An anatomical study of ipsilateral retinal projections in the quail using radioautographic, horseradish peroxidase, fluorescence and degeneration techniques.
The topographical organization of ipsilateral retinal projections was investigated in the pigmented quail using different anatomical tracing techniques. The orthograde labeling patterns were examined after intraocular injections of tritiated tracers (autoradiography), horseradish peroxidase (HRP) either alone or combined with wheat germ agglutinin (WGA), the fluorescent tracer rhodamine beta-isothiocyanate (RITC) and after unilateral retinal ablations using degeneration methods where the material was observed at both light and electron microscope levels. The different techniques provided extremely variable results with regard to demonstrating ipsilateral retinal projections. Whereas the latter could not be revealed in the radioautographic preparations, the results derived using the degeneration and HRP methods were fragmentary. The RITC method was found to be the most effective and made it possible to accurately define the different ipsilateral optic contingents and their terminal arborizations within various thalamic, pretectal and tegmentomesencephalic centers. The contradictory data in the literature regarding the existence of ipsilateral retinal projections in various avian species may be explained by differences in methodology based upon the relative degrees of resolution offered by the different techniques.
D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology*; D003370:Coturnix / Q000033:anatomy & histology*; D005456:Fluorescent Dyes; D006735:Horseradish Peroxidase; D008854:Microscopy, Electron; D009410:Nerve Degeneration; D009900:Optic Nerve / Q000033:anatomy & histology; D011784:Quail / Q000033:anatomy & histology*; D012160:Retina / Q000502:physiology; D014795:Visual Pathways / Q000033:anatomy & histology*
D005456:Fluorescent Dyes; D006735:Horseradish Peroxidase