[Changes of the structure of neuronal connections in visual cortex of cats with experimentally induced bilateral...

The spatial distribution of neuronal connections in cortical area 17 in cats with bilateral convergent strabismus, surgically induced on postnatal days 10-14, was investigated. Single cortical columns of areas 17 and 18 were microiontophoretically injected with horseradish peroxidase and retrogradely labeled cells in both hemispheres were detected. The intrahemispheric connections in area 17 along the mediolateral direction (the projection of visual field horizontal meridian) were found to be either dilated or reduced. For most columns, the interhemispheric connections in this direction were increased, which may provide for more reliable unification of two visual hemifields. Moreover, the extension of intra- and interhemispheric connections in rostrocaudal direction (along the visual field vertical meridian projection) was detected in some cortical columns. Thus bilateral strabismus induced during the developmental critical period, modifies the structure of both of intra- and inter-hemispheric spatial neuronal connections of individual cortical columns in areas 17 and 18.