[The divergence of the axonal collaterals of the thalamic neurons to the visual and associative cortexes in cats].

Projections of the thalamic neurons to the visual (area 17) and the parietal association (area 7) cortices were examined by retrograde axonal transport of fluorescent dyes. It was found that the pulvinar neurons can be divided into three groups with respect to their connections with these cortical areas: 1--projecting to area 7 (the largest cell group); 2--projecting to area 17 (a smaller cell group) and 3--sending their axons to the both cortical areas (only few cells). Neurons belonging only to first two groups were found in the lateral posterior nucleus. Divergence of axonal collaterals of pulvinar neurons can secure the existence of parallel pathways transmitting information to the visual and associative cortices.