Cerebral Fissure Patterns

Abstract

Whereas the neocortex of many mammals is without fissures, the cortex of others has a species-variable number. Fissures form gradually in development and are more numerous in species with large brains. Fissures are more frequent and shallower in mammals with thinner cortex. Mechanical forces during pre- and postnatal growth cause fissure formation. However, the regional specialization of the cortical sheet impacts on the placement and form of cortical fissures. According to Van Essen, the connections that form between cortical areas exert tension that influences where cortex folds or buckles. Additionally, folds are likely to occur at structurally weaker septal zones within somatosensory cortex. Thus, the positions of sulci sometime provide clues to the functional organization of cortex.