title: Glutamatergic metabolites are associated with visual plasticity in humans.
abstract: Long-term potentiation (LTP) is a basic cellular mechanism underlying learning and memory. LTP-like plasticity in the visual cortex can be induced by high frequency visual stimulation in rodents and humans. Since glutamate plays a fundamental role in LTP, this study investigated if visual cortical glutamate and glutamine levels, measured by proton magnetic resonance spectroscopy (MRS), relate to visual plasticity in humans. Since plasticity requires a delicate excitation and inhibition balance, GABA was also explored. Eighteen healthy participants completed MRS and a visual fMRI paradigm. Results revealed enhanced fMRI activations after high frequency visual stimulation, suggesting visual plasticity occurred. Higher activations were associated with higher resting glutamine levels after family wise error-correction. Exploratory analyses revealed that higher resting glutamate and GABA levels were associated with visual plasticity, suggesting there may be a critical excitation-inhibition balance necessary for experience dependent plasticity. This is the first empirical evidence that resting glutamine levels and potentially glutamate and GABA levels are associated with visual plasticity in humans.
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA. Electronic address: awijtenburg@mprc.umaryland.edu.
authors.forename: S Andrea
authors.initials: SA
authors.lastname: Wijtenburg
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: West
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Korenic
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Franchesca
authors.initials: F
authors.lastname: Kuhney
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Gaston
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Hongji
authors.initials: H
authors.lastname: Chen
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: Meredith
authors.initials: M
authors.lastname: Roberts
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA; Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kochunov
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA.
authors.forename: L Elliot
authors.initials: LE
authors.lastname: Hong
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD 21228, USA; Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, 601 N. Caroline Street, Baltimore, MD 21287, USA; Department of Psychology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Rowland
mesh_terms: D000328:Adult; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009473:Neuronal Plasticity / Q000502:physiology*; D014793:Visual Cortex / Q000378:metabolism*; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005973:Glutamine; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid
keywords: GABA; Glutamate; Healthy adults; Magnetic resonance spectroscopy; Visual plasticity; fMRI