Distribution of optic fibers in the cat

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Abstract
This study undertook to investigate pathways and connections of optic tract fibers in the pulvinar, hypothalamus, ventral lateral geniculate, pretectal region and superior colliculus.Thirty‐five adult cats were utilized — 28 experimental subjects and seven controls. The right eye was removed and the cats allowed to survive for periods from three to 61 days. The chief method of investigation was the silver impregnation technique of Nauta‐Gygax ('54), supplemented by Marchi and luxol‐blue cresyl‐fast‐violet methods.Study of fiber patterns of degeneration in serial sections of the Nauta‐Gygax preparations revealed no preterminal axonal degeneration in the hypothalamus or pulvinar. Portions of a completely crossed accessory optic tract as described by Hayhow ('59) were identified. Preterminal degeneration of fine collaterals of the larger optic fibers was found in the dorsal one‐third of the lateral portion of the ventral lateral geniculate. Large areas of preterminal degeneration and many fibers of passage were observed in the pretectal region. Localized areas of pretermimal degeneration in this region were interpreted as belonging to the pretectal nucleus and to the nucleus of the optic tract. A large number of fine optic fibers was found terminating in the superficial stratum opticum of the superior colliculus. Two areas of preterminal degeneration lateral to the colliculus were interpreted as extension of the pretectal nucleus and as the nucleus olivaris colliculi.