The presylvian cortex as a transitional prefronto-motor zone in dog.

Connnections of the cortical region situated in the medial and lateral walls of the presylvian fissure in the dog were investigated using the method of retrograde HRP transport. The patterns of subcortico-cortical and cortico-cortical projections sho,w that the cortical field of the medial presylvian wall (paraorbital area) is related to prefrontal cortex, while the cortical field of the lateral presylvian wall (anterior composite area) is connected with motor cortex. Additionally, short reciprocal connections exist between paraorbital and composite anterior areas. The distribution of these connections and the cytoarchitectonic features of the presylvian cortex suggest that it should be considered as a transitional prefronto-motor zone.