Temporal Scaling Mechanism during Brain Development

How humans acquired a cerebral cortex with higher functions is a fundamental question in neuroscience and human evolutionary studies. Although the basic program for development of cortex is conserved across mammals, the period for neurogenesis varies widely; for example, it lasts less than 1 week in mouse, around 1 month in ferret and around 4 months in human. Prolonged neurogenesis is largely associated with increased brain size. However, the molecular mechanisms for such temporal scaling are still unclear. Here, I aim to understand how these temporal genes scale their expression pattern to fit the different developmental rates among different species.