The isocortex of the ox (Bos taurus). I. The sulci and gyri

A simplified scheme of the functionally important gyri and the sulci delimiting these areas, in the ox, is presented. The criteria used are the cyto- and myelo-architecture of the different areas and their correlation with the available physiological information of the nearest ungulates. The preparation of the brain map and experimental studies to determine the thalamocortical connections and later electrophysiological studies are thus possible. The following conclusions have been drawn: 1. The coronoansate sulci are the equivalents of the central sulcus of man. 2. The cruciate sulcus delimits the motor cortex caudally. 3. The equivalent of the calcarine sulcus of man, is the caudal part of the intralimbic sulcus, the axial sulcus of the striate area. 4. The suprasylvian sulcus forms the equivalent of the parietooccipital fissure of man. 5. The equivalent gyri of the isocortical areas of man are defined and the mechanical processes involved in the deformation pattern of the sagittaly oriented gyri of the subprimate mammals resulting in the coronal gyral pattern of man, are described.