Evolutionary mechanisms controlling brain size and complexity

点击翻译按钮获取中文摘要

All vertebrate brains, from fish to human, are formed of the same regions (forebrain, midbrain and hindbrain) but the relative size and complexity of each of these vary tremendously across evolution. The telencephalon (part of the forebrain forming our brain hemispheres) and the cerebellum (part of the hindbrain) are the two areas showing the biggest variation, reaching the highest complexity and being the most common target in human developmental and neurodegenerative disorders. It is therefore of crucial importance to understand how this complexity is reached during development and what are the initial genetic driving elements ensuring formation of a normal complex brain such as ours. Our lab is an international leader in early brain development, having unveiled the signalling mechanism establishing the telencephalic territory inside the forming brain. We very recently found that changes in timing of signalling inside the very early brain tissue (called the neural plate) modify the size and the complexity of the telencephalon. Here, we propose to identify the cellular and molecular mechanisms controlling timing of signalling and understand the complexity-generating progression triggered by this temporal change. As the events controlling brain size and complexity are the prime targets for disorders, identifying them will lead to new understanding of disorder mechanisms and to new candidate disorder-causing genes.