Velocity Magnitude Maps.

<p>(a) A two-dimensional depiction of the average motility of all cells at a given distance from the wound edge (<i>y</i>-axis) at a given time (<i>x</i>-axis). Each bin (<i>t</i>,<i>d</i>) represents the average motility (µm hour⁻¹) of all cells at distance <i>d</i> from the wound at time <i>t</i>. Examples of two representative velocity magnitude maps are shown: untreated and HGF/SF-treated. The two vertical lines in each map define the partition to the three phases in the healing process. (b) The maps constructed from single-cell tracking. Examples of untreated and HGF/SF-treated cells are displayed. Comparison with the corresponding multi-cellular maps reveals that this approach provides a significant advantage over single-cell analysis. (c) Single cell tracking at several distances from the wound. Only the velocity component toward the wound is considered.