Brain fiber architecture, genetics, and intelligence: a high angular resolution diffusion imaging (HARDI) study.
We developed an analysis pipeline enabling population studies of HARDI data, and applied it to map genetic influences on fiber architecture in 90 twin subjects. We applied tensor-driven 3D fluid registration to HARDI, resampling the spherical fiber orientation distribution functions (ODFs) in appropriate Riemannian manifolds, after ODF regularization and sharpening. Fitting structural equation models (SEM) from quantitative genetics, we evaluated genetic influences on the Jensen-Shannon divergence (JSD), a novel measure of fiber spatial coherence, and on the generalized fiber anisotropy (GFA) a measure of fiber integrity. With random-effects regression, we mapped regions where diffusion profiles were highly correlated with subjects' intelligence quotient (IQ). Fiber complexity was predominantly under genetic control, and higher in more highly anisotropic regions; the proportion of genetic versus environmental control varied spatially. Our methods show promise for discovering genes affecting fiber connectivity in the brain.
Chiang
Ming-Chang
MC
Laboratory of Neuro Imaging, Dept. of Neurology, UCLA School of Medicine, Los Angeles, CA, USA.
Barysheva
Marina
M
Lee
Agatha D
AD
Madsen
Sarah
S
Klunder
Andrea D
AD
Toga
Arthur W
AW
Mcmahon
Katie L
KL
de Zubicaray
Greig I
GI
Meredith
Matthew
M
Wright
Margaret J
MJ
Srivastava
Anuj
A
Balov
Nikolay
N
Thompson
Paul M
PM
D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology*; D004058:Diffusion; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007360:Intelligence / Q000235:genetics*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014427:Twins / Q000235:genetics*; D055815:Young Adult