Polarity-sensitive modulation of cortical neurotransmitters by transcranial stimulation

J Neurosci. 2009 Apr 22;29(16):5202-6. doi: 10.1523/JNEUROSCI.4432-08.2009.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping / methods
  • Cerebral Cortex / anatomy & histology*
  • Cerebral Cortex / physiology*
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy / methods
  • Male
  • Middle Aged
  • Neurotransmitter Agents / metabolism*
  • Neurotransmitter Agents / physiology
  • Transcranial Magnetic Stimulation / methods*
  • Young Adult


  • Neurotransmitter Agents