Polarity-Sensitive Modulation of Cortical Neurotransmitters by Transcranial Stimulation

• DOI: 10.1523/jneurosci.4432-08.2009
• Publication Date: 2009-04-22T17:50:09Z
• Authors: Charlotte J. Stagg; Jonathan G. Best; Mary C. Stephenson; Jacinta O'Shea; Marzena Wylezinska; Z. Tamas Kincses; Peter G. Morris; Paul M. Matthews; Heidi Johansen-Berg
• Keywords: Transcranial Direct Current Stimulation; Polarity (international relations)

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) glutamatergic activity with a highly correlated reduction GABA, presumably due to close biochemical relationship between two neurotransmitters.