Modulation of GABA and resting state functional connectivity by transcranial direct current stimulation.

TitleModulation of GABA and resting state functional connectivity by transcranial direct current stimulation.
Publication TypeJournal Article
Year of Publication2015
AuthorsBachtiar V, Near J, Johansen-Berg H, Stagg CJ
Date Published2015 Sep 18
KeywordsAdult, Female, gamma-Aminobutyric Acid, Healthy Volunteers, Humans, Magnetic Resonance Imaging, Male, Motor Cortex, Transcranial Direct Current Stimulation, Young Adult

We previously demonstrated that network level functional connectivity in the human brain could be related to levels of inhibition in a major network node at baseline (Stagg et al., 2014). In this study, we build upon this finding to directly investigate the effects of perturbing M1 GABA and resting state functional connectivity using transcranial direct current stimulation (tDCS), a neuromodulatory approach that has previously been demonstrated to modulate both metrics. FMRI data and GABA levels, as assessed by Magnetic Resonance Spectroscopy, were measured before and after 20 min of 1 mA anodal or sham tDCS. In line with previous studies, baseline GABA levels were negatively correlated with the strength of functional connectivity within the resting motor network. However, although we confirm the previously reported findings that anodal tDCS reduces GABA concentration and increases functional connectivity in the stimulated motor cortex; these changes are not correlated, suggesting they may be driven by distinct underlying mechanisms.

Alternate JournalElife
PubMed ID26381352
PubMed Central IDPMC4654253
Grant List090955 / / Wellcome Trust / United Kingdom
102584/Z/13/Z / / Wellcome Trust / United Kingdom

McGill Logo

CIUSSS ouest montreal logo


  • Douglas Hospital
  • Dobell Pavillion
  • Brain imaging centre