CompletedNCT02794298TRAINSTIM1Updated Jan 6, 2017

tDCS Effects on GABA Concentration and Brain Functional Connectivity in Young Adults

An interventional study of Transcranial direct current stimulation (tDCS) and sham-tDCS in Healthy Young Adults, sponsored by Charite University, Berlin, Germany. Completed at 1 site in Germany. Open to participants aged 18 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-01-06.

Sponsored by Charite University, Berlin, Germany · Not applicable, Interventional, and Treatment

Phase: Not applicable
Study type: Interventional
Enrollment: 32
Allocation: Randomized
Ages: 18 Years to 30 Years
Sex: All

Study summary

The aim of this study is to investigate whether anodal tDCS over the left M1 leads to a decrease of GABA concentration and alterations of functional brain connectivity in younger people, compared to sham tDCS.

Conditions studied

Healthy Young Adults

In context

Lead sponsor

Charite University, Berlin, Germany is the lead sponsor of 836 studies on the registry; 129 are open to participants now.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years to 30 Years
Sexes eligible: All
Accepts healthy volunteers: Yes

Inclusion criteria

unobtrusive neuropsychological screening
age: young adults: 18-30 years

Exclusion criteria

Exclusion Criteria:

Mild cognitive impairment (MCI) or other neurological diseases
History of severe alcoholism or use of drugs
Severe psychiatric disorders such as depression, psychosis (if not in remission) and severe untreated medical problems
Contraindication for MRI (claustrophobia, metallic implants, ferromagnetic metals in the body, disorders of thermoregulation, pregnant women)

Study design

Phase: Not applicable
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover assignment
Masking: Single (Participant)
Enrollment: 32 participants (actual)

Study arms

Experimental
Anodal tDCS
Anodal stimulation during resting state fMRI
Device: Transcranial direct current stimulation (tDCS)
Experimental
Cathodal tDCS
Cathodal stimulation during resting state fMRI
Device: Transcranial direct current stimulation (tDCS)
Sham comparator
sham tDCS
Sham stimulation during resting state fMRI
Device: sham-tDCS

Interventions

DeviceTranscranial direct current stimulation (tDCS)
Devicesham-tDCS

What researchers measure

Primary outcomes

Measurement of GABA concentration by magnetic resonance spectroscopy (MRS) after anodal tDCS adjusted for baseline levels.
Investigation whether anodal tDCS leads to a significant reduction of M1-GABA concentration in younger adults compared to sham stimulation.
Time frame: assessed immediately before and after a 15-min stimulation time

Secondary outcomes

GABA concentration assessed by MRS after cathodal tDCS adjusted for baseline levels
To assess stimulation effects on GABA concentration by magnetic resonance spectroscopy are measured before and after cathodal tDCS.
Time frame: assessed immediately before and after a 15-min stimulation time
Resting-state functional connectivity changes
Functional connectivity as measured by resting-state fMRI during tDCS compared to sham
Time frame: assessed during a 15-min stimulation time
Genotyping of learning related polymorphisms.
To assess predictors of positive reaction to brain stimulation, genotyping of several learning related polymorphisms will be performed.
Time frame: assessed during baseline screening

Study locations

1 site

Charité Universitätsmedizin Berlin
Berlin, 10117, Germany

References and documents

Publications

Bachtiar V, Near J, Johansen-Berg H, Stagg CJ. Modulation of GABA and resting state functional connectivity by transcranial direct current stimulation. Elife. 2015 Sep 18;4:e08789. doi: 10.7554/eLife.08789. PubMed 26381352 ↗
Amadi U, Allman C, Johansen-Berg H, Stagg CJ. The Homeostatic Interaction Between Anodal Transcranial Direct Current Stimulation and Motor Learning in Humans is Related to GABAA Activity. Brain Stimul. 2015 Sep-Oct;8(5):898-905. doi: 10.1016/j.brs.2015.04.010. Epub 2015 May 1. PubMed 26279408 ↗
Stagg CJ, Bachtiar V, Amadi U, Gudberg CA, Ilie AS, Sampaio-Baptista C, O'Shea J, Woolrich M, Smith SM, Filippini N, Near J, Johansen-Berg H. Local GABA concentration is related to network-level resting functional connectivity. Elife. 2014 Mar 25;3:e01465. doi: 10.7554/eLife.01465. PubMed 24668166 ↗

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Jan 6, 2017, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT02794298
Lead sponsor: Charite University, Berlin, Germany
Collaborators: Physikalisch-Technische Bundesanstalt Institut Berlin (PTB)
Responsible party: Agnes Flöel (Prof. Dr., Charite University, Berlin, Germany) — Principal investigator
First posted: Jun 9, 2016
Start date: Apr 2016
Primary completion: Dec 2016
Completion: Dec 2016
Last update: Jan 6, 2017

Study contacts

Agnes Flöel, Prof. Dr.

principal investigator · Charite University, Berlin, Germany

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Jan 2017. You cannot join it, but the record below documents what was studied.

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