Abstract

Motile cells inside living tissues often encounter junctions, where their path branches into severalalternative directions of migration. We present a theoretical model of cellular polarization for cellsmigrating along one-dimensional lines, arriving at a symmetric Y-junction and extending protrusionsalong the different paths that emanate from the junction. The model predicts the spontaneousemergence of deterministic oscillations between competing protrusions, whereby the cellular polarizationand growth alternates between the competing protrusions. The oscillations are modified bycellular noise, but remain as a dominant feature which affects the time it takes the cell to migrateacross the junction. These predicted oscillations in the cellular polarization during the directionaldecision making process at the junction are found experimentally for two different cell types, noncancerousendothelial and cancerous glioma cells, migrating on patterned network of thin adhesivelanes with junctions.