INTEGRATIVE ACTION IN THE CAT'S LATERAL GENICULATE BODY,
HARVARD MEDICAL SCHOOL BOSTON MASS NEUROPHYSIOLOGY LAB
Pagination or Media Count:
Cells were recorded with tungsten electrodes in the dorsal lateral geniculate body of the cat. Receptive fields of these units were mapped out, in the light-adapted state, with small sports of light. In their general arrangement geniculate receptive fields resembled those of retinal ganglion cells, having an excitatory on centre and inhibitory off preriphery, or reverse. The two portions of a receptive field were mutually antagonistic the decrease in centre responses cauded by inclusion of peripheral portions of receptive fields was termed peripheral suppression. Cells recorded in layers A and B of the lateral geniculate body were driven from the contralateral eye cells in layer A1 from the ipsilateral eye. In penetrations normal to the layers receptive fields of cells in a single layer were close together or superimposed, and from one layer to the next occupied exactly homologous positions in the two retinas. Binocular interaction was not observed in any of the cells studied. All three layers of the lateral geniculate contained both on-centre and off-centre units. Cells in layers A and A1 were similar both in their firing patterns and in average receptive field size. Cells in layer B were more sluggish in their responses to light stimuli, and tended to have larger receptive field centres. Cells with receptive fields within or near the area centralis tended to have smaller field centres and stronger suppression by the receptive field periphery than cells with their fields situated in more peripheral regions of the retina.