Retinal receptive field changes produced by auditory and somatic stimulation

Abstract

The existence of efferent influences on the cat retinal ganglion cell was shown in previous studies. Those experiments, utilizing both chronic macroelectrode and acute microelectrode techniques, demonstrated responses in the optic nerve to auditory and somatic stimuli. Afferent activity in the optic nerve was also found to be modified by these stimuli. The present experiments were undertaken as an extension of this effort. Retinal receptive fields were mapped in immobilized cats. The value of the mapping technique used for these experiments is that it provides an accurate definition of receptive field boundaries. Auditory or somatic stimuli were shown to induce reliable dimensional changes in 76% of the receptive fields examined. Changes in the firing strength of units were also produced by the nonvisual stimuli. These changes were not directly correlated with the dimensional changes observed. No lawful relationship was found between direction of change and the type of efferent stimulation or type of receptive field or both. Changes in receptive field dimension were also elicited by a change in ambient illumination. An interaction between the changes caused by nonvisual sensory stimulation and those brought about by a change in ambient illumination was found in two instances.