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tDCS Effects on GABA Concentration and Brain Functional Connectivity in Older Adults Of Working Age (TRAINSTIM1)

This study has been completed.
Physikalisch-Technische Bundesanstalt Institut Berlin (PTB)
Information provided by (Responsible Party):
Agnes Flöel, Charite University, Berlin, Germany Identifier:
First received: April 5, 2016
Last updated: January 5, 2017
Last verified: January 2017
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 older people, compared to sham tDCS.

Condition Intervention
Healthy Older Adults
Device: tDCS
Device: sham-tDCS

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
Official Title: Effects of Transcranial Direct Current Stimulation (tDCS) on GABA Concentration and Brain Functional Connectivity in Older Adults.

Further study details as provided by Charite University, Berlin, Germany:

Primary Outcome Measures:
  • GABA concentration assessed by magnetic resonance spectroscopy (MRS) before and after anodal tDCS adjusted for baseline levels [ Time Frame: assessed immediately before and after a 15-min stimulation time ]
    Investigation whether anodal tDCS leads to a significant reduction of M1-GABA concentration in older adults compared to sham stimulation.

Secondary Outcome Measures:
  • GABA concentration assessed by MRS before and after cathodal tDCS adjusted for baseline levels [ Time Frame: assessed immediately before and after a 15-min stimulation time ]
    To assess stimulation effects on GABA concentration by magnetic resonance spectroscopy are measured before and after cathodal tDCS.

  • Resting-state functional connectivity changes [ Time Frame: assessed during a 15-min stimulation time ]
    Functional connectivity as measured by resting-state fMRI during tDCS compared to sham

  • Genotyping of learning related polymorphisms [ Time Frame: assessed during baseline screening ]
    To assess predictors of positive reaction to brain stimulation, genotyping of several learning related polymorphisms will be performed.

Enrollment: 24
Study Start Date: April 2016
Study Completion Date: August 2016
Primary Completion Date: July 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Anodal tDCS
Anodal stimulation during resting state fMRI
Device: tDCS
Experimental: Cathodal tDCS
Cathodal stimulation during resting state fMRI
Device: tDCS
Sham Comparator: sham tDCS
Sham stimulation during resting state fMRI
Device: sham-tDCS


Ages Eligible for Study:   50 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • unobtrusive neuropsychological screening
  • age: older adults of working age: 50-65 years

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).
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Please refer to this study by its identifier: NCT02794272

Charité Universitätsmedizin Berlin
Berlin, Germany, 10117
Sponsors and Collaborators
Charite University, Berlin, Germany
Physikalisch-Technische Bundesanstalt Institut Berlin (PTB)
Principal Investigator: Agnes Flöel, Prof. Dr. Charite University, Berlin, Germany