This grant requests funds to upgrade a Noran Odyssey XL confocal microscope presently part of the shared facilities in the Rammelkamp Research Institute. This machine was purchased shortly after its introduction into the market. The capacity for image acquisition and analysis has been enhanced since the original purchase of the Odyssey XL. The upgrade (Noran OZ) will provide important and needed additional laser and software with deconvolution power and, finally, higher spatial and time resolution. Training, management and accounting procedures are already in pace. The use of the present machine by the major investigators listed below has been in general two areas. One major use has been to identify and localized with high resolution the intracellular and extracellular proteins in a variety of tissues using immunocytochemical agents, fluorescent track tracers and GFP as signals. Tissue include cultured cell lines expressing particular ion channel constructs (HEK cells, L cells), cultured cells (fibroblasts, endothelial sf9 cells), primary cultures (neuronal, myocytes, epithelial, parathyroid), and tissue slices (brain, heart, kidney). The second major use has been dyes such as calcium, membrane potential and other indicators to assess the roles of these ions in cellular function. In this method we take advantage of the time resolution as will as spatial resolution of the technique. These measurements are combined with electrophysiological measurements. They have been used for studying localized calcium influx in endothelial and other cells in response to agonists and studies of voltage-sensitive dye changes in arterial baroreceptor terminals.