Transcranial direct current stimulation of prefrontal cortex: An
event-related potential and proton magnetic resonance spectroscopy study
-
1
University of Newcastle, Priority Centre for Translational Neuroscience & Mental Health Research, Australia
-
2
University of Newcastle, Australia
Background: Transcranial direct current stimulation (tDCS) is a non-invasive intervention altering neural plasticity by modulating neuronal excitability of pre- and postsynaptic neuron populations. Hence, tDCS may support cognitive remediation in schizophrenia.
Methods: We investigated the effects of a single session of 20 min of 2 mA left-prefrontal anodal vs sham stimulation on event-related potentials (ERPs) in 16 healthy subjects and 14 patients diagnosed with schizophrenia (DSM-IV) by employing a randomized single-blind crossover design. Stimulation effects on cortical glutamate (Glu) and glutamine (Glx) levels were subsequently measured in 12 of the 16 healthy subjects in a 3 Tesla proton magnetic resonance spectroscopy scan.
Results: Patients presented with significantly smaller N1, Mismatch Negativity and P3b amplitudes, which remained unchanged with tDCS. In healthy subjects, tDCS was associated with a significant increase of N1 amplitudes while smaller P3b amplitudes correlated with higher cortical Glu and Glx levels in the stimulated brain area when performing an auditory go/no-go discrimination task. tDCS did not significantly change task performance, nor cortical Glu/Glx levels which, together with N1 amplitudes, depended on stimulation order ("sham" vs "active").
Conclusion: Increased N1 amplitudes are consistent with higher levels of cortical excitability following prefrontal anodal tDCS. No such effects were confirmed for schizophrenia patients, possibly due to medication confounds. A significantly advanced age in the patient group was another study limitation. The failure to replicate Glu/Glx changes with tDCS may have been masked by between-session carry-over effects while ceiling effects may have masked tDCS effects on task performance. Future research should investigate the effects of repeated tDCS intervention in schizophrenia when combined with cognitive training.
Keywords:
Schizophrenia,
ERP,
MMN,
tDCS,
P3b
Conference:
XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014.
Presentation Type:
Poster
Topic:
Cognition and Executive Processes
Citation:
Knechtel
L,
Schall
U,
Cooper
G,
Jolly
T,
Stanwell
P,
Ramadan
S and
Thienel
R
(2015). Transcranial direct current stimulation of prefrontal cortex: An
event-related potential and proton magnetic resonance spectroscopy study.
Conference Abstract:
XII International Conference on Cognitive Neuroscience (ICON-XII).
doi: 10.3389/conf.fnhum.2015.217.00259
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
19 Feb 2015;
Published Online:
24 Apr 2015.
*
Correspondence:
Prof. Ulrich Schall, University of Newcastle, Newcastle, Australia, Ulrich.Schall@newcastle.edu.au