Intra-Regional Glu-GABA vs Inter-Regional Glu-Glu Imbalance: A 1H-MRS Study of the Neurochemistry of Auditory Verbal Hallucinations in Schizophrenia.

Autor:	Hjelmervik H; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway., Craven AR; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway., Sinceviciute I; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway., Johnsen E; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.; Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway., Kompus K; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway., Bless JJ; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway., Kroken RA; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.; Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway., Løberg EM; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.; Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.; Department of Clinical Psychology, University of Bergen, Bergen, Norway., Ersland L; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway., Grüner R; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Department of Radiology, Haukeland University Hospital, Bergen, Norway.; Department of Physics and Technology, University of Bergen, Bergen, Norway., Hugdahl K; Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.; NORMENT Center of Excellence, Haukeland University Hospital, Bergen, Norway.; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.; Department of Radiology, Haukeland University Hospital, Bergen, Norway.
Jazyk:	angličtina
Zdroj:	Schizophrenia bulletin [Schizophr Bull] 2020 Apr 10; Vol. 46 (3), pp. 633-642.
DOI:	10.1093/schbul/sbz099
Abstrakt:	Glutamate (Glu), gamma amino-butyric acid (GABA), and excitatory/inhibitory (E/I) imbalance have inconsistently been implicated in the etiology of schizophrenia. Elevated Glu levels in language regions have been suggested to mediate auditory verbal hallucinations (AVH), the same regions previously associated with neuronal hyperactivity during AVHs. It is, however, not known whether alterations in Glu levels are accompanied by corresponding GABA alterations, nor is it known if Glu levels are affected in brain regions with known neuronal hypo-activity. Using magnetic resonance spectroscopy (MRS), we measured Glx (Glu+glutamine) and GABA+ levels in the anterior cingulate cortex (ACC), left and right superior temporal gyrus (STG), and left inferior frontal gyrus (IFG), in a sample of 77 schizophrenia patients and 77 healthy controls. Two MRS-protocols were used. Results showed a marginally significant positive correlation in the left STG between Glx and AVHs, whereas a significant negative correlation was found in the ACC. In addition, high-hallucinating patients as a group showed decreased ACC and increased left STG Glx levels compared to low-hallucinating patients, with the healthy controls in between the 2 hallucinating groups. No significant differences were found for GABA+ levels. It is discussed that reduced ACC Glx levels reflect an inability of AVH patients to cognitively inhibit their "voices" through neuronal hypo-activity, which in turn originates from increased left STG Glu levels and neuronal hyperactivity. A revised E/I-imbalance model is proposed where Glu-Glu imbalance between brain regions is emphasized rather than Glu-GABA imbalance within regions, for the understanding of the underlying neurochemistry of AVHs. (© The Author(s) 2019. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.)
Databáze:	MEDLINE
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