Shaping the nervous system: role of the core planar cell polarity genes.

Planar cell polarity (PCP) is complementary to the intrinsic polarization of single cells and refers to the global coordination of cell behaviour in the plane of a tissue, and by extension to the signalling pathways that control it. PCP is most evident in cell sheets and research into PCP was for years confined to studies in Drosophila. However, PCP has more recently emerged as an important phenomenon in vertebrates where it regulates various developmental processes and is associated with multiple disorders. In particular, core PCP genes are crucial for the development and function of the nervous system. They are involved in neural tube closure, ependymal polarity, neuronal migration, dendritic growth and axon guidance