How does the little brain get its folds?

Cerebellar foliation is "simpler" than cerebral gyrification in several important ways. All mammal species have a folded cerebellar cortex, with an underlying ten-fold motif. The cortical structure has fewer layers than that of the cerebrum, and the morphogenesis problem is effectively a two-dimensional one, resulting in rows of parallel folia. This relative simplicity makes the cerebellum an attractive problem from a physics point of view, but the mechanism by which the cusped folia are formed remains unclear. In this talk, I will describe our three-pronged investigation of cerebellum folding onset involving analysis of experimental data, computational modeling, and analytical techniques. Specifically, we map out the Bergmann glia fiber distribution to look for evidence of fold prepatterning as well as characterize localized buckling and creasing instabilities in this living matter. Informed by results from the latter two queries, we simulate cerebellum growth and morphogenesis using a two-dimensional active vertex model.