Morphological fine tuning of retinotopy within the cat lateral geniculate nucleus.

The course of optic tract fibres from small parts of the cat retina to the terminal projections in the dorsal lateral geniculate nucleus (dLGN) was demonstrated with anterograde tracer substances. Fibres headed towards the same projection columns enter the dLGN at its ventral border parallel to each other and widely scattered. Within the dLGN the fibres converge into a well defined, narrow projection area. Fibre courses and orientation of the projection columns are not identical. Only roughly presorted in the tract, the fibres are extensively rearranged within the dLGN to produce the high precision of retinogeniculate topography.