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Liu X, Li Y, Mo Y, Chen B, Hou X, Zhu J, Xu Y, Xue J, Wen H, Wang X, Wen Z. GABAergic imbalance in Parkinson's disease-related depression determined with MEGA-PRESS. Neuroimage Clin 2024; 43:103641. [PMID: 39032208 DOI: 10.1016/j.nicl.2024.103641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 07/10/2024] [Accepted: 07/10/2024] [Indexed: 07/22/2024]
Abstract
OBJECTIVE The pathogenesis of depression in patients with Parkinson's disease (PD) is poorly understood. Therefore, this study aimed to explore the changes in γ-aminobutyric acid (GABA) and glutamate plus glutamine (Glx) levels in patients with PD with or without depression determined using MEscher-GArwood Point Resolved Spectroscopy (MEGA-PRESS). MATERIALS AND METHODS A total of 83 patients with primary PD and 24 healthy controls were included. Patients with PD were categorized into depressed PD (DPD, n = 19) and nondepressed PD (NDPD, n = 64) based on the 17-item Hamilton Depression Rating Scale. All participants underwent T1-weighted imaging and MEGA-PRESS sequence to acquire GABA+ and Glx values. The MEGA-PRESS sequence was conducted using 18.48 mL voxels in the left thalamus and medial frontal cortex. The GABA+, Glx, and creatine values were quantified using Gannet 3.1 software. RESULTS The GABA+ and Glx values were not significantly disparate between patients with PD and controls in the thalamus and medial frontal cortex. However, the levels of N-acetyl aspartate/creatine and choline/creatine in the left thalamus were significantly lower in patients with PD than in controls (P = .031, P = .009). The GABA+/Water and GABA+/Creatine in the medial frontal cortex were higher in DPD than in NDPD (P = .001, P = .004). The effects of depression on Glx or other metabolite levels were not evident, and no significant difference in metabolite values was noted in the left thalamus among all groups (P > .05). CONCLUSIONS GABA+ levels increased in the medial frontal cortex in DPD, which may be more closely related to depressive pathology. Thus, alterations in GABAergic function in special brain structures may be related to the clinical manifestations of PD symptoms, and hence mediating this function might help in treating depression in PD.
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Affiliation(s)
- Xinzi Liu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yuxin Li
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yixiang Mo
- Department of Functional Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Baoling Chen
- Department of Neurology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xusheng Hou
- Department of Functional Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jianbin Zhu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | | | - Jingyue Xue
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Haitao Wen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xianlong Wang
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhibo Wen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
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Jafarian A, Hughes LE, Adams NE, Lanskey JH, Naessens M, Rouse MA, Murley AG, Friston KJ, Rowe JB. Neurochemistry-enriched dynamic causal models of magnetoencephalography, using magnetic resonance spectroscopy. Neuroimage 2023; 276:120193. [PMID: 37244323 DOI: 10.1016/j.neuroimage.2023.120193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 05/11/2023] [Accepted: 05/24/2023] [Indexed: 05/29/2023] Open
Abstract
We present a hierarchical empirical Bayesian framework for testing hypotheses about neurotransmitters' concertation as empirical prior for synaptic physiology using ultra-high field magnetic resonance spectroscopy (7T-MRS) and magnetoencephalography data (MEG). A first level dynamic causal modelling of cortical microcircuits is used to infer the connectivity parameters of a generative model of individuals' neurophysiological observations. At the second level, individuals' 7T-MRS estimates of regional neurotransmitter concentration supply empirical priors on synaptic connectivity. We compare the group-wise evidence for alternative empirical priors, defined by monotonic functions of spectroscopic estimates, on subsets of synaptic connections. For efficiency and reproducibility, we used Bayesian model reduction (BMR), parametric empirical Bayes and variational Bayesian inversion. In particular, we used Bayesian model reduction to compare alternative model evidence of how spectroscopic neurotransmitter measures inform estimates of synaptic connectivity. This identifies the subset of synaptic connections that are influenced by individual differences in neurotransmitter levels, as measured by 7T-MRS. We demonstrate the method using resting-state MEG (i.e., task-free recording) and 7T-MRS data from healthy adults. Our results confirm the hypotheses that GABA concentration influences local recurrent inhibitory intrinsic connectivity in deep and superficial cortical layers, while glutamate influences the excitatory connections between superficial and deep layers and connections from superficial to inhibitory interneurons. Using within-subject split-sampling of the MEG dataset (i.e., validation by means of a held-out dataset), we show that model comparison for hypothesis testing can be highly reliable. The method is suitable for applications with magnetoencephalography or electroencephalography, and is well-suited to reveal the mechanisms of neurological and psychiatric disorders, including responses to psychopharmacological interventions.
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Affiliation(s)
- Amirhossein Jafarian
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Laura E Hughes
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Natalie E Adams
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom.
| | - Juliette H Lanskey
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Michelle Naessens
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Matthew A Rouse
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Alexander G Murley
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom.
| | - Karl J Friston
- The Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, United Kingdom.
| | - James B Rowe
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
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Peek AL, Rebbeck TJ, Leaver AM, Foster SL, Refshauge KM, Puts NA, Oeltzschner G. A comprehensive guide to MEGA-PRESS for GABA measurement. Anal Biochem 2023; 669:115113. [PMID: 36958511 PMCID: PMC10805000 DOI: 10.1016/j.ab.2023.115113] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/25/2023]
Abstract
The aim of this guideline is to provide a series of evidence-based recommendations that allow those new to using MEGA-PRESS to produce high-quality data for the measurement of GABA levels using edited magnetic resonance spectroscopy with the MEGA-PRESS sequence at 3T. GABA is the main inhibitory neurotransmitter of the central nervous system and has been increasingly studied due to its relevance in many clinical disorders of the central nervous system. MEGA-PRESS is the most widely used method for quantification of GABA at 3T, but is technically challenging and operates at a low signal-to-noise ratio. Therefore, the acquisition of high-quality MRS data relies on avoiding numerous pitfalls and observing important caveats. The guideline was developed by a working party that consisted of experts in MRS and experts in guideline development and implementation, together with key stakeholders. Strictly following a translational framework, we first identified evidence using a systematically conducted scoping literature review, then synthesized and graded the quality of evidence that formed recommendations. These recommendations were then sent to a panel of 21 world leaders in MRS for feedback and approval using a modified-Delphi process across two rounds. The final guideline consists of 23 recommendations across six domains essential for GABA MRS acquisition (Parameters, Practicalities, Data acquisition, Confounders, Quality/reporting, Post-processing). Overall, 78% of recommendations were formed from high-quality evidence, and 91% received agreement from over 80% of the expert panel. These 23 expert-reviewed recommendations and accompanying extended documentation form a readily useable guideline to allow those new to using MEGA-PRESS to design appropriate MEGA-PRESS study protocols and generate high-quality data.
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Affiliation(s)
- A L Peek
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia.
| | - T J Rebbeck
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia.
| | - A M Leaver
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia.
| | - S L Foster
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia; Department of Radiology, Westmead Hospital, Hawkesbury Road, Westmead, New South Wales, 2145, Australia.
| | - K M Refshauge
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, 2141, Australia.
| | - N A Puts
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, Kings College London, UK.
| | - G Oeltzschner
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, 21205, United States.
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4
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Lin SHN, Lien YR, Shibata K, Sasaki Y, Watanabe T, Lin CP, Chang LH. The phase of plasticity-induced neurochemical changes of high-frequency repetitive transcranial magnetic stimulation are different from visual perceptual learning. Sci Rep 2023; 13:5720. [PMID: 37029245 PMCID: PMC10082079 DOI: 10.1038/s41598-023-32985-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 04/05/2023] [Indexed: 04/09/2023] Open
Abstract
Numerous studies have found that repetitive transcranial magnetic stimulation (rTMS) modulates plasticity. rTMS has often been used to change neural networks underlying learning, often under the assumption that the mechanism of rTMS-induced plasticity should be highly similar to that associated with learning. The presence of visual perceptual learning (VPL) reveals the plasticity of early visual systems, which is formed through multiple phases. Hence, we tested how high-frequency (HF) rTMS and VPL modulate the effect of visual plasticity by investigating neurometabolic changes in early visual areas. We employed an excitatory-to-inhibitory (E/I) ratio, which refers to glutamate concentration divided by GABA+ concentration, as an index of the degree of plasticity. We compared neurotransmitter concentration changes after applying HF rTMS to the visual cortex with those after training in a visual task, in otherwise identical procedures. Both the time courses of the E/I ratios and neurotransmitter contributions to the E/I ratio significantly differed between HF rTMS and training conditions. The peak E/I ratio occurred 3.5 h after HF rTMS with decreased GABA+, whereas the peak E/I ratio occurred 0.5 h after visual training with increased glutamate. Furthermore, HF rTMS temporally decreased the thresholds for detecting phosphene and perceiving low-contrast stimuli, indicating increased visual plasticity. These results suggest that plasticity in early visual areas induced by HF rTMS is not as involved in the early phase of development of VPL that occurs during and immediately after training.
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Affiliation(s)
- Shang-Hua N Lin
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yun R Lien
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | | | - Yuka Sasaki
- Department of Cognitive, Linguistics, and Psychological Sciences, Brown University, Providence, USA
| | - Takeo Watanabe
- Department of Cognitive, Linguistics, and Psychological Sciences, Brown University, Providence, USA
| | - Ching-Po Lin
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Li-Hung Chang
- Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Institute of Philosophy of Mind and Cognition, National Yang Ming Chiao Tung University, Taipei, Taiwan.
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5
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Mancini V, Rochas V, Seeber M, Grent-'t-Jong T, Rihs TA, Latrèche C, Uhlhaas PJ, Michel CM, Eliez S. Oscillatory Neural Signatures of Visual Perception Across Developmental Stages in Individuals With 22q11.2 Deletion Syndrome. Biol Psychiatry 2022; 92:407-418. [PMID: 35550793 DOI: 10.1016/j.biopsych.2022.02.961] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 12/28/2022]
Abstract
BACKGROUND Numerous behavioral studies have highlighted the contribution of visual perceptual deficits to the nonverbal cognitive profile of individuals with 22q11.2 deletion syndrome. However, the neurobiological processes underlying these widespread behavioral alterations are yet to be fully understood. Thus, in this paper, we investigated the role of neural oscillations toward visuoperceptual deficits to elucidate the neurobiology of sensory impairments in deletion carriers. METHODS We acquired 125 high-density electroencephalography recordings during a visual grating task in a group of 62 deletion carriers and 63 control subjects. Stimulus-elicited oscillatory responses were analyzed with 1) time-frequency analysis using wavelets decomposition at sensor and source level, 2) intertrial phase coherence, and 3) Granger causality connectivity in source space. Additional analyses examined the development of neural oscillations across age bins. RESULTS Deletion carriers had decreased theta-band (4-8 Hz) and gamma-band (58-68 Hz) spectral power compared with control subjects in response to the visual stimuli, with an absence of age-related increase of theta- and gamma-band responses. Moreover, adult deletion carriers had decreased gamma- and theta-band responses but increased alpha/beta desynchronization (10-25 Hz) that correlated with behavioral performance. Granger causality estimates reflected an increased frontal-occipital connectivity in the beta range (22-40 Hz). CONCLUSIONS Deletion carriers exhibited decreased theta- and gamma-band responses to visual stimuli, while alpha/beta desynchronization was preserved. Overall, the lack of age-related changes in deletion carriers implicates developmental impairments in circuit mechanisms underlying neural oscillations. The dissociation between the maturation of theta/gamma- and alpha/beta-band responses may indicate a selective impairment in supragranular cortical layers, leading to compensatory top-down connectivity.
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Affiliation(s)
- Valentina Mancini
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland.
| | - Vincent Rochas
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland; Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Martin Seeber
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Tineke Grent-'t-Jong
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, Scotland; Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Charité Universitätsmedizin, Berlin, Germany
| | - Tonia A Rihs
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Caren Latrèche
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland
| | - Peter J Uhlhaas
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, Scotland; Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Charité Universitätsmedizin, Berlin, Germany
| | - Christoph M Michel
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland; Center for Biomedical Imaging, Lausanne, Switzerland
| | - Stephan Eliez
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland; Department of Genetic Medicine and Development, University of Geneva School of Medicine, Geneva, Switzerland
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Abstract
RATIONALE Proton magnetic resonance spectroscopy (1H-MRS) is a cross-species neuroimaging technique that can measure concentrations of several brain metabolites, including glutamate and GABA. This non-invasive method has promise in developing centrally acting drugs, as it can be performed repeatedly within-subjects and be used to translate findings from the preclinical to clinical laboratory using the same imaging biomarker. OBJECTIVES This review focuses on the utility of single-voxel 1H-MRS in developing novel glutamatergic or GABAergic drugs for the treatment of psychiatric disorders and includes research performed in rodent models, healthy volunteers and patient cohorts. RESULTS Overall, these studies indicate that 1H-MRS is able to detect the predicted pharmacological effects of glutamatergic or GABAergic drugs on voxel glutamate or GABA concentrations, although there is a shortage of studies examining dose-related effects. Clinical studies have applied 1H-MRS to better understand drug therapeutic mechanisms, including the glutamatergic effects of ketamine in depression and of acamprosate in alcohol dependence. There is an emerging interest in identifying patient subgroups with 'high' or 'low' brain regional 1H-MRS glutamate levels for more targeted drug development, which may require ancillary biomarkers to improve the accuracy of subgroup discrimination. CONCLUSIONS Considerations for future research include the sensitivity of single-voxel 1H-MRS in detecting drug effects, inter-site measurement reliability and the interpretation of drug-induced changes in 1H-MRS metabolites relative to the known pharmacological molecular mechanisms. On-going technological development, in single-voxel 1H-MRS and in related complementary techniques, will further support applications within CNS drug discovery.
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Affiliation(s)
- Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park, London, UK.
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7
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Ferland MC, Therrien-Blanchet JM, Proulx S, Klees-Themens G, Bacon BA, Dang Vu TT, Théoret H. Transcranial Magnetic Stimulation and H 1-Magnetic Resonance Spectroscopy Measures of Excitation and Inhibition Following Lorazepam Administration. Neuroscience 2020; 452:235-246. [PMID: 33246064 DOI: 10.1016/j.neuroscience.2020.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/16/2020] [Accepted: 11/09/2020] [Indexed: 12/21/2022]
Abstract
This study aimed at better understanding the neurochemistry underlying transcranial magnetic stimulation (TMS) and magnetic resonance spectroscopy (MRS) measurements as it pertains to GABAergic activity following administration of allosteric GABAA receptor agonist lorazepam. Seventeen healthy adults (8 females, 26.0 ± 5.4 years old) participated in a double-blind, crossover, placebo-controlled study, where participants underwent TMS and MRS two hours after drug intake (placebo or lorazepam; 2.5 mg). Neuronavigated TMS measures reflecting cortical inhibition and excitation were obtained in the left primary motor cortex. Sensorimotor cortex and occipital cortex MRS data were acquired using a 3T scanner with a MEGA-PRESS sequence, allowing water-referenced [GABA] and [Glx] (glutamate + glutamine) quantification. Lorazepam administration decreased occipital [GABA], decreased motor cortex excitability and increased GABAA-receptor mediated motor cortex inhibition (short intracortical inhibition (SICI)). Lorazepam intake did not modulate sensorimotor [GABA] and TMS measures of intra-cortical facilitation, long-interval cortical inhibition, cortical silent period, and resting motor threshold. Furthermore, higher sensorimotor [GABA] was associated with higher cortical inhibition (SICI) following lorazepam administration, suggesting that baseline sensorimotor [GABA] may be valuable in predicting pharmacological or neuromodulatory treatment response. Finally, the differential effects of lorazepam on MRS and TMS measures, with respect to GABA, support the idea that TMS measures of cortical inhibition reflect synaptic GABAergic phasic inhibitory activity while MRS reflects extrasynaptic GABA.
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Affiliation(s)
| | | | | | | | | | - Thien Thanh Dang Vu
- Center for Studies in Behavioral Neurobiology and Perform Center, Department of Health, Kinesiology and Applied Physiology, Concordia University, Montreal, QC, Canada; Research Center, Institut Universitaire de Gériatrie de Montréal, Montréal, Qc, Canada
| | - Hugo Théoret
- Département de psychologie, Université de Montréal, Québec, Canada; Centre de recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte-Justine, Montréal, Québec, Canada.
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8
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Song Y, Gong T, Edden RAE, Wang G. Feasibility of Measuring GABA Levels in the Upper Brainstem in Healthy Volunteers Using Edited MRS. Front Psychiatry 2020; 11:813. [PMID: 32922319 PMCID: PMC7456914 DOI: 10.3389/fpsyt.2020.00813] [Citation(s) in RCA: 1] [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: 01/31/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To assess the feasibility of small-voxel MEGA-PRESS in detecting gamma-aminobutyric acid (GABA) levels of the upper brainstem in healthy volunteers. MATERIALS AND METHODS Forty-two healthy volunteers, aged between 20 and 76 years were enrolled in this study, and underwent a 3.0T MRI scan using an eight-channel phased-array head coil. The MEGA-PRESS sequence was used to edit GABA signal from a 10x25x30 mm3 voxel in the upper brain stem. The detected signal includes contributions from macromolecules (MM) and homocarnosine and is therefore referred to as GABA+. All the data were processed using Gannet. RESULTS Thirty-four cases were successful in measuring GABA in the upper brainstem and 8 cases failed (based on poor modeling of spectra). The GABA+ levels were 2.66 ± 0.75 i.u. in the upper brainstem of healthy volunteers, ranging from 1.50 to 4.40 i.u. The normalized fitting residual (FitErr in Gannet) was 12.1 ± 2.8%, ranging from 7.4% to 19.1%; it was below 15.5% in 30 cases (71%). CONCLUSIONS It is possible to measure GABA levels in the upper brainstem using MEGA-PRESS with a relatively small ROI, with a moderate between-subject variance of under 30%.
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Affiliation(s)
- Yulu Song
- Department of Imaging and Nuclear Medicine, Shandong Medical Imaging Research Institute, Cheeloo College of Medicine, Shandong University, Jinn, China
| | - Tao Gong
- Department of Imaging and Nuclear Medicine, Shandong Medical Imaging Research Institute, Cheeloo College of Medicine, Shandong University, Jinn, China
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States.,FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Guangbin Wang
- Department of Imaging and Nuclear Medicine, Shandong Medical Imaging Research Institute, Cheeloo College of Medicine, Shandong University, Jinn, China
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9
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Pretzsch CM, Freyberg J, Voinescu B, Lythgoe D, Horder J, Mendez MA, Wichers R, Ajram L, Ivin G, Heasman M, Edden RAE, Williams S, Murphy DGM, Daly E, McAlonan GM. Effects of cannabidiol on brain excitation and inhibition systems; a randomised placebo-controlled single dose trial during magnetic resonance spectroscopy in adults with and without autism spectrum disorder. Neuropsychopharmacology 2019; 44:1398-1405. [PMID: 30758329 PMCID: PMC6784992 DOI: 10.1038/s41386-019-0333-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/14/2019] [Accepted: 01/19/2019] [Indexed: 01/20/2023]
Abstract
There is increasing interest in the use of cannabis and its major non-intoxicating component cannabidiol (CBD) as a treatment for mental health and neurodevelopmental disorders, such as autism spectrum disorder (ASD). However, before launching large-scale clinical trials, a better understanding of the effects of CBD on brain would be desirable. Preclinical evidence suggests that one aspect of the polypharmacy of CBD is that it modulates brain excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) levels, including in brain regions linked to ASD, such as the basal ganglia (BG) and the dorsomedial prefrontal cortex (DMPFC). However, differences in glutamate and GABA pathways in ASD mean that the response to CBD in people with and without ASD may be not be the same. To test whether CBD 'shifts' glutamate and GABA levels; and to examine potential differences in this response in ASD, we used magnetic resonance spectroscopy (MRS) to measure glutamate (Glx = glutamate + glutamine) and GABA+ (GABA + macromolecules) levels in 34 healthy men (17 neurotypicals, 17 ASD). Data acquisition commenced 2 h (peak plasma levels) after a single oral dose of 600 mg CBD or placebo. Test sessions were at least 13 days apart. Across groups, CBD increased subcortical, but decreased cortical, Glx. Across regions, CBD increased GABA+ in controls, but decreased GABA+ in ASD; the group difference in change in GABA + in the DMPFC was significant. Thus, CBD modulates glutamate-GABA systems, but prefrontal-GABA systems respond differently in ASD. Our results do not speak to the efficacy of CBD. Future studies should examine the effects of chronic administration on brain and behaviour, and whether acute brain changes predict longer-term response.
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Grants
- MR/N026063/1 Medical Research Council
- R01 MH106564 NIMH NIH HHS
- U54 HD079123 NICHD NIH HHS
- Infrastructure and training support from the National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust and King's College London https://www.nihr.ac.uk/about-us/how-we-are-managed/our-structure/infrastructure/biomedical-research-centres.htm Sackler Institute for Translational Neurodevelopment at King’s College London https://www.kcl.ac.uk/ioppn/depts/fans/sackler-group/index.aspx Autistica St Saviours House, 39-41 Union St, London SE1 1SD, UK
- NIH R01 MH106564 and U54 HD079123
- EU-AIMS (European Autism Interventions)/EU AIMS-2-TRIALS, a European Innovative Medicines Initiative Joint Undertaking under Grant Agreements No. 115300 and 777394, the resources of which are composed of financial contributions from the European Union’s Seventh Framework Programme (Grant FP7/2007–2013).
- RCUK | Medical Research Council (MRC)
- GW Pharmaceuticals, Sovereign House Vision Park Histon Cambridge CB24 9BZ United Kingdom Tel: +44 (0) 1223 266800 Autistica: St Saviours House, 39-41 Union St, London SE1 1SD, UK EU-AIMS (European Autism Interventions)/EU AIMS-2-TRIALS, a European Innovative Medicines Initiative Joint Undertaking under Grant Agreements No. 115300 and 777394, the resources of which are composed of financial contributions from the European Union’s Seventh Framework Programme (Grant FP7/2007–2013). https://ec.europa.eu/research/fp7/index_en.cfm
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Affiliation(s)
- Charlotte Marie Pretzsch
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Jan Freyberg
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Bogdan Voinescu
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - David Lythgoe
- Department of Neuroimaging Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Jamie Horder
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Maria Andreina Mendez
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Robert Wichers
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Laura Ajram
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Glynis Ivin
- South London and Maudsley NHS Foundation Trust Pharmacy, London, UK
| | - Martin Heasman
- South London and Maudsley NHS Foundation Trust Pharmacy, London, UK
| | - Richard A E Edden
- Russel H Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Steven Williams
- Department of Neuroimaging Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Declan G M Murphy
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Eileen Daly
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Gráinne M McAlonan
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
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10
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Louis ED, Hernandez N, Dyke JP, Ma RE, Dydak U. In Vivo Dentate Nucleus Gamma-aminobutyric Acid Concentration in Essential Tremor vs. Controls. THE CEREBELLUM 2019; 17:165-172. [PMID: 29039117 DOI: 10.1007/s12311-017-0891-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Despite its high prevalence, essential tremor (ET) is among the most poorly understood neurological diseases. The presence and extent of Purkinje cell (PC) loss in ET is the subject of controversy. PCs are a major storehouse of central nervous system gamma-aminobutyric acid (GABA), releasing GABA at the level of the dentate nucleus. It is therefore conceivable that cerebellar dentate nucleus GABA concentration could be an in vivo marker of PC number. We used in vivo 1H magnetic resonance spectroscopy (MRS) to quantify GABA concentrations in two cerebellar volumes of interest, left and right, which included the dentate nucleus, comparing 45 ET cases to 35 age-matched controls. 1H MRS was performed using a 3.0-T Siemens Tim Trio scanner. The MEGA-PRESS J-editing sequence was used for GABA detection in two cerebellar volumes of interest (left and right) that included the dentate nucleus. The two groups did not differ with respect to our primary outcome of GABA concentration (given in institutional units). For the right dentate nucleus, [GABA] in ET cases = 2.01 ± 0.45 and [GABA] in controls = 1.86 ± 0.53, p = 0.17. For the left dentate nucleus, [GABA] in ET cases = 1.68 ± 0.49 and [GABA] controls = 1.80 ± 0.53, p = 0.33. The controls had similar dentate nucleus [GABA] in the right vs. left dentate nucleus (p = 0.52); however, in ET cases, the value on the right was considerably higher than that on the left (p = 0.001). We did not detect a reduction in dentate nucleus GABA concentration in ET cases vs. CONTROLS One interpretation of the finding is that it does not support the existence of PC loss in ET; however, an alternative interpretation is the observed pattern could be due to the effects of terminal sprouting in ET (i.e., collateral sprouting from surviving PCs making up for the loss of GABA-ergic terminals from PC degeneration). Further research is needed.
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Affiliation(s)
- Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, LCI 710, 15 York Street, PO Box 208018, New Haven, CT, 06520-8018, USA. .,Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA. .,Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA.
| | - Nora Hernandez
- Department of Neurology, Yale School of Medicine, Yale University, LCI 710, 15 York Street, PO Box 208018, New Haven, CT, 06520-8018, USA
| | - Jonathan P Dyke
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA
| | - Ruoyun E Ma
- School of Health Sciences, Purdue University, West Lafayette, IN, USA.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
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11
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Duncan NW, Zhang J, Northoff G, Weng X. Investigating GABA concentrations measured with macromolecule suppressed and unsuppressed MEGA‐PRESS MR spectroscopy and their relationship with BOLD responses in the occipital cortex. J Magn Reson Imaging 2019; 50:1285-1294. [DOI: 10.1002/jmri.26706] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 12/24/2022] Open
Affiliation(s)
- Niall W. Duncan
- Centre for Cognition and Brain DisordersHangzhou Normal University Hangzhou China
- Taipei Medical University Centre for Brain and Consciousness Research Taipei Taiwan
- Graduate Institute of Humanities in MedicineTaipei Medical University Taipei Taiwan
| | - Jianfeng Zhang
- College of Biomedical Engineering and Instrument SciencesZhejiang University Hangzhou China
| | - Georg Northoff
- Centre for Cognition and Brain DisordersHangzhou Normal University Hangzhou China
- Institute of Mental Health ResearchUniversity of Ottawa Ottawa Canada
- Mental Health CentreZhejiang University School of Medicine Hangzhou China
| | - Xuchu Weng
- Institute for Brain Research and RehabilitationSouth China Normal University Guangzhou China
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12
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Reuveni I, Nugent AC, Gill J, Vythilingam M, Carlson PJ, Lerner A, Neumeister A, Charney DS, Drevets WC, Bonne O. Altered cerebral benzodiazepine receptor binding in post-traumatic stress disorder. Transl Psychiatry 2018; 8:206. [PMID: 30287828 PMCID: PMC6172250 DOI: 10.1038/s41398-018-0257-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 07/19/2018] [Accepted: 08/17/2018] [Indexed: 12/27/2022] Open
Abstract
Agonists of the γ-aminobutyric acid (GABA) type A benzodiazepine (BZD) receptor exert anxiolytic effects in anxiety disorders, raising the possibility that altered GABA-ergic function may play a role in the pathophysiology of anxiety disorders, such as post-traumatic stress disorder (PTSD). However, few neuroimaging studies have assessed the function or binding potential of the central GABAA BZD receptor system in PTSD. Therefore, our aim was to compare the BZD receptor binding potential between PTSD patients and healthy controls. Twelve medication-free participants with a current diagnosis of PTSD and 15 matched healthy controls underwent positron emission tomography (PET) imaging using [11C] flumazenil. Structural magnetic resonance imaging (MRI) scans were obtained and co-registered to the PET images to permit co-location of neuroanatomical structures in the lower resolution PET image data. Compared to healthy controls, PTSD patients exhibited increased BZD binding in the caudal anterior cingulate cortex and precuneus (p's < 0.05). Severity of PTSD symptoms positively correlated with BZD binding in the left mid- and anterior insular cortices. This study extends previous findings by suggesting that central BZD receptor system involvement in PTSD includes portions of the default mode and salience networks, along with insular regions that support interoception and autonomic arousal.
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Affiliation(s)
- Inbal Reuveni
- 0000 0001 2221 2926grid.17788.31Department of Psychiatry, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Allison C. Nugent
- 0000 0004 0464 0574grid.416868.5Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD USA
| | - Jessica Gill
- 0000 0001 2297 5165grid.94365.3dCenter for Neuroscience and Regenerative Medicine (CNRM), National Institutes of Health, Bethesda, MD USA
| | - Meena Vythilingam
- Deployment Health Clinical Center, Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, Silver Spring, MD USA
| | - Paul J. Carlson
- 0000 0001 2193 0096grid.223827.eDepartment of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT USA
| | - Alicja Lerner
- 0000 0001 2243 3366grid.417587.8Controlled Substance Staff, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD USA
| | - Alexander Neumeister
- 0000 0001 2182 2255grid.28046.38Institute of Mental Health Research (IMHR), University of Ottawa, Ottawa, ON Canada
| | - Dennis S. Charney
- 0000 0001 0670 2351grid.59734.3cMood and Anxiety Disorders Program, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Wayne C. Drevets
- grid.417429.dJanssen Research and Development, LLC of Johnson & Johnson Inc., Titusville, NJ USA
| | - Omer Bonne
- Department of Psychiatry, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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13
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Bang JW, Shibata K, Frank SM, Walsh EG, Greenlee MW, Watanabe T, Sasaki Y. Consolidation and reconsolidation share behavioral and neurochemical mechanisms. Nat Hum Behav 2018; 2:507-513. [PMID: 30505952 PMCID: PMC6258036 DOI: 10.1038/s41562-018-0366-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 05/18/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Ji Won Bang
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
- Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA
| | - Kazuhisa Shibata
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
- Department of Cognitive and Psychological Sciences, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya City, Japan
| | - Sebastian M Frank
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
- Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Edward G Walsh
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Mark W Greenlee
- Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Takeo Watanabe
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
- Department of Neuroscience, Brown University, Providence, RI, USA.
| | - Yuka Sasaki
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA
- Department of Neuroscience, Brown University, Providence, RI, USA
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14
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Maron E, Lan CC, Nutt D. Imaging and Genetic Approaches to Inform Biomarkers for Anxiety Disorders, Obsessive-Compulsive Disorders, and PSTD. Curr Top Behav Neurosci 2018; 40:219-292. [PMID: 29796838 DOI: 10.1007/7854_2018_49] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Anxiety disorders are the most common mental health problem in the world and also claim the highest health care cost among various neuropsychiatric disorders. Anxiety disorders have a chronic and recurrent course and cause significantly negative impacts on patients' social, personal, and occupational functioning as well as quality of life. Despite their high prevalence rates, anxiety disorders have often been under-diagnosed or misdiagnosed, and consequently under-treated. Even with the correct diagnosis, anxiety disorders are known to be difficult to treat successfully. In order to implement better strategies in diagnosis, prognosis, treatment decision, and early prevention for anxiety disorders, tremendous efforts have been put into studies using genetic and neuroimaging techniques to advance our understandings of the underlying biological mechanisms. In addition to anxiety disorders including panic disorder, generalised anxiety disorder (GAD), specific phobias, social anxiety disorders (SAD), due to overlapping symptom dimensions, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD) (which were removed from the anxiety disorder category in DSM-5 to become separate categories) are also included for review of relevant genetic and neuroimaging findings. Although the number of genetic or neuroimaging studies focusing on anxiety disorders is relatively small compare to other psychiatric disorders such as psychotic disorders or mood disorders, various structural abnormalities in the grey or white matter, functional alterations of activity during resting-state or task conditions, molecular changes of neurotransmitter receptors or transporters, and genetic associations have all been reported. With continuing effort, further genetic and neuroimaging research may potentially lead to clinically useful biomarkers for the prevention, diagnosis, and management of these disorders.
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Affiliation(s)
- Eduard Maron
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, UK.
- Department of Psychiatry, University of Tartu, Tartu, Estonia.
- Department of Psychiatry, North Estonia Medical Centre, Tallinn, Estonia.
| | - Chen-Chia Lan
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, UK
- Department of Psychiatry, Taichung Veterans General Hospital, Taichung, Taiwan
| | - David Nutt
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, UK
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15
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Examining alterations in GABA concentrations in the basal ganglia of patients with Parkinson's disease using MEGA-PRESS MRS. Jpn J Radiol 2017; 36:194-199. [PMID: 29280067 DOI: 10.1007/s11604-017-0714-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/11/2017] [Indexed: 12/24/2022]
Abstract
PURPOSE The aim of this study was to compare the gamma-amino butyric acid (GABA) levels in the left basal ganglia (BG) of patients with Parkinson's disease (PD) to those of healthy control (HC) volunteers using proton magnetic resonance spectroscopy (1H MRS). MATERIALS AND METHODS The GABA+ signal-the composite signal from GABA, macromolecules (MMs), and homocarnosine-was detected. GABA+ levels were examined in 21 PD patients and 15 age- and sex-matched HCs. 3T-1H-MRS using the Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) sequence was performed in order to detect GABA+ levels in the left BG, and the spectra were processed using the Gannet software. Differences in GABA+ levels between the two groups were analyzed using independent t-test analysis. RESULTS The GABA+ levels were significantly lower (P < 0.001) in the left BG of the patients with PD (1.31 ± 0.21 i.u.) than in the left BG of the HCs (1.62 ± 0.26 i.u.). CONCLUSION The lower GABA+ levels in the left BG of the PD patients suggest that GABA plays an important role in the pathogenesis of PD. The reduced GABA+ levels in the PD patients may be associated with GABAergic dysfunction.
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16
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Mick I, Ramos AC, Myers J, Stokes PR, Chandrasekera S, Erritzoe D, Mendez MA, Gunn RN, Rabiner EA, Searle GE, Galduróz JCF, Waldman AD, Bowden-Jones H, Clark L, Nutt DJ, Lingford-Hughes AR. Evidence for GABA-A receptor dysregulation in gambling disorder: correlation with impulsivity. Addict Biol 2017; 22:1601-1609. [PMID: 27739164 PMCID: PMC5697606 DOI: 10.1111/adb.12457] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/14/2016] [Accepted: 08/30/2016] [Indexed: 12/11/2022]
Abstract
As a behavioural addiction, gambling disorder (GD) provides an opportunity to characterize addictive processes without the potentially confounding effects of chronic excessive drug and alcohol exposure. Impulsivity is an established precursor to such addictive behaviours, and GD is associated with greater impulsivity. There is also evidence of GABAergic dysregulation in substance addiction and in impulsivity. This study therefore investigated GABAA receptor availability in 15 individuals with GD and 19 healthy volunteers (HV) using [11C]Ro15‐4513, a relatively selective α5 benzodiazepine receptor PET tracer and its relationship with impulsivity. We found significantly higher [11C]Ro15‐4513 total distribution volume (VT) in the right hippocampus in the GD group compared with HV. We found higher levels of the ‘Negative Urgency’ construct of impulsivity in GD, and these were positively associated with higher [11C]Ro15‐4513 VT in the amygdala in the GD group; no such significant correlations were evident in the HV group. These results contrast with reduced binding of GABAergic PET ligands described previously in alcohol and opiate addiction and add to growing evidence for distinctions in the neuropharmacology between substance and behavioural addictions. These results provide the first characterization of GABAA receptors in GD with [11C]Ro15‐4513 PET and show greater α5 receptor availability and positive correlations with trait impulsivity. This GABAergic dysregulation is potential target for treatment.
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Affiliation(s)
- Inge Mick
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
| | - Anna C. Ramos
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
- Department of Psychobiology; Universidade Federal de São Paulo; Brazil
| | - Jim Myers
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
| | - Paul R. Stokes
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
- Centre for Affective Disorders, Department of Psychological Medicine; Institute of Psychiatry, Psychology and Neuroscience, King's College London; UK
| | - Samantha Chandrasekera
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
| | - David Erritzoe
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
| | - Maria A. Mendez
- Forensic and Neurodevelopmental Sciences; Institute of Psychiatry, King's College; UK
| | - Roger N. Gunn
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
- Imanova Ltd.; Centre for Imaging Sciences; UK
| | - Eugenii A. Rabiner
- Imanova Ltd.; Centre for Imaging Sciences; UK
- Department of Neuroimaging; Institute of Psychiatry, King's College; UK
| | | | | | - Adam D. Waldman
- Department of Imaging, Division of Experimental Medicine, Department of Medicine; Imperial College; UK
| | - Henrietta Bowden-Jones
- National Problem Gambling Clinic, CNWL NHS Foundation Trust; Imperial College London; UK
| | - Luke Clark
- Centre for Gambling Research at UBC, Department of Psychology; University of British Columbia; Canada
| | - David J. Nutt
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
| | - Anne R. Lingford-Hughes
- Centre for Neuropsychopharmacology, Division of Brain Sciences, Faculty of Medicine; Imperial College London; UK
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17
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Neuroimaging studies of GABA in schizophrenia: a systematic review with meta-analysis. Transl Psychiatry 2017; 7:e1147. [PMID: 28585933 PMCID: PMC5537645 DOI: 10.1038/tp.2017.124] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/26/2017] [Accepted: 05/03/2017] [Indexed: 01/17/2023] Open
Abstract
Data from animal models and from postmortem studies suggest that schizophrenia is associated with brain GABAergic dysfunction. The extent to which this is reflected in data from in vivo studies of GABA function in schizophrenia is unclear. The Medline database was searched to identify articles published until 21 October 2016. The search terms included GABA, proton magnetic resonance spectroscopy (1H-MRS), positron emission tomography (PET), single photon emission computed tomography (SPECT), schizophrenia and psychosis. Sixteen GABA 1H-MRS studies (538 controls, 526 patients) and seven PET/SPECT studies of GABAA/benzodiazepine receptor (GABAA/BZR) availability (118 controls, 113 patients) were identified. Meta-analyses of 1H-MRS GABA in the medial prefrontal cortex (mPFC), parietal/occipital cortex (POC) and striatum did not show significant group differences (mFC: g=-0.3, 409 patients, 495 controls, 95% confidence interval (CI): -0.6 to 0.1; POC: g=-0.3, 139 patients, 111 controls, 95% CI: -0.9 to 0.3; striatum: g=-0.004, 123 patients, 95 controls, 95% CI: -0.7 to 0.7). Heterogeneity across studies was high (I2>50%), and this was not explained by subsequent moderator or meta-regression analyses. There were insufficient PET/SPECT receptor availability studies for meta-analyses, but a systematic review did not suggest replicable group differences in regional GABAA/BZR availability. The current literature does not reveal consistent alterations in in vivo GABA neuroimaging measures in schizophrenia, as might be hypothesized from animal models and postmortem data. The analysis highlights the need for further GABA neuroimaging studies with improved methodology and addressing potential sources of heterogeneity.
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18
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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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19
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Shibata K, Sasaki Y, Bang JW, Walsh EG, Machizawa MG, Tamaki M, Chang LH, Watanabe T. Overlearning hyperstabilizes a skill by rapidly making neurochemical processing inhibitory-dominant. Nat Neurosci 2017; 20:470-475. [PMID: 28135242 PMCID: PMC5323354 DOI: 10.1038/nn.4490] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 01/04/2017] [Indexed: 12/17/2022]
Abstract
Overlearning refers to the continued training of a skill after performance improvement has plateaued. Whether overlearning is beneficial is a question in our daily lives that has never been clearly answered. Here, we report a new important role: Overlearning abruptly changes neurochemical processing to hyper-stabilize and protect trained perceptual learning from subsequent new learning. Usually, learning immediately after training is so unstable that it can be disrupted by subsequent new learning, unless waiting for passive stabilization, which takes hours. However, overlearning so rapidly and strongly stabilizes the learning state that it not only becomes resilient against, but disrupts, subsequent new learning. Such hyper-stabilization is associated with an abrupt shift from glutamate-dominant excitatory to gamma-aminobutyric-acid-dominant inhibitory processing in early visual areas. Hyper-stabilization contrasts with passive and slower stabilization, which is associated with a mere reduction of an excitatory dominance to baseline levels. Utilizing hyper-stabilization may lead to efficient learning paradigms.
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Affiliation(s)
- Kazuhisa Shibata
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA.,Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Yuka Sasaki
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
| | - Ji Won Bang
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
| | - Edward G Walsh
- Department of Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Maro G Machizawa
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
| | - Masako Tamaki
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
| | - Li-Hung Chang
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
| | - Takeo Watanabe
- Department of Cognitive, Linguistics, &Psychological Sciences, Brown University, Providence, Rhode Island, USA
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20
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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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21
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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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22
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van Veenendaal TM, IJff DM, Aldenkamp AP, Hofman PAM, Vlooswijk MCG, Rouhl RPW, de Louw AJ, Backes WH, Jansen JFA. Metabolic and functional MR biomarkers of antiepileptic drug effectiveness: A review. Neurosci Biobehav Rev 2015; 59:92-9. [PMID: 26475992 DOI: 10.1016/j.neubiorev.2015.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 10/07/2015] [Accepted: 10/12/2015] [Indexed: 12/30/2022]
Abstract
As a large number of patients with epilepsy do not respond favorably to antiepileptic drugs (AEDs), a better understanding of treatment failure and the cause of adverse side effects is required. The working mechanisms of AEDs also alter neurotransmitter concentrations and brain activity, which can be measured using MR spectroscopy and functional MR imaging, respectively. This review presents an overview of clinical research of MR spectroscopy and functional MR imaging studies to the effects of AEDs on the brain. Despite the scarcity of studies associating MR findings to the effectiveness of AEDs, the current research shows clear potential regarding this matter. Several GABAergic AEDs have been shown to increase the GABA concentration, which was related to seizure reductions, while language problems due to topiramate have been associated with altered activation patterns measured with functional MR imaging. MR spectroscopy and functional MR imaging provide biomarkers that may predict individual treatment outcomes, and enable the assessment of mechanisms of treatment failure and cognitive side effects.
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Affiliation(s)
- Tamar M van Veenendaal
- Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Dominique M IJff
- School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands; Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands
| | - Albert P Aldenkamp
- School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands; Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands; Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; Department of Neurology, Gent University Hospital, De Pintelaan 185, 9000 Gent, Belgium; Faculty of Electrical Engineering, University of Technology Eindhoven, PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Paul A M Hofman
- Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands; Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands
| | - Marielle C G Vlooswijk
- School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands; Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands; Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Rob P W Rouhl
- School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands; Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands; Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Anton J de Louw
- Epilepsy Center Kempenhaeghe, PO Box 61, 5590 AB Heeze, The Netherlands; Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; Faculty of Electrical Engineering, University of Technology Eindhoven, PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Walter H Backes
- Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Jacobus F A Jansen
- Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.
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23
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Patel AB, de Graaf RA, Rothman DL, Behar KL. Effects of γ-Aminobutyric acid transporter 1 inhibition by tiagabine on brain glutamate and γ-Aminobutyric acid metabolism in the anesthetized rat In vivo. J Neurosci Res 2015; 93:1101-8. [PMID: 25663257 DOI: 10.1002/jnr.23548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/14/2014] [Accepted: 12/02/2014] [Indexed: 12/24/2022]
Abstract
γ-Aminobutyric acid (GABA) clearance from the extracellular space after release from neurons involves reuptake into terminals and astrocytes through GABA transporters (GATs). The relative flows through these two pathways for GABA released from neurons remains unclear. This study determines the effect of tiagabine, a selective inhibitor of neuronal GAT-1, on the rates of glutamate (Glu) and GABA metabolism and GABA resynthesis via the GABA-glutamine (Gln) cycle. Halothane-anesthetized rats were administered tiagabine (30 mg/kg, i.p.) and 45 min later received an intravenous infusion of either [1,6-(13)C2]glucose (in vivo) or [2-(13)C]acetate (ex vivo). Nontreated rats served as controls. Metabolites and (13)C enrichments were measured with (1)H-[(13)C]-nuclear magnetic resonance spectroscopy and referenced to their corresponding endpoint values measured in extracts from in situ frozen brain. Metabolic flux estimates of GABAergic and glutamatergic neurons were determined by fitting a metabolic model to the (13)C turnover data measured in vivo during [1,6-(13)C2]glucose infusion. Tiagabine-treated rats were indistinguishable (P > 0.05) from controls in tissue amino acid levels and in (13)C enrichments from [2-(13)C]acetate. Tiagabine reduced average rates of glucose oxidation and neurotransmitter cycling in both glutamatergic neurons (↓18%, CMR(glc(ox)Glu): control, 0.27 ± 0.05 vs. tiagabine, 0.22 ± 0.04 µmol/g/min; ↓11%, V(cyc(Glu-Gln)): control 0.23 ± 0.05 vs. tiagabine 0.21 ± 0.04 µmol/g/min and GABAergic neurons (↓18-25%, CMR(glc(ox)GABA): control 0.09 ± 0.02 vs. tiagabine 0.07 ± 0.03 µmol/g/min; V(cyc(GABA-Gln)): control 0.08 ± 0.02 vs. tiagabine 0.07 ± 0.03 µmol/g/min), but the changes in glutamatergic and GABAergic fluxes were not significant (P > 0.10). The results suggest that any reduction in GABA metabolism by tiagabine might be an indirect response to reduced glutamatergic drive rather than direct compensatory effects.
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Affiliation(s)
- Anant B Patel
- Department of Diagnostic Radiology and the Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Robin A de Graaf
- Department of Diagnostic Radiology and the Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut
| | - Douglas L Rothman
- Department of Diagnostic Radiology and the Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut
| | - Kevin L Behar
- Department of Psychiatry and the Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut
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24
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Magnetic Resonance Spectroscopy Studies of Glutamate and GABA in Autism: Implications for Excitation-Inhibition Imbalance Theory. CURRENT DEVELOPMENTAL DISORDERS REPORTS 2014. [DOI: 10.1007/s40474-014-0032-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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25
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Muthukumaraswamy SD. The use of magnetoencephalography in the study of psychopharmacology (pharmaco-MEG). J Psychopharmacol 2014; 28:815-29. [PMID: 24920134 DOI: 10.1177/0269881114536790] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Magnetoencephalography (MEG) is a neuroimaging technique that allows direct measurement of the magnetic fields generated by synchronised ionic neural currents in the brain with moderately good spatial resolution and high temporal resolution. Because chemical neuromodulation can cause changes in neuronal processing on the millisecond time-scale, the combination of MEG with pharmacological interventions (pharmaco-MEG) is a powerful tool for measuring the effects of experimental modulations of neurotransmission in the living human brain. Importantly, pharmaco-MEG can be used in both healthy humans to understand normal brain function and in patients to understand brain pathologies and drug-treatment effects. In this paper, the physiological and technical basis of pharmaco-MEG is introduced and contrasted with other pharmacological neuroimaging techniques. Ongoing developments in MEG analysis techniques such as source-localisation, functional and effective connectivity analyses, which have allowed for more powerful inferences to be made with recent pharmaco-MEG data, are described. Studies which have utilised pharmaco-MEG across a range of neurotransmitter systems (GABA, glutamate, acetylcholine, dopamine and serotonin) are reviewed.
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