a: Comparison of ferret and human developmental timelines. Using percent maximum brain weight, ferret brain development was aligned with human to determine comparative ages. At P20, ferrets are 30% of their maximum brain weight. b, c, d: Maps of DCX+ cells with migratory morphology in the P20 ferret. Sagittal (b), Coronal (c), and Horizontal orientations (d). Scale bar = 1 mm.