The handling of the birds was in agreement with the Australian code of practice for the treatment and use of animals for medical purposes. All sections containing parts of the ION were imaged to find out the extent to which the IO neurons had adopted the tracer. To organize flat mounts, the eyecup was rinsed with PBS and selective c-Met inhibitor cut in two with an individual dorsalventral cut just temporal to the pecten. The pecten was watchfully excised, to make sure minimum loss of retina. The retina was taken from the sclera and pigment epithelium before being prepared using standard immunohistochemistry techniques. The retinas employed for the smooth support reports, in which we mapped the distribution of rEF devices, came only from animals in which tracer had been taken up by all of the IO neurons, as confirmed by checking parts drawn from the entire extent of the ION. To organize radial portions of the retina, the eyecup was rinsed with PBS and two 5 mm 5 mm pieces, corresponding to the areas of the retina where efferent fibers are found in highest density, were cut-out from either side of the pecten. These retinal pieces were separated in the sclera and put into half an hour sucrose solution at 4 C until equilibrated. The next day these were stored at 20 C until sectioning, frozen on dry ice, and embedded in OCT medium. Sections of 12 20 um Eumycetoma were cut on a cryostat, mounted on gelatin coated slides, and stored at 20 C. To recognize TCs we used the same anti parvalbumin antibody used by Fischer and Stell for this purpose. For smooth mounts marked with both Fluoro Ruby and antiparvalbumin, a solution containing ten percent normal goat serum, 1000 BSA, and 0. Hands down the Tween 20 in PBS was requested 1 hr at room temperature. Retinas were incubated in mouse anti parvalbumin diluted 1:1000 in blocking solution for 7 days at 4 C, washed 3x in PBS, then incubated for 1 5 days at 4 C in secondary antibodies diluted 1:500 in PBS. Finally, the level supports were washed with PBS and coverslipped applying VectaShield hard set mounting medium. The next day the slides were covered using DPX. Retinal sections were processed for immunohistochemistry using methods similar to those described for level supports, except that sections were quenched with E2 conjugating 10 percent glycine in 0. Thirty three percent Triton PBS for 15 min prior to blocking remedy, and the incubation times for primary and secondary antibodies were reduced to 1 2 hours and overnight, respectively. Flat brackets and stained areas were analyzed using an inverted confocal microscope using argon and krypton lasers. Images were converted to 24 bit TIF photographs in Fluoview pc software then utilized in Adobe Photoshop for change of sharpness, contrast and brightness. Images of antibody labeled tissue were often prepared identically to pictures of the corresponding secondary only control. These aren’t shown, since they were uniformly black.