López-Gil, Xavier and Amat-Roldan, Iván and Tudela, Raúl and Castańé, Anna and Prats-Galino, Alberto and Planas, Anna M. and Farr, Tracy D. and Soria, Guadalupe
DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests.
Frontiers in Aging Neuroscience, 6
The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3mm3 isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.
||This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission.
||DWI, DTI, Connectomics, Executive function, Vascular cognitive impairment, Animal models, In-vivo MRI, Hypertension
||University of Nottingham, UK > Faculty of Medicine and Health Sciences > School of Life Sciences
||15 Apr 2016 12:57
||13 Sep 2016 14:42
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