  The migratory dynamics of cells can be influenced by the complex
micro-environment through which they move. It remains unclear how the motility
machinery of confined cells responds and adapts to their micro-environment.
Here, we propose a biophysical mechanism for a geometry-dependent coupling
between cellular protrusions and the nucleus that leads to directed migration.
We apply our model to geometry-guided cell migration to obtain insights into
the origin of directed migration on asymmetric adhesive micro-patterns and the
polarization enhancement of cells observed under strong confinement.
Remarkably, for cells that can choose between channels of different size, our
model predicts an intricate dependence for cellular decision making as a
function of the two channel widths, which we confirm experimentally.
