[Pathways of visual and auditory information transmission in the caudate nucleus of the cat]

Visual and auditory projections to the caudate nucleus were studied in cat by combination of the HPR method and experimental degeneration of retinal axons. It was shown that visual information comes to the caudate nucleus not only through the well-known polysynaptic pathways from the cerebral cortex, but also through both oligosynaptic (via pulvinar, lateroposterior nucleus, suprageniculate nucleus and nucleus limitans of the thalamus) and disynaptic pathways (via medial and lateral terminal nuclei of the accessory optic tract, pulvinar, pretectum, intermediate superior colliculus layer, supraoptic nucleus) some of which were found for the first time. Direct retinal inputs to the suprageniculate nucleus were found. Additional sources of auditory information to the caudate nucleus were revealed being as follows: the dorsal nucleus of parvocellular division of the medial geniculate nucleus, deep superior colliculus layer, dorsal and ventral nuclei of the lateral lemniscus. Physiological significance of the revealed pathways for the possible transmission of visual and auditory impulses and a new principle of organization of sensory inputs to the caudate nucleus are discussed.