This shared instrument grant proposal is for the purchase of a Carl Zeiss LSM 510 Confocal Inverted Microscope System. This state-of-the-art confocal system, if funded, will be housed in the Biomedical Imaging Core of the Uniformed Services University (USU) Biomedical Instrumentation Center (BIC) and will be operated and maintained by Dr. Dennis McDaniel, the Chief Scientist of the BIC Imaging Facility. Operation of this instrument will be further directed by the principal investigator, Dr. Chou-Zen Giam and the BIC Imaging Faculty Advisory Committee, comprised of Drs. Brian Schaefer (Chair), Michael Schell, Regina Armstrong and Sharon Juliano. Drs. McDaniel, Giam and Schaefer, in consultation with the supervisory committee, will provide the administrative/scientific oversight for the instrument. All participating investigators have indicated a strong need for the proposed microscope in order to support their respective NIH-funded projects with sophisticated imaging applications, including fluorescence recovery after photobleaching (FRAP), fixed- and live-cell fluorescence resonance energy transfer (FRET), and high-speed multi-parameter live cell imaging. The existing PASCAL laser scanning confocal microscope in the BIC simply cannot satisfy these needs. The various features of the requested LSM 510 confocal microscope are therefore critical for the aforementioned technical demands. NIH-funded research projects to be supported by this instrument include: (1) Molecular Biology and Pathogenesis of HTLV-1 (Giam); (2) Enveloped Virus-host Cell Interactions (Broder); (3) Molecular mechanisms of T cell receptor (TCR)-initiated cytoplasmic signal transduction to the NF-?B transcription factor (Schaefer); (4) Imaging NADH in cancer cells and in brain cells, and regulation of the actin cytoskeleton and IP3 metabolism in dendritic spines (Schell); (5) The mechanism of cytoplasmic dynein's targeting to the microtubule plus end (Xiang); (6) Glutamate receptors in epileptogenesis (Bausch); (7) Dimerization of the Angiotensin II Receptors (Feng); and (8) Pathogenesis of enterohemorrhagic Escherichia coli & cytotoxic necrotizing factor of E. coli (O'Brien). The priority for use of the instrument will be given to the participating investigators (95%) and the remaining time (5%) will be allotted to other intramural USU investigators on a first- come-first-served basis. The use of the microscope will be open to extramural investigators only when the instrument is not otherwise occupied. The USU Office of Research Administration has made a commitment to further upgrade this instrument with the addition of a Ti-Sapphire laser, to enable various multiphoton applications, needed for the present and future NIH funded research projects of the participating investigators. Overall, the acquisition of the Carl Zeiss LSM 510 Confocal Inverted Microscope is required for the execution of 13 different NIH funded projects awarded by 5 different NIH institutes. This instrumentation request is thus of obvious importance to the overall mission of the NIH, to fund research that will improve public health. ? ? ?