FLUORO-GREEN AND FLUORO-RED - 2 NEW FLUORESCENT RETROGRADE TRACERS WITH A NUMBER OF UNIQUE PROPERTIES

As a means of improving nerve tract-tracing in the peripheral and cent ral nervous systems we experimented with two (retrograde) fluorescent emulsions, which we have tentatively named Fluoro-Green (FGr) and Fluo ro-Red (FRe), and which we believe possess the following seven advanta ges: (1) they show little diffusion beyond the injection site; (2) the ir excitation/emission characteristics allow their use in double-traci ng experiments; (3) they do not 'leak' from labeled cells; (4) their f luorescence is presented as large granules in the cytoplasm and its pr ocesses; (5) the fluorescence lasts for a sufficiently long time to pe rmit repeated observation; (6) they may be used in combination with a wide variety of other neuroanatomical tracing methods; (7) they are ec onomical, non-toxic and easy to utilize.