Regulation of Contralateral Cortical Projection by the EphA Receptors

IBN 0095040 Zhou, Renping Title: Regulation of Contralateral Cortical Projection by the EphA Receptors The human brain has been considered the most complex object in the universe known to man. Trillions of neurons are wired together precisely through thousands of times more connections. In this immensely complicated network, neurons are interconnected through wire-like processes called axons. How does this complex organ develop? What are the molecular signals that direct the formation of axon pathways and guide the growing axon tip toward proper target? These questions have fascinated scientists for centuries. Recent studies from our laboratory and the laboratories of others indicated that a family of cell surface molecules, termed receptors, that sense extracellular signals, play key roles in guiding axons. This project utilizes several molecular techniques to examine how the Eph receptors and their signaling partners regulate the formation of corpus callosum, an axon fiber that connects the two cerebral hemispheres, and is important for left and right coordination. Experiments examine where these molecules are located, how they affect axon growth and migration, and what are the effects on corpus callosum formation in development when these molecules are inactivated. Results from these studies will reveal the molecular mechanism of axon guidance and help to understand how this extremely complex organ, the brain, is wired together.