We recently received funding to replace an obsolete BioRad 600 confocai microscope with a Leica TCS SP Spectral confocal microscope (S10 RR16708). The day-to-day running of the new confocal is under the direction of Mr. Edward Dougherty, an experienced microscopist. Dougherty's salary is currently paid in part by the Drosophila program project grant (N $44232), partly by Marder's N S 17813, and partly by Biology Department funds. The confocal is available on a fee-for-usage basis for all investigators at Brandeis. The confocal is presently heavily used (60-70 hours/week) as several laboratories (Marder, White, Hall, Griffith) have projects that intensively depend on the confocal, for the study of fixed and processed tissue. There is an urgent need for additional instrumentation and personnel to meet the needs of our user group. A subset of our user" group (Turrigiano [PI], Marder, Griffith, Lisman and Nelson) applied for a Shared Equipment Grant to purchase a Leica Spectral Confocal/Multiphoton microscope, to allow for the study of live tissue combhled with electrophysiology (S10 RR017938). This grant did very well and stands an excellent chance of being funded. The University has committed funds for the installation of this instrument and renovations to accommodate it, but there are currently no institutional funds available for support personnel. Mr. Ed Dougherty will provide oversight for the new confocal and the multiphoton instrument, but the day-to-day running of these new pieces of equipment will require an additional technician. We also lack funds to purchase the electrophysiology equipment needed to fully utilize the potential of the multiphoton set-up. The availability of combined electrophysiology and multiphoton imaging to the user group would allow us to extend our research programs in important new directions. A second gap in our imaging arsenal is the lack of instrumentation and software for time-lapse imaging. A number of the projects of our user group require time-lapse measurements of multiple fluorophores. The set-up costs for this imaging rig (manipulators, stimulators, culture chamber stage) have been prohibitive for any individual, since it would not receive full-time use in a single lab. The addition of equipment and software for this type of analysis would extend existing projects and allow users to investigate these new, highly relevant avenues of research.