Fig 2. Sketch of the impact of CR (left) and FR (right) repolarization mechanisms on a head-tail collision.

Contour lines of ϕ are shown in black. The front of the cells with a high value of ρ is marked with red. The solid blue line shows edges of the micropattern χ. Cyan parts of the cell boundary mark inhibitor production near the cell edge from CR/FR. The inhibitor diffuses to other parts of the cell (cyan stripes) and inhibits ρ there. With CR the cells produce inhibitor when they are in contact with any part of another cell. This causes the left cell to repolarize. For FR, there is only inhibitor production when the cell is in contact with the front of another cell. Thus, no cell will repolarize in this head-tail collision.