Journal of Neuroscience, Vol 2, 907-911, Copyright © 1982 by Society for Neuroscience
Retinal projections in tyrosinase-negative albino cats
D Creel, AE Hendrickson and AG Leventhal
Retinal projections were examined in two tyrosinase-negative albino cats
using autoradiographic techniques. Cats from this colony have pink eyes;
their retinal pigment epithelium, ciliary body, and iris epithelium are
completely devoid of melanin pigment. Test breeding for five generations
indicates that these cats are true albinos (cc). The most striking feature
of the albino cats' visual pathways was a reduction in ipsilateral input
which was more severe than that reported for Siamese cats. The only
evidence of ipsilateral input to the laminated dorsal lateral geniculate
nucleus of the albino was a small lateral normal segment and a small
projection to the lateral portion of lamina C1. Ipsilateral projections to
the medial interlaminar nucleus, retinal recipient zone of the pulvinar
complex, ventral lateral geniculate nucleus, superior colliculus, and
pretectum also were reduced. Ipsilateral projections to the suprachiasmatic
nucleus appeared to be normal in the albino cats studied. Our findings
indicate that, compared to the normal cat as well as to the
tyrosine-positive Siamese cat, the tyrosinase-negative albino has reduced
ipsilateral retinal projections. The albino cat is a model system analogous
to tyrosinase-negative albinism found in mammals.