The triggering, curving and stopping of excitable waves during cell migration

摘要

Recent advances in the understanding of cell migration in amoeboid cells have demonstrated the existence of excitable dynamics in the regulation of the extension and retraction of pseudopodia. In particular, traveling waves of biochemical signaling and actin polymerization have been observed in a number of different cell types. These waves appear to be triggered at a point on the cell cortex and propagate along the perimeter of the cell, pushing the membrane outward to create pseudopods. These waves, however, do not always spread throughout the entire cell cortex. More often than not, they stop after traveling a certain distance along the membrane. In this paper, we look at the factors that create the traveling front, and influence the stopping of the wave. We show that the speed of the wave is controlled by the initial set point of the excitable system, as well as the existence of a critical point for each system, that governs the stopping of the wave.