Brain folding as a soft layered instability: Unique features and puzzles

(University of Florida Biomedical Engineering seminar - March 2021)

During development, instabilities develop in the brain, giving it its characteristic wrinkled shape. These instabilities are very complex and still not well understood. In the first part of the talk, I will discuss the sensitivity of soft layered materials such as the brain to small changes in loading and geometry. In the second part of the talk, I will share our theoretical, computational, physical, and imaging approaches to understanding the role of mechanics in the patterns of cortical thickness in the brain - another unique feature of soft layered instabilities.


The role of physical forces in cortical morphogenesis

(American Physical Society March Meeting 2020 - invite keynote)

Between individuals and across species, brain morphology is strikingly consistent in some significant ways. One example is a characteristic pattern of cortical thickness in gyrencephalic, or folded, brains - thick outer folds, or gyri, and thin inner folds, or sulci. This raises the question: which factors (genetic, biochemical, physical, and/or others) lead to this morphological consistency? In a recent combined theoretical, numerical, and experimental study, we found that the physical forces generated by buckling instabilities were sufficient to generate physiological gyral-sulcal thickness ratios. We now consider the more complex, fully three-dimensional pattern of cortical thickness in the brain, and investigate the role of physical forces in its evolution, consistency, and variability.