Fig. 6. Geometric factors induce reorganization of deeper subcortical layers.

a Deep fiber organization resulting for ellipsoidal cases of increasing elongation, as reflected by initial geometry aspect ratio (AR). From top to bottom, initial AR = 1.01, 1.10, 1.25. Results are shown for solid ellipsoids (left) and ellipsoids containing an inner lumen (right) at simulation time T = 1. For prolate ellipsoidal geometries, cortical expansion induces tension parallel to the long axis and reorganization of fibers in this direction. For models containing an internal lumen as opposed to solid core, tangential tension also develops at the interface, with reorganization of fibers to run along the ventricular surface. b Evolution of deep fiber organization in an ellipsoidal model with internal lumen, approximating the shape of the brain and lateral ventricle. From top to bottom, simulation time T = 0, 0.5, 0.75.