DESCRIPTION (provided by applicant): State-of-the art confocal microscopy is required for NIH-funded projects at Iowa State University (ISU). The existing multi-user confocal system at ISU is housed and operated by the Image Analysis and Confocal Microscopy Facility, but a new system is needed, because: 1) the existing Leica System TCS/NT (1998) is aging, cannot handle the live cell imaging needs of major users, and lacks needed accessories such as FRET and 3D- reconstruction, and 2) no other confocal system with these capabilities is available to ISU investigators for a 100 mile radius. Through survey and discussion, we have determined that a Leica TCS SP5 would provide the fast scan rates, high resolution, high sensitivity to reduce light load and damage to cells, and ability to fine tune excitation and emission channels to aid in simultaneous acquisition of multiple fluorescence channels needed for five major NIH-funded projects as well as minor projects, some also NIH-funded, outlined in this proposal. These investigators have much experience in confocal microscopy, but are stifled by the limitations of our existing system. Major user projects include: axonal fascicle formation, JIL-1 kinase effects on chromatin structure and gene expression, PKC4 signaling, oxidative stress, and dopaminergic degeneration in neurons, aptamer tags for assessing gene expression and neuronal stem cell development and plasticity, and retrotransposon gene targeting. The Image Analysis and Confocal Facility at ISU is also well suited to handle this new system for the major and minor users. The facility is supported by the Office of Biotechnology at ISU, has existed since 1984. Ackermann (PI) with Carter (collaborator) acquired, operated, and managed the existing confocal system since 1998. Ackermann is a minor user in this proposal, but has an R01- funded project. The facility handles all aspects of the confocal system (maintenance, training, usage, upgrades, etc.) and has had an active user committee since inception and provides annual reports to the Council of the Office of Biotechnology. This instrumentation is relevant to public health in terms of supporting already funded NIH- projects that range from a better understanding of gene expression to neuronal stem cell development and plasticity.