Two-unit recordings from the lateral geniculate nucleus of the cat: Some inhibitory interactions

Abstract

Pairs of units were recorded by single electrodes from cat’s LGN. Three types of pairs were distinguished. Two of them were classified as retinogeniculate pairs with positive cross-correlograms (ON center – ON center, and OFF center – OFF center); the third type consisted of negatively correlated pairs of LGN neurones. In each case the spatiotemporal organizations of both receptive fields (RFs) were analyzed at several levels of background luminance. An increase of background illumination induced more pronounced compression of the retinal than of the related geniculate ON-center RFs; a strong, central stimulation evoked oscillatory responses only in the LGN cells. The LGN neuron pairs showed a significant overlap of their RFs antagonistic areas. Potentiation of inhibition at the LGN level is discussed in relation to a proposed functional model.