Микроструктура внутриполушарных восходящих путей в экстрастриарные поля коры кошки

Abstract

To study the microstructure of intrahemispheric connections between cortical areas of different hierarchical levels, horseradish peroxidase was microionophoretically injected into the vertical columns of areas 19, 21a. Retrogradely labeled cells in areas 17 and 18 were identified and reconstructed on the unfolded cortical surface. It was found that the columns of areas 19, 21a, in addition to the inputs from the zones of contralateral visual hemifield projection in areas 17, 18, also receive afferentation from the transition zone 17/18, which partly represents ipsilateral hemifield. The distance between these zones of afferentation depended on the distance of the injected column from the projection of the central vertical meridian of the visual field and coincided with the visual projection maps of areas 17, 18. Revealed changes in the position of afferent cells in the transition zone 17/18 were also dependent on the azimuth of the columns. It indicates the transition zone 17/18 division into two retinotopically ordered subzones related to areas 17 and 18. It is assumed that the convergence of inputs from areas 17, 18 makes it possible for the neurons of areas 19, 21a to tune for more complex features in the configuration of images and the spatial location of objects in comparison with neurons in areas 17, 18.