. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 60 i § 8 40 - B. 50 100 seconds 150 200 Figure 1. <A) A pulled optical fiber, which has been inserted into ci capiilarv tithe with ti 5-^jLin opening mul placed in a tli\h containing fluorescein. Laser-generated ultraviolet light has been coupled to the fiber that is inducing fluorescence of the fluorescein solution. Fluorescence was detected through a 520-nm emission filter. IB) Oregon Green fluorescence from a retinal horizontal cell loaded with NP-EGTA and stimulated with ultraviolet light from a nearb\ optical fiber.
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 60 i § 8 40 - B. 50 100 seconds 150 200 Figure 1. <A) A pulled optical fiber, which has been inserted into ci capiilarv tithe with ti 5-^jLin opening mul placed in a tli\h containing fluorescein. Laser-generated ultraviolet light has been coupled to the fiber that is inducing fluorescence of the fluorescein solution. Fluorescence was detected through a 520-nm emission filter. IB) Oregon Green fluorescence from a retinal horizontal cell loaded with NP-EGTA and stimulated with ultraviolet light from a nearb\ optical fiber. Arrows indicate ultraviolet light pulses delivered via the pulled fiber optic. diately after the ultraviolet stimulus was removed. In contrast, changes in fluorescence with NP-EGTA-loaded cells persisted for many seconds after the UV stimulus was turned off. Additionally, the size of the fluorescent signal did not decay with subsequent UV stimuli. Our work demonstrates that local stimulation of caged cal- cium trapped within horizontal cells by ultraviolet light deliv- ered by small optic fibers can be used to increase intracellular levels of calcium in isolated horizontal cells. For future studies, this approach must be modified to achieve the proper spatial resolution of calcium uncaging. Currently, we are examining various methods to decrease the UV light output of the pulled optical fiber by adding neutral density filters and optimal align- ment of the laser source. We hope to use this technique, in conjunction with self-referencing recordings of H+ flux from horizontal cells, to examine the spatial dependence of proton flux from these cells. This work was supported by grants from the National Center for Research Resources (P4I RR01395), the National Science Foundation (009-1240), and a Grass Foundation Summer Fel- lowship. Literature Cited 1 Baylor, D. A., M. G. Fuortes, and P. M. O'Bryan. 1971. J. Physiol. 214: 265-294. 2. Kamermans, M., and H. Spekreijse. 1999. Vis
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
