title: Polarity-sensitive modulation of cortical neurotransmitters by transcranial stimulation.
abstract: Transcranial direct current stimulation (tDCS) modulates cortical excitability and is being used for human studies more frequently. Here we probe the underlying neuronal mechanisms by measuring polarity-specific changes in neurotransmitter concentrations using magnetic resonance spectroscopy (MRS). MRS provides evidence that excitatory (anodal) tDCS causes locally reduced GABA while inhibitory (cathodal) stimulation causes reduced glutamatergic neuronal activity with a highly correlated reduction in GABA, presumably due to the close biochemical relationship between the two neurotransmitters.
authors.affiliation: Centre for Functional Magnetic Resonance Imaging of the Brain, Department of Clinical Neurology, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom. cstagg@fmrib.ox.ac.uk
authors.forename: Charlotte J
authors.initials: CJ
authors.lastname: Stagg
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Best
authors.forename: Mary C
authors.initials: MC
authors.lastname: Stephenson
authors.forename: Jacinta
authors.initials: J
authors.lastname: O'Shea
authors.forename: Marzena
authors.initials: M
authors.lastname: Wylezinska
authors.forename: Z Tamas
authors.initials: ZT
authors.lastname: Kincses
authors.forename: Peter G
authors.initials: PG
authors.lastname: Morris
authors.forename: Paul M
authors.initials: PM
authors.lastname: Matthews
authors.forename: Heidi
authors.initials: H
authors.lastname: Johansen-Berg
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D018377:Neurotransmitter Agents / Q000378:metabolism* / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
chemical_list: D018377:Neurotransmitter Agents