Development of the Ordered Organization of Corticocortical Connections between Field 17 and the Posteromedial Wall of the Lateral Suprasylvian Sulcus in Early Postnatal Ontogeny in Cats

The development of the clustered organization of corticocortical connections between visual field 17 and the posteromedial wall of the lateral suprasylvian sulcus (field PMLS) was studied in cats. The retrograde axonal marker horseradish peroxidase was microinjected into the PMLS region. The distribution of labeled initial neurons was analyzed in field 17 in kittens aged five and 12 weeks. A significant increase in the area of cortex containing labeled neurons and a decrease in their distribution density were seen between week 5 and week 12. Analysis of Fourier amplitude and phase spectra demonstrated differences in the distributions of labeled neurons in kittens of different ages and provided evidence of the incomplete formation of the clustered organization of connections in these animals. The temporal morphofunctional characteristics of the development of intercortical connections of the PMLS zone as compared with other visual areas of the cortex are discussed.