NEURONOGRAPHIC ANALYSIS OF MEDIAL AND BASAL CEREBRAL CORTEX. I. CAT

Abstract

Phylogenetic, ontogenetic and cytoarchitectural studies, together with recent physiological and psychological investigations, suggest that the limbic system represents an early neural development involved in affectively detd. processes. The system comprises the cortex contained in the great limbic lobe of Broca and its associated subcortical cell stations. Further analysis of the functions of the limbic system requires a more detailed knowledge about its anatomical relationship with the rest of the nervous system. This investigation was undertaken to show on a comparative basis in the cat and monkey the interrelationship of the limbic and extralimbic cortex. The method of physiological neuronography was employed. 18 cats were used in this study. Results indicate that 5 regions of limbic-extraiimbic cortex can be differentiated if one allocates to a region all those areas of cortex that are reciprocally connected. Together these regions surround the hilus of the hemisphere. They are named according to their topographical location. Further analysis shows that the total area of cortex fired by all points within a region forms a large cortical segment. The 5 resulting segments collectively cover the entire cerebral mantle with the exception of parts of the visual auditory and somatic areas.