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Title: Baseline effects of transcranial direct current stimulation on glutamatergic neurotransmission and large-scale network connectivity

Transcranial direct current stimulation (tDCS) modulates glutamatergic neurotransmission and can be utilized as a novel treatment intervention for a multitude of populations. However, the exact mechanism by which tDCS modulates the brain's neural architecture, from the micro to macro scales, have yet to be investigated. In this paper, using a within-subjects design, resting-state functional magnetic resonance imaging (rs-fMRI) and proton magnetic resonance spectroscopy (1H MRS) were performed immediately before and after the administration of anodal tDCS over right parietal cortex. Group independent component analysis (ICA) was used to decompose fMRI scans into 75 brain networks, from which 12 resting-state networks were identified that had significant voxel-wise functional connectivity to anatomical regions of interest. 1H MRS was used to obtain estimates of combined glutamate and glutamine (Glx) concentrations from bilateral intraparietal sulcus. Paired sample t-tests showed significantly increased Glx under the anodal electrode, but not in homologous regions of the contralateral hemisphere. Increases of within-network connectivity were observed within the superior parietal, inferior parietal, left frontal–parietal, salience and cerebellar intrinsic networks, and decreases in connectivity were observed in the anterior cingulate and the basal ganglia (p<0.05, FDR-corrected). Individual differences in Glx concentrations predicted network connectivity in most of these networks. Finally,more » the observed relationships between glutamatergic neurotransmission and network connectivity may be used to guide future tDCS protocols that aim to target and alter neuroplastic mechanisms in healthy individuals as well as those with psychiatric and neurologic disorders.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [2] ;  [2]
  1. The Univ. of New Mexico, Albuquerque, NM (United States); The Mind Research Network, Albuquerque, NM (United States); The Univ. of New Mexico School of Medicine, Albuquerque, NM (United States)
  2. The Univ. of New Mexico, Albuquerque, NM (United States); The Mind Research Network, Albuquerque, NM (United States)
  3. The Mind Research Network, Albuquerque, NM (United States)
  4. The Mind Research Network, Albuquerque, NM (United States); The Univ. of New Mexico School of Medicine, Albuquerque, NM (United States); The Univ. of New Mexico, Albuquerque, NM (United States)
Publication Date:
OSTI Identifier:
1344389
Grant/Contract Number:
FG02-99ER62764; P20GM103472; R01EB005846; R01EB006841
Type:
Accepted Manuscript
Journal Name:
Brain Research
Additional Journal Information:
Journal Volume: 1594; Journal ID: ISSN 0006-8993
Publisher:
Elsevier
Research Org:
Univ. of New Mexico, Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; transcranial direct current stimulation (tDCS); resting-state functional magnetic resonance imaging (rs-fMRI); magnetic resonance spectroscopy (MRS); independent component analysis (ICA); functional network connectivity (FNC); glutamine–glutamate (Glx); parietal lobe