Visual Fiber Anatomy in the Infrageniculate Pathway of the Primate

The classical approach to the topographical representation of the retina in the anterior visual system has been to produce specific retinal lesions in experimental animals, followed by histoanatomic demonstration of nerve-fiber degeneration (by the Marchi technique) in sections of the optic nerves, chiasm, and optic tracts. Despite the competent investigations of the past, many details of the organization of the infrageniculate visual fibers are lacking. During the past decade a silver-staining technique has been developed for demonstration of degenerating axons (rather than the staining of degenerating myelin by the Marchi technique). This technique and the Zeiss retinal photocoagulator provide a new approach for observations of the nerve-fiber organization in the optic nerves, chiasm, and optic tracts. We wish to report anatomic studies which employ these techniques. Previous Experimental Studies For more than a century it has been believed that the nerve fibers originating from specific retinal areas have a definite,