Behavioral aspects of neutrophil motility.

The ability to move is one of the most basic and critical functions of the neutrophil. The neutrophil changes its shape from round to highly polar and glides along the surface, pausing every 45 to 60 seconds to reestablish its direction. Iterations of this sequence of small-scale motion, or shape change, sum to form the large-scale trajectories that have fascinated many investigators over the years. Recent studies of neutrophil motion using novel stimuli and high-temporal resolution measurements of motion have unveiled extremely regular behaviors with periods of approximately 8 seconds. These and previous studies suggest that neutrophil shape change consists of high-frequency ruffling and lower-frequency development of morphologic polarity. These components of shape change are superimposed, because of separate cytoskeletal mechanisms, and are regulated differently. The fundamental motor of the neutrophil seems to be nonrandom and driven by two clocks, one with a highly regular period of 8 seconds and another with a period of 45 to 60 seconds.