Funds are requested to purchase a Leica TCS NT confocal microscope system to establish a multiple user confocal facility. This system best fits the needs of the user group and the diverse projects and approaches proposed here. The user group represents a cross section of the Salk faculty and departmental representation. The11 listed users of the requested confocal system include faculty representatives of 5 departments of the Salk Institute. The 7 major users include faculty representatives of 4 departments, and the 4 minor users listed include faculty representatives of 3 departments. The research projects contained within this proposal emphasize cellular and molecular approaches to study a broad range of issues in experimental biology, including chromosome replication and segregation, regulators of DNA replication, the trafficking of macromolecules from the nucleus to the cytoplasm, localization of neurotransmitter receptors and ion channel in the brain, and fundamental events in neural development such as neural induction, cell fate and differentiation, neuronal migration and axon guidance, and the development of neural circuits.