ABSTRACT This grant application requests funding support for the purchase of a shared Confocal Microscope System with a high-resolution detector to be installed in the Intellectual and Developmental Disabilities Research Center Cellular Imaging Core, a shared microscopy facility at Boston Children’s Hospital (BCH). The requested instrument combines enhancements in high signal-to-noise ratio, fast acquisition speed and enhanced resolution that are not achievable by other instruments available in the area. These features will benefit a growing number of NIH-funded research studies at BCH and Harvard Medical School that require sub-cellular localization of proteins in fixed and living tissue at high acquisition speeds. Other research programs that need high-resolution & high-throughput screening for translational applications will benefit immensely from this instrument. After installation in the Cellular Imaging Core in the Department of Neurobiology and F.M. Kirby Neurobiology Center at BCH, this state-of-the-art microscope will benefit the 84 Harvard Medical School area laboratories that use the core facility for basic and translational research. Primary Investigators from these labs will use the system to study a wide variety of pressing questions regarding organelle mobility and dynamics, subcellular architecture, protein-protein and cell-cell interactions, and the relations of these basic processes in normal brain development, in axon regeneration and neuronal survival, and in neurodevelopmental and neurodegenerative disorders.