Genetic Abnormality of the Visual Pathways in a "White" Tiger

  title={Genetic Abnormality of the Visual Pathways in a "White" Tiger},
  author={R. Guillery and J. Kaas},
  pages={1287 - 1289}
"White"tigers show an inherited reduction of pigment, produced by an autosomal recessive gene. The brain of one of these tigers shows an abnormality of the visual pathways similar to abnormalities that are associated with albinism in many other mammals. There is a close relationship between the reduced pigment formation, the pathway abnormality, and strabismus. 
Congenitally abnormal vision in Siamese cats
In albino mammals, the absence of pigmentation in the eye is associated with abnormalities of the visual pathway and these result in a scrambled input to the visual centres of the brain, and research on Siamese cats shows that there are several ways in which the cortex can deal with the abnormal input. Expand
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Visually evoked potentials recorded from two types of human ocular albinos demonstrated significant hemispheric asymmetry following monocular stimulation. The asymmetry is indicative ofExpand
Congenitally abnormal visual pathways in mink (Mustela vison) with reduced retinal pigment
An abnormal retinogeniculate pathway has been found in all mink in which the retinal pigment is reduced and most of the abnormally routed nerve fibers arise in the temporal retina and cross in the chiasm, instead of staying ipsilateral as is normal. Expand
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Autoradiographic methods have been used to demonstrate the retino‐geniculate pathways, and retrograde degeneration or the retrograde transport of horseradish peroxidase has been used for the geniculo‐cortical pathways. Expand
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A suspected relation between pigment production and the physiology of visual pathways was examined in white cats with two yellow eyes, two blue eyes or one blue and one yellow, which conformed to the patterns described for ordinary pigmented cats. Expand
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  • Psychology, Medicine
  • ILAR journal
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These experiments showed that the lack of normal levels of pigment in the retina in Siamese cats (and other hypopigmented mammals) was the critical factor in the misdirection of many of the projections of the retina to the brain, the nature of the projection error, and the developmental consequences of the relay of the misdirected retinal inputs to visual cortex. Expand
Two distinct patterns of visual evoked response asymmetry in human albinism
Results are presented which confirm that in human albinos each cerebral hemisphere receives a predominantly monocular input from the contralateral eye, giving rise to an asymmetry of the visualExpand
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  • Biology, Medicine
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It has been found that albino and Himalayan rabbits, which both lack all melanin pigment in the eye, have a similar abnormality of the retinogeniculate pathway. Expand
Changes in brain morphology in albinism reflect reduced visual acuity
Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation, and decreased gyrification in the ventral extrastriate cortex. Expand


Mutants with Abnormal Visual Pathways: An Explanation of Anomalous Geniculate Laminae
Rats with geniculate laminae that run perpendicular to the lines of projection are described, and the chiasmatic course of axons arising in a patch of retinal ganglion cells is wrongly specified. Expand
Anomalous Retinal Pathways in the Siamese Cat: An Inadequate Substrate for Normal Binocular Vision
All major retinal pathways in the Siamese cat are abnormal, with almost total crossing of the projections to the pretectum and superior colliculus. These projections represent a marked disruption inExpand
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The uncrossed visual pathways to the principal primary optic centers of hooded rats are substantially larger than those of albino rats. This provides an anatomical basis for the results of a recentExpand
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Ecology and Palaeoecology of Marine Environments
__'._x t 7 of organisms in the North Sea, and he determines their influ...e^ . ..... : . nce on the marine sediment. 9Ze^.-as,;,^,; ^;'Functional morphology, mode of life and death of marine animals,Expand
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An abnormal retinogeniculate projection in Siamese cats.