Premium
Cytoarchitecture and visual field representation in area 17 of the tammar wallaby ( macropus eugenii )
Author(s) -
Vidyasagar T. R.,
WyeDvorak J.,
Henry G. H.,
Mark R. F.
Publication year - 1992
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903250211
Subject(s) - cytoarchitecture , biology , macropus , magnification , tammar wallaby , anatomy , meridian (astronomy) , visual cortex , lateral geniculate nucleus , extrastriate cortex , neuroscience , receptive field , midbrain , central nervous system , marsupial , zoology , optics , physics , astronomy
Tritiated proline was injected into one eye in the tammar wallaby and transported label was studied in the cortex after transneuronal passage through the lateral geniculate nucleus. The autoradiographic label and cytoarchitecture were used to anatomically demarcate the borders of area 17. Electrophysiological recordings from single units were done to obtain a retinotopic map of area 17. Single units in area 17 were found to have orientation sensitivity comparable‐to those seen in placental mammals such as cat and monkey. They could also be classified as simple, complex, and hypercomplex cells. Changes in the cortical areal magnification factor with eccentricity were found to match the drop off in retinal ganglion cell density only along the vertical meridian representation. Along the horizontal meridian, the cortical magnification falls off significantly with eccentricity, whereas the ganglion cell density shows only a mild reduction. Thus central vision, especially the binocular segment, is heavily represented at the cost of the periphery. © 1992 Wiley‐Liss, Inc.