Abstract: | The size (somatic area) of 658 cells located in layers 2/3 of cortical areas 17, 18 of both hemispheres in intact monocularly deprived and bilateral strabismic cats was measured. These cells were retrogradely labelled after injections of horseradish peroxidase into ocular dominance columns in areas 17, 18. In all groups of cats, the mean somatic area of callosal cells was significantly larger than the mean somatic area of intrahemispheric cells. It was found that the mean somatic area of callosal cells was increased by 26.6% in monocularly deprived cats and by 20.2% in strabismic cats in relation to the mean somatic area of callosal cells in intact cats. In addition, the mean somatic area of intrahemispheric cells in monocularly deprived cats was indistinguishable from the mean somatic area of intrahemispheric cells in strabismic cats and in intact cats. It is concluded that early binocular vision impairments produce enlargement of callosal cells' size in the visual cortex. |