title: Neuroimaging markers of glutamatergic and GABAergic systems in drug addiction: Relationships to resting-state functional connectivity.
abstract: Drug addiction is characterized by widespread abnormalities in brain function and neurochemistry, including drug-associated effects on concentrations of the excitatory and inhibitory neurotransmitters glutamate and gamma-aminobutyric acid (GABA), respectively. In healthy individuals, these neurotransmitters drive the resting state, a default condition of brain function also disrupted in addiction. Here, our primary goal was to review in vivo magnetic resonance spectroscopy and positron emission tomography studies that examined markers of glutamate and GABA abnormalities in human drug addiction. Addicted individuals tended to show decreases in these markers compared with healthy controls, but findings also varied by individual characteristics (e.g., abstinence length). Interestingly, select corticolimbic brain regions showing glutamatergic and/or GABAergic abnormalities have been similarly implicated in resting-state functional connectivity deficits in drug addiction. Thus, our secondary goals were to provide a brief review of this resting-state literature, and an initial rationale for the hypothesis that abnormalities in glutamatergic and/or GABAergic neurotransmission may underlie resting-state functional deficits in drug addiction. In doing so, we suggest future research directions and possible treatment implications.
authors.affiliation: Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Electronic address: scott.moeller@mssm.edu.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Moeller
authors.affiliation: Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Departments of Psychiatry and Biobehavioral Sciences, and Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Edythe D
authors.initials: ED
authors.lastname: London
authors.affiliation: Brain Imaging and Neuroethics Research Unit, Institute of Mental Health Research, Ottawa, Canada. Electronic address: georg.northoff@theroyal.ca.
authors.forename: Georg
authors.initials: G
authors.lastname: Northoff
mesh_terms: D000818:Animals; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D059906:Neuroimaging / Q000379:methods; D019966:Substance-Related Disorders / Q000503:physiopathology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid
keywords: Drug addiction; GABA; Glutamate; Magnetic resonance spectroscopy; Neurochemistry; Positron emission tomography; Resting-state; fMRI