Title
Relationship between excitability, plasticity and thickness of the motor cortex in older adults.
Abstract
The relationship between brain structure, cortical physiology, and learning ability in older adults is of particular interest in understanding mechanisms of age-related cognitive decline. Only a few studies addressed this issue so far, yielding mixed results. Here, we used comprehensive multiple regression analyses to investigate associations between brain structure on the one hand, i.e., cortical thickness (CT), fractional anisotropy (FA) of the pyramidal tract and individual coil-to-cortex distance, and cortical physiology on the other hand, i.e. motor cortex excitability and long-term potentiation (LTP)-like cortical plasticity, in healthy older adults (mean age 64years, 14 women). Additional exploratory analyses assessed correlations between cortical physiology and learning ability in the verbal domain. In the regression models, we found that cortical excitability could be best predicted by CT of the hand knob of the primary motor cortex (CT-M1HAND) and individual coil-to-cortex distance, while LTP-like cortical plasticity was predicted by CT-M1HAND and FA of the pyramidal tract. Exploratory analyses revealed a significant inverse correlation between cortical excitability and learning ability. In conclusion, higher cortical excitability was associated with lower CT and lower learning ability in a cohort of healthy older adults, in line with previous reports of increased cortical excitability in patients with cortical atrophy and cognitive deficits due to Alzheimer's Disease. Cortical excitability may thus be a parameter to identify individuals at risk for cognitive decline and gray matter atrophy, a hypothesis to be explored in future longitudinal studies.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2013.07.033
NeuroImage
Keywords
DocType
Volume
TMS,MEP,APB,rMT,CCD,LTP,PAS,CT,FA,PT,M1,AD,VD,MRI,TR,TE,FLAIR,DTI,ROI,WMH,GLM,TMT,AVLT,GABA,NMDA
Journal
83
ISSN
Citations 
PageRank 
1053-8119
2
0.37
References 
Authors
8
7
Name
Order
Citations
PageRank
Jonathan List120.37
Jan C Kübke220.37
Robert Lindenberg381.84
Nadine Külzow420.37
Lucia Kerti540.75
A Veronica Witte6483.79
Agnes Flöel7517.91