I. Exploring the origin and evolutionary process of the neocortex

In all vertebrate species, the dorsal part of the telencephalon is recognized as homologous brain region, which is called the "pallium". However, the anatomical structures of the pallial derivetives in mature brains are extensively diverged among vertebrates, particularly in amniotes. For example, the mammalian pallium elaborates the cerebral cortex, which is characterized by tangentially expanded surface area and a six-layered laminar structure. On the contrary, the reptilian and avian pallium constitute a three-layered simple cortex or nuclear structures. Distinct styles of pallial architectures are thought to be formed by differential regulations of neural stem/progenitor cell proliferation and differentiation during embryogenesis; although resposible changes in the developmental programs are yet to be determined. 

   Here we focus on the divergence of the pallial structures in amniotes, and try to identify the developmental programs that provided species-specific brain architectures. In vivo electroporation, genetic fate mapping and in vitro re-construction experiments are relevant and powerful tools to tackle brain evo-devo, which will shed light on the history of cortical evolution during 3 hundred million years.

II. Comparative developmental approaches to understand human evolution

Modern humans exhibit unique anatomical characteristics, such as enormously expanded cerebral cortex and skeletal systems adapted for bipedal walking. What kinds of changes in developmental processes contributed to the evolution of human specific traits? To tackle this question, we take advantage of developmental and evolutionary approaches to explore changes in cellular and molecular mechanisms underlying human evolution.