IN-VIVO VISUALIZATION OF HIPPOCAMPAL CELLS AND DYNAMICS OF CA2- FEASIBILITY OF A FIBER OPTIC PLATE MICROSCOPE SYSTEM FOR IN-VIVO EXPERIMENTS( CONCENTRATION DURING ANOXIA )

The feasibility of a fiber-optic plate (FOP) microscope system employi ng a bundle of optical fibers and videomicroscopy for in vivo experime nts was investigated. The FOP used here consisted of optical fibers 3 mu m in diameter. By inserting the FOP into an animal, optical signals from the deep-lying tissue invisible from the surface could be obtain ed as two-dimensional images. Using this system, hippocampal cells sta ined with a fluorescent dye in an anesthetized rat were visualized. El evation of intracellular free calcium concentration ([Ca2+](i)) in the hippocampus of the rat during anoxic exposure was also detected with a fluorescent indicator dye. These results showed that the FOP microsc ope system was sufficiently applicable to in vivo experiments for stud ying tissue structure and physiological activity even in the deep regi ons with fluorometric techniques.