Visual deprivation does not affect the orientation and direction sensitivity of relay cells in the lateral geniculate nucleus of the cat

Visual deprivation in early life profoundly affects the char-acteristic sensitivity of visual cortical cells to stimulus ori-entation and direction. Recently, relay cells in the lateral geniculate nucleus (LGNd) have been shown to exhibit sig-nificant degrees of orientation and direction sensitivity. The effects of visual deprivation upon these properties of sub-cortical cells are unknown. In this study cats were reared from birth to 6-12 months of age in total darkness; the orientation and direction sen-sitivities of area 17 (striate cortex) and LGNd cells were compared. All cells were studied using identical quantitative techniques and statistical tests designed to analyze distri-butions of angles. The results confirm previous work and indicate that the orientation and direction sensitivities of cells in area 17 are profoundly reduced by dark rearing. I