| Abstract: | Connections of the somatosensory cortex surrounding the postcruciate fossa with the lateral region of the motor area (in the cruciate sulcus) were established by the Nauta-Gygax and Fink-Heimer methods and also by the retrograde horse-radish peroxidase transport method. A high degree of differentiation was found in the organization of transcortical sensomotor projections. The pyramidal, stellate, and inverted pyramidal neurons in the third layer of the cortex were shown to take part in the formation of these pathways. Results obtained by the experimental degeneration method combined with electron microscopy showed that afferentation from the first somatosensory area of the cortex reaches mainly cells in layers III and V. It is suggested that the influence of the association fibers on projection neurons in the motor area is transmitted either directly or through interneurons.M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 13, No. 5, pp. 460–466, September–October, 1981. |
