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Duration-dependent effects of the BDNF Val66Met polymorphism on anodal tDCS induced motor cortex plasticity in older adults: a group and individual perspective

Citation

Puri, R and Hinder, MR and Fujiyama, H and Gomez, R and Carson, RG and Summers, JJ, Duration-dependent effects of the BDNF Val66Met polymorphism on anodal tDCS induced motor cortex plasticity in older adults: a group and individual perspective, Frontiers in Aging Neuroscience, 7 Article 107. ISSN 1663-4365 (2015) [Refereed Article]


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Copyright Statement

© 2015 Puri, Hinder, Fujiyama, Gomez, Carson and Summers. [This Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permission. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

DOI: doi:10.3389/fnagi.2015.00107

Abstract

The brain derived neurotrophic factor (BDNF) Val66Met polymorphism and stimulation duration are thought to play an important role in modulating motor cortex plasticity induced by non-invasive brain stimulation (NBS). In the present study we sought to determine whether these factors interact or exert independent effects in older adults. Fifty-four healthy older adults (mean age = 66.85 years) underwent two counterbalanced sessions of 1.5 mA anodal transcranial direct current stimulation (atDCS), applied over left M1 for either 10 or 20 min. Single pulse transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability (CSE) before and every 5 min for 30 min following atDCS. On a group level, there was an interaction between stimulation duration and BDNF genotype, with Met carriers (n = 13) showing greater post-intervention potentiation of CSE compared to Val66Val homozygotes homozygotes (n = 37) following 20 min (p = 0.002) but not 10 min (p = 0.219) of stimulation. Moreover, Met carriers, but not Val/Val homozygotes, exhibited larger responses to TMS (p = 0.046) after 20 min atDCS, than following 10 min atDCS. On an individual level, two-step cluster analysis revealed a considerable degree of inter-individual variability, with under half of the total sample (42%) showing the expected potentiation of CSE in response to atDCS across both sessions. Intra-individual variability in response to different durations of atDCS was also apparent, with one-third of the total sample (34%) exhibiting LTP-like effects in one session but LTD-like effects in the other session. Both the inter-individual (p = 0.027) and intra-individual (p = 0.04) variability was associated with BDNF genotype. In older adults, the BDNF Val66Met polymorphism along with stimulation duration appears to play a role in modulating tDCS-induced motor cortex plasticity. The results may have implications for the design of NBS protocols for healthy and diseased age

Item Details

Item Type:Refereed Article
Keywords:asgeing, neuroplasticity, BDNF, TMS, tDCS
Research Division:Medical and Health Sciences
Research Group:Neurosciences
Research Field:Neurosciences not elsewhere classified
Objective Division:Health
Objective Group:Specific Population Health (excl. Indigenous Health)
Objective Field:Health Related to Ageing
Author:Puri, R (Mr Rohan Puri)
Author:Hinder, MR (Dr Mark Hinder)
Author:Fujiyama, H (Dr Hakuei Fujiyama)
Author:Summers, JJ (Professor Jeffery Summers)
ID Code:104364
Year Published:2015
Deposited By:Psychology
Deposited On:2015-11-10
Last Modified:2018-01-31
Downloads:387 View Download Statistics

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