Consistency and variation in the placement of cortical folds: A perspective

Abstract

Cortical folds, known as gyri and sulci, are prominent features of the human brain that play a crucial role in its function. These folds exhibit both consistency and variation within and across individuals and species, presenting a scientific challenge to our understanding of the underlying mechanisms. In this perspective paper, we summarize current knowledge about fold development and placement. We discuss the temporal and anatomical differences between primary, secondary, and tertiary folds, highlighting the consistency of primary folds and the increasing variation in later-developing folds. We explore the biological and mechanical factors that influence fold placement, including gene expression, tissue growth, axonal tension, curvature, thickness, and stiffness, which likely work together in a complex, coupled manner. We also highlight the need for advanced computational modeling approaches to unravel the mechanisms of precise placement of primary folds and further our understanding of brain complexity.

Statement of significance: Understanding the factors driving both the consistency and variation in fold patterns is essential for unraveling the functional implications and potential links to neurological and psychiatric disorders. Ultimately, gaining deeper insights into fold development and placement could have significant implications for our fundamental understanding of the brain, as well as mental health research and clinical applications.