IBN-9708656 PI: MOODY The neurons that populate the mammalian brain are generated during embryonic development from cells that line the ventricles. These cells divide repeatedly, and then migrate away from the ventricles to populate the brain itself. It is critically important that the processes of division and migration occur correctly in order for the brain to develop normally. Although it is well known that mature neurons in the brain use electrical signalling to process information, there is also some evidence that modified forms of electrical signalling are used during the processes of division and migration that create the brain during early embryogenesis. Dr. Moody will use quantitative techniques to record electrical signals from individual cells lining the ventricles of the embryonic mouse brain to determine how such signals are used in early brain development. By using living slices of embryonic brain tissue, it will be possible to identify individual cells according to their state of division and migration, and to then detemine the exact nature of the electrical signals they can generate. Once this is understood, specific drugs that block different aspects of those signals will be used to determine whether normal patterns of division and migration require this type of signalling. Results from this project will allow us to understand whether the normal adult forms of electrical communication between neurons in the brain are also used in modified form to mediate critical aspects of neural development.