University, Jinan, China
| | - Cheng Liu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Bo Liu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Xue Bai
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Bin Zhao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
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85
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Cleve M, Gussew A, Reichenbach JR. In vivo detection of acute pain-induced changes of GABA+ and Glx in the human brain by using functional 1H MEGA-PRESS MR spectroscopy. Neuroimage 2014; 105:67-75. [PMID: 25462698 DOI: 10.1016/j.neuroimage.2014.10.042] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 02/01/2023] Open
Abstract
In vivo(1)H MR spectroscopic detection of pain associated metabolic changes in the human brain may allow for an objective evaluation of the perceived pain intensity and assessment of the involved neurotransmitters. Ultimately, it may lead to a deeper understanding of the mechanisms that underlie neuronal pain processing. The present study reports results of time-resolved measurements of acute heat pain induced changes of the excitatory (Glx) and inhibitory (GABA+) neurotransmitter turnover in the anterior cingulate cortex (ACC) and occipital cortex (OC) by using (1)H MEGA-PRESS spectroscopy. In ACC and OC, the ratio Glx/tCr increased by median values of 21.5% (p < 0.001) and 15.7% (p < 0.001), respectively. At the same time, GABA+/tCr decreased by median values of 15.1% (p = 0.114) in ACC and 12.7% (p < 0.001) in OC. To our knowledge, this study demonstrates for the first time the possibility of quantifying pain-induced neurotransmitter changes in the brain by using functional (1)H MEGA-PRESS. The increase of Glx/tCr may be ascribed to an elevated glutamatergic turnover, while the decrease of GABA+/tCr may reflect reduced activity of the inhibitory system in ACC and OC during pain processing.
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Affiliation(s)
- Marianne Cleve
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3 (Gebäude 5, MRT am Steiger), 07743 Jena, Germany.
| | - Alexander Gussew
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3 (Gebäude 5, MRT am Steiger), 07743 Jena, Germany.
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3 (Gebäude 5, MRT am Steiger), 07743 Jena, Germany.
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86
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Why are cortical GABA neurons relevant to internal focus in depression? A cross-level model linking cellular, biochemical and neural network findings. Mol Psychiatry 2014; 19:966-977. [PMID: 25048001 PMCID: PMC4169738 DOI: 10.1038/mp.2014.68] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 04/16/2014] [Accepted: 05/19/2014] [Indexed: 12/15/2022]
Abstract
Major depression is a complex and severe psychiatric disorder whose symptomatology encompasses a critical shift in awareness, especially in the balance from external to internal mental focus. This is reflected by unspecific somatic symptoms and the predominance of the own cognitions manifested in increased self-focus and rumination. We posit here that sufficient empirical data has accumulated to build a coherent biologic model that links these psychologic concepts and symptom dimensions to observed biochemical, cellular, regional and neural network deficits. Specifically, deficits in inhibitory γ-aminobutyric acid regulating excitatory cell input/output and local cell circuit processing of information in key brain regions may underlie the shift that is observed in depressed subjects in resting-state activities between the perigenual anterior cingulate cortex and the dorsolateral prefrontal cortex. This regional dysbalance translates at the network level in a dysbalance between default-mode and executive networks, which psychopathologically surfaces as a shift in focus from external to internal mental content and associated symptoms. We focus here on primary evidence at each of those levels and on putative mechanistic links between those levels. Apart from its implications for neuropsychiatric disorders, our model provides for the first time a set of hypotheses for cross-level mechanisms of how internal and external mental contents may be constituted and balanced in healthy subjects, and thus also contributes to the neuroscientific debate on the neural correlates of consciousness.
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87
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Associations of regional GABA and glutamate with intrinsic and extrinsic neural activity in humans—a review of multimodal imaging studies. Neurosci Biobehav Rev 2014; 47:36-52. [PMID: 25066091 DOI: 10.1016/j.neubiorev.2014.07.016] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 06/30/2014] [Accepted: 07/17/2014] [Indexed: 01/04/2023]
Abstract
The integration of multiple imaging modalities is becoming an increasingly well used research strategy for studying the human brain. The neurotransmitters glutamate and GABA particularly lend themselves towards such studies. This is because these transmitters are ubiquitous throughout the cortex, where they are the key constituents of the inhibition/excitation balance, and because they can be easily measured in vivo through magnetic resonance spectroscopy, as well as with select positron emission tomography approaches. How these transmitters underly functional responses measured with techniques such as fMRI and EEG remains unclear though, and was the target of this review. Consistently shown in the literature was a negative correlation between GABA concentrations and stimulus-induced activity within the measured region. Also consistently found was a positive correlation between glutamate concentrations and inter-regional activity relationships, both during tasks and rest. These findings are outlined along with results from populations with mental disorders to give an overview of what brain imaging has suggested to date about the biochemical underpinnings of functional activity in health and disease. We conclude that the combination of functional and biochemical imaging in humans is an increasingly informative approach that does however require a number of key methodological and interpretive issues be addressed before can meet its potential.
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88
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Resting GABA and glutamate concentrations do not predict visual gamma frequency or amplitude. Proc Natl Acad Sci U S A 2014; 111:9301-6. [PMID: 24927588 DOI: 10.1073/pnas.1321072111] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gamma band oscillations arise in neuronal networks of interconnected GABAergic interneurons and excitatory pyramidal cells. A previous study found a correlation between visual gamma peak frequency, as measured with magnetoencephalography, and resting GABA levels, as measured with magnetic resonance spectroscopy (MRS), in 12 healthy volunteers. If true, this would allow studies in clinical populations testing modulation of this relationship, but this finding has not been replicated. We addressed this important question by measuring gamma oscillations and GABA, as well as glutamate, in 50 healthy volunteers. Visual gamma activity was evoked using an established gratings paradigm, and we applied a beamformer spatial filtering technique to extract source-reconstructed gamma peak frequency and amplitude from the occipital lobe. We determined gamma peak frequency and amplitude from the location with maximal activation and from the location of the MRS voxel to assess the relationship of GABA with gamma. Gamma peak frequency was estimated from the highest value of the raw spectra and by a Gaussian fit to the spectra. MRS data were acquired from occipital cortex. We did not replicate the previously found correlation between gamma peak frequency and GABA concentration. Calculation of a Bayes factor provided strong evidence in favor of the null hypothesis. We also did not find a correlation between gamma activity and glutamate or between gamma and the ratio of GABA/glutamate. Our results suggest that cortical gamma oscillations do not have a consistent, demonstrable relationship to excitatory/inhibitory network activity as proxied by MRS measurements of GABA and glutamate.
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89
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Myers JFM, Evans CJ, Kalk NJ, Edden RAE, Lingford-Hughes AR. Measurement of GABA using J-difference edited 1H-MRS following modulation of synaptic GABA concentration with tiagabine. Synapse 2014; 68:355-62. [PMID: 24756906 DOI: 10.1002/syn.21747] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 03/28/2014] [Accepted: 04/17/2014] [Indexed: 12/26/2022]
Abstract
Though GABA is the major inhibitory neurotransmitter in the brain, involved in a wide variety of brain functions and many neuropsychiatric disorders, its intracellular and metabolic presence provides uncertainty in the interpretation of the GABA signal measured by (1)H-MRS. Previous studies demonstrating the sensitivity of this technique to pharmacological manipulations of GABA have used nonspecific challenges that make it difficult to infer the exact source of the changes. In this study, the synaptic GABA reuptake inhibitor tiagabine, which selectively blocks GAT1, was used to test the sensitivity of J-difference edited (1)H-MRS to changes in extracellular GABA concentrations. MEGA-PRESS was used to obtain GABA-edited spectra in 10 male individuals, before and after a 15-mg oral dose of tiagabine. In the three voxels measured, no significant changes were found in GABA+ concentration after the challenge compared to baseline. This dose of tiagabine is known to modulate synaptic GABA and neurotransmission through studies using other imaging modalities, and significant increases in self-reported sleepiness scales were observed. Therefore, it is concluded that recompartmentalization of GABA through transport block does not have a significant impact on total GABA concentration. Furthermore, it is likely that the majority of the magnetic resonance spectroscopy (MRS)-derived GABA signal is intracellular. It should be considered, in individual interpretation of GABA MRS studies, whether it is appropriate to attribute observed effects to changes in neurotransmission.
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Affiliation(s)
- James F M Myers
- Division of Brain Sciences, Centre for Neuropsychopharmacology, Imperial College London, London, W12 0NN, United Kingdom; Psychopharmacology Unit, University of Bristol, Bristol, BS8 2BN, United Kingdom
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90
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de la Vega A, Brown MS, Snyder HR, Singel D, Munakata Y, Banich MT. Individual differences in the balance of GABA to glutamate in pFC predict the ability to select among competing options. J Cogn Neurosci 2014; 26:2490-502. [PMID: 24742191 DOI: 10.1162/jocn_a_00655] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Individuals vary greatly in their ability to select one item or response when presented with a multitude of options. Here we investigate the neural underpinnings of these individual differences. Using magnetic resonance spectroscopy, we found that the balance of inhibitory versus excitatory neurotransmitters in pFC predicts the ability to select among task-relevant options in two language production tasks. The greater an individual's concentration of GABA relative to glutamate in the lateral pFC, the more quickly he or she could select a relevant word from among competing options. This outcome is consistent with our computational modeling of this task [Snyder, H. R., Hutchison, N., Nyhus, E., Curran, T., Banich, M. T., O'Reilly, R. C., et al. Neural inhibition enables selection during language processing. Proceedings of the National Academy of Sciences, U.S.A., 107, 16483-16488, 2010], which predicts that greater net inhibition in pFC increases the efficiency of resolving competition among task-relevant options. Moreover, the association with the GABA/glutamate ratio was specific to selection and was not observed for executive function ability in general. These findings are the first to link the balance of excitatory and inhibitory neural transmission in pFC to specific aspects of executive function.
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91
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Silveri MM. GABAergic contributions to alcohol responsivity during adolescence: insights from preclinical and clinical studies. Pharmacol Ther 2014; 143:197-216. [PMID: 24631274 DOI: 10.1016/j.pharmthera.2014.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 02/28/2014] [Indexed: 01/04/2023]
Abstract
There is a considerable body of literature demonstrating that adolescence is a unique age period, which includes rapid and dramatic maturation of behavioral, cognitive, hormonal and neurobiological systems. Most notably, adolescence is also a period of unique responsiveness to alcohol effects, with both hyposensitivity and hypersensitivity observed to the various effects of alcohol. Multiple neurotransmitter systems are undergoing fine-tuning during this critical period of brain development, including those that contribute to the rewarding effects of drugs of abuse. The role of developmental maturation of the γ-amino-butyric acid (GABA) system, however, has received less attention in contributing to age-specific alcohol sensitivities. This review integrates GABA findings from human magnetic resonance spectroscopy studies as they may translate to understanding adolescent-specific responsiveness to alcohol effects. Better understanding of the vulnerability of the GABA system both during adolescent development, and in psychiatric conditions that include alcohol dependence, could point to a putative mechanism, boosting brain GABA, that may have increased effectiveness for treating alcohol use disorders.
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Affiliation(s)
- Marisa M Silveri
- Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
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92
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Silveri MM, Cohen-Gilbert J, Crowley DJ, Rosso IM, Jensen JE, Sneider JT. Altered anterior cingulate neurochemistry in emerging adult binge drinkers with a history of alcohol-induced blackouts. Alcohol Clin Exp Res 2014; 38:969-79. [PMID: 24512596 DOI: 10.1111/acer.12346] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/22/2013] [Indexed: 01/17/2023]
Abstract
BACKGROUND Binge alcohol consumption is associated with multiple neurobiological consequences, including altered neurophysiology, brain structure, and functional activation. Magnetic resonance spectroscopy (MRS) studies have demonstrated neurochemical alterations in the frontal lobe of alcohol users, although most studies focused on older, alcohol-dependent subjects. METHODS In this study, neurochemical data were acquired using MRS at 4.0 Tesla from emerging adults (18 to 24 years old) who were binge alcohol drinkers (BD, n = 23) or light drinkers (LD, n = 31). Since binge drinking is also associated with increased prevalence of experiencing an alcohol-induced blackout, BD were stratified into alcohol-induced blackout (BDBO) and non-blackout (BDN) groups. RESULTS Overall, BD had significantly lower gamma amino-butyric acid (GABA) and N-acetyl-aspartate (NAA) in the anterior cingulate cortex (ACC) than LD. When stratified by blackout history, BDBO also had lower ACC glutamate (Glu) than LD. No group differences in MRS metabolites were observed in the parietal-occipital cortex. Lower ACC GABA and Glu remained significant after accounting for lower gray matter content in BD, however, NAA differences were no longer evident. In addition, low ACC GABA levels were associated with greater alcohol use consequences, and worse response inhibition and attention/mental flexibility in BD. CONCLUSIONS These data indicate that binge drinking affects frontal lobe neurochemistry, more so in those who had experienced an alcohol-induced blackout. Characterization of the neurochemical profiles associated with binge alcohol consumption and blackout history may help identify unique risk factors for the later manifestation of alcohol abuse and dependence, in young individuals who are heavy, frequent drinkers, but who do not meet the criteria for alcohol abuse disorders.
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Affiliation(s)
- Marisa M Silveri
- Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, Massachusetts; McLean Imaging Center, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
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93
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Stagg CJ. Magnetic Resonance Spectroscopy as a tool to study the role of GABA in motor-cortical plasticity. Neuroimage 2014; 86:19-27. [DOI: 10.1016/j.neuroimage.2013.01.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 11/16/2012] [Accepted: 01/07/2013] [Indexed: 11/16/2022] Open
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94
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Rosso IM, Weiner MR, Crowley DJ, Silveri MM, Rauch SL, Jensen JE. Insula and anterior cingulate GABA levels in posttraumatic stress disorder: preliminary findings using magnetic resonance spectroscopy. Depress Anxiety 2014; 31:115-23. [PMID: 23861191 PMCID: PMC3894264 DOI: 10.1002/da.22155] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/31/2013] [Accepted: 06/12/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Increased reactivity of the insular cortex and decreased activity of the dorsal anterior cingulate cortex (ACC) are seen in functional imaging studies of posttraumatic stress disorder (PTSD), and may partly explain the persistent fear and anxiety proneness that characterize the disorder. A possible neurochemical correlate is altered function of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). We report results from what we believe is the first study applying proton magnetic resonance spectroscopy ((1) H-MRS) to measure brain GABA in PTSD. METHODS Thirteen adults with DSM-IV PTSD and 13 matched healthy control subjects underwent single voxel (1) H-MRS at 4 Tesla. GABA was measured in the right anterior insula and dorsal ACC, using Mescher-Garwood Point-Resolved Echo Spectroscopy Sequence (MEGAPRESS) spectral editing. Subjects were interviewed with the Structured Clinical Interview for DSM-IV and the Clinician Administered PTSD Scale, and also completed the State and Trait Anxiety Inventory. RESULTS Insula GABA was significantly lower in PTSD subjects than in controls, and dorsal ACC GABA did not differ significantly between the groups. Insula GABA was not significantly associated with severity of PTSD symptoms. However, lower insula GABA was associated with significantly higher state and trait anxiety in the subject sample as a whole. CONCLUSIONS PTSD is associated with reduced GABA in the right anterior insula. This preliminary evidence of the (1) H-MRS GABA metabolite as a possible biomarker of PTSD encourages replication in larger samples and examination of relations with symptom dimensions. Future studies also should examine whether insula GABA is a marker of anxiety proneness, cutting across clinical diagnostic categories.
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Affiliation(s)
- Isabelle M. Rosso
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, MA,Department of Psychiatry, Harvard Medical School, Boston, MA
| | - Melissa R. Weiner
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, MA
| | - Davidan J Crowley
- Department of Psychiatry, Harvard Medical School, Boston, MA,Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, MA,McLean Imaging Center, McLean Hospital, Belmont, MA
| | - Marisa M. Silveri
- Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, MA,McLean Imaging Center, McLean Hospital, Belmont, MA
| | - Scott L. Rauch
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, MA,Department of Psychiatry, Harvard Medical School, Boston, MA
| | - J. Eric Jensen
- Department of Psychiatry, Harvard Medical School, Boston, MA,McLean Imaging Center, McLean Hospital, Belmont, MA
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95
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Bestmann S, Feredoes E. Combined neurostimulation and neuroimaging in cognitive neuroscience: past, present, and future. Ann N Y Acad Sci 2013; 1296:11-30. [PMID: 23631540 PMCID: PMC3760762 DOI: 10.1111/nyas.12110] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Modern neurostimulation approaches in humans provide controlled inputs into the operations of cortical regions, with highly specific behavioral consequences. This enables causal structure–function inferences, and in combination with neuroimaging, has provided novel insights into the basic mechanisms of action of neurostimulation on distributed networks. For example, more recent work has established the capacity of transcranial magnetic stimulation (TMS) to probe causal interregional influences, and their interaction with cognitive state changes. Combinations of neurostimulation and neuroimaging now face the challenge of integrating the known physiological effects of neurostimulation with theoretical and biological models of cognition, for example, when theoretical stalemates between opposing cognitive theories need to be resolved. This will be driven by novel developments, including biologically informed computational network analyses for predicting the impact of neurostimulation on brain networks, as well as novel neuroimaging and neurostimulation techniques. Such future developments may offer an expanded set of tools with which to investigate structure–function relationships, and to formulate and reconceptualize testable hypotheses about complex neural network interactions and their causal roles in cognition.
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Affiliation(s)
- Sven Bestmann
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, United Kingdom.
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96
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Tremblay S, Beaulé V, Proulx S, de Beaumont L, Marjanska M, Doyon J, Pascual-Leone A, Lassonde M, Théoret H. Relationship between transcranial magnetic stimulation measures of intracortical inhibition and spectroscopy measures of GABA and glutamate+glutamine. J Neurophysiol 2012; 109:1343-9. [PMID: 23221412 DOI: 10.1152/jn.00704.2012] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can provide an index of intracortical excitability/inhibition balance. However, the neurochemical substrate of these measures remains unclear. Pharmacological studies suggest the involvement of GABAA and GABAB receptors in TMS protocols aimed at measuring intracortical inhibition, but this link remains inferential. Proton magnetic resonance spectroscopy ((1)H-MRS) permits measurement of GABA and glutamate + glutamine (Glx) concentrations in the human brain and might help in the direct empirical assessment of the relationship between TMS inhibitory measures and neurotransmitter concentrations. In the present study, MRS-derived relative concentrations of GABA and Glx measured in the left M1 of healthy participants were correlated with TMS measures of intracortical inhibition. Glx levels were found to correlate positively with TMS-induced silent period duration, whereas no correlation was found between GABA concentration and TMS measures. The present data demonstrate that specific TMS measures of intracortical inhibition are linked to shifts in cortical Glx, rather than GABA neurotransmitter levels. Glutamate might specifically interact with GABAB receptors, where higher MRS-derived Glx concentrations seem to be linked to higher levels of receptor activity.
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Affiliation(s)
- Sara Tremblay
- Centre de recherche en neuropsychologie et cognition, Université de Montréal, Montreal, Quebec, Canada
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97
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Muthukumaraswamy SD, Myers JFM, Wilson SJ, Nutt DJ, Lingford-Hughes A, Singh KD, Hamandi K. The effects of elevated endogenous GABA levels on movement-related network oscillations. Neuroimage 2012; 66:36-41. [PMID: 23110884 DOI: 10.1016/j.neuroimage.2012.10.054] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/13/2012] [Accepted: 10/07/2012] [Indexed: 10/27/2022] Open
Abstract
The EEG/MEG signal is generated primarily by the summation of the post-synaptic potentials of cortical principal cells. At a microcircuit level, these glutamatergic principal cells are reciprocally connected to GABAergic interneurons and cortical oscillations are thought to be dependent on the balance of excitation and inhibition between these cell types. To investigate the dependence of movement-related cortical oscillations on excitation-inhibition balance, we pharmacologically manipulated the GABA system using tiagabine, which blocks GABA Transporter 1(GAT-1), the GABA uptake transporter and increases endogenous GABA activity. In a blinded, placebo-controlled, crossover design, in 15 healthy participants we administered either 15mg of tiagabine or a placebo. We recorded whole-head magnetoencephalograms, while the participants performed a movement task, prior to, one hour post, three hour post and five hour post tiagabine ingestion. Using time-frequency analysis of beamformer source reconstructions, we quantified the baseline level of beta activity (15-30Hz), the post-movement beta rebound (PMBR), beta event-related desynchronisation (beta-ERD) and movement-related gamma synchronisation (MRGS) (60-90Hz). Our results demonstrated that tiagabine, and hence elevated endogenous GABA levels causes, an elevation of baseline beta power, enhanced beta-ERD and reduced PMBR, but no modulation of MRGS. Comparing our results to recent literature (Hall et al., 2011) we suggest that beta-ERD may be a GABAA receptor mediated process while PMBR may be GABAB receptor mediated.
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Affiliation(s)
| | - J F M Myers
- Psychopharmacology Unit, School of Social and Community Medicine, University of Bristol, BS8 2BN, UK
| | - S J Wilson
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, W12 0NN, UK
| | - D J Nutt
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, W12 0NN, UK
| | - A Lingford-Hughes
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, W12 0NN, UK
| | - K D Singh
- CUBRIC, School of Psychology, Cardiff University, Cardiff, CF103AT, UK
| | - K Hamandi
- The Epilepsy Unit, University Hospital of Wales, Cardiff, CF14 4XW, UK
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98
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Nitsche MA, Müller-Dahlhaus F, Paulus W, Ziemann U. The pharmacology of neuroplasticity induced by non-invasive brain stimulation: building models for the clinical use of CNS active drugs. J Physiol 2012; 590:4641-62. [PMID: 22869014 DOI: 10.1113/jphysiol.2012.232975] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The term neuroplasticity encompasses structural and functional modifications of neuronal connectivity. Abnormal neuroplasticity is involved in various neuropsychiatric diseases, such as dystonia, epilepsy, migraine, Alzheimer's disease, fronto-temporal degeneration, schizophrenia, and post cerebral stroke. Drugs affecting neuroplasticity are increasingly used as therapeutics in these conditions. Neuroplasticity was first discovered and explored in animal experimentation. However, non-invasive brain stimulation (NIBS) has enabled researchers recently to induce and study similar processes in the intact human brain. Plasticity induced by NIBS can be modulated by pharmacological interventions, targeting ion channels, or neurotransmitters. Importantly, abnormalities of plasticity as studied by NIBS are directly related to clinical symptoms in neuropsychiatric diseases. Therefore, a core theme of this review is the hypothesis that NIBS-induced plasticity can explore and potentially predict the therapeutic efficacy of CNS-acting drugs in neuropsychiatric diseases. We will (a) review the basics of neuroplasticity, as explored in animal experimentation, and relate these to our knowledge about neuroplasticity induced in humans by NIBS techniques. We will then (b) discuss pharmacological modulation of plasticity in animals and humans. Finally, we will (c) review abnormalities of plasticity in neuropsychiatric diseases, and discuss how the combination of NIBS with pharmacological intervention may improve our understanding of the pathophysiology of abnormal plasticity in these diseases and their purposeful pharmacological treatment.
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Affiliation(s)
- Michael A Nitsche
- M. A. Nitsche: Georg-August-University, University Medical Centre, Dept Clinical Neurophysiology, Robert-Koch-Str. 40, 37099 Göttingen, Germany.
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