Cortical Architecture, Midline Guidance, and Tractography of 3D White Matter Tracts

The cerebral cortex is the largest and most complex region of the brain. Its development is precisely regulated, first by genetic and molecular mechanisms and later by activity-dependent experience. The formation of correct cortical circuits relies upon initial patterning of the early brain into nascent functional domains, the generation of the precise number and position of neurons, and finally their assembly into functional circuits. Our current understanding of these processes in humans and animal models is based on technologies spanning cellular and molecular biology to advanced magnetic resonance imaging techniques. Here, we review our current understanding of the mechanisms regulating the development of cortical wiring, with a focus on the major interhemispheric and descending projections. Decades of work to understand these basic mechanisms are now being translated to understand the causes of human brain wiring disorders, opening new avenues for the development of therapeutics for brain wiring repair.