Modulation of GABA and resting state functional connectivity by transcranial direct current stimulationc
Abstract
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). Here, 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 minutes of 1mA 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.
Article and author information
Author details
Reviewing Editor
- Jody C Culham, University of Western Ontario, Canada
Ethics
Human subjects: Participants gave their informed consent to participate in this study in accordance with ethical approval from the East London Research Ethics Committee (Ref: 10/H0703/50).
Version history
- Received: May 18, 2015
- Accepted: September 18, 2015
- Accepted Manuscript published: September 18, 2015 (version 1)
- Accepted Manuscript updated: September 23, 2015 (version 2)
- Version of Record published: November 20, 2015 (version 3)
Copyright
© 2015, Bachtiar et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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