The pretectal complex of the cat: cells of origin of projections to the pulvinar nucleus.

The pretectal projection to the pulvinar nucleus in the cat was examined using the retrograde transport of wheat germ agglutinin-horseradish peroxidase. These data show that both visual and non-visual areas of the pretectal complex contribute to the projection. Specifically, large numbers of labeled neurons are located within the pretectal olivary nucleus with a substantial number of labeled neurons observed within the nucleus of the optic tract. Labeled neurons are also located within the medial, anterior and posterior nuclei, but not to the degree observed in the other pretectal nuclei. Morphometric analysis of labeled and Nissl-stained neurons indicate that the pretectopulvinar pathway is not correlated to any single cell size.