Emi Takahashi1, Glenn D. Rosen2, Guangping Dai1, Van J. Wedeen1, Albert M. Galaburda2, Ellen Grant1
1Radiology, Massachusetts General Hospital, Charlestown, MA, USA; 2Beth Israel Deaconess Medical Center, Boston, MA, USA
Abnormalities in brain development are increasingly reported in dyslexia. RNA interference of Dyx1c1 disrupts neuronal migration in developing embryonic neocortex in the rat and resulted in unmigrated neurons similar to those seen in the brains of dyslexics. To determine if detectable cortical and white matter organizational changes were associated with subtle heterotopia in the rat Dyx1c1 knock-down, we used diffusion spectrum imaging (DSI). DSI tractography detected abnormal tissue organization beyond the small focus of heterotopia at the white/gray matter boundary in Dyx1c1 transfected rat brains with the transfected hemisphere having fewer cortical and white matter fibers compared to control brains.