Studies of retinal representations within the cat's optic tract

Journal Article · Wed Nov 10 04:00:00 EST 1982 · J. Comp. Neurol.; (United States)

DOI:https://doi.org/10.1002/cne.902110405· OSTI ID:6252269

Torrealba, F; Guillery, R W; Eysel, U; Polley, E H; Mason, C A

The manner in which each retina can be mapped onto a single cross section of the optic tract of the cat has been defined by neuroanatomical methods. It has been found that the contralateral nasal hemi-retina and both temporal hemi-retinae are represented in each tract by multiple, rough maps which partially overlap one another. All maps show the same general orientation, with area centralis represented dorsomedially, lower retina represented dorsolaterally, and upper retina represented ventromedially. The peripheral part of the horizontal meridian is represented ventrolaterally. Labeling all of the fibers from one eye by axonal degeneration or autoradiographic methods shows that the crossed map is displaced dorsally and medially relative to the uncrossed map, leaving a dorsomedial crescent of pure crossed fibers. Localized retinal lesions or injections of /sup 3/H-amino acid show the general orientation of the maps. Lesions within the dorsomedial pure crossed crescent show that fibers in this crescent arise from retinal areas close to the optic disc, near the site of the early fetal fissure. Localized injections of horseradish peroxidase into the optic tract show the relationships of the several maps in terms of the retinal distribution of retrogradely labeled retinal ganglion cells. They show that axons of large and small cells map ventrolaterally in the tract while intermediate sizes map dorsomedially. They confirm that the crossed map is displaced relative to the uncrossed maps. It is suggested that the optic tract develops by fibers taking a position in the tract in accordance with their time of arrival at the chiasm. The several maps are displaced because they develop sequentially and the optic tract can be read as a developmental record, the most dorsomedial axons being the oldest.

• Research Organization: Department of Pharmacological and Physiological Sciences, The University of Chicago, Illinois
• OSTI ID: 6252269
• Journal Information: J. Comp. Neurol.; (United States), Journal Name: J. Comp. Neurol.; (United States) Vol. 211:4; ISSN JCNEA
• Country of Publication: United States
• Language: English

Related Subjects

550801* -- Morphology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
BODY
BODY AREAS
CARBOXYLIC ACIDS
CATS
EYES
FACE
HEAD
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MORPHOLOGY
NERVE CELLS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RETINA
SENSE ORGANS
SOMATIC CELLS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES