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Topography of ganglion cells in the dog and wolf retina
Author(s) -
Peichlcu Leo
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.903240412
Subject(s) - retina , giant retinal ganglion cells , biology , canis , ganglion , cresyl violet , retinal , retinal ganglion cell , streak , anatomy , neuroscience , optics , genetics , physics , staining , paleontology , biochemistry
Abstract The topographical distribution of retinal ganglion cells in seven breeds of dog ( Canis lupus f. familiaris ) and in the wolf ( Canis lupus ) was studied in retinal wholemounts stained with cresyl violet or with a reduced silver method. A prominent feature of all wolf retinae was a pronounced “visual streak” of high ganglion cell density, extending from the central area far into both temporal and nasal retina. By contrast, either a pronounced or a moderate visual streak was found in dog retinae. It is hypothesized that a pronounced streak is an archetypal feature of Canis lupus , and that the moderate streak in some dogs is a corollary of breeding during domestication. Irrespective of the differences in streak form and retinal area, the estimated total number of ganglion cells was about 200,000 cells in the wolf and 115,000 in the dog. Ganglion cell density maxima in the central area of the wolf were about 12,000–14,000/mm 2 , and in the dog they ranged from 6,400/mm 2 to 14,400/mm 2 . This implies individual differences in visual acuity. Alpha ganglion cells constituted 3–14% of all ganglion cells in the dog and 1–18% in the wolf, depending on retinal location. A distinct feature of all dogs and wolves was the absence of alpha cells in a substantial region of temporal peripheral retina. This has not been found in any other mammalian species and suggests corresponding functional deficits.